IRC_ SP-35

Indian Roads CongressSpecial Publication 35 GUIDELINES FOR INSPECTION AND MAINTENANCE OF BRIDGES NEW DELHI 1990 << Indian Roads Congress Special Publication 35 GUIDELINES FOR INSPECTION AND MAINTENANCE OF BRIDGES P ublished by: The Indian Roads Congress Copies can be hadfrom the Secretary Indian Roads Congress Jamnagar House Shahjahan Road. New Delhi - 110011 NEW DELHI 1990 Price Rs 72/- (Plus packing & postage charges) << Published in September 1990 Reprinted : February, 2000 (The Rights of Publication and Translation are reserved) Printed at DEE KAY PRINTERS, New Delhi-110015 (500 copies) << Roorkee 6. L. Flat No. 4. Guwahati (Assam) 4 N. Aggarwal Director. Deptt. Lal Engineer-in-Chief-cum-Spl. PWD. Bhagwagar Consulting Engineer. Pvt. Director General (Bridges). UP. Rajasthan PWD B&R Jaipur << . New Friends Colony. D-l037. Sidhartha Enclave.K. Mukherjee Chief Engineer (Bridges). HP.. Ray Chaudhuri 148. Deptt. Treatment Co..K. Karnataka 3. SR..S. Stup (India) Ltd. PWD. New Delhi I~ ~. Ministry of Surface (Member-Secretary) Transport (Roads Wing) 3. New Delhi ~. MEMBERS OF THE BRIDGES SPECIFICATIONS AND STANDARDS COMMITFEE I. 6. BMRDA.T. Director General (Bridges) (Retd. Mathur Chief Engineer & AddI.ucknow I. Bassi Addi. Bombay 20. Krishnamurthy Chief Engineer. Consultants Pvt Ltd.Chatterjee Chief Engineer (Roads)~PWD(Roads). Bombay 0 S. Alimchandani Chairman & Managing Director. NGH Society. Lucknow 4. Chakrahorty Managing Director. Secy. Directorate.N.). Patna 4 C. S. Engg. Arya Head. Tamil Nadu 22. Grover Chief Engineer (Retd).S. Gokhale Anant Patel Road. Calcutta 19. P.). Calcutta 9 AG. Gujarat R&B Deptt. Ltd.. Dave Chief Engineer (RRP) and Joint Secretary. Assam Govt. Ministry of Sur- (Convenor) face Transport (Roads Wing) 2.S. West Bengal IS. M.. L. New Delhi L Dr.-Secy. Gandhinagar. Services (India). Transport & Communications Division. Bombay 5. Chakraharti Chief Engineer (Bridges).University o1~ Roorkee. Borkar Chief. Research Designs & Standards Organisa- tion.B. New Delhi ~l. M. AS. PWD NH. Shimla IS Achyut Ghosh Director. V. Ninan Koshi Addi. Kanakaratnam Chief Engineer (H&RW).R. D. Ministry of Surface Transport (Roads Wing) Ii. 42. New Dtlhi 7. of Earthquake Engg~. Metal Engg.P. Press Road. C. PWD.N Choudhury Chief Engineer (Retd. Dr. l)harm Vir Engineer-in-Chief. Road Constn. Hi. P C. P. Consulting Engg. Bhasin Adviser (Technical) Hooghly River Bridge Com- missioners.. P. AK. l)harm Pal Engineer-in-Chief. Central Design Organisation 37.. NC. MG. Riyadh-1l42l (Saudi Arabia) << .MinistsyofSurface Transport (Roads Wing) 34. C/o U. V K. Tandon Consultants Pvt Ltd.). (B&S). The Secretary Indian Roads Congress (D. New Delhi 4~i. 33A.V.P. Lucknow 38.O. of Maharashtra PWD. Subba Rao Managing Director. P. Secretary to the Govt of India (K. G.P. P. Bombay 28. iS. Flat No. Madras-25. Saha Chief Engineer Hindustan Constn. Dr. PB. 25.Er-officio Corresponding Members 44 Dr.K. Sikka AddI. Madras- 600036. Bombay 3!. N. Bombay 30. Mahesh Tandon Managing Director. Secretary to the Govt.B. The President Indian Roads Congress (V. of Gujarat. TN. Subramanyam Chief Engineer (Design) C.Er-officio 42... Ghaziabad (UP) 39. No. S. K.D.P. Naik Chief Technical Consultant. Structural Engg. Bombay 26. R. Raina United Nations Expert in Civil Engg. P.. Merani Principal Secretary to the Govt. Seetharaman Chief Engineer(Bridges) (Retd. H-Block. New Delhi-llOt~l7 33. Gup4a). UP.D. G. Kamdar). Sam) — Ex-officio 43. DDA Self Financing Scheme. Raman Director (Civil Engineering). Saket. MV..N. The Director Highways Research Station.Y. Sarkar Chief Engineer (Bridges).P. AK Mullick Director..W.: lIT. Dr. Sodhi Chief Engineer (Retd. Research Centre. Ltd. Gilcon Project Ser- vices Ltd. Dr. Bureau of Indian Standards 29. Chandigarh 35. Sastry Chief Engineer (Bridges). Ministry of Surface Transport (Roads Wing) 32. Co.16. 558.). The Director General (Road Development) & AddI.. Dr.W. Cor- poration Ltd. Rajagopalan Indian Institute of Technology. . Gammon India Ltd. K. 546/Sector. Guindy.P. By.D. 4!.P. Dr. Tamhankar Deputy Director. Ministry of Surface Transport (Roads Wing) ~h. 45. National Council for Cement& Building Materials. . New Delhi 27. State Bridge Constn. Saxena Managing Director.DirectorGeneral(Roads). Inspection of Bridges and Documentation 18 4. Bridge Management System 4 3. CONTENTS Page 1. Maintenance Techniques 24 5.’ Inspection Proforma (for Routine Inspection) 41 Appendix 5: Inspection Proforina (Check list for Inspection Report) 43 Appendix 6: Standard Tools 49 Appendix 7: Possible Assessment Methods (only indicative) 50 Appendix 8: Tests 51 Appendix 9: Suggested Action Plan 54 << . Introduction 1 2. Suggested Strategies 26 6. Maintenance: Research and Development Aspects 29 7. Bibliography 31 APPENDICES Appendix 1: Inventory of Road Bridges (Suggested contents of 33 Data base) Appendix 2. Inventory of Road Bridges (Specimen for oneBridge) 38 Appendix 3: Simplified Bridge Inventory Form 40 Appendix 4. C. Gantayat Mahesh Tandon P. Narain (A. Prabhu Director. Bhasin M. Chakraborty Surjit Singh B..F. Merani . Mukheijee) MG. Saxena P. This aspect. incidences of structural deterioration and collapse of bridges have been growing in the recent past. have constituted a Committee (B-I0) for Bridge Maintenance and rehabilitation to look into the various aspects of bridge management and to evolve appropriate guidelines thereto with the following personnel NV.K Mathur Rep. Borkar .B. ofCRRI G. of West Bengal PWD AD.1.. Attention in the next few decades thus needs to be focussed on the preservation and rational management ofthe largestock of bridges built in the recentpast and to rehabilitate and strengthen the older bridges which have deteriorated due to inadequate maintenance.P. Sharma S. A large number of bridges have been constructed on various roads all over this country and the pace of activity has been particularly intensive in the last two or three decades.V. Lal (M. Member-Secretary Members CR. GUIDELINES FOR INSPECTION AND MAINTENANCE OF BRIDGES 1. T. Bridges are the vital infrastructure elements of Highway net- work.. realising the paramount need for maintaining durability of such assets. Dave Dr. HRS.N. Subba Rao S.C. Rao) R. INTRODUCTION 1. Alimchandani N. Thatte V.G. Due to lack of regular main- tenance of such bridges. unfortunately. 1. has not hitherto been given the importance it deserves.J.P.2. Maintainingserviceability of bridges and consequently retaining their level of reliability during their life time deserves high priority from techno-economic considerations. Gokhale N. Kamdar Rep.S.C. Madras << .. (i’onvenor AG. The Indian Roads Con- gress.S. G. Gupta) Corresponding Members MR.). Later on. This manual covers guidelines on inspection and maintenance of bridges and suggested strategy for a phased programme to ultimately achieve the recommended objectives. Vinayak Rep. Sarin) The Secretary. << . Reddy : Member MC. IRC (V.A. Raj Kumar) The Committee decided that it should bring out guidelines on all relevant aspects of bridge management viz: (i) Inspection and maintenance ofbridges (ii) Evaluation ofload carrying capacity of bridges and (iii) Methods and techniques of major repairs. The other Iwo guidelines are to be issued as separate documents. Kamdar) The D.G. It is hoped that the application. Kapla) (C. of these guidelines will assist in improvingthe understandingofthe bridge structures and their long term durability and serviceability. these guidelines were finalised. (RD. the modified guidelines were approvedby the Executive Committee in their meeting held at New Delhi on 20thApril 1990 and the Council ofthe Indian Roads Congress in theirmeeting held on 29th April 1990 at Shimla. stre~theningand rehabiI~tation ofbridges. The Subcommittee for preparing these guidelines. of Structure for Cement and Building Engg. (LK. Thatte : Member The Committee held four meetingsand at thefourth meeting heldon 9th March 1990. Tandon : Member N.P.2 Ex-officw The President. Borkar : Convenor MG. consisted of: AG. of National Council Rep. The guidelines finalised by the Committee were considered and approved by the Bridge Specifications and Standards Committee in their meeting held at Bombay on 5th and 6th April 1990 subject to certain modifications. IRC (D. Research Centre Materials (MS. Prabhu : Member S. Sharma : Member MC.P. In the absence of proper data base and regular inspection.: Guidelines have been laid down for inspection of road bridges covering also culverts. additional resources will have to be provided hereaftertowards maintaining the existing bridges. 3 Any suggestions on these guidelines for future revisions will be appreciated. (iii) Assessment of present situation as regards the bridge maintenance: (iv) Making a brief inventory of the different methods and techniques of bridge maintenance’ << . results of inspection etc. 1.3. bringing outwhatto look forduring inspectionof each class ofbndge. Maintenance ofbridges generajly gets neglected in this country because ofthe prevailing misconception that the bridges once constructed do not need any %ubstantial maintenance particularly in the first couple of decades after construction. with more and more cases of bridge deterioration coming to light coupled with increased use ofthe existing stock of bridges. The type of inspection have been classified together with their respective periodicity and the level of engineering officers to inspect. (b) MsIa*enaNce: The guideljnes cover — (i) Defining the goals of bridge management and maintenance policy indicating the means to be employed and the strategies for implementation: (ii) Evolving a methodology of utilisation of data provided by bridge inspection.4. minor and major bridges. and the tools and instrumentation to be used for inspection and testing. Scope of the guidelines on inspection and maintenance of bridges is as follows: (a) I*spectio. This emphasises the need for optimal utilisation of resources. Need for periodical reviewof the guidelines can hardly be over emphasised. as well as submersible bridges. generallyad-hoc decisions are taken regarding main- tenance as a sort of fire fighting operation or crisis management without appreciating the magnitude ofthe overall problem orinterse priorities at road network level. The guidelines give proformae to record the details oforiginal bridge features. The result is that we have not been able to optimise the utilisation of maintenance grants. Again. Lack of regular maintenance of bridges in India has led to deterioration of some bridges rather early in their life and quite a few bridges have had to be replaced much earlier than their designed life. 1. The guidelines also indicate the various inspection facilities necessary depending on the type and importance of the bridge. depending on the importance and environment of the bridge. whether by strengthening to carry heavier loads.6.. Recommen- dations included in the guidelines are of a general nature and do not exhaustively deal with specific technical issues. and regulations in respect of its bridges. BRIDGE MANAGEMENT SYSTEM In these guidelines the following definitions have been adopted: 2. 4 (v) Defining the research areas to improve the bridge maintenance techniques.5.1. The guidelines are to be looked upon as a document on suggested ~good practices” and not as mandatory specifications. It excludes any work leading to improvement of the structure. Special type of bridges such as suspension bridges and cable stayed bridges have been excluded as these are very few in number and their maintenance needs a more specialised approach. While using these guidelines there is an obvious need for each State or Authority to adapt them to develop its own set of detailed instructions. 2. Maintenance This is defined as the work needed to preserve the intended load car- tying capacity of the bridge and ensure the continued safety of road users. £yclone~. rehabilitation and strengthening of bridges are to be issued as separate documents. It should benoted that theguidelines have been evolved only for normal types of bridges (which constitute the majority of existing bridges). The maintenance operations begin with the opening of the bridge to traffic. etc. procedures. but it includes preventive maintenance. 1. 1. earthquake. but are larger in scope and cost than maintenance.2. Guidelines for Evaluation of Load Carrying Capacity of bridges and Guidelines for Methods and Techniques of major repairs. 1.fire. The guidelines are intended to serve as a document to be con- sulted before making decisions in bridge manageñient. Repairs and Rehabilitation These activities also meet the above definitionof maintenance.7. Rehabilitation << . 2.by widening or by verti- cal realignment of the road surface. It excludes repairs of any damage caused by exceptional causes like landslides. 5 operations aim at restoring the bridge to the service level it once had and has now lost.4. The maintenance is governedby economic and traffic considerations. excluding bridge planning. vertical clearance. The criteria ~appliedare the engineering criterion and the financial criterion. Occasional inspections are carried out though they may not result in proper maintenance repairs. However.5. (width of carriageway. The criterion used on engineeringbasis is normally the subjec- tive assessment by an engineer with experience or training in main- tenance and repairs work mostly at the level of an Executive Engineer. aim at upgrading the level of service of a structure. because of the deficiencies in the original design or construction. B ridge Management Present Scenario Bridge Management deals with activities related to bridge “from their entry into service until their reconstruction”. Most of the authorities carry out inspections and maintenance of bridges through their own engineers.3. The basic parameters taken into account in such improvements are: Load carrying capacity. 2. In some cases this consists of giving the bridge the service levelwhich was intended. For improvemthit of complexstructures the asessment is supplemented by advice from a specialist or the assessment is completely left to the specialist At times. Improvements Strengthening. raising etc. 2. etc. widening. investigations on testing for detecting the deficien- cies.) 2. The present maintenance manage- ment practicesvary from Stateto Stateand only a handful ofthese States have compiled the requirements of periodical inspection and main- tenance of bridges for the use of their staff. Replacement or Reconstruction are the works carried out when the whole structure or at least its major components such as whole superstructure are removed and replaced. design and construction. and geometric parameters. but whichhas neverbeen attained. records and data base are usually inadequate. some authorities are not well equipped and get this done through contractors and consultants. there << . or the presence of deleterious materials is done. However. footpaths. In a few States. In most of the States again.effectiveness of maintenance or repairs. strengthening. etc. Cost of inspection. repairs for rehabilitation. and testing. no separate budget provision exists for maintenance of bridges. In general the level of expenditure on bridge maintenance is rather low and the exercise ofcomparingthe cost ofbridge maintenance or repairs or strengthening with the capital cost for reconstruction or replacement is seldom done. traffic warning signs and control. In most of the cases there is no exclusive organisation for inspection and maintenance of bridges. The personnel in Public Works or Highways organisations look after the inspection and maintenance of bridges along with the highways and other construction works. a certain amount per metre length of the bridge and this includes the cost of ordinary main- tenance and that of unpredictable work that is needed from time to time. In most ofthe States regular and systematic maintenance inspection of bridge is not a rule and a rational annual programme of maintenance is not drawn upon the basis ofwhich funds could be asked for. Requirement for Adoption of Scientific Bridge Management System A scientific bridge management system is a collection of organisational << elements.. is sufficient to preventthe progressive deterioration ofthe bridge by pur- suing a policy of preventive and remedial maintenance and repairs. The engineeringpersonnel learnby experience. No formal studies are usually made and expenditurejustified by the benefits obtained. Sufficient data is not available to enable financial requirements to be quantified for satisfactory standard ofmaintenance or repairs. the funds are asked for on the basis of some established financial norms. are also included in this. but no formal training in this discipline is given. standards and procedures to . the provision of funds in the budget is for maintenance of roads and bridges together i. say. improve- ment etc.6. 2. The maintenance policy thus aims at merely ensuringthat sufficient work is done each year to preventaccumulation of work which would impose a heavy burden on future highway budgets.e. The funds allocated normally are far short of requirements and consequently the maintenance and other repairs suffer. regulations.6 appears to be no systematic examination of the general.. It may only be possible to expressqualitatively whether the allocation of funds. The bridge stock can be classified according to construction << .7.!. bridge inspection record and maintenance. 2.7. The BMS enables the engineers and administrators at all levels to select optimvm solutions to achieve the desired level of service within the funds allocated and to assess the future funding requirements. analyse and implement the activities following bridge con- struction. allocating funds for main- tenance. Network level Major Maintenance. rehabilitation. Project Level Interface Module (6). administrative unit. reconstruction. Maintenance Module (4). Road authorities can use the bridge management system to achieve optimum use of available funds. Reportng Module The data base is the core module ofthe system. Bridge inventory: The bridge inventory consists of the main administrative and technical data for each bridge such as name. Historical Data Analysis Module (5). loca- tion. repair and rehabilitation data. In otherwôrds. design loadingclassifica-. replacement. 7 monitor. Rehabilitation and Replacement (MR&R) Selection Module (3). construction data. Data Base Module (2). all utilise the core. identifying and prioritisingbridges for various actions and finding cost effective alternatives for each bridge. etc. scheduling maintenance. how the other modules and submodules which operate on the d~itato perform the function of bridge management. Data Base Module A pre-requisite for attempting any scientific system of management ofbridge maintenance is to have a proper data base module compriabn~ bridge inventory. adaptation ofexisting bridges to traffic needs and public safety. monitor- ing and rating of bridges and maintaining information data base. defining bridge conditions. Fig. substructure and superstructure). such as predicting bridge needs. type of road. strengthening. the bridge management system (BMS) is a rational and systematic approach to organising and carrying out all the activities concerning bridges. tion. 2. I will show. Its logical development would include a minimum of the following six major modules and associated submodules: (i). technical data (foundation. S Figure I. Modules and submodules comprising the model KMS. (SOURCE NCHRP REPORT 300) << . In addition to the basic design data and construction data. Maintaining Authority.2. special points. Cross reference to crossing road. Structural Data: Structure: road bridge. services etc. it contains maintenance. skew etc. Form: number and length of spans. File No. type of material. and can be useful for decidingthe maintenance organisation. arch << . if any. The bridge data bank should contain the following informationfor all bridges Identification Unique structure number related to road network Map reference. trafficdata and reports of exceptional events such as earthquakes. frame. 2. 9 data. Bridgeinspection record: Bridge inspection record consists of data gathered and recorded while checking the condition olvarious spans and followingup the-deterioration processfrom one inspection to another. landslides. Administrative Data: Owner. Year constructed.3. Simply supported orcontinuous. Load carrying capacity clear width. Environment Data: Conditions of exposure/mildfmoderate/severe/very severe/extreme Crossing Data: Over or under road. The data as stored provides adequate information to make decisions on bridge strengthening or load limits. abnormal floods. length. A specimen is given in Appendix 2. repair and rehabilitation data file (MR&R): This is the collection of all the data pertaining to the history and condi- tion of the bridge since its inception. definition of different service levels. Bridgemaintenance. any problem faced.7. etc. In Chapter3 detailed guidelines for inspection ofbridges have been given.. Asuggested format is given inAppendix I (major bridges) andAppendix3 (minor bridges). type of structure etc. Design certificates and recordS. carriageway width. culvert etc. retaining wall. railway water etc. Statutory mains.7. Agreements. Head-room. solutions adopted. repairs or improvement work data including the recorded drawings of major repairs. Construction Data: The method of construction. 2. listing of functionally inadequate bridges or substandard bridges under the given circumstances. foundations. Ancillaries: Expansion joints. 2. water- Utility Services: Type of services.8.2. 2 isa chart indicating various steps for assessing a structure and deciston making regarding repairs/strengthening/demolition/no action which constitute the data base module. Inspection Data: Date last inspected. Bearings Railings/Parapets. approaches.8.8.- tressed concrete. Fig.1. Evaluation of bridges whichappear to be in a critical condition. The structural adequacy covers not only the load carrying capacity but also the overall hydraulic and structural soundness including aspects like scour. etc. 2. It may also be economical to improve the main- tenance techniques so as to limit the expenditure on major repairs or replacement. Feedback of specific defails. summaryofconditions. Some elements of the bridge structure such as expansion joints. 2. repairs for maintenance. etc.3. Durabilityofcomponents. reinforced concre$e. wearing courses. drainage spouts.structural steeL masoniyorbrickwork. economic benefits/loss also should receive due weightage. Rehabilitation or strengthening must be preceded by condi- tion evaluation and proper assessment of repair needs. Replacement of a bridge becomes necessary only after the existing bridge has outlived its life or is considered not suitable for strengthening to cope with the increased demands or when the costs of << . In evaluation ofload cat-tying capacity though safety considerations are of prime importance. 10 C onstniction :~solid slab. should be carried out on emergency basis. Paintor coating systems. Particular problems: Maintenancecosts. which account for nearly 15 to 20 per cent ofthe total cost ofthe bridge may not have the same life as that ofthe bridge proper and may require frequent repairs and replacement. railings. pre. Improvements might be necessary on account of sflengthening required to cater for increased loads or widening to cater for increased volume of traffic. The. Bridge Management Process 2. foundations. considerations relating to flow and comfort of traffic. strengthen- ing and rehabilitation and replacement or reconstruction. flood protection works.8. phases of bridge management process are inspection. evaluation ofthe bridge adequacy. bearings. Supporting arrangements. Evaluation ofexecuted maintenance and repairs. waterproofing. parapets. 11 DATA BASE MODULE OF THE BRIDGE MANAGEMENT SYSTEM Fig. 2. << 12 strengthening and rehabilitation are too high compared to replacement costs considering the residual life of the existing structure. A factor in favour of replacement could be that traffic can continue to use theexist- ing bridge while it may not always be possible to permit traffic on a bridge which is being strengthened or rehabilitated. On the other hand funds being limited, rehabilitation may allow more than one bridge to be brought back into service as against one replacement. Replacement should, therefore, be examined as an alternative solution to strengthen- ing or rehabilitation. 2.8.4. Suggested guidelines 2,8.4.1. Bridge management is a part of the general road manage- ment function as well as a part of the general bridge policy, the latter set- ting the standards from the first design phase through construction and maintenance to the final replacement if need be. The concept of bridge management policy to be adopted should take into account availability of resources and forecast of the future needs. This would necessarily involye having a reliabledata base of the existing stock ofbridges, traffic loads, environmental and socio-economic constraints. The various options available deserve careful consideration. A proper rationale will have to he established for estimating the extent of priorities, ranking of overall bridge needs, including the existing stock. Similarly, ajudicious choice from the various options available for a given bridge like doing nothing, regular maintenance, imposing load restrictions, keeping the bridge under extensive surveillance, repairing, strengthening and replacement will have to be made and also prioritisation will have to be done amongst the bridges at network level for various actions. So far as maintenance is concerned detailed policy proposals are given in the subsequent paragraphs. 2.8.4.2. Broad guidelines for rehabilitation and strengthening of exist- ing bridges comprise the following: (a) Forecasting of the following needs: (i) Traffic trends as regards traffic volume, vehicle loads and size. ii) Environmental constraints due to increasing trend in favourofpie- servation and safeguarding the environment while carrying Out bridge works, in particular, avoiding permanent changes. (iii) Socio-economic considerations These apply to increase demand for overall safety and to maintaning ofexisting service levels, avoid- << 13 ing traffic restrictions during rehabilitation and strengthening which may imply major additional costs. (b) In planning rehabilitation and strengthening work priority setting con- cepts using discount rates can be employed. This method is suggested to estimate future expenditure while evaluating the various solutions to a given problem. (c) A choice must be made between rehabilitation and strengthening or replacement. Intermediate solution such as limited rehabilitation, servic- ing to postpone replacement may also be envisaged. Their respective merits should be analysed in the light ef the following: (a) The cost and benefits including those occurring in etc future, with appropriate discounting. (b) The technical and financial uncertainties of rehabilitation or strengthening. and (c) Inconvenience caused by replacement (to users, i’esidents, possible environment damage etc.) Such analysis should be made in all cases where works of any significant scale are needed on existing structures. 2.8.4.3. Prioritisation of strengthening/rehabilitation : It is essential that before prioritisation for repairs, inspections are carried out and evaluation of load carrying capacity is also done. The former, i.e., inspection, will decide the condition marks and the latter, i.e., evalua- tion of load capacity, will determine the load marks of each bridge. These will form the basis of ranking of bridges in need of repairs. The importance of each element in the functioning and safety of the bridge and also the importance of route are considered before a final ranking point is calculated for the bridge. The rank of each element will thus reflect: — the current condition — the load carrying capacity in relation to the current traffic. — the importance of the element for the functioning of the bridge. — the importance of the route on which the bridge is located. Alternative repair plans should be considered for the bridge in the top of the ranking list for which repair works can be carried out within << The bridge maintenance includes all operations needed to keep the bridge in good order till it is replaced. such as (I) conservation of original facilities. Though at present. therefore. As mentioned earlier. it might be advan- tageous to set up exclusive units within the department to carry out most of these operations departmentally with the help of trained engineers and special equipment and machinery procured for the purpose. These three considerations may carry slightly different weightages for different classes of roads on which the bridges are situated. Depending on the work load in the organisation. The maintenance policy. Likewise. Principal and special instructions require spe- cial skills and experience and could be carried out by special departmental teams assisted by outside agencies as may be necessary.4. These have to he supplemented by selected outside agencies to excute such special works according to specific needs. ~iajor repairs~rehabilitation and strengthening measures are specialised tasks requiring expert agencies for implementation. Selection among evaluated repairs plans is normally based on the net present value of the repairs plan applying appropriate discount rate with possible consideration of t~fficcosts imposed on users by the work programme (detours etc.) and (3) repairs of accidental damage. has implied prerequisites like satisfac- tory design and construction.) 2. 14 available budgets.9.9. Organisatlon and Personnel : Routine inspection and main- tenance are best carried out by the normal aeparLmenutt stan iii caurge of the concerned bridges.4. While sanctioning staff for such departmental units it must be recognised that the norms of work load for them have to be more conservative than for routine construc- tion and maintenance jobs.e. the safety aspect shall prevail. climate etc.8. 2. maintain’ ing the loadcarrying capacity as per design and the level of comfort and functional security both for users and those in its viciitity. effective bridge inspection and documen- << . maintenance covers all operations aimed at maintaining the state of serviceability i. However.1. Maintenance policy will include three important considerations: (a) safety (h) flow of traffic and (c) economic and technical aspects. Suggested Maintenance Policy 2. the bridge maintenance policy varies from State to State a need for a well defined common policy cannot he overemphasised. (2) repairs of damage due to environmental effects (traffic loads. 9. Safety aspects: Safety of bridges should be considered as an important aspect of bridge maintenance policy.tC cycle ofbridge must be considered.9. To quantify this. Within the cycle of maintaining and replacing the bridges many decisions have to be made. bridge building and maintenance techniques offer a choice of quality levels within which the tasks can be performed. significance of future costs has to be assessed.9. A division of bridges into three categories in accordance with the traffic importance. The maintenance work usually allows a choice of quality levels. quality of design and construction and quality of maintenance and repairs. Inferior maintenance is likely to cause potential loss of investments or initiate major repairs. In evaluation of alternatives. Disregard of deterioration and faults in structural members may create risks offailure by collapse. The future costs are of lower present value (LPV) or consequence than present costs.3.4.This fact must enterinto the maintenance policy. provided that requirements for safety of the user are not neglected. Within the designated life cycle of the bridge there is a choice of both qualities and techniques for maintenance. These alternatives need to be evaluated. 2. 2. traffic volume and traffic risks may serve the purpose for allocating funds for bridge maintenance. An evaluation ofthe risks and their potential consequences must be made. The time it takes for a full cycle is the life span of a bridge and the life of the bridge very greatly depends on the environment (traffic loads. climatic condition). Traffic aspects :1 t should be recognised that strengthening of bridges for increasing traffic volumes and loads is more difficult than the same for roads. << . satisfactory evaluation techniques and a suitable maintenance organisation qualified to implement the maintenance policy. Even though the risks arisingfrom the collapse of bridges are very low as compared to those from other causes. the concept of discounting should he employed. Economic aspects: When considering bridge maintenance from economic point of view the li. thereshould be no doubt that preservation of struc- tural safety is of paramount importance in bridge maintenance not only because it is technically feasible to safeguard the structure but also because it is economically sensible to do so. 2. because of cost and tech nical complexities. The consequences of not taking up maintenance repairs In time should also he worked out in financial terms in a similar manner.2. In a given environment. 15 tation. However. utility services. etc. should not interfere with the requirements of effective maintenance of the bridge. These accesses can be in the form of stairs. steel. Also. (b) the deck top is adequately waterproof and (c) expansionjoints and constructionjoints and bearings which are vulnerable elements are as few as practicable. In fact the designer and constructing agency of the bridge should prepare a main- tenance manual for such a bridge highlighting the special requirements to suit its construction method and design. Use of more advanced inspection and maintenance equipment such as travellers. 16 2. and hand Over the same to the authority who will maintain the bridge according to the instructions << . radical changes of materials for bridges should be investigated thoroughly before using them. preventive main- tenance should start with the design. At present. assessment for maintenance depends on the individual experience of the engineer. The bridge should be so designed that the need for maintenance is minimised with due regard to the possible increase in construction costs. Engineering aspects :The existing bridges could be of timber. mobile bridge inspection units should be encouraged. For ordinary bridges built with conven- tional materials and techniques. Provision of appropriate instrumentation in the bridges during construction could help in monitoring the condition and performance of the bridges.9. The bridge design should consider the total cost of the structure throughout its life span including maintenance.5. In fact. cast iron. and masonry each of whichhas itsown main- tenance problems. It is likely that such experience will continue to provide the basis in many decisions on the various tasks that com- prise maintenance. maintenance require- ments of each such bridge will be different and special. There is a real need for collective experience on bridge maintenance to he assembled and evaluated at both the State level as well as National level. The choice of material is also important. concrete. repairs and replacement and it should be emphasised that feed-back of main- tenance experience to the designers is imperative for the reduction and improvement of future maintenance operations. ladder or negotiable slopes. It is felt that maintenance work and Cost can be reduced significantly when the design of bridge considers that (a) the bridge deck is drained properly. However. assessment of requirements of main- tenance should not be a problem. Accessibility to all parts requiring inspection and maintenance is a must. for important bridges and bridges designed and constructed with specialised techniques and/or using comparatively non-conventionalmaterials. Sometimes just an inspection path will do. if provided. 10. Training Bridge management requires extensive team work involving various levels of responsibility and skills. The main- tenance of bridges should be the responsibility of the Authority usually responsible for maintaining the associated network. It is always advantageous to restrict centralisation to only the bridges on the primary routes for the purpose of decision making and allocation of funds while bridges located in remote areas or serving rural areas are better maintained by those who have constructed them viz. by making it a contract condition. This will indicate where improvements are needed and will enable the engineerto assess the long term durability of different materials and methods. record and review the effectiveness and condition ofmaintenance work done in previous years. The maintenance organisation should systematically examine. 17 in the manual. (ii) Inspection and maintenance of a bridge should be the responsihilitv of’a single Authority only. Bridges form a part of the transport network. Bridge management requires in depth knowledge of inspec- tion of individual bridges which is better acquired at local level than from a remote governmental agency. (iv) Authority responsible for inspection and maintenance should keep the other Authority informed with regard to all works carried out on the bridge. Along with this the issue to be considered is centralisation versus decentralisation.9. en to the former in carrying out the maintenance. for such bridges should make it a practice to insist on a maintenance manual for such special bridges from the designer and builder. (Due to extant provisions in the Railway Act this will not apply Ip bridges over or under railway linet. Responsibility for maintenance 2. The following principles are recommended: (i) A Bridge may often he common to networks eg~where a road crosses over or under a waterway or another road belonging to a different network In such cases maintenance should be carried out as far as possible by the Authority of the overpassing network. preference should he gi’. The road authority. unless some complex administrative or legal problems are likely to arise. 2.9.6. (iii) When one of the Authorities concerned is considerably better equipped than another to inspect and maintain abridge. Training programmes need to << . 2. local authorities. The costs are also better assessed locally.6.1. 18 be organised in order to develop such expertise and team work. 3. flood or oveiloading). (This relates to the gradual deterioration ofthe bridge with time or to an accidental occurrence such as impact. (to pro- vide necessary information on which decision will be made for carrying out maintenance repairs.1. 3. it is necessary to compile << . the bridges and cross drainage works will be classified into two categories. strengthening or replacement of the structure. 3 For the purpose of maintenance inspection. (i) Major bridges with length between abutment faces upto 60 met- res or more. Training facilities should be set up at central level for training of trainers and at local level for imparting training to actual field engineers. Documents In accordance with the provisions contained in IRC: SP-l8- “Manual ofHighway Bridges and Inspection”. (ii) Minor bridges and culverts with length between abutment faces less than 60 metres. (c) to record systematically and penodically the state of the structure. Bridges could further be classified according to the typeof environ- ment to which they are exposed and/or according to the form of the bridge or the material. Local consultants and specialised agencies could be involved for this purpose. The purpose of bridge inspection can be identified as follows: (a) to provide assurance that the bridge is structurally safe and fit for its designed use. (b) to identify actual and potential sources of trouble at the earliest possible stage: and propose remedial and preventive measures.) and )d) to provide feed-hack ofinformation to designers and custodians of bridges on those features which are likely to give maintenance problems and to which necessary attention is best given during design and construction stages.3. Purpose of Inspection Bridge inspection is undertaken to ensure safety and serviceability to the user. INSPECTION OF BRIDGES AND DOCUMENTATION 3. The informationcontained in the original bridge report will be utilised to compile the bridge inventory record given in~AppendixI (for major bridges) and Appendix 3 (for minor bridges). The routine inspection will have to rely mainly on visual assessment using conven- tional standard tools (Appendix 6) and methods.4. The routine inspection of minor bridges and culverts shall be the responsibility ofjunior level officers (say below the rank of Executive Engineer) while the routine inspection of major bridges shall be the responsibility of senior level officers (say at the level of Executive Engineer and above). There should be three classes of maintenance inspection as below: (I) Routine Inspection: Routine inspection shall be carried out periodically by competent and qualified ~ngineering officers of the authority in charge ofbridges. This inspection shall bó carried out by a senior level engineer against a comprehensive check list of items related to the material. bridges located in hilly terrain prone to effects of landslides and bridges in severe exposure con- ditions shall be inspected twice a year before and after the monsoon. if not attended to promptly. a typical case of a bridge has been compiled and is given at Appendix 2. Each officer responsible for inspection shall prepare a calendar of inspection of bridges in his jurisdiction. To facilitate proper routine inspection. The first principal inspection shall be done before the defect liability period of contract expires but not later than 6 months after completion and opening of the bridge to traffk and later this principal inspection << . before and after monsoon. cqndition and situation ofthe structure as given inAppendix 5. Detailed inspection of the foundation should also be included and it may involve underwater inspection’ wherever appropriate. ft will be primarily close visual assessment supplemented by stan- dard instrumented aids. details of reinforcement and other details sup- plemented by site inspection. a simple checklist is suggested (Appendix 4). 3. (2) Principal Inspection: This is a more intensive and detailed inspection and will involve close examination ofelements of the struc- ture. The fre- quency of inspection shall be at least once a year. However. 19 an original bridge report on the basis ofas-built drawings alongwith the design assumptions. The purpose is to report the fairly obvious deficiencies which might lead to traffic accidents or cause high main- tenance and repairs cost. An inventory so prepared will form a part of the data base module in due course as discussed in Chapter 2. but preferably twice a year. More frequent inspections shall be essential if the routine inspection reveals any distress in the bridge structure. Advantage should be taken of any situation whichwill facilitate inspec- tion such as erection of scaffolding for repair work. passage of unusual loads or floods. and it obstructs one lane oftraf- fic on the bridge. Acalendar also for principal inspections of bridges shall be prepared by each officer responsible for such inspections. A preliminary visit to the bridge site to locate the positions of bridge inspection unit is desirable. The activities scheduled during the inspections of the bridge should be planned in detail including sequence of inspection. all such bridges may be subjected to special inspections. Such inspections may require a good deal of.5. Inspection Procedure 3. 3. 4 and 5 should be used. major weaknesses noticed during routine or principal inspection. 3.1. closure of traffic lanes of road works etc. and substan- tial changes of traffic pattern.5. (3) Special Inspection: This shall be undertaken in the event of unusual occurrences such as strong earthquake. The observations made in the first principal inspection shall serve as a bench mark for subsequent inspection observations. accidents. unusual settlement of foundations. In addition to recording defects or damages their << .5.2. Every point should be noted as’ soon as the observation is made. supplementary testing and structural analysis and will invariably require detailed involvement of design organisations and experts in the relevant fields who should be senior level engineers. The earlier inspection reports should be studied so that the condition of the defects earlier noticed could be checked.20 shall be followed by subsequent inspections at intervals of maximum three years. Where mobile bridge inspection unit is decided to be used the inspection should be carefully planned before hand so as to minimise the period ofuse ofsuch equipment as the hourly cost of use ofmobileinspection unit is quite high. The inspecting Engineer should familiarise himself with the details of the structure and as to how it is intended to function. 3. Effectiveness of an inspection depends on proper recording of the actual state of affairs. When any bridge of similar design and constructed almost at the same time are showing some distresses. Forms atAppendices 1. algae. parapets. Underwater inspection is a highly specialised activity and as such should be entrusted only to competent agencies experienced in under- water inspection. If despite detailed underwater inspection there is still concern for the safety of the structure it will be necessary to dewater the area (where possible) with the help of suitable cofferdams or small air locks to enable visual inspection of the com- ponents under dry condition. Expansion joints Condition of approaches Condition of protective works. hydraulic andlor structural.3. Such agencies should be fully briefed on the com- ponents to be inspected and the nature of defects to be inspected. drainage.5. Close circuit television may be used where the water is reasonably clear. so as to enable closer inspection. A typical pattern of inspection may be on the following basis Foundations Abutments Wing walls/returns Piers Columns and bearings Soflits of the deck including beams Details under the deck Condition of road surface. etc. If any previously noted defects have been rectified the same should be noted and recorded. some of the parameters << . 3. Detailed inspection for obtaining more information of deteriorated areas should be done. 21 absence also should be recorded. 3. has been done on the basis of model experiments. The purpose ofthis inspection should be to detect hid: den damages or loss of cross section area and to assess the integrity of the material. after clearing the surface growth. The inspection should follow a pre-determined pattern to ensure that no component is overlooked.4. portable echo sounding equipment can be used to provide a reasonably accurate profile. Where design of a bridge.5. Where underwater damages are repor- ted or are expected special inspection shall be carried out which shall utilise selected non-destructive testing methods or even destructive sam- pling procedures. Where visibility is poor. Underwater inspection: Visual examination of the surface maybe done by minimum cleaning to remove marine growth like coral deposits. For every means of access. during floods. the inspect- ing personnel should utilise the services Of special equipment and divers and where possible necessary television cameras with remote control brought into proper position by a diver with the advice from inspecting personnel could be employed. Mobile equipment: (i) equipment operating under the bridge (travellers) from the ground boatJbarges’ (ii> equipment operating from the bridge deck (s000pers). Assessment Techniques and Equipment These should be considered as an integral part of bridge in~pec- tion. scaffolding etc. (ii) manholes: (iii) hand-rails: (iv) catwalks: (v) platforms: (vi) inspection pits: (vii) provision for setting up planking.7.g. For underwater inspection.6. ease and convenience. special emphasis shall be laid on safety. Provision should be made for power supply for connection of lamps.: (viii) fixtures and provisions for operation of semi-stationery inspection equipment: Ill. 22 emerging out ofsuch model study may also be monitored during inspec- tions e. local and climatic conditions of the bridge site. Built-in access: 11. They should he selected in relation to the number and type o << . The possible means of access can be of the follow- ing type: I. minimum water level. tools or other electrically operated type of equipment. velocity etc. 3. 3. height. safety etc. scour depth. topographical. possible clearance. It is absolutely essential that every state should have adequate number of mobile bridge inspection units. Semi-mobile access: (i) access ladders. Means of Access Appropriate means of access are a prerequisite for all the three fonns of inspection. Due consideration shall be given at the design stage itselfto the provision of proper means of access taking into account individual requirements of the structure and its components such as typeofstructure. very old bridges for which neither record drawings << . (only indicative) arc listed in. 23 bridges to be inspected. principal. the bridge will have to be evaluated for its load carrying capacity. the personnel available with appropriate stan- dard of professional training and level of inspection. Apart from reporting defects and deficiencies any proposals or recom- mendations for strengthening and repairs of the affected components should also he included.8. For taking photographs reference number of the bridge and the location ofthe defects may he written in colour at the appropriate place. Inspection Report The inspection report shall he in the prescribed formats given at Appendices 4 and 5. 3. Standard tools listed inAppendix6 could be used alone with the Guidelines on field tests. The size and location of the defects should he dimensioned though the sketch itself need not be to scale. Follow up Action Minor points or shortcomings noticed during inspection shall be immediately attended to by the engineer in charge. Sketches or photographs should be used to illustrate the defects and other condition ofthe bridge. In a very general way routine inspection will be by visUal assess- ment using conventional standard tools listed in Appendix 6.4ppendi~7. special) any bridge is lou nd to indicate distress of serious nature leading to doubt about struc- tural adequacy. If during the inspections (routine. including tests of non- destructive and destructive type are given in Appendix 8. However.9. Special inspection may require rather advanced techniques and equipment apart from visual assessment. Principal inspection will also have to rely primarily on visual assessment but will be supported by more advanced tools and methods. Possible instrument-aided assessment methods. in case of any important or major shortcoming/distress noticed either during routine inspection or principal inspection the matter shall be reported to the senior level engineerand the latter should decide further the line of action in consultation with the Design Organisations or Design Con- sultants. 3. if he considers it necessary and give detailed instructions as to whether special inspection is called for. Free hand sketches should b~made during the inspection at the site itself. Similarly. It is difficult to give any quantified norms based on inspection only. (iii) Replacement or strengthening of the bridge or its affected part should be undertaken.2. If the bridge inspection reveals deficiencies in its hydraulic design and hehvaiour. (ii) The bridge should be closed for all traffic where the rated capacity of the bridge is lower than the lowest level of traffic load expected to ply on it. 4. will be able to discern whether such an assessment (evaluation of the load capacity) is called for. however. 24 are available nor the design loads are known. If the assessment shows the bridge to be inadequate for the design loads. The operations of << . the engineer may evaluate its load carrying capacity. appropriate actions to provide additional spans. Where design is based on model experiments and inspections show substantial variation from the assumptions made. In this Chapter. Maintenance Operations These operations can be of two types. ordinary maintenance operations and specialised maintenance operations. Thecondi- tion of the bridge should he monitored by special inspections at intervals not exceeding six months. This selection will have to be left to the judgement. MAINTENANCE TECHNIQUES 4]. 4. for selecting a bridge for rating. it is proposed to very briefly cover only the more important techniques currently used in bridge maintenance. Guidelines on Methods and Techniques for repairs for strengthening and rehabilitation are covered under a separate docu- ment. with the help of a design engineer. of a senior engineer who. if necessary. such parameters should be reported and if so advised by the designer the model experiments may be redone and necessary corrective measures taken. The operations described in this Chapter have been selected for fre- quent need of their application. to raise the level and/or to provide protective measures will have to he taken as per the design engineer’s advice. one or more of the following actions should be taken: (i) The load on bridge should be restricted to its assessed capacity. viz. verges. salts or the atmosphere by means of painting (protective films). Clearing of ventholes in superstructure (L’ocalised painting operations to protect against corrosion: renewal of protective treatments on timber: Lubrication and greasing operations). ordinary and specialised maintenance operations. using bituminous materials. etc. greas- ing and substitution of wearing parts of same.g. synthetic mortars. However. lobe carried out with different techniques (simple or special cement mortars. disinfestation of timber structures: Injection of cement grout or thermosetting resin into cracks in brick. fillers in expansion joints. drains. The list of these maintenance operations.): removal of foreign material such as trash or parasitic vegetation and similar operations: Substitution of deteriorated elements by removal and replacement operations (e.) Restoration of brick or masonry structure. viz. sealing and repairs with cement or resin mortars: Localised repairs to pavements and waterproofing. is divided into two parts. it must be admitted that the line separating them is rather a fine one. The specialised maintenance operations are those which are unpredictable regarding their necessity and are relatively more complex. Maintenance of bolts or weldingsof metal structures. joints. gutters etc. safety barriers): Small restorations. etc. replace- ment of missing stones. repointing of masonry and brickwork. Injection of cement grout or synthetic resin (pure or with additives) into sheaths containing pre-stressing tendons. cleaning. (h) Specialised Maintenance Operations Restoration of concrete (reinforced or otherwise) structural parts. Protection ofconcrete or masonry from degrading action by frost. 25 repetitive or periodical type are in generaFtechnically rather simple and could he classified as ordinary maintenance operations. Anti-corrosion protection of metal structures entailing complete strip- ping and repainting of part or all of the surface: << . (a) Ordinary Maintenance Operations Simple cleaning by mechanical means or by hand (of carriageways. stone. impregnation. reinforced or prestressed concrete structure. gulleys. foot- paths. It should also he appreciated that as the technology advances. depend- ing on their types: Maintenance of hearings by means ofdifferent operations depending on the type(repainting and graphiting.lists will have to he updated.1. channels. Where so justified by the work load separate units may be set up for inspections. materials of construction etc. creating data base and inventorisation in phases. particularly the principal and special ones for important bridges. Repairs for damages to guide hunds. It is necessary for the road authorities to issue detailed instruc- tions for classification of their bridges according to size. Steps should he taken to procure the necessary means of accesses for bridge inspections. 5. the. SUGGESTED STRATEGIES 5. forexample): setting of same. condition of exposure.2. It is desirable that one senior engineer for the whole organisation in the road authority should he exclusively provided for this purpose. and assign the responsibilities for their inspections (routine.3. type of structure. vulnerability and complexity ofihe structure. including at least one mobile bridge inspection unit in each State. The lists in para 4. but only indicative. aprons for raft foundations. collector and discharge pipes etc): Repair ot reconstruction of pavements or waterproofing of deck: Repair or reconstruction (partial or total) ofexpansion joints. span length. 4. also by raising decks: Reclamation operations to river and sea beds to protect foundation structures. Making up settlement on bridge approaches: Replacement of any structural members (mainly for timber or steel structure). Equally important is the task of adequate monitoring to ensure that the necessary inspections as prescribed are being actually carried out properly and the necessary follow up actions arising out of these inspec- tions are initiated and implemented. are not exhaustive. 26 Repair or reconstruction of drainage systems (gullies. << . along with periodicities of such inspec- tions. principal and special) at various levels depending on the importa nce. for dealing with which con- sultation with experts from different relevant fields both within the << . Inspections should also be carried out particularly in respect ofbridges known to have some history ofdistress or those located in aggressive environments. 5. involving structural defects. major State Highways or through roads carrying traffic exceeding 10000 tonnes per day. There is a need to develop bridge maintenance and bridge rehabilitation agencies. While it might he relativelyeasier to compile a bridge inventory on basic data from record drawings (which may also not be readily available in many cases). More often than not the officer directly in charge of bridge structures may not have the expertise to deal with major distresses in a bridge structure. All new bridges should be inspected soon after their construction. concrete technology. This will help in noticing the defects wititin the defect liability period of the contract. 27 5. The major distresses in a bridge could form a multi-disciplinary problem. con- siderable efforts will be required to compile the bridge data files after carrying out inspections. and to serve as a bench mark for subsequent inspections. Specialised equipment required for bridge rehabilitation and strengthening should be procured by the concerned authorities and preferably some core units should be set up to carry out such works departmentally. soil mechanics etc.3. corrosion. It might be necessary to encourage and develop consultancy firms for bridge inven- torisation and rehabilitation in addition to the agencies for carrying out the actual work of rehabilitation~and maintenance of bridges which work is going to increase considerably in the coming years. For any particular bridge where problems are of complex nature consultants should be employed depending on the nature and magnitude of the work. their causes and finding remedial meas~iresrequire special expertise. the road authorities should at the earliest carry out Principal/Special Inspec- tions of all major bridges to assess their conditions. deficiencies in hydraulic design. It is recommended that in following the guidelines. In some cases it will be necessary to supplement the Departmental efforts by consultants whowould he in a position to comrr and the required man-power as well as expertise to cope with the increased work load on short term basis.2. Investigation of the distresses. 5. Only the experienced and competent bridge engineers are able to diagnose the distresses and sug- gest most appropriate methods of repairs in a given situation. Considering the magnitude of the work involved the compilation in the first phase may have to be confined to bridges on selected arterial or important routes such as the National Highways.4. A separate manual for training of personnel engaged in bridge inspection needs to he compiled and made available to organisations having a large num- ber of bridges under their control. eye shields. on scaffolding. It is also important that the main- tenance team working on site is adequately insured against the risks and should know and practice the safety precautions needed in main- tenance work and this should include the use of protective clothing. therefore. handling equipment and tools. 28 Department as well as from outside may become necessary and extremely useful. The manual should contain detailed instructions for the personnel in charge of inspections at all levels. use of camera for taking appropriate photographs etc. materials and maintenance pro- cedure.5. the funds for repairs and maintenance are normally allocated in lumpsum amounts for repairs and main- tenance of roads including bridges. The instructions must he in simple language and formats like “Do’s and Dont’s” and should he illustrated with appropriate sketches and photographs to guide the bridge inspection personnel in their task. 5. working on elevated structures. it is recommended that there should be a separate budget item for inspection. Training ofthese personnel is essen- tial. As already mentioned. In order to focus attention of both the Government and Engineers. the engineers and the authorities should be aware of the importance of non-technical aspects << . their qualifications. hreathing mask. The management of bridges has not been receiving as much attention as it should. be prepared every year and funds to the extent of estimated expenditure should be provided in the budget 5. practical courses are desirable for all main- tenance teams with addiiional short courses whenever new material and techniques are introduced. helmet. Maintenance of structure has to be handled by experienced engineers and trained technicians. observance of necessary safety precautions. Similarly. The concerned engineerwill find it difficult to keep his knowledge uptodate on the testing techniques. 5. rehabilitation and strengthening of bridges.6. concerning both the financial and engineering inputs. A bridge maintenance programme along with cost estimates should. safety belts. repairs. in confined places and over water. Apart from the technical aspects. especially for important and vital bridge structures.7. So in-service training courses addressed by specialists in the field are most valuable and are recommended and these should be held frequently. filling in of inventory forms and inspection forms. The con- tingency plan has to be prepared in consultation with all concerned Departments. 5. 6. 29 of management of distressed bridges. the main requirements of research and development in maintenance can be sum- marized as follows (a) The need to investigate the effectiveness of present methods of maintenance. updating it from time to time. (b) The need to develop performance criteria for evaluation ofdifferent main- tenance strategies.1. Merely investigating the causes of distresses and carrying out remedial measures and restoring the traffic is not enough. One must also draw lessons from such occurrences for improvements in future structures so as to minimise chances of recurrence. The lessons learnt should be made known to other engineers also. << . metal protection. such as public safety. It is somewhat difficult to clearly separate out research con- siderations that pertain only to bridge maintenance. For vital bridges and bridges of strategic importance. Suggested action plan for Road Authorities as well as for IRC is given at Appendix 9. MAINTENANCE: RESEARCH AND DEVELOPMENT ASPECTS 6. damaged concrete repairs. as soon as distresses are noticed a contingency plan should be worked out and kept ready for implementation the moment it becomes necessary. their waterproofing and corrosion protection of reinforcement.8. legal issues. These aspects need to be handled tactfully and competently at the top level of management depending on the importance of the bridge. public relations. However. As soon as distresses or damages to the bridge come to light and if the traffic is either to be restricted or diverted or stopped completely it is essential to keep the public informed of all the facts regarding the bridge through suitable media. etc. etc. Requirements A great deal of research is going on in India and other parts of the world on structural aspects. repairs to prestressed concrete members. strengthen- ing of old bridges. These deal with concrete bridge deck. A standard hand-out should b’e kept ready and should be distributed. (vi) Use ofpolymer modified concrete. and protective coating. practices and policies. (iv) Grouting technology of prestressing cables including techniques for examining the quality of grout in embedded cables. 6.. to the distressed structures. a great deal of knowledge ofall aspects of bridge maintenance must yet be gained and disseminated. To close the gap.2. Successful bonding to the parent structure requires development of appropriate gluing materials as well as techniques of execution. 6. Research needs for physical maintenance could be: (i) Repairs of concrete like crack repairs. platesilats etc. (vii) Development of appropriate instrumentation and computer based multi channel data acquisition system. 30 (c) Developing improved materials and techniques for bridge maintenance and (d) The study of economics of maintenance of bridges of various ages and types. 40R and 7OR as per IRC: 6. (xi) Strengthening by external prestressing.2. methods and techniques to repair deteriorated concrete. Future Research It will he observed that there is a considerable gap between the pre- sent bridge maintenance practices and the desired maintenance prac- tices.1. (iii) Development of expansion joints and bearings with improved service- ability. Carefully planned and executed research has to be continued. (ii) Corrosion protection of high tensile steel in prestressed concrete. development of suitable material. The research could be broadly classified into (a) physical maintenance research and (b) non- physical maintenance research dealing with costs. (The instrumentation would be based on deflection transducers. strain gauges and temperature gauges). latex modified concrete and fibre con- crete in replacement of removed concrete. << . N) Measurement of prestressing forces in embedded tendons. 24R. (v) Fatigue crack repairs in steel bridges. (ix) Addition of steel reinforcement in the shape of bars. (viii) i)evelopmentofa special standard testing vehicle in which itis possible to gradually increase the axle loads conforming to national classification such as IR. 6.3. (c) Techniques should preferably involve proven technology.2. The research needs of non-physical aspects of maintenance will be: )i) Proper maintenance accounting: (ii) Long term behaviour studies for methodical evaluation of effectiveness of various repair techniques. Condition Surveys of Concrete Bridge Components — Users Manual — by Minor. 2. and new ideas should he introduced with due care and attention. it is necessary to meet the criteria of practicability like: (a) Techniques must be robust and should not he unduly sensiti~c to workmanship or defects. (xiii) Underwater bridge inspection and repairs: (xiv) Techniques. forcontrolied and rapid removal of concrete without damage to concrete and steel left in place. 6. BIBLIOGRAPHY IRC SP: 18 — 1978. Manual of Highway Bridge Maintenance Inspection. IRC SP: 9 . 4. << . (iii) Assessment of bridge condition by sufficiency ratings.2. 31 (xii) Non-destructive method of detecting corrosion in prestressing steel and to measure rate of corrosion of steel in concrete. White and BUSCH — National Cooperative Highway Research Programme Report 312 (1988). (iv) Maintenance strategies and their effectiveness. The above lists are not exhaustive. (xv) Assessment of residual prestress in case of snapped tendons in parts awa~ from the snapped section. 1972 Rating of Bridges.2. Bridge Maintenance — A Report prepared by an OECD Road Research Group (September 1981). In seeking to devise improved techniques to carry out ma in- tenance and repairs. (xvi~ Improvements in metallurgy of steel reinforcement and for prestressing steel to improve corrosion resistance. 3. (b) Techniques must he resistant to environmental conditions. As time goes on and with more modern facilities more areas for research will he opened. 19. tO. 1989. Durability of Concrete Road Bridges — A Report by Road Transport Research Group of OECD (1989). Bridge Management Systems — NCHRP Report 300. 6.000 Bridges in Thailand by Sorensen and Per. 21. Brilge Inspection Guide — HMSO (1983) — Department of Transport. Government of Maharashtra Public Works Department Technical Circular for In:~pectionof Bridges dated 21. MOST Circular RW/33037/1/87/NH (Std) dt. UK. Durability of Prestressed Concrete Highway Structure — NCHRP Synthesis of Highway Practice Report 140. Underwater lnspection and repairs ofBridge NCHRP — Transportation Research Board.3. IS. 1987. Bridge Inspection — A Report prepared by Road Research Group of OECD (1976). Maintenance and~Rehabilitation— V. RDSO. 23. Ministry of Railways. Bridge Management System for 10.1. National Research Council — Washington DC (1981). MOST Circular RW/NH-33054/33/89-DO II dated 29th March. 16. Indian Railways — Bridge Rehabilitation and Modernisation Plan — Prepared by Civil Engineering Directorate — Railway Board. Detroit. Merani (All India Seminar on Ion- gevity of Bridges — 1989). 22.. Corrosion of Protection of Prestressing Systems in Concrete Bridges — NCHRP Report 313 18. 7.1988. 23rd Sept. 17. MOST Report of High Level Technical Committee on Technical Issues pertaining to the collapse of Nehru Bridge on Mandvi river (1989). Raina (1988). II. Draft Manual for Inspection and Maintenance of Concrete Bridges (1988) — Government of India. 20.K. 24. Clausen. 1988) — Michel Demarre — Discussion !‘aper (The World Bank Policy Planning and Research Staff). Departmental Standard BD 22/84 on Inspection and recording of Highway Struc- tures —-Roads and Transport Directorate of Department of Transport of UK 9~ Departmental Standard BD 21/84 on the assessment of Highway Bridges and Structures —Road and Transporl Directorate of Department of Transport of UK. (1989). AC! Manual of Concrete Inspection — ACI Publication SP-2. Management of Distressed Bridges By NV. 14. 1. A Basic Guide for Bridge Management (September. << . 32 5. Concrete Bridge Practice Construction. 12. 8. of Spans 3 << . Overall Bridge Length 4 14. Highway/Circle/Division 30 II. Vertical and Horizontal Clearance 10 37. Design Scour Level at Abutment 4 27. Design Discharge to 20. Information item Suggested field No. Yearoflnventory 4 18. Importance Factor 3 39. Overall Deck Width 4 32. HTL 7 21. Whether Navigable 36. Conditions of Exposure 20 35. Type of Structure 25 9. Soffit Level at Centre of Bridge 7 38. Road Level 4 30. 33 Appendü I INVENTORY OF ROAD BRIDGES (Suggested contents of Data Base) Sr. Category of Road 3 3. State 2 2. Design HFL 4 23. Popular/Official Name 15 0. Design Loading 4 17. LWL 7 25. Load Rating 4 16. Total No. No. of Lanes 5. Design Velocity in rn/sec 5 19. Approach Roadway Width Including Shoulders 3 33. width in D Base for coding I. 3 4. Footpath Width 3 31. LTL 7 22. Average Skew 2 34. Nearest City/Town 20 12. ~Design Scour Level at Pier 4 26. Features Interesected 25 8. Road No. Structure Number 5 7. OFL 7 24. Founding Strata 28~ Whether Bridge has any Gradient 29. Location Chainage ft 6. Section 30 5. Yearof Construction 4 13. the informa- tion to he given in the field widths suggested above is indicated below for some ofthe items tn the data base. Type of Railing 2 50. However. Item 1: State (2 digits) Mention two digit code for States as under: State Name Code ‘•\rtLlhra Pradesh AP Arunachal Pradesh AR Assam AS Bihar BR Goa GO Gujarat GJ Ha rya na HR Himachal Pradesh HP << . Type of Wearing Coat I 4K. Type of Bearings 1 47. Suspension of Traffic 3 54. Abutment Type 2 44. Distress and Repairs in Foundation 3 5~. Type of Expansion Joint I 40. Pier Type 2 43. Distress and Repairs in Guide Bunds 3 641 Distress and Repairs in Substructure 3 61 Distress and Repairs in Superstnicture 3 67 Any Other Observation/Data 100 Using the above list a suitable data base can he created to suil individual needs s~hcre~rirestnctionsofl field width arenotnecessary. Floor Protection Type 4 51. Pier Foundation Type 2 45. 34 Sr.asanexample. Abutment Foundation Type 2 46. width in D Base for coding 40. Type of Superstructure 4 42. Abnormal Flood Level 6 5K. Information Item Suggested field No. Bank Protection Type 4 52. Corrosion Protection 3X3 51. Maximum Span 5 41. Abnormal Scour Level Around Abutments 6 57. Erosion of Banks/Bunds 3 55 Abnormal Scour Level Around Piers 6 56. T.g. Code 2nd structure after completion of 280 km 281/2 28120 5th structure after completion of 84 km 85/5 08550 << .& Location Code 281.) Location of the centre of the bridge should be given in nos.) PD Daman & Dju (UT.T.T. NAWADAH — BARHI hem 5 — Location (6 digits. 35 Jammu and Kashmir 3K Karnataka KN Kerala KR Madbya Pradesh MP Maharashtra MH Manipur MN Meghalaya MG Mizoram MZ Nagaland NO Orissa OR Punjab PN Rajasthan RJ Sikkim SK Tamil Nadu TN Tripura TR Uttar Pradesh UP West Bengal WB Andaman & Nicobar Islands (U.) DH Delhi (U.) DL Lakshadweep Island (U.380 281380 84.) LK Pondicherry (UT.T.120 084120 item 6 — Structure No.) AN Chandigarh (U. (5 digits) Structure number may be noted as follows Location o?Structures Structure No. The last three digits show thousandth of a Kilometre e.) DA item 4 — Section (30 digits) Record the name ofthe section ofthe highway on which the bridge falls. As such the spaces unifilled by thename ofSection should be left blank and no zeroes need be put therein e.) CH Dadra and Nagar Haveli (UT. This item is justified without trailing zeroes. the lefthand side structure will have asuffix ‘L’ and right hand side structure will have a sufTht ‘R’. NEHRU HRIDGF. For multi-lane carriageways~there would be either one combined structure or separate bridge structures. hem.g. This item is justified without trailing zeroes. However. creek etc.secte4 (25 digits) Theinformation to be recorded forthis item will bethe name or names ofthe feature intersected by the structure. Ifit is an under bridge. e. 33 — Superstructure type (4 digits) The superstructure type should refer to the most important main spans. This will be filled in a four digit code as under: First digit — Material Second digit — Type of design/construction Third and Fourth digit — System << . canal. (i) Left side structure 28 1/2 2812 L (ii) Right side structure 281/2 2812 R 5th structure after completion of 84 km (i) Left side structure 85/5 0855 1 (ii) Rightside structure 85/5 0855 R item No~7— Features inter. item 28 — Average skew (2 digits) Indicate average skew angle of the bridge in degrees. railway line. nallah. Code 2nd structure after completion of 280 km. If there are more than one feature intersected by the same bridge. the structure number shall benoted as mentioned above. In the case of one combined structure. It would however be advisible to reserval structure numbers for structures likely to be added in future. the names ofall features should be separated by semi-colon or a coma. if necessary. if the type in some of the main spans is different. 36 Ifany structureis added subsequently betweenstructure number 281/2 and 281/3. Commonly use and meaningful abbreviations may be used. item 9— Popular/official name (15 digits): Give the popular or official name of the bridge e. the same may be numbered as 281/2A and codified as 28l2A. As thç kilometreage ofthe Section pmgresses.g. The item is justified without trailing zeroes. road. the struc- ture number shall be indicated as follows. the features intersected above the strructure should be given. in case ofseparatebridge structure. Location of structures Structure No. like a river. MALVIYA BRIDGE. If there is no skew write 00. I P. Joists with decking 8 Others 9 << .S.C.S. 37 (a) Material Code RC.C. 2 Steel 3 Steel and concrete Masonry 4 S Timber 6 (b) 1)’pe of design/construction Code Slab T-beam and slab 2 Box-girders-with single cell 3 Box-girders with multiple cell 4 Arches with packfill 5 Open spandrel arches 6 Truss 7 Plate girders/R. State MH 2. Section Pune-Solapur 5. 38 Appendix 2 INVENTORY OF ROAD BRIDGES (Specimen for one Bridge) Sr. No. Soffit Level at Centre of Bridge 448. 3.9 19. 09. Hit Nil 21. Approach Roadway Width Including 11. Design Loading 70 R 17. Year of Construction 1989 13. Type of Structure High Level Bridge 9. 444. Design Discharge in Cumecs 1285 20.88 m 14. Overall Bridge Length 85. Design Scour Level at AbUtment 436.45 32.H.100 30. Highway/Circle/Division NH-9/Solapur/Solapur It. LWL Nil 25. Average Skew 18 34. Conditions of Exposure Moderate 35. Whether Navigable No 36. Structure Number 225 AR 7. —Nala on N. NH 9 4. Location Chainage 225000 6. Load Rating 70R 16. Information Item Information of Bridge across Sawaleswar No.000 27.35 38.900 24. Popular/Official Name Sawaleswar Bridge 10. Features Intersected Nalta 8. Vertical and Horizontal Clearance 1. Design Scour Level at Pier 438.700 23. Founding Strata Hard Rock • 28. Road Level in m 450.2 M 37. Whether Bridge has any Gradient Nil 29. Category of Road NH 3~ Road No. Nearest City/Town Solapur 12.000 26. of Lanes 2 15. Design Velocity in m/Sec. Year of Inventory 1990 t8. 9 Pune — Solapur Section 1. Importance Factor I << .45 Shoulders in m 33. Design HIt 446. LTL Nit 22. Footpath Width in m Nit 31. Overall Deck Width in m 8. Maximum Span 17. Type of Railing II 50. Abnormal Scour Level Around Piers 000 56.39 Sr. information Item lnformation ofBridgeacross Sawaleswar No. Type of Expansion Joint I 49. 9 Pune — Solapur Section 39. Total No. Abnormal Scour Level Around 000 Abutments 57. Type ofWearing Coat 48. Distress and Repairs in Guide Bunds 000 60. Type of Bearings 2 47. Abutment Type 12 44. Any other Observation/Data The bridge is functioning satisfactorily both hydraulically and structurally. Bank Protection Type 000 52. Abnormal Flood Level in m 000 58. Distress and Repairs in Substructure 000 61. .H. Corrosion Protection 000 51. of Spans 5 40. << . Pier Type 32 43. —Nala on N. Distress and Repairs in Foundation 000 59. Suspension of Traffic 000 54. Floor Protection Type 000 53. Abutment Foundation Type 46. Distress and Repairs in Superstructure 000 62. Pier Foundation Type 12 45. Erosion of Banks/Bunds 000 55.26 41. Type of Superstructure 12 42. ._ Traffic limitations DYes ONo Name of Builder contractor.~.._ — . GENERAL DATA Traffic volume Authority responsible for management: (at km point . ~.~...~. TECHNICAL DATA Total length : _.. sketch (showing span .~ District ~.. ~ .. ~. Material~ Bearings: Type~ FOUNDATIONS Type: . .~ Road crossed: D Road nb River.~ Construction date : Design load :_.. .... SUBSTRUCTURE Abutments : Type: Material: . — ... 40 Appendix 3 SIMPLIFiED BRIDGE INVENTORY FORM Identification Number: Name -~rn... ~ (Prefarably Coloured) ~ ~. . waterway D Railway Year Volume_ U Under 0 Under 0 Above 0 Above . ~ .. . Number of spans : Distribution of spans: Totalwidth Carriagewaywidth Widthof Vertica1. State’ ... or Section ~...DAbove: U Under footpaths clearance SUPERSTRUCTURE Material: U Steel 0 Concrete 0 Composite 0 Timber Cross section .Utilities DYes 0 No.. Channel protection 0 Yes 0 No Type Piers: Type: -.....~ — Photograph Road number: ..~. - arrangement) ~(ilometnc point: ... Expansion joints 0 Yes 0 No Type .. Possible detour 0 0 Date of latest improvement/rehabilitation: Design load: Detour length . ~ .~ ..~ Observations : Equipment required forinspections DYes 0 No Utilities U Yes 0 No carried << .~ ... L. guidebunds) 5. Type of Bridge Higb level/submersible 2. apron. Bearings (Statecondition/movements/deformation/cleanlinetis/ condition of grease) 8. toes. Superstructure (a) Concrete (RCC and PSC) (State whether leaching/stains/cracks/spalling/ scaling/excessive deflection condition of articulation and.inside box) (b) Steel (State condition of protective system/corrosion! deformations/rivet and weld condition/buckling and kin king/waviness/fracture/cleanlines) (c) Masonry Arches (Statecondition ofjoints/cracks/vegetation growth! bulging of spandrel walls and parapets/ deformation).3. Miscellaneous (a) Wearing )urse (Surface condition and drainage) << (b.2. Yes/No (b) Inadequacy of waterway Yes/No (c) Erosion of banks as evident Yes/No 6. 41 Appendix 4 INSPECTION PROFORMA (for Routine Inspection) General 1. Condition of (a) Approaches (b) Protective works (Pitching. floor. Name of Highway/Location of Bridge 1. Name of bridge/No. of bridge/Name of river 1. Traffic Intensity PCU/T per day (latest census) 4. Drama ~Spouts/Ventholes/cloggingfcleanliness) . Foundation and substructure (State whether any abnormal scour. 9. settlement/tilting! cracks/cavitationidamages/growth of vegetation) 7.1. Last Routine inspection on by 3.F. State (a) H. (condition and profile) (d) Footpath (condition and drainage) (e) Expansion joints (Cleanliness/Wearing out and alignment! gap width/hump/drainage/deformation! corrosion/cracks) (f) Utilities (State condition) 10. designation and dated signature of and dated signature reviewing officer of inspecting Officer (Next higher[ Authority of the Inspecting Officer) << . designation Name. Have actions been taken on the observations and Yes/No recommendations from the last Routine/Principal inspection? II. etc.. Recommended corrective measures (Attach separate sheet if space is insufficient) Name. 42 (c) Parapets and Handrails. undergrowth etc.4. pot boles.1.7. << 6. erosion of toe walls. cracks movement etc.1. Check any abnormal scour noticed. condition of pitching/turfing. Type.1. 5. island formation. 5. tilting. GENERAL 1. Name of the Highway. Check any abnormal change in flow pattern . PROTECTIVE WORKS 5. width and thickness of appron.3.) 4. (Condition of impervious floor. etc.5. Condition of pavement surface (check unevenness settlement. approaches in cutting and embankment 4. any signs of slope failure etc.2. APPROACHES 4. Erosion ofembankment by raincuts or anyotherdamage to embankment. Retaining walls: (Checks. thickness of pitching in the slopes. 43 Appenthx 5 INSPECTION PROFORMA Check List for Inspection Report I. Approach geometrics (check whether it satisfies the standards in force). 5. of the bridge/Name of the River.4. Check damage to the layout. subsidence. Check condition of slope pitching.5.) 5.2. Check condition offloor protection works. etc.3. Side slopes/(Check pitched or unpitched. Approach slab (check settlement.) 5. WATERWAY 6. Reserve store material (check against specified quality). Bridge Location 2. vegetation.2. condition of weepholes guardstone and railing) 4. 1. curtain walls.1. apron and toe walls indicating the nature of damage if any(check for properslope.) 4. cracking. 6. 5. Accumulation of silt and debris on submersible. indicate nature of damage if any. Check presence ofobstruction.6.6.2. 4. etc. cross section profile (check whether the layout and the general cross sections are in order). Type of Bridge — High kveLfSubmenlhle 3(A) Date of last such Inspection by (B) Date oflast routine Inspection by (C) Traffic Intensity PCU/T per day (The latest census) 4. (mention whether guidebund or protection around abutments or spurs). Name of bridge/No. flexible appron.) 4. Check condition: of pads (oxidation. Elastomeric hearings (State numbers) 9.4.3. Bs. etc. displacements.1.1.1.2. Check general condition (check rusting. Check settlement.3. check maximum flood level observed during the year and mark the same on the pier/abutment both on the U/S and D/S (Local enquiry if necessary) 6. etc.3.1. 8. Check conditions of side retaining waits like cracking.2.4. Check damages to protective measures to pier and abutments (for viaducts. cleanliness. Check damage due to impact of floating bodies. 8. Check damages to protective coating or paint 9. Metallic hearings (State types/Sliding plate/Rocker Roller/PTFE/Pot hearings 9. disintegration and seepage.3.2.) 8. creep.3. boulders. Check adequacy of waterway 6.O. if any 7. etc. Check tilting. Check of erosion of bank 7. flattening.) 8. tilting. FOUNDATiON 7. splitting. vehicle impact. decay.1. 7. Check cracking. bulging.4. if any) 9.2. Check general cleanliness << .) 9.1. Concrete bearings 9. Check loss of shape 9. For sub-ways repori seepage. cracking. Check large excavations done in the road below in the vicinity offlyover or road over bridge of viaduct 8.3.5.1. abutments.3. Check signs of abnormal aflux from U/S & D/S watermarks on piers if any 6. dishing etc.3. Check any signs of distress (cracking. Check efficacy of drainage of the backfill behind abutments (check functioning of weep holes. tilting. erosion. flyover and R. SUBSTRUCTURE: (piers. disintegration. etc. spalling. seizing of plates).3. jumping off guides) 9. if any.1.2. return walls and wing walls). Greasing (check date of last greasing/oil bath and whether to be redone or not) 9. BEARINGS 9.5. Effectiveness of anchor bolts (check whether they are in position and tightened’) 9. silting. 44 6.6. disintegration decay and other damages. damage to the foun- dations. 8.2. cavitation etc. if any (For subways) 8.3. Check any excessive shifting 9.4.2. accumulation of dirt in case of submersible bridges 9.1. Functioning (check excessive ~novemen1. disintegrating staining. 7.1. Check general cleanliness 9.4. evidence of moisture on abutment faces. abnormal scour.6.2. Check alignment of members 10.1. construction joints or thin component sections of the deck viz.1. Interior diaphragms will also require examination.2. Check condition of connection (adequacy.12. Check cracking (pattern.5..1.4.1.18.specially on connection ofstringers to cross girders.2. Check Steel Members 10. Check condition of drainage system (spouts.2. bolts or wornout welds. Check excessive vibrations. Reinforced concrete and prestressed concrete members 10. pedestal) 9.1. The size and distribution of cracks and their penetration should lie noted) 10. of cantilever for cantilever bridge 10.15. looseness of rivets.7. (special attention. if any.19. Check excessive deflections (sag) or loss ofcamber if any at same point each time 10. if any 10.9.1. Check condition of articulation (cracks. Check spalling.1.1.4.1.) 10. Check condition of protective system 10.11. Check peeling off of protective coat or paint 10.3. around anchorage zone for prestressed concrete members 10. SUPERSTRUCTURE 10. to be given at points of bearings) 10. Check wear of deck surface 10. if any 10.10.4. kerbs. sheathing and tendons if visible 10. Condition of d/s stoppers (for submersible bridges) 10.1. tip.5.17. etc.1. explain preferably by photograph and plotting on sketch.1.2. location.2. the interior faces of flangers and webs need to be examined for signs of cracking and report excessive accumulation of waterordebris.2. Check leakage (Leakages of water can take place through concrete decks.13. Check excessive vibrations. Check exposed reinforcement. Check cracks if any in supporting member (abutment cap.1. pier cap.1. Check scaling (This is gradual and continuous loss of surface mortar and aggregate over irregular areas) 10.1. exposed reinforcement if any) 10.16.2.8.3.1.1.1.) 10. Check damages if any due to moving vehicles 10. etc. disintegration or honey combing. Check accumulation of silt and debris on surface of deck (for submers- ible bridges) 10. if any 10.1. Check corrosion of reinforcements. collection pits. par- ticularly for any signs of cracking at their junction to the webs 10. Check surface stains and rust stains along with the locations 10. Check Leaching (Effects are most usually evident on the soffits of dec1~ 10. In box girders. Check excessive deflection (sag) at central hinge.5. grating.1. 45 9. if any 10.14. Check corrosion.1. Check cracks.2.1. cross << . A map of the cracking should he produced.6. Check on the cleanliness of members and joints (check choking of drainage holes provided in the bottom booms) 10. check for splitting.5.2. disintegration. as such the inspection process has to take into account the variability of materials.4.10. etc.3. Check secureness of the joints 11.4. if any 1027. warping and waviness 1028. masonry. Check condition of joints mortar.6. etc. depth: explain by sketches) 10. condition of hinges. splices.6. Check masonry arches 10.1. etc. Check buckling. cracking. 11. lop sliding plate (check corrosion.9. oxidation. Checkcracks. Check growth of vegetation 10. if any 11. pointing.3. pattern.) 11.l I. extent. Check surface condition (cracks. Locking of joints (Check locking of joints especially for finger type expansion joints).) 11. check for thickoess as against actual thickness. 46 girders to main girders.) 10. etc. Report rattling.1.2.3. (‘heck conditions inside the closed members 10. Check drainage for expansion joint 11. These materials occurin older bridges and the defects which theyexhihit are in general very similar to those described above for steel.9. Check alignment and clearance 12. Check for debris in joints 11.3. bulging and forbitumen filler. Functioning (cracks in wearing course.4.8.3. Check conditiod of sealing material (for neoprene sealing material. excessive noise.3. etc. WEARING COAT (CONCRETE/BiTUMEN) 12. ifany.. creep. It should be recognised that the homogeneity and purity of the material will not be upto the present day standards of steel. 10. (Blow holes and cs~kingare probably the main defects that occur during the casting of the metal and its cooling. report flattening by observing rise of the arch at centre and quarter points 10.3. pot holes. kinking.2.2.2. damage to welds. EXPANSION JOINTS 11. Check evidence of wear (Tell-Tale rings. Check all Cast Iron/Wrought Iron Components 10. check for hardening. existence of normal gap.4.) 11. flattening.7. etc. Check excessive wear (such as in pins in joints of truss) and their locations requiring close monitoring tO. Check drainage of spandrel fillings (check bulging of spandrel walls. spalling. gussets or splices.3.) I 1. Check excessive loss of camber and excessive deflections and defor- mations.) 12.2.1. if any) 10.5. Check Profile. Check apparent fracture if any 102.1. (indicate location. check data of last inspection) << . Check general condition (damage due to mounting of vehicles) 15. Cleanliness ofducts along footpaths 16.1. For submersible bridges. AESTHFflCS 19. Check condition of lighting facilities 16. 47 12.4. if any 132. Check adequacy thereof l3.) 14.1. hoarding. ENViRONMENT Cheek for signs of aggressiveness 19. Check any damage by telephone and electric cables 16. Check damages due to any other utilities 17.~ For subways report about adequacy of drainage and pumping arrangements. etc. HANDRAILS.1. Compare additional thickness with design thickness. WDGE NUMBER 17. Check genera~1condition (check expansion gaps. with reference to kesh height 13. etc. Check alignment (report any abruptness in profile) 15. deterioration and damage. Check leakage of water and sewage pipes 162.3. MAINTENANCE AND IMPROVEMENT RECOMMENDATION S. 192. Check missing footpaths slabs 153.3.2. Check whether all actions for maintenance and repairs recommended during last inspection have been done or not (give details) 20. missi’ng parts if any etc. UI1LI1’IES 16. Item needing Action Time by which to Remarks attention recommended be completed << ..3.1. Check damage due to collision 14.1. DRAINAGE SPOUTS AND VENT HOLES 13. FOOTPATHS 15.1. Check the projection of the spout on the underside (see whether stnac- tural members are being af1ect~d) 13. 133. Check condition of painting 18.2. vegetation on structural mem- bers.No.3. PARAPETS 14.4. Check clogging. report on funetioning 14. Check any visual intrusion. Signature of the Inspecting Officer Date i)uration of Inspection From AM/PM to AM/PM Method of inspection << .48 21. Certificate to be accorded by the inspecting official Certified that I have personally inspected this bridge. callipers Straight edge. binoculars. inspection mirror. chalk. magnifying glass. markers. camera Flash light Pocket knife. protector. folding rules. clamps etc. wire brush Chipping hammer Thin steel rod for use as probe (8 to 20 mm diameter) Crack meter Scrapper and emery paper Plastic Jars and bags (for samples) << . plumb bob. Pocket tapes. tapes (10 m to 50 m) Feeler gauges. spirit level Thermometers. 49 Appendtx 6 STANDARD TOOLS Clip boards. electrical resistivity meter. vibrations Aceleromettr widening of cracks Glass tell-tales << . 50 AppendLx 7 POSSIBLE ASSESSMENT METhODS (ONLY INDICATIVE) Assessment of Possible method (s) Concrete Strength “Schmidt-hammer” Quality Ultra-sonic. Global behaviour Surveying instruments. pressures. movements dial gauges (straining gauges) extensometric Strain gauges and measurement extensometers. Lamination Sounding cover Profometer Steel Cracks Ultra-sonic. Cable/wire failure radiographic. Forces Pressure transducers or load cells Miscellaneous thickness of coatings Paint film gauge waterproofing (digital elecometer) membranes electrical resistance. corrosion electrical halfcell potential. These methods are par- ticularly useful to detect corrosion of reinforcement 6. 4408) 8. The results indicate extent of attack due to sulphates or sea water and any unusual hydration product 9. Non-Destnsctlve Tests I. 2. Non-destructive testing should be undertaken only by agencies qualified for the purpose.~have been used for assessing the strength of concretc. ElectroeheScal Potentials The procedure is as per ASTM C876. Magnetic Methods — The magnetic methods are used for determining the position of reinforcement as well as the assessment of the concrete cover. Some of the test procedures for concrete are listed below A. The hammer is used to compare the quality ofcon- crete in different parts of the bridge rather than to determining the absolute values of strength. Rebound and penetration tests that measure the hardness of concrete are used to predict the strength ofconcrete. . << . The travel time of the sonic pulse beiween monitoring points is related to the mtxtulus ofelasticity and hence the strength. 51 Appendix 8 TESTS A large number ofdestructive and non-destructive test (NDT) procedures are avail- able fsr evaluating the strength of components of bridges.3. X-Ray diffraction aS differential thermal analysis olcoacrete saasples —‘ This is usc~ ful in determining hydration characteristics. Such meters can measure concrete coverwtth an accuracyof±mm in the range ofupto TS mm. The relative strength of concrete can also be assessed by the Windsor probe.— Gamma radiation techniques have been particularly useful for assessment of voids in concrete as well as in grouted tendon ducts (Vide ILS. However the limitations con. The correlation between the pulse velocity and compressive strength is reasonably good provided (he system has been calib- rated with cores of the particular concrete being evaluated Corrections are required to be made to account for any reinforcement present 4. The system is capable of detecting differences between areas of sound and unsound concrete. The moisture measurements are used to determine the possibility of corrosion of reinforcement 7. caning the use of non-destructive testing andthê reliabilityof the results should be closely examined. 5. Sonic Methods — Electronics sonic methosI. Ultrasonic Teekniqnes — These techniques are used for measuring the velocity of pulse in concrete. Etectrical Methods — Electrical methods for inspection of concrete bridge com- ponents include resistance and potential measurements. Naetnr Methods — Nuclear methods are used to measure the moisture content in concrete by neutron absorptiontechniques. Several portable battery operated cover meters are available for the purpose. ‘Fhe pulse velocity depends on the composition and maturity of the concrete and its elastic properties. RadIography . This is useful in finding the condition of embedded steel. ~. Crack Meters -. A combination ofvarious non-destructive tests may be required to assess the struc- ture Usually no single non-destructive test can be relied upon to furnish the necessary information. The depth of carbonation is measured by painting the freshly coated c:oncrete surfaces with the 2 per cent solution of phenolphthaiein. Carbonation Carbonation of concrete in the cover region results in loss ofprotection of the steel agaitsst corrosmn.wailahie iti various formats fur taking cores in horizontal. Strain Measurements — i’hese are done with the help of ER strain gauges and strain measuring bridges. Pull Out Test ‘I’his measures the torce required to pull out a steel road with enlarged head cost in concrete or introduced. Pull Off Test This is used to evaluate the tensile strength of concrete or the bond tensile strength between two different concrete or mortar layers. The tensile force is applied to a circular steel disk . Dye PenetrationTest and Optical Microscopy — These tests give qualitative evalua~ tion of incidence of pores and voids in concrete. 52 10. 14. 5i6-1959) from concrete component under n:trrence results in the actual strength of concrete being obtained. Concrete strength Testing core samples (As per 1.to operate at site and can he used specially for the quality contraii of repaired concrete surfaces. external source Endorscopes are used for detailed examination of parts of the bridge structure which could not otherwise he assessed. << . Battery powered portable versions are also available 2. theodolites.5. The colour of the con- crete surface after painting may be compared with standai~dcharts to indicate the areas of carbonation. Endorseope Fndorscope consists of usually flexible viewing tubes that can be inserted into holes drilled into the concrete bridge components A light is provided by optic fibres frons an. Core dnlling equip- rm~ntis . Deflection Monitoring .t mom diameters glued to a concrete surface by an epoxy resin. This is done with precision levels. 12. It is possible to estimate compressive and tensile strersgth of concrete by correlating svith the pull out force.-. IS. 5. The steel disc diameter isSO mm and the putt-off for a ranges from 500 N to 5t$XXt N depending on the type of the equipment T’h is tcst is easy.. Destrectise Tests 1. 3. Microscopic Examination Sag opticsi and polarised light microscopy — Useful in identifying ag.gregate source. vertical or inclined ch rections. Electrical Re~istivltyManagement --. B. presence of slag etc. Endorscopes are also available with attaclsrnents for a camera or TV monitor. The test can be carried out with a portable lightweight equipment. laser aligne:rs. This also is useful in indicating the condition of embedded steel. by drilling.To measure the width of cracks. 4. it. Break Off Test This is mainly used to estimate flexural tensile strength of concrete. 53 6. It is used to estimate tensile concrete strength of concrete through a correlation with the pull out force. RapiiL Chloride Teat and Rapid Sulphate Teat Results in terms of chloride content and also depthwise penetrat. 55 MM diameter core. The specimen is sealed in a permeability test rig and water pressure applied on one faceand the flow rate is measured. The test is susceptible to laboratory conditions of storage. Analysis of Hardened Concrete Determination of cement content is possible in hardened concrete. << . I0. if Water Penetration Test In this’ the flow rate of water through concrete is measured and this indicates the degree of protection of reinforcement offered by the concrete cover. Ii Optical microscopy and expansion test on concrete cores This can detect the alkali-aggregate reaction.ion are possible. The testcan also be used to evaluate bond between two concrete or mortars of different ages. 70 MM deep is prepared and the force required at the top and right angles to the axis to break off the axis to break off the core at the bottom is measured~Thecore is drilled in the hardened concrete. 9. 7. tntensal Fracture Test in this the force required to pull out an anchor bolt is measured. 54 AppendL~9 SUGGESTE[) ACTION PLAN << .