ABSTRACTIn this dissertation an attempt is made to evaluate the performance of skew bridge using different skew angles and by using grillage analogy method. In India most of the bridges have a maximum span of 40.00m. In recent years as there is tremendous growth of traffic and lack of area, so we are adopting skew bridges. In designing skew bridge, in variation of angles we compare the bending moments, shear force. We use Grillage analogy method and design the most effective skew bridge by using STAAD Pro software. To achieve main objective of this project a 50.00m span, RCC bridge by using code IRC112:2011 and IRC6 2010 code for loadings. The results obtained from this analysis will be useful in designing of skew bridge. 1 TABLES OF CONTENTS CONTENTS PAGE NO. ABSTRACT 1 CHAPTER 1: INTRODUCTION 1.1 1.2 1.3 1.4 Problem description Outline of the project Outline of the project report Input data 2 4 4 3 CHAPTER 2: LITERATURE REVIEW 2.1 Introduction 5 2.2 Literature Review 6 2.3 Conclusion 8 CHAPTER 3: SKEW BRIDGE 3.1 Introduction 3.2 Codes used 3.3 Different types of loads on bridges 9 9 10 CHAPTER 4: ANALYSIS OF DIFFERENT SKEW ANGLES 4.1 Introduction 12 4.2 Analysis of skew angles using STAAD Pro 13 4.3 Comparative study 18 4.4 conclusions 18 CHAPTER 5: DESIGNING OF TYPICAL T-BEAM GIRDER BRIDGE CHAPTER 6: CONCLUSION 57 REFERENCES 58 Basic terminology used in bridge Engineering Bridges 2 O.S.Skew Support reactions Bending moments Shear forces Grillage Loads Abbreviations: M.T – Ministry Of Surface Transport SERC – Structural Engineers Research Centre CAD – Computer Aided Design STAAD Pro – Structural Analysis and Design computer Program Notations bw = Breadth of web 3 . max = Maximum shear stress in concrete τv = Nominal shear stress ɸ = Diameter of bar CHAPTER 1 4 .be = Effective breadth Ec = Modulus of elasticity of concrete Es = Modulus of elasticity of steel Fck = Characteristic cube compressive strength of concrete Fy = Characteristic strength of steel m = Modular ratio y = Depth of neutral axis α = Angle V = Shear force M = Bending moment D = Over all depth Q = Moment factor J = Level arm σst = Permissible stress in steel in tension σsc = Permissible stress in steel in compression τc. providing the angle. reactions at supports.. adopting the method of design for construction of bridge and almost every structural engineer is facing problems like geo-technical problems. Considering the ever increasing the population and traffic as well as limited area. In this the deck is represented by an equivalent grillage beams. And is a computer aided method & can analyse fast. deflection & transverse moments are computed by grillage analogy method &results are compared for different skew angles. Thus the design of bridges. Methods for analysing bridge: 1. As the other methods are highly numerical and always carry a heavy cost penalty. horizontally more expanding of bridges in construction of bridges in metropolitan cities is not possible Grillage analysis is the most common method used in bridge analysis. Finer grillage mesh. both major and minor bridges. provide more accurate results as compared with other experimental methods.INTRODUCTION 1. Finite difference method 5. Finite element method 2. less area for construction of bridges. effect of loads. Longitudinal moment. Grillage analogy method. water currents in rivers etc. type of bridge. Orthotropic plate theory methods 5 .1 Problem Description Recently there has been a considerable increase in the construction of bridges. for this reason there is need to design skew bridge using grillage analogy. The presence of skew in a bridge makes the analysis and design of bridge decks. The importance of grillage analogy is emerging in India ever since along period. using STAAD Pro 4. Finite strip method 3. and the modern trend is towards Express highways. The angle of skew has a considerable effect on the behaviour of the bridges. Semi-continuum method. torsion and deflections caused by the bridges. the RCC deck with normal girders and varying the skew by 15. Effect on support reactions of skew bridge is presented by Trilok Gupta and Anurag Misra. Shreedhar and Rashmikharde.Comparing the support reactions. The analysis of bridge considerations are. bending moments. The comparative study of Grillage method and Finite element method of RCC bridge deck has been studied by R. Design of the bridge elements as per latest code IRC: 112-2011.6.. shear forces. Folded plate method 7. Span of 50. An attempt has been made to develop information using a latest code IRC-112-2011 using grillage analogy method. A comparison of skew angles in a bridge by support reactions.00m.. 35 degrees. 6 . It is found that which method is preferable for the construction of RCC Bridge. 25. shear forces and torsion with skew angle. bending moments. 15m Grade of concrete = M 45 Grade of steel = Fe 500 Young’s Modulus of elasticity ‘E’ = 3. 35 Type of construction = RCC girders and In-situ slab.00m No of lanes = 4 Depth of slab = 250mm Skew angles = 0.5m at both sides) 3.2010 Method adopted for analysis = Grillage = All members as per IRC 112- 0. No.5 m c/c Spacing. of traverse girders = 5 Nos. (2.Input data Slab .girder Span of the bridge deck = 50.End diaphragms and Depth of the girder = 3.00m (including crash barrier Carriage way width = 15. of longitudinal girder = 8 Nos.00m Total width of the deck = 20. STAAD Pro RCC design 2011 7 . @ 2. 1623 X 106T/m3 Support conditions = simply supported Loading = as per latest IRC: 6. 15.on . No.Intermediate diaphragm) analogy method. 25. 2. To achieve the objective. shear forces. moving loads are applied with variation of skew angles. 1. In the chapter-2 various research papers related to computational methods. It provides an overview of the literature related to the effect on skew angles. 3. the objective of the study and the organization of the project report. deciding the most applicable angle and designing the bridge using latest IRC codes.3 Outline of the Project Report This dissertation is organized into 5 chapters with the following contents: The chapter-1 gives the introduction about the project. and designing with a suitable skew angle as per latest IRC codes. Conclusion and the future scope of the work are also presented in this chapter. In the chapter-3 described the analysis of loads. member properties &support reactions using STAAD Pro as per code IRC 6-2010. In the chapter-4 describes the comparative study of bending moments. the work is divided as following stages. And analysed. comparative study of bending moments & shear forces at critical section. At the end conclusion on the literature are described in this chapter.1 Introduction 8 .1. In the second stage. CHAPTER-2 LITERATURE REVIEW 2.2 Objective of project The objective of the dissertation work is to design a skew bridge using grillage analogy with variation of skew angles. In the first stage. 1. support reactions. In the third stage. Finally a summary of the project work is described in the chapter-5. Trilok Gupta and Anurag Misra (2007) In order to cater to high speed and more safety requirements of the traffic. at. In this method. In this method the deck is represented by an equivalent grillage of beams. modern highways are to be straight as far as possible and this has required the provision of increasing number of skew bridges. effect of skew angles and response of skew. Shreedhar. edge Stiffening and isolated supports. is increasingly being used in the analysis and design of bridges. The grillage analogy method. provide more accurate results. It provides an overview of the literature related to the study of computational methods. In the next section the description of literature under various heading is given.In this chapter various research papers related to introduce categories of the bridges. It is a versatile in nature and the contribution of kerb beams. 2. The finer grillage mesh. (2012) In this paper describes Grillage analysis is the most common method used in the bridge analysis. The method is also suitable in cases where bridges exhibits complicating features such as heavy skew. connected together at a number of nodes. Finally conclusion on the literature are drawn and presented at the end. It was found that the results obtained from grillage analysis compared with experiments and more rigorous methods are accurate enough for design purpose. referred to as finite element.2 Skew bridges analysis using grillage analogy Vikash Khatri et. the actual continuum is replaced by an equivalent idealized structure composed of discrete elements. R. as it is capable of accommodating many complexities in the solution. which is a computer. The finite element method is a wellknown tool for the solution of complicated structural engineering problems.oriented technique. The inclination of the centre line of traffic to the normal to the centre line of the river bridge or other corresponding obstruction is called the skew angle. Rashmi Kharde (2013) 9 . (2008) This method is usually used for analysis of bridges based on the consideration of the bridge deck as an elastic continuum in the form of an orthogonally anisotropic plate.The grillage analogy method involves a plane grillage of discrete interconnected beams. Using the stiffness method of structural analysis. In this method the deck is represented by an equivalent grillage of beams and is based on stiffness matrix approach.service skewed bridges have been shown to be lower when compared against those in similar right bridges. shears and moments have been shown to 10 . grillage analysis is the most common method used in bridge analysis. (2004) There is a growing demand for skewed steel bridges as the needs for complex interaction and the problems with space constraints in urban areas arise. torsional rotation. Skewed bridges are useful when roadway alignment changes are not feasible or economical due to the topography of the site and also at particular areas where environmental impact is an issue. Generally. finite element method and finite strip method . 2. the concentration of moments and torque cannot be given by this method Dr. Critical values for vertical deflections and bending moments within in. it became possible to analyse the bridge deck structure as an assembly of elastic structural members connected together at discrete nodes. The finer grillage mesh. al. folded plate method. If the load is concentrated on an area which is smaller than the grillage mesh. There are four distinct techniques which have been found useful by bridge engineers: grillage and space frame analysis. The effect of skew on the response of completed structures has been well documented. with effects being shown to be more significant for skew angles greater than 30◦. provide more accurate results. it was found that the results obtained from grillage analysis compared with experiments and more rigorous methods are accurate enough for design purposes.Many methods are used in analysing bridges such as grillage and finite element methods. Conversely.3 Behaviour of a skew bridge Tze-Wei Chooaet. al.MaherQaqishet. studies have also demonstrated that interaction between main support girders and transverse bracing members influences skewed bridge load distribution due to an increase in torsional rotations at certain sections of longitudinal girders. The twisting moments at the supports because of bi-directional curvature are small and hence can be neglected. Torsional moments developed in steel bridges with large skews are difficult to predict during construction. Arindam Dhar et. as the alignment of the screed can result in an uneven distribution of wet concrete dead loads across the superstructure that increase the skew effects. the slab showed asymmetric bending with increasing deflection at obtuse corner and decreasing deflection at the acute corner. Most importantly. al. In a non-skewed bridge the deck behaves orthogonally in flexure i. There are few studies to say the behaviour that is. (2013) The behavioural aspects of a skew bridge and compare them with those of the straight counterparts using a 3D Bridge model in Finite Element Analysis. Such changes in the moment are generally not considered while designing a straight bridge. the support shear and mid-span moments of obtuse longitudinal girders increase while these parameters decrease in the corresponding acute longitudinal girders. Using the stiffness method of structural analysis. It is evident that the load from the slab is transferred to supports directly through flexure. There are four distinct techniques which have been found 11 .be larger for skewed bridges. The results of the bridge model as increase in the skew angle. the increasing skew angle rapidly increases the torsional moment in the obtuse angled girder. it became possible to analyse the bridge deck structure as an assembly of elastic structural members connected together at discrete nodes. In addition. (2008) This method is usually used for analysis of bridges based on the consideration of the bridge deck as an elastic continuum in the form of an orthogonally anisotropic plate. a simply supported RC Bridge was adopted. Dr. Maher Qaqish et. With increasing skew angle. with the principal moments being in both these directions where shows the deflection pattern of a non-skewed slab bridge deck. al. both in longitudinal and transverse directions.e. To understand the trend clearly. in constraint areas and knowing the effectiveness of the bridge as there is an increase in skew angle make a huge difference when compared to right angled bridge. folded plate method. finite element method and finite strip method .useful by bridge engineers: grillage and space frame analysis. hence the bridge must be designed considering the angles present in the site 12 . 2.The grillage analogy method involves a plane grillage of discrete interconnected beams.4Conclusion on literature By studying the literature as mentioned above it is found that skew bridges designed using Grillage analogy plays a very important role in the life cycle of bridges. 13 . forces and permissible stresses in the fourth revision published in 2000. The section –II of the code deals with loads and stresses was revised in the second revision published in 1964. The metric version was introduced in the third revision of 1966. 5. As the other methods are highly numerical and always carry a heavy cost penalty. Types of bridges: 1. In this the deck is represented by an equivalent grillage beams. 2.CHAPTER 3 SKEW BRIDGE ANALYSIS 3.1 Introduction The inclination of the centre line of traffic to the normal centre line of the river in case of a river bridge or other corresponding obstruction is called the skew angle. 2. The IRC: 6 have been revised to include the combination of loads. 6. And this type of bridge is called skew bridge. Piers Abutments Bearings Sub-structure Wing walls Bed blocks Backing walls Grillage analysis is the most common method used in bridge analysis. Finer grillage mesh. provide more accurate results as compared with other experimental methods. Normal bridge Skew bridge Curved bridge Reverse bridge Components of bridge: 1. 3. It is a computer aided method & can analyse fast.2 Codes: The first loading standards (IRC: 6) India was published by the Indian Roads Congress in 1958 and subsequently reprinted in 1962 and 1963. 7. 4. 3. 3. 4. Types of loads Dead loads Live loads Impact loads Wind loads Longitudinal loads Centrifugal loads Seismic loads 3. 1966 and 2000. The dead loads initially assumed shall be checked after the design is completed and the design shall be revised.3.3 Loads: Highway bridge decks have to be designed to withstand the live loads specified by the Indian Roads Congress.2 Live load: IRC Class AA loading IRC Class 70 R loading IRC Class A loading IRC Class B loading IRC Class AA loading: Two different types of vehicles are specified under this category.1 Dead load: The dead load is the weight of the structure and any permanent loads fixed thereon. The different categories of loading were first formulated in 1958 and they have not changed in the subsequent revisions of 1964.3. 14 . 3. if the actual calculated dead load exceeds the assumed dead load by more than 2 ½% or if the assumed dead loads effect dead load on a member varies from the actual dead load effect to such an extent as to adversely affect the design of such member.3. Alternatively. 2. 15 . 70R tracked vehicle. Wheeled vehicle with a train of vehicles on seven axles with a total load of 1000 KN. IRC 70 R loading consists of total load 700 KN with two tracks each weighing 350 KN. Wheeled vehicles (1000 KN) All the bridges located on national highways and state highways have to be designed for this heavy loading. IRC Class 70 R loading: 1.1. Tracked vehicle: Wheeled vehicle: But the main loads which we use in the design of bridge are 3 lane class a. Wheeled vehicles comprising 4 wheels. another type of loading designed as Class 70R is specified instead of Class AA loading. 3. Tracked vehicles (700 KN) 2. 70R wheeled vehicles. each with a load of 100 KN totalling 400 KN. 16 . 4. Click create.4 Supports: 1. 1. And assign at supports. 3. 2. 4. Select support. Plotting the bridge deck of 50. and select pinned then add and close 3. Select the general.CHAPTER-4 METHOD SKEW BRIDGE ANALYSES 4. As we are designing a skew bridge we need to change the angles. Importing the skeleton of the bridge from CAD to Staad. leaving 0. Iz ie.00m span in AUTO-CAD.00m.5m both sides for crash barriers ie. And assign the properties to members.2Preparing the skeleton of the bridge 1. And width of the deck 19. The support conditions were imposed directly on the end nodes of the girder: the end of the girder and intermediate girder supports were pinned. 17 . 4. Composite action between the steel girder and concrete deck was modelled using constraint equation. 2. and close.00m. 2. 3. Ix.3Analysis of skew bridge in Staad-pro. General: Assigning the member properties to the skeleton of the bridge. a prismatic section and material as concrete. 4.1 Introduction The bridge was modelled using a combination of beam elements from the girder and beam elements and shell elements from concrete deck.. We get a support-whole structure 2. Finally will get the skeleton of skew bridge. Go to define. and select general and enter the values of Ax. total width 20. shear force diagram. load cases details.5 DEAD LOAD CALCULATIONS 4. Add & close it 4.475KN/m 4.4. And staad model will be created. In load cases detail we can give self-weight & moving loads.8560×25 1. In definitions go to vehicles definitions and select type-1. Select Analyse 2.856×25 Extra weight of girder due to Web thickening Load = (cross sectional area at support – cross sectional area at center) × 25 = (1. 4.8560) × 25 = 11.3150×25 Uniform weight of Girder = 0.3150-0. it will generate the details. Finally we get bending moment.400 Cross sectional area of girder at Support = 1. 18 . 2. 3.3150 m2 Load = 32. 5.5. 4. Select loads & definitions we get 3 cases definition.5 Loading: 1. 1 lane of 70R Tracked vehicle.4KN/m = = 0. In moving loads we are considering 3 lanes of class A. Now Run load generator 5. Perform run analysis 2. 1 lane of 70R wheeled vehicle.1 Self Weight of the Girder Cross sectional area of girder at Mid Span = 0.6 Perform analysis: 1. type-2. If no errors than we can get the bending moments and shear force values.875 KN/m = 21.8560 m2 Load = 21. Select design code. load envelopes. Modelling page Moving loads on bridge 19 . 673. 8 12.3 0 0.3 0 0. 35 55.3 0 0.507. 11 18. 2 0.7524 0 -18.45236 0 -18.02916 0 -10.6292 0 -10.3 0 0.01428 0 -2. 46 4.3 0 0. 21 38. 16 28.24106 0 -17.4321 0 -12. 13 22.2351 0 -14.2202 0 -5. 51 8.81726 0 -3.3 0 0.673.83213 0 -12.3 0 0.62023 0 -5.3 0 0.17514.6 0 0.3 0 0.1262.7851.0381 0 -15. 37 57.05 TYPE CONCRETE STRENGTH FCU 2812. 10 16.3 0 0. 58 18 DEFINE MATERIAL START ISOTROPIC CONCRETE E 2. 32 53. 53 8. 12 20.3 0 0.229. 45 3. 41 0.1262.3 0 0. 40 59.7524 0 -18.06308.61911. 27 50.6143 0 -2.3 0 0.40262 ALPHA 1e-005 DAMP 0. 57 16. 48 5.951. 39 58.3 0 0.3 0 0.06308.28 END DEFINE MATERIAL MEMBER PROPERTY AMERICAN 20 . 31 52.63511 0 -14.3 0 0.1262.42321 0 -7.211309 0 -0.1262.17 DENSITY 2. 44 2. 52 8.1262. 38 58.3 0 0. 29 50.3 0 0.229. 3 2.75237 0 -18.17514.3 0 0. 28 50. 49 6. 30 51. 15 26.21467e+006 POISSON 0. 17 30.0232 0 -7.43808 0 -15.61911. 14 24.Staad output STAAD SPACE DXF IMPORT OF 25. 50 7.8262 0 -9. 9 14.8411 0 -17.8113 0 -0.DXF START JOB INFORMATION ENGINEER DATE 27-Jun-14 END JOB INFORMATION INPUT WIDTH 79 UNIT METER MTON JOINT COORDINATES 1 0 0 0.7851. 34 54. 47 5. 6 8.1262.89712.3 0 0.453154.951.507. 26 48.1262. 4 4.3 0 0. 23 42.89712. 42 1. 25 46.3 0 0. 54 10.34109.7524 0 -18.0524 0 -18. 5 6.4173 0 -3.3 0 0.34109.3 0 0. 36 56. 19 34. 55 12. 24 44.3 0 0. 56 14. 7 10. 22 40.453154. 33 54.7524 0 -18. 18 32.22618 0 -9.3 0 0. 43 1. 20 36. 2 1.17831 CONSTANTS MATERIAL CONCRETE ALL SUPPORTS 80 82 84 86 88 PINNED 355 357 359 361 363 PINNED DEFINE MOVING LOAD *Class A vehicle with 10% Impact TYPE 1 LOAD 3.35 9.4 DIST 1.457 0.000951 IZ 3.07548 IY 0.457 0.457 0.31012 141 TO 148 201 TO 208 261 TO 268 321 TO 327 328 PRIS AX 1.1 TO 27 52 TO 78 418 TO 444 661 TO 686 687 PRIS AX 0.457 0.35 9.93 *Class 70R Tracked Vehicle with 10% Impact TYPE 3 LOAD 1.52 3.185 IX 0.5 IX 0.000951 391 392 416 417 472 473 497 498 526 527 551 552 580 581 605 606 634 635 659 660 PRIS AX 3.0317 IY 0.2 3.85 3.925 DIST 0.49685 393 415 474 496 528 550 582 604 636 658 PRIS AX 2.6 4.485 1.457 WID 2.50862 IX 0.0019 79 TO 90 379 TO 390 PRIS AX 1.0038 IY 0.37 3.457 0.6 6.000951 IZ 1.03594 394 TO 414 475 TO 495 529 TO 549 583 TO 603 637 TO 656 657 PRIS AX 1.457 0.13 1.000951 IZ 1.8 *Class 70R Wheeled Vehicle with 10% Impact TYPE 2 LOAD 9.05 1.96 WID 1.85 1.85 3.74 3.25 ZD 0.000951 IZ 3.457 0.313 IX 0.457 0.000951 IZ 0.27 6.0019 IY 0.1 WID 1.74 3.85 3.925 3.8179 IX 0.25898 IY 0.74 3.3 1.57503 445 TO 471 499 TO 525 553 TO 579 607 TO 632 633 PRIS AX 0.05 91 TO 140 149 TO 200 209 TO 260 269 TO 320 329 TO 377 378 PRIS AX 0.85 3.37 2.27 1.06 ********************************************************************* ** LOAD 1 DL & SIDL 21 .485 DIST 3 3 3 4.35 9.000951 IZ 1.5445 IX 0.85 3.85 3.85 3.85 3.48626 IY 0.02689 IY 0.17831 28 TO 51 PRIS YD 0.000951 IZ 0.00521 IY 0.365 IX 0.19934 IX 0.457 0.000951 IZ 2.35 6.74 6. SELFWEIGHT Y -1 **Crash Barrier MEMBER LOAD 1 TO 27 52 TO 78 418 TO 444 661 TO 687 UNI GY -1.5 *TYPE 1 52 0 -6.5 *1 Lane of Class 70R (Tracked) + 1 Lane Class A *LOAD GENERATION 120 ADD LOAD 1 *TYPE 3 38 0 -3 XINC 0.3212 *Wearing Coat FLOOR LOAD YRANGE 0 0 FLOAD -0.723 0 -14.341 XINC 0.5 TYPE 1 3.5 *1 Lane of Class 70R (Wheeled) + 1 Lane Class A *LOAD GENERATION 120 ADD LOAD 1 *TYPE 2 26.341 XINC 0.723 0 -10.063 XINC 0.52 0 -9.5 XINC 0.5 TYPE 1 3.723 0 -7.92 0 -12.165 GY ********************************************************************* *** *3 Lanes of Class A LOAD GENERATION 120 ADD LOAD 1 TYPE 1 3.563 XINC 0.5 ********************************************************************* **** PERFORM ANALYSIS PRINT MEMBER FORCES FINISH 22 .841 XINC 0.5 *TYPE 1 31. 872 F B.66 18. % 0.927 % 1. .24 261.1 248.71 123. % 13.08 123.53 1. 1.09 702 52 % 7 % 264 % Conclusion: 23 1.68 30.54 .798 122. 4.01 % 0.77 91. 702 226 53 % 23105 2.54 .895 0.66 17.7 121.49 1.118 1.05 525 2234 942 2249 % 0.6 % 0. 155 .66 19. 30.89 of M S.8 1.8 1.36 218.5 F B.06 M S.7 121. 30.014 2234 635 2257 % 1.14 48 23115 % 2. .98 122.36 227.54 .60 91.65 302 30877 1.09 7 302 % 30305 0.53 91.98 7 302 % 836 30296 0. Class A -0 Varia tion 2234 2246 0. 702 226 M S.832 122. . F 70R(W h)+ Class A 70R(Tr )+ Class A -25 tion 3 Lanes B.7 121.3 % 0.Load Ske Skew % of Ske Skew % of Skew Skew % of Combi w-0 -25 Varia -25 Varia nation w-0 tion 226 23489 3. % 11.50 % 1.8 1. only 5% change can be observed. 24 .As we are increasing the skew angle we cannot see much difference in bending moments. We find design examples in bridge engineering books by victor. Balanced cantilevers in PSC 10. T-beam decks in VRCC M20. 3.3 DESIGN OF DECK SLAB: It is very easy to design the deck slab super structures as it is a case of simply supported one – way slab subjected to dead load and live load concentric point load. Deck slabs in VRCC M20.CHAPTER-5 Design of typical Tee. Single cell box girder in PSC 8. M25.1 DESIGN OF BRIDGES 1. M30. Design of super structure Design of sub-structure Design of foundations Design of bridge components In this project we design only super structure. M25 2. Voided slab in VRCC M25. etc.beam girder 5. Steel bridge decks 11. 5. Twin cell box girder in VRCC 7. 2. Cable stayed decks 5. 3. Composite decks (PSC + RCC) 12. 25 . T-beam decks in PSC 4. 5. vazirani.2 Types of super structures: 1. Twin cell box girder in PSC 9. 4. Single cell box girder in VRCC 6. 26 . This type of Super Structure involves rigorous analysis of load distribution between longitudinal girders.pro with beam and slab elements and analyze with moving loads input.RCC T.BEAM TYPE SUPER STRUCTURES DESIGN: 1. We have readymade charts developed by SERC Roorkee for shear force and bending moments at critical points in girders to design steel 3. cross girders and panel slabs. Output gives BM and SF in girders and BM in panel slabs so that the required steel can be calculated. 2. The SERC Roorkee have also developed design charts bending moments at salient points in slab panels to design steel 4. We can also develop model in STAAD. The maximum positive strains always occurred in the edge girder or one girder in from the edge i. Negative moments appeared at the pinned ends at the obtuse corner. moment of inertia. As we are designing a bridge with a skew angle areas. The influence of diaphragms and support modelling was studied.CHAPTER-6 CONCLUSION In this project.The transverse distribution of strains was parallel to the skew line. As a result. And finally need to calculate area of steel. The influence of slight variation was very small. slab-on-girder Bridge with a skew 25° was analysed. negative moments appear at the pinned ends due to effect of diaphragms. 27 . 2 & 5. Loads are applied on the bridge. Diaphragms plays more important role in load distribution. A Grillage Analogy method was used to analyse the bridge. the effect of end diaphragm might be considered as an equivalent thickness. percentage of steel that to be provided to keep safe the structure. a single span. simply supported bridge. The bridge is behaving linearly. so it was not concern in evaluating load distribution of the bridge. The Grillage Analogy provided close results to the measured values. At the obtuse corner of the skewed bridge. It plays same effect on deck. neutral axis have to be calculated. It should be noted that the moments at pinned ends of girders may not be zero. After adding diaphragms load distribution factor decreased.e. The results were compared with Skew 0°. Maiti. Krishna Raju. “Design of T-beam bridge by finite element method”. R. IRC: 6-2010. Vikash Khatri. Maher. Singh and Ansumankar. 2. 10. 9. 12. Somnath Karmkar. “Pre-stressed Concrete”. No./ISSN: 2250-3005”. N. Delaware Transportation institute. 1. 4. Anurag misra (2007). Varanasi.. Rashmikharde. Newark. Shreedhar. Emad Akawwi.S. “Analysis of skew bridge using computational methods. (2013). Krishna Raju. moment) and deck slab of an IRC skew bridge. Journal of bridge engineering. Mithil Mazumder. (2013). P. Vol. 6. New Delhi. No. (2009). Mc Graw Hill education. (2009). “Code of Practice For Concrete Road Bridges”. ARPN. IBM publication.O.. M. Trilok Gupta. Eyad Fadda. “Analysis and Testing of a Highly Skewed Bridge”. issue feb-2013. P. IRC: 112-2011. Vol. “Design of bridges”. Arindam Dhar. “Effect on support reaction of skew bridges”. International journal of scientific &engineering research. Vazirani. Michael. “Standard Specifications & Code of Practice For Road Bridges”.8. 8. Ratwani. Shenton III. Chajes.T-1990. Harry. 11. 7.R.K. The Indian Concrete Journal. “Effect of skew angles on longitudinal girder (shear. Delhi.Banaras Hindu University. Delaware. “Standard Drawings for Road Bridges”. (2010). Haoxiong Huang. “Design of Reinforced Concrete structure”. 1. ISSN 2229-5518. New Delhi.. “Effect of skew bridge for moving loads”.. (2009). Khanna publications. (KMITL).N. N. 28 . 5. 2. 3. Fourth Edition. (2008). Fifth Edition. 16th edition..M. New Delhi. M. J.References 1. vol -4. V. 29 .