CIRCLY 5.0 User Manual

C I R C LY 5User Manual MINCAD Systems Pty. Ltd. P.O. Box 2114, Richmond South, Vic., 3121 Australia Tel.:(03) 9427 1085 Intl. +613 9427 1085 Fax:(03) 9428 1197 Intl. +613 9428 1197 Email: [email protected] Web: http://www.mincad.com.au January 2004 © MINCAD Systems Pty. Ltd. i Contents Summary CIRCLY End User Licence Agreement Introduction 3 5 7 Overview ........................................................................................................................................7 Special Features for Pavement Engineering .................................................................................8 Cumulative Damage Concept ..............................................................................................8 Material performance ...........................................................................................................9 Traffic and Loading ............................................................................................................10 Wheel Loadings .................................................................................................................10 Automatic thickness design ...............................................................................................10 ESA Multipliers...................................................................................................................10 Methods for handling Damage Pulses...............................................................................10 Overview of User Interface 11 Introduction...................................................................................................................................11 Creating, Opening and Saving Files ............................................................................................12 Creating and Editing Input Data ...................................................................................................12 Database Approach ...........................................................................................................13 Running CIRCLY32 Analysis and Plotting Results ......................................................................13 Run Analysis ......................................................................................................................13 Plot Results ........................................................................................................................13 Options .........................................................................................................................................13 What's New in Version 5.0 15 Overview ......................................................................................................................................15 Support of Austroads 2004 Pavement Design Guide ..................................................................15 New "built-in" Graphics Engine ....................................................................................................16 Cost Calculation ...........................................................................................................................18 Automatic Parametric Analysis ....................................................................................................19 How to Start Using CIRCLY 21 Getting Started: Assembling and Running a Job .........................................................................21 Global Coordinate System ...........................................................................................................28 Alternative Calculation Options 31 Overview ......................................................................................................................................31 Damage Calculation Details.........................................................................................................31 Thickness Design Capability ........................................................................................................33 Calculate Selected Results at User-defined z-Values .................................................................34 ii Contents How to Use Advanced Features 37 Cost Calculation ...........................................................................................................................37 Calculation of Total Cost....................................................................................................37 Material Costs ....................................................................................................................38 Automatic Parametric Analysis ....................................................................................................39 Example—Cost Optimization .......................................................................................................41 How to Modify the Databases 47 Introduction...................................................................................................................................47 Units ...................................................................................................................................47 Sign Convention.................................................................................................................48 Overview of Database Approach .......................................................................................49 The "Layered System" and "Materials" Databases ......................................................................50 Overview of Layered System and Material Properties ......................................................50 Cross-anisotropy and isotropy in road pavement materials ..............................................51 Creating a new Layered System........................................................................................52 Defining the Layer properties.............................................................................................53 Duplicating a Layered System ...........................................................................................54 Adding a new Elastic Material............................................................................................55 Adding a new Performance Criterion.................................................................................57 Adding a new Material Type ..............................................................................................59 The "Loads" and "Traffic Spectrum" Databases ..........................................................................60 Introduction ........................................................................................................................60 Adding a new Traffic Spectrum..........................................................................................60 Duplicating a Traffic Spectrum...........................................................................................61 Coordinate System for Loads ............................................................................................62 Adding a new Load Group (i.e., a Vehicle or Axle Group).................................................63 Defining Load Locations (i.e., Wheel positions).................................................................65 Important Note about Axle Locations.................................................................................65 Important Note about Damage Pulses...............................................................................67 Coordinates for Results................................................................................................................69 Appendices Overview of Austroads 2004 Features 71 73 Model of Standard Axle......................................................................................................74 Project Reliability ...............................................................................................................75 Material Properties.............................................................................................................75 How to Use New Austroads 2004 Features 79 Modelling the Standard Axle ..............................................................................................79 How to Use Project Reliability............................................................................................80 Changes to Materials .........................................................................................................81 Austroads 2004 Examples .................................................................................................82 References ...................................................................................................................................83 This feature will optimise up to three layers. Combining this with a Cost Analysis feature. and automatic sub-layering of unbound granular materials. fully continuous (rough) or fully frictionless (smooth) layer interfaces. etc. Other geotechnical applications. As well as using the usual 'equivalent' single wheel and axle load approximations. while simultaneously designing the thickness of another layer. including selection of: cross-anisotropic and isotropic material properties. It is an integral component of the Austroads Pavement Design Guide (Austroads. optionally the contribution of each vehicle/load configuration can be explicitly analysed. The system calculates the cumulative damage induced by a traffic spectrum consisting of any combination of user-specified vehicle types and load configurations..3 Summary CIRCLY software is for the mechanistic analysis and design of road pavements. The first mainframe version of CIRCLY was released in 1977 and the current Windows version is Version 5. 1992. a comprehensive range of load types. including vertical. such as foundation engineering and settlement analysis. CIRCLY uses state-of-the-art material properties and performance models and is continuously being developed and extended. horizontal. A Parametric Analysis feature can loop through a range of thicknesses for one or two layers. non-uniform surface contact stress distributions. . allows for fine-tuning of layer thicknesses to minimize construction and maintenance costs. CIRCLY has many other powerful features. can also be analysed using CIRCLY. 2004) that is widely used in Australia and New Zealand. torsional. . tortious or otherwise) to Customer in respect of any loss or damage (including. reproduced. . However. 22. which appears under the CIRCLY "About" dialogue box which provides (in part).1. the payment of the cost of replacing the goods or of acquiring equivalent goods. are excluded. or the payment of the cost of having the services supplied again. Copyright This manual is copyright and may not be copied. photocopied. without the prior written consent of Mincad Systems. 21. consequential loss or damage) howsoever caused. translated or reduced to any electronic medium or machine readable form. relating in any way to the subject matter of this Agreement or to this Agreement generally. Acknowledgement 22. 21.Exclusions and Limitation of Liability 21. the repair of such goods. which may be suffered or incurred or which may arise directly or indirectly in respect to the supply of goods or services pursuant to this Agreement or the act. at the option of Mincad Systems. the liability of Mincad Systems for any breach of such term shall be limited.5 CIRCLY End User Licence Agreement CIRCLY (c) Mincad Systems Pty Ltd ABN 27 006 782 832. without limitation. Customer warrants that it has not relied on any representation made by Mincad Systems or upon any descriptions or illustrations or specifications contained in any document including any catalogues or publicity material produced by Mincad Systems.1 Customer acknowledges and agrees that: (a) pavement design and engineering is a complex area and the CIRCLY is not designed as a substitute in any way for professional advice. to any one or more of the following: if the breach related to goods: the replacement of the goods or the supply of equivalent goods. or the payment of the cost of having the goods repaired. implied. such term shall be deemed to be included in this Agreement.2 To the maximum extent permitted by law and subject only subject only to the warranties and remedies set out in Clause 12 and Sub-clause 21. statutory or otherwise. in whole or part. All rights Reserved. This documentation is licensed and sold pursuant to the terms and conditions of the CIRCLY End User Licence Agreement. failure or omission of Mincad Systems. Mincad Systems shall not be under any liability (contractual. Where legislation implies in this Agreement any condition or warranty and that legislation avoids or prohibits provisions in a contract excluding or modifying the application of or the exercise of or liability under such term.1 To the maximum extent permitted by law all warranties whether express. and if the breach relates to services the supplying of the services again. (b) CIRCLY is supplied with certain operating instructions and a failure to follow these instructions carefully could result in erroneous data being produced by CIRCLY. Customer shall fully indemnify and keep indemnified Mincad Systems. taxes or liability whether direct or indirect arising out of: (a) use of CIRCLY. 22. and (e) It shall obtain professional advice in relation to all results provided by CIRCLY. costs. expenses. demands. its officers.6 CIRCLY 5. . 23. (b) a breach of this agreement by Customer. Indemnity Customer warrants that any materials supplied to Mincad Systems by Customer do not infringe Intellectual Property Right of any person. CIRCLY is designed to be used by persons who have a detailed knowledge of.0 User's Guide (c) Whilst CIRCLY may be used by persons without a detailed knowledge of computers. unlawful or negligent act or omission of Customer.2 CIRCLY is licensed on the basis set out in this Agreement on the understanding that to the extent permitted by law Mincad Systems is not responsible for the results of any actions taken. without limitation the relevant industry recognised engineering design guides. including. or (c) any wilful. either by Customer or a third party relying on figures supplied or not supplied by CIRCLY. (d) It shall manually check all results provided by CIRCLY for any anomalies. without limitation: (i) the applicable engineering standards for paving and concrete. against any loss. To the extent permitted by law. and (ii) All appropriate legislation and other relevant instruments. employees and agents. The interfaces between the layers can be either fully continuous (rough) or fully frictionless (smooth). it is not necessary to approximate multi-wheel configurations by ‘equivalent’ single loads. or a combination of both types. As well as the usual isotropic properties. CIRCLY can also be used for other geotechnical applications such as foundation engineering and settlement analysis. CIRCLY can also model non-uniform contact stress distributions. torsional wheel loads due to cornering. cross-anisotropic material properties can also be considered. such as the finite element method. horizontal wheel loads due to traction and braking. For most problems the program uses less computer time than a finite element program. moments about horizontal axes or contact stresses due to foundation roughness. Databases are used for material properties and loadings. CIRCLY is an integral component of the Austroads Pavement Design Guide (Austroads 1992. surface of natural or man-made stratified deposits. In many soil and rock engineering problems. Because the contribution of each vehicle/load configuration can be explicitly considered. CIRCLY has a user-friendly menu-driven interface that runs under Microsoft Windows. loads may be applied to soil or rock pavement layers in the form of vertical wheel loads. A cross-anisotropic material is assumed to have a vertical axis of symmetry. piers and rafts may be applied as vertical forces. . foundation loads on footings. Anisotropies of this type have been observed in soil and rock deposits due to processes involved in their formation. or near horizontal.7 CHAPTER 1 Introduction Overview CIRCLY is a powerful package that analyses a comprehensive range of load types acting on layered elastic systems. permitting the rational assessment of ultimate stability and the behaviour under working loads. loads are applied to the horizontal. strains and displacements that are developed in these systems. In practice. Results can be obtained in tabular form or as report-quality plots on any printer or plotter supported by Microsoft Windows. Input data for the program is much simpler than that required for most finite element programs. Typical runs take less than a second on Pentium™ PCs. The system calculates the cumulative damage induced by a traffic spectrum consisting of any combination of vehicle types and load configurations. The program allows all of these load types to be simulated for a circular loaded shape. 2004) that is widely used in Australia and New Zealand. thus eliminating the need to constantly re-key information. horizontal forces. In addition. CIRCLY has special features for the convenient mechanistic analysis and design of pavements using state-of-the-art material properties and performance models. Results can be easily exported to other application packages such as spreadsheets for further processing. CIRCLY is based on integral transform techniques and offers significant advantages over other linear elastic analysis techniques. and the "gripping" load developed by pneumatic tyres on pavements. CIRCLY calculates the stresses. 0 was released in early 2004. The Cumulative Damage Factor (CDF) for the parameter is given by summing the damage factors over all the loadings in the traffic spectrum: Cumulative Damage = ∑ ni Ni The system is presumed to have reached its design life when the cumulative damage reaches 1. If the cumulative damage is less than 1. The procedure takes account of: the design repetitions of each vehicle/load condition.0 was released in late 1996 and included many improvements. Version 3. and the material performance properties used in the design model. Version 4.0 see What's New in Version 5. The damage factor for the i-th loading is defined as the number of repetitions (ni) of a given response parameter divided by the ‘allowable’ repetitions (Ni) of the response parameter that would cause failure. CIRCLY was first released in 1977 and handled polynomial type radial variations in contact stress and multiple loads which provide a much closer representation of the actual loading conditions (Wardle 1977).4) was made in early 1996. A limited release of the first Windows version (Version 2. If the cumulative damage is greater than 1.8 CIRCLY 5.0 the system has excess capacity and the cumulative damage represents the proportion of life consumed. CIRCLY was commercialised in 1988 by MINCAD Systems.0 was released in early 1999 and extended the software to include an automatic thickness design capability. For an overview of the new features of Version 5. MINCAD Systems. This approach allows analyses to be conducted by directly using a mix of vehicle or axle types. Wardle and Gerrard 1972). CIRCLY had its genesis in software developed at CSIRO for relatively simple loading cases (Harrison. It is not necessary to approximate passes of different vehicles or axles to passes of an ‘equivalent’ standard load. Version 5. Version 4. .1 was released in early 2003. including a major re-write of the integration algorithms and automatic sub-layer generation for granular materials.0 the system is predicted to ‘fail’ before all of the design traffic has been applied.0 User's Guide This Australian designed system has been developed by the Melbourne company. Cumulative Damage Concept The system explicitly accumulates the contribution from each loading in the traffic spectrum at each analysis point by using Miner's hypothesis. It has been in regular use in Australia and worldwide for more than two decades.0 (see "Overview" on page 15) Special Features for Pavement Engineering CIRCLY has many features to facilitate pavement analysis and design.0. proving its worth in thousands of design applications. . CIRCLY represents models in the form: k  N =  ε  where N k b ε b is the predicted life (repetitions) is a material constant is the damage exponent of the material is the induced strain (dimensionless strain) Log-log relationships can be readily converted to the above form. CIRCLY generates a file that can be read by most spreadsheet and technical graphics programs. You can use your own performance equations by specifying values for ‘k’ and ‘b’ and the particular component to be used. Material performance Generally most performance models may be represented graphically by a plot of tolerable strain versus load repetitions (generally by a straight line of 'best fit' on a log-log plot). for example vertical strain. CIRCLY is supplied with a comprehensive range of published performance models. etc. maximum tensile strain.Chapter 1 Introduction 9 The current version of the software uses the cumulative damage concept to sum the damage from multiple vehicle/load cases for one set of layered system material properties. vertical deflection. The figure below is a sample cumulative damage plot produced by CIRCLY. and a single pulse that reflects the overall loading on the axle group.1. This procedure is very fast and takes only a few seconds on a Pentium™ PC. You can specify these multipliers (e.g. for large depths. 1. 10) for each material type. Further details are given in Important Note about Damage Pulses (on page 67). The 'load case' allows the loading for a given vehicle or axle group to be treated in more detail if required. Automatic thickness design You can automatically determine the optimum thickness of a given layer.0 User's Guide Traffic and Loading You define the anticipated repetitions over the design period for each vehicle or axle group and 'load case'. for shallow depths. The two extremes of behaviour are– multiple distinct pulses resulting from each axle. the traffic expressed in ESAs must be multiplied by a factor that depends on each material type. Methods for handling Damage Pulses The damage that a given point in the pavement will experience during the passage of a multiple axle primarily depends on the depth below the road surface. CIRCLY lets you specify the method to be used to calculate the damage. Wheel Loadings The load on each wheel is defined by tyre contact radius and contact pressure (generally assumed to be the tyre inflation pressure). ESA Multipliers For design methods such as Austroads that use an equivalent standard wheel approach. For further details see Damage Calculation Details (on page 31). CIRCLY can compute results from non-vertical loads such as braking and cornering loads. Although the loads are usually vertical.10 CIRCLY 5. For further details see Thickness Design Capability (on page 33). . but most commands can be accessed directly from the toolbar as shown below: .11 CHAPTER 2 Overview of User Interface Introduction CIRCLY has a standard format Microsoft Windows menu. etc. then clicking Save As.clo Jobname. Updates the current job file. .dmx CIRCLY32 input data file CIRCLY32 'printable' results file CIRCLY32 raw results file (i. Three icons on the toolbar allow you to create. You can also save your job under a different name by clicking on the File Menu. strains. prompting you to save any changes.e. then opens an existing job.cls CIRCLY data file.. If the job name is Jobname the following files are used– Jobname. Opening and Saving Files You supply a 'Jobname' to use as the basis for naming all of the files associated with a 'job' or analysis. All the other files are generated automatically by the system: Jobname.this is used to save the details of your job.cli Jobname.12 CIRCLY 5.) CIRCLY32 cumulative damage results file (for plotting) CIRCLY32 results summary file (damage factors and critical strains) All of these files are text files that can be opened by standard text editors.0 User's Guide Creating. open and save job files. Each icon corresponds to one of the main groups of data necessary to fully define a Job.prn Jobname. Creating and Editing Input Data The following seven icons allow you to create and modify your input data.dam Jobname. then creates a new job. Closes the current job. Icon Description Closes the current job. prompting you to save any changes. Most of the input data is handled using a relational database approach.) . During a long analysis you can switch to another application (CIRCLY will continue to run at a lower priority using Microsoft Windows multitasking).Chapter 2 Overview of User Interface 13 Database Approach Some of the input data items are entered using very simple input forms. all Layered systems that use that material and subsequently all Jobs that use those layered systems will automatically access the modified material properties. the data for a commonly used material need only be entered into the system once. stress or strain component.e. Running CIRCLY32 Analysis and Plotting Results Run Analysis This invokes the CIRCLY32 analysis. If this data is subsequently modified. stress or strain component at your chosen Z-values (i. Alternatively. This is designed to eliminate re-entry of data for design loads and material properties. vertical distances/depths below the surface of the pavement) and results can be plotted for a selected displacement. this command will produce a graph of the damage contribution from each vehicle type and the overall total (damage contribution from all the traffic). The relational database approach gives maximum flexibility in data preparation. For example.. Options The Options screen allows specification of the following directory: location for all data files (Defaults to the same directory that CIRCLY has been installed. as an option you can produce a graph of a selected displacement. Plot Results Usually. You can tailor each of the databases to contain specific sets of regularly used data. . A Guide to the Structural Design of Road Pavements) was first published in 1992 (Austroads 1992). Support of Austroads 2004 Pavement Design Guide The Austroads Pavement Design Guide (the full title is Pavement Design . . Detailed instructions on how to use the new features are given in How to Use New Austroads 2004 Features (on page 79).0. Changed Subgrade Performance model for subgrade materials.0 if you have used earlier versions such as CIRCLY 4. Crossreferences to the rest of the manual show you where to look for information on these topics. Changed methodology for sub-layering of unbound granular material. The 2001 Draft (Austroads 2001) was the most recent published version at the time of writing this manual. The Guide has undergone a major re-write over the last few years. Briefly. CIRCLY 5. In what follows.1.15 CHAPTER 3 What's New in Version 5.0 Overview You will find many improvements in CIRCLY 5. The technical content of the new Guide was finalized in June 2003 and that the Guide is expected to be published in the first quarter of 2004.0 implements the following changed features in the Guide: Standard Axle modelled in full (Austroads 1992 uses only one side or half the axle) Project Reliability as chosen by the designer. the new Guide will be referred to as the 2004 Guide. Latest improvements include new features to make designing pavements easier. Introduction of Select Fill as a particular type of unbound granular material. more transparent and more efficient.0 or 4. These changes are outlined in more detail in Overview of Austroads 2004 Features (on page 73). This section gives a quick overview of the new and improved features in CIRCLY 5. Here is a sample Cumulative Damage graph: You can choose a graph for a different layer (without re-analysing the system): . The graphics can be customized.16 CIRCLY 5. exported and printed.0 User's Guide New "built-in" Graphics Engine CIRCLY now uses its own "built-in" Graphics Engine to create on-screen graphics almost instantaneously. In most cases. results for different layers or Z-depths in a layered system can be created without reanalysing the system. 0 17 Here is a sample "Three-dimensional" graph of vertical displacement: You can customize the graph via the context-sensitive graph menu that drops down when you right click with the mouse pointer anywhere on the graph. Click on “Customization Dialog” to customize the graph: .Chapter 3 What's New in Version 5. etc.0 User's Guide This lets you customize many of the graph parameters such as Minimum and Maximum axis values. such as surface treatments. Cost Calculation The unit costs for the materials laid and constructed in the layers can be specified using a combination of both a volumetric (or weight) component and an areal component. subgrade stabilization and the like.18 CIRCLY 5. The areal component lets you take account of costs that are primarily a function of area. . The areal component can also be used in circumstances where the relationship between total layer cost and thickness has a non-zero component for zero thickness. Minimum Total Cost Automatically generated plot: Total Cost vs.0 19 Automatic Parametric Analysis Automatic Parametric Analysis lets you automatically loop through a range of thicknesses for one or two nominated layers. For example.Chapter 3 What's New in Version 5. By combining Automatic Parametric Analysis with the Cost Analysis feature you can finetune layer thicknesses to optimise construction cost. for each combination of those layer thicknesses. you can automatically design the thickness of another layer. Additionally. Layer 2 Thickness . you can have Layer 2 vary from 100 mm to 200 mm in steps of 10 mm. . You will be using an existing traffic spectrum and an existing layered system.21 CHAPTER 4 How to Start Using CIRCLY Getting Started: Assembling and Running a Job In the interests of providing instant hands-on experience. Start a new Job file button. this worked example assumes that most of the input data is already in the appropriate databases. Follow this procedure: 1. Click on the . 3.0 User's Guide Enter your Job Name and Job Title (this is used on the graphs). Click on the Click on the Spectrum tab. This will bring up the list of available Traffic Spectra: If you have not already selected a spectrum the blue highlight will be positioned on the first entry. 2. Specify Layered System button.22 CIRCLY 5.Unbound Granular Pavement’ by moving the mouse pointer to this line and then clicking on it. Click on the Click on the Layered System tab.Example 1 . Select Traffic Spectrum button. Select ‘Austroads 2004 . This will bring up the list of available Layered Systems: . Example 1 . 4. Specify Coordinates for Results button.Chapter 4 How to Start Using CIRCLY 23 If you have not already selected a Layered System. Select ‘Austroads 2004 . the blue highlight will be positioned on the first entry. Two alternative formats are available for specifying the points to be used for results calculation: An array of equally spaced points along a line parallel to the X-axis A grid of points with uniform spacing in both the X-direction and the Y-direction Enter the data as shown below.Unbound Granular Pavement’ by moving the mouse pointer to this line and then clicking on it. . Click on the This screen has fields for specifying the locations for which results are to be computed. 24 CIRCLY 5. This invokes the CIRCLY32 analysis. Click on the When the CIRCLY32 analysis starts you may see a blue "progress bar" at the bottom left corner of the screen. When the CIRCLY32 analysis is complete the results for the damage factor (CDF) will be transferred to the top table on the screen.0) at intervals of 165 mm. the dimensions are in millimetres (see Units (on page 47) for further details). Analyses typically take about a second on a Pentium™ PC. as shown below.0 User's Guide The data entered as above will create a line along the X-axis from (0.0) to (165. 5 Run the CIRCLY32 analysis button. The sub-section Assumed number of damage pulses per movement is dealt with later in Important Note about Damage Pulses (on page 67). . To comply with the Austroads Guide. This will generate a graph of the results: Click on the . Plot the Results button.Chapter 4 How to Start Using CIRCLY 25 6. You can also copy the graph to the clipboard and then paste into another application such as Microsoft Word or Powerpoint. You do this via the context-sensitive graph menu that drops down when you right click with the mouse pointer anywhere on the graph: .26 CIRCLY 5.0 User's Guide You can print a copy of the chart by clicking on the Print icon on the toolbar. Chapter 4 How to Start Using CIRCLY 27 Then click on 'Export Dialog'. . but for most purposes select 'Metafile' to ensure that the graphics are scalable. The 'Export Dialog' lets you export to a variety of formats. . A grid of points with uniform spacing in both the X-direction and the Y-direction.0 User's Guide Global Coordinate System A global coordinate system is used to define load locations. The Y-axis is then parallel to the direction of vehicle travel. Two alternative formats are available for specifying the points to be used for results calculation: An array of equally spaced points along a line parallel to the X-axis.28 CIRCLY 5. The global coordinate system is also used to describe the resultant displacements and stress and strain tensors. the layered system geometry and the points below the road surface at which results are required. Figure 1: Global Coordinate System The Z-axis is vertically downwards with Z = 0 on the pavement surface. The X-axis is usually taken as the direction transverse to the direction of vehicle travel. Chapter 4 How to Start Using CIRCLY 29 Y Direction of Travel 0 X Xmin Xdel Xmax Results points Figure 2: Coordinates for results defined by a line of equally spaced points Ymax Y Ydel Ymin X 0 Xmin Xdel Xmax Results points Direction of Travel Figure 3: Coordinates for results defined by a uniform grid of points . . between one layer (the subgrade) and three layers (asphalt surfacing. Damage Calculation Details Typically.31 CHAPTER 5 Alternative Calculation Options Overview CIRCLY 5. you will calculate the damage factors (CDF) for your pavement. Click on the button.0 offers a number of calculation options. stress or strain component at selected Z-values (depths below the road surface). Normally. You can automatically determine the optimum thickness of a given layer. Alternatively. This will bring up the following screen: 1 2 3 . cementstabilised layer and subgrade) will have performance criteria associated with them. you can calculate results for any given displacement. The multipliers are simply used to increase the ESA count (in the 'Movements' field) that is specified in the Traffic Spectrum screen. When operating in 'calculate damage factors' mode. These multipliers are necessary to take account of the material type and the actual traffic mix. The current thickness of any layer can be changed from this screen.0 User's Guide 1 Two alternative calculation options are available: Calculate damage factors (CDF).32 CIRCLY 5. Here the Traffic Multipliers are multipliers that are used in Equivalent Single Axle (ESA) calculations (as described in the Austroads Pavement Design Guide.5). Calculate selected results at user-defined Z-values (see Calculate Selected Results at User-defined Z-Values (on page 34)). 2 3 . This table is a summary of the properties for those layers that have a performance criterion. Also the current Cumulative Damage Factors (CDFs) will be shown if the problem has been run previously. the key features on the screen (the numbers refer to the screenshot above) are: This table is a summary of the layered system including material titles and current thicknesses. Section 7. 1992. This procedure is very fast. The tick-box can be toggled on and off by clicking on it. The layer selected will be highlight in blue. 1 2 3 .Chapter 5 Alternative Calculation Options 33 Thickness Design Capability You can automatically determine the optimum thickness of a given layer. By default. You select the layer you wish to design by moving the mouse pointer to the appropriate layer and clicking the mouse button once. The design involves bringing the maximum damage factor to 1. 1 2 3 Here a tick ( ) denotes that the layer will be included in the maximum damage factor calculation. the design will use the maximum damage factor (CDFmax) from all the layers that have a performance criterion.0 by varying the thickness of the highlighted layer. In some circumstances. it may be necessary to ignore one or more layers when calculating the maximum damage factor. typically taking a few seconds on a Pentium™ PC. The thickness design capability is invoked by clicking on the checkbox that is labelled 'Design thickness of layer highlighted below'. This will bring up the following screen: 1 2 3 4 5 6 . If a specified maximum or minimum thickness limit prevents attainment of a CDF of 1. you may need to calculate selected results (displacements. When you use this option. the CDF for the thickness limit will be computed. so that no constraints are applied. or these fields can be left blank. damage factors are not calculated. stresses and strains) at selected Z-values (depths). stress or strain component.0 User's Guide Minimum and maximum thicknesses can be specified for each layer. Specify first convenient Z-values and then plot results for a selected displacement. Click on the button. Calculate Selected Results at Userdefined z-Values In some circumstances.34 CIRCLY 5.0. Chapter 5 Alternative Calculation Options 35 This option is invoked by clicking the button that is labelled 'Calculate selected results at user-defined Z-values'. You can choose the component that is to be plotted by first clicking on the 'Component type' tab. You can then define the component type (e.g. displacement, strain etc.) by clicking on the down arrow on the right hand side of the 'component type' combo box. This will invoke this drop down list: 1 2 Click on the component type that you wish to use. The actual component (e.g., vertical, etc.) is specified by clicking on the down arrow on the right hand side of the 'Component' combo box. A drop down list of alternatives will appear: 3 Click on the Component that you wish to use. 4 Now you can define the Z-values. Each Z-value is added by clicking the New button 6 . You can delete any entry by clicking on it and then clicking the Delete button. When a Z-value coincides with the interface between two layers, you can specify which side of the interface is to be used (i.e. above the interface, or below the interface). 5 37 CHAPTER 6 How to Use Advanced Features Cost Calculation Calculation of Total Cost CIRCLY 5.0 can automatically calculate Total Cost for a pavement from the unit costs of materials in each layer. Click on the button. This will bring up the following screen: Total Cost 1 1 Click on the Calculate Cost checkbox 38 CIRCLY 5.0 User's Guide Material Costs The unit costs for the layers can be specified using a combination of both a volumetric (or weight) component and an areal component. The areal component lets you take account of costs that are primarily a function of area such as surface treatments, subgrade stabilization, etc. The areal component can also be used in circumstances where the relationship between total layer cost and thickness has a non-zero component for zero thickness. Unit Material Costs The Total Cost for a given layer is calculated as follows: Total Cost (layer no. i) ($/m2) = Unit Volumetric Cost (layer no. i) ($/m3) x Thickness (layer no. i) (mm) + Unit Areal Cost (layer no. i) ($/m2) The Unit Volumetric Cost can be defined in terms of: 1 Cost/Volume, or 2 Cost/Weight and the density of the material (Weight/Volume). .e. you can have Layer 2 vary from 100 mm to 200 mm in steps of 10 mm. Combining this with the Cost Analysis feature lets you fine-tune layer thicknesses to optimize construction cost. Click on the button. the number of Layers for which you are varying the thickness): 1. Additionally. This will bring up the following form: 1 2 3 4 1 This combo box lets you specify the number of Independent Variables (i. 2 This section gives the details of the first Independent Variable. you can automatically design the thickness of another layer. This will bring up the following screen: 1 1 Click to switch on Parametric Analysis. For example.Chapter 6 How to Use Advanced Features 39 Automatic Parametric Analysis Automatic Parametric Analysis lets you automatically loop through a range of thicknesses for one or two nominated layers. One Independent Variable. or 2. for each combination of those layer thicknesses. Two Independent Variables. 0 User's Guide 3 This lets you choose which layer (thickness) is to be used as the first Independent Variable. 1 2 3 4 2 This section gives the additional details for the second Independent Variable 3 Here you specify which layer (thickness) is to be used as the second Independent Variable 4 Here you specify the range of thicknesses to be used for that layer: The thickness will range from T2minimum to T2maximum in steps of T2step. 4 Here you specify the range of thicknesses to be used for that layer: The thickness will range from T1minimum to T1maximum in steps of T1step. click the combo box ( 1 on the screenshot below).40 CIRCLY 5. . To use two Independent Variables. Class 4 $50 / m3 Subgrade. Type T Unit Cost $288 / m3 T2 = ? $288 / m3 T3 = ? Crushed Rock: 20 mm . CBR = 3 Step 1.Chapter 6 How to Use Advanced Features 41 Example—Cost Optimization In this example you will use the Automatic Parametric Analysis feature to automatically loop through a range of thicknesses for one layer (Layer 2) and to determine which thickness has the minimum Total Cost. 1 2 .Pavement Option B2". Open the sample file "Economic Analysis . Type H Asphalt: Size 20. Step 2. For each Layer 2 thickness. Thickness T1 = 40 mm Asphalt: Size 14. you will get CIRCLY to automatically design the thickness of Layer 3. One Independent Variable. the thickness of Layer 2. you will let Layer 2 vary in thickness from 160 mm to 230 mm in steps of 10 mm. Enter the following values: Minimum: 160.0 User's Guide 1 Make sure the Calculate Cost check-box is ticked. Step 3. the number of Layers for which you are varying the thickness). 4 Here you specify the range of thicknesses to be used for Layer 2: For this example. (as you are varying the thickness of Layer 2).e. Now set the automatic thickness design feature to Layer 3. This will bring up the following form: 1 2 3 4 1 This combo box lets you specify the number of Independent Variables (i. Step: 10. 2 Click the Parametric Analysis check-box.42 CIRCLY 5. 3 This lets you choose which layer (thickness) is to be used as the first Independent Variable. For this example change this to "2". . 2 This section gives the details of the Independent Variable. For this example you will use the default. Maximum: 230. Plot the Total Cost vs Layer 2 thickness. click on to plot the results. Click in the "Minimum Thickness" cell on this row and enter 100 (mm). Minimum Total Cost This plot shows the Minimum Total Cost condition for Layer 2 thickness is 220 mm (to a resolution of 10 mm). 1 2 1 Click the check-box labelled 'Design thickness of layer highlighted below'. 2 Click anywhere on the Layer 3 row.Chapter 6 How to Use Advanced Features 43 Click on the "Summary" tab (left of the "Variables" tab). Now click on to run the analysis. Step 4. . When the analysis is finished. Click on the Parameter combo box. Click on the Layer combo box. Click on the Parameter combo box. Select Size 20 Type T .Plot the Layer 3 thickness (Design Layer) vs. Layer 2 thickness. Select CDF (Select Layer =>).Plot the CDF (for Layer 2) vs. .0 User's Guide Step 5.40km/h (This is Layer No.44 CIRCLY 5. 2) Step 6. Layer 2 thickness. Chapter 6 How to Use Advanced Features 45 Select Thickness (Layer used for Thickness Design). Comments on these results. the Layer 3 thickness is 100 mm. the "designed" thickness of Layer 3 exceeds 5000 mm.91. . If there was no Minimum Thickness constraint. the Layer 3 thickness would be 39.6 mm. If the Layer 2 thickness is 220 mm. If the Layer 2 thickness is 160 mm or less. because of the Minimum Thickness constraint and because the CDF is 0. Therefore a Layer 2 thickness of less than 160 is not viable if supported by the Layer 3 material. This would be inconsistent with the Austroads (1992) sub-layering requirement that the minimum thickness of a sub-layer is 50 mm. . Quantity Length. Output stresses will have the same units as used to define the loading stresses and the elastic moduli. These units must be used for all Austroads applications involving sub-layering of granular materials. Pressure Metric* mm MPa Metric m kPa Metric m MPa Imperial ft lb/ft2 Imperial in lb/in2 (psi) . all data must be in a consistent set of units. as long as sub-layering of granular materials is not used. Other compatible systems of units can be used as shown in the following table. Displacement Elastic modulus. Pressure Force Moment Strain Units mm MPa N N.47 CHAPTER 7 How to Modify the Databases Introduction Units In order for CIRCLY to deliver coherent results. Quantity Length.mm mm/mm This system of units is consistent with the Austroads Pavement Design Guide and has been used for all the data files provided with CIRCLY. the strains are dimensionless and the displacements will have the same units as the load dimension and the layer thicknesses. The recommended system of units is given below. Displacement Elastic modulus. 0 User's Guide Force Moment Strain N N. The sign conventions used in the rectangular coordinate system and cylindrical local coordinate system are illustrated below.m m/m lbf lbf.ft ft/ft lbf lbf.mm mm/mm kN kN. Positive shear stresses are defined on the basis that both the stress and strain tensors obey the right hand rule. Hence a load causing a positive stress acts in the positive coordinate direction. Figure 4: Sign Convention . Displacements in negative coordinate directions are considered to be positive.48 CIRCLY 5.in in/in *This system of units must be used for Austroads applications involving sub-layering of granular materials.m m/m MN MN. Sign Convention Compressive direct stresses and strains are considered to be positive. A consequence of the relational database approach is that data should generally be prepared from the 'bottom up'. . Figure 5: Relationships between elements in Layered System databases A similar hierarchy applies for the Traffic database. 2 Create a new entry in the Layered Systems database. Each load group referenced by the Traffic Spectrum is linked to a record in the Load Group data. each of the components that make up a Layered System is linked to entries in the Elastic Material Properties database via an ID (index) field of up to 10 characters. Load Group data must be entered before the Traffic Spectrum Components data. the data for a commonly used material need only be entered into the system once. Here. If this data is subsequently modified. This means that: Elastic Materials Properties data must be entered before the Layered System Components data.Chapter 7 How to Modify the Databases 49 Overview of Database Approach The relational database approach is designed to eliminate re-entry of data for design loads and material properties. The Figure below illustrates the relational database concept for the elastic material properties. To create a new layered system. For example. all Layered Systems that use that material and subsequently all Jobs that use those Layered Systems will automatically access the modified material properties. these steps must be followed: 1 Create any materials that are not already in the Elastic Materials database. The bottom layer may extend to a finite depth or to a semi-infinite depth (see the figure below). and the contact can be either fully continuous (i. Interfaces between the layers can be either fully continuous (rough) or fully frictionless (smooth).0 User's Guide 3 Define each of the Materials and thicknesses for each of the Layers using the Layered System Components database. The "Layered System" and "Materials" Databases Overview of Layered System and Material Properties CIRCLY models road pavements as a system of layers. rough) or fully frictionless (i. it is assumed to rest on a rigid base.. NL Rough rigid base Smooth rigid base Semi-infinite base ∞ . The layered system consists of one or more layers. The layer interface planes are horizontal and each layer is assumed to be of infinite extent in all horizontal directions.e. Worked examples in the following sections show how you can create new data. 1 Layer No. smooth). If the bottom layer is of finite depth. or a combination of both types.50 CIRCLY 5. 2 Layer No. each with differing elastic properties.e.. Layer No. Chapter 7 How to Modify the Databases 51 Cross-anisotropy and isotropy in road pavement materials The elastic material in each layer of the pavement/road structure is assumed to be homogeneous and of cross-anisotropic or isotropic symmetry. Data values for all five constants are rarely available. the horizontal Elastic modulus (Eh).νhv σzz) (1/Ev) (.5 > ν > -1.νvh σxx .νhv σzz) (1/Eh) (. The stress-strain relations for a cross-anisotropic material in a particular layer are: εxx = εyy = εzz = εxy = εxz = εyz = (1/Eh) (σxx .e. In the Austroads pavement design method (1992 and 2002) cross-anisotropic properties are used for subgrade materials and unbound granular aggregates and isotropic properties are used for bound materials such as asphalt and cemented materials. the Poisson’s ratio (νvh). these properties are different from those in the direction parallel to the axis. radial directions). whereas isotropic materials have the same elastic properties in both the vertical and horizontal directions. the Poisson’s ratio (νh) and the Shear modulus (f). In general.νvh σyy + σzz) ((1+νh)/Eh) σxy (1/f) σxz (1/f) σyz The moduli and Poisson's ratios are related by the following equation: νvh/Ev = νhv/Eh The condition that the strain energy must be positive imposes restrictions on the values of the elastic constants: Eh > 0 1 > νh > -1 Ev > 0 f>0 1-νh-2νhvνvh > 0 For isotropic materials the restrictions become: E>0 0.. which is assumed to be vertical. i. A cross-anisotropic material has an axis of symmetry of rotation.νh σxx + σyy . .νh σyy .0 To be able to model a cross-anisotropic material you need to specify five constants: the vertical Elastic modulus (Ev). the elastic properties are equivalent in all directions perpendicular to the axis of symmetry (in horizontal. as they are assumed to be the same in all directions. Now you can define the details of the layers in your layered system. Click on the New button.52 CIRCLY 5.5 Ev νvh = νh = ν f = Ev/(1+ν) In this case. only the Elastic modulus and Poisson’s ratio need to be entered. Ev.0 User's Guide The Austroads Pavement Design Guide uses the following simplifications to model subgrade and unbound granular materials: Eh = 0. . ν. For isotropic materials. Click on the Layered System tab. For this example you can type in 'MyLayers' as the ID and 'Example of creating a new Layered System' as the Title. You should now type in your ID (index) field of up to 10 characters and a descriptive title (up to 72 characters). A dialog box will appear as shown below. and a single Poisson's ratio. Creating a new Layered System Click on the button. the material is defined simply by the vertical Elastic modulus. Click the OK button. You will now choose the Material Type. as shown below. or a combination of both types. The subgrade will extend to an infinite depth if you enter the thickness as 0.. starting with asphalt or cemented material. You repeat this process to add as many layers as you require. click on the appropriate line then click the OK button. interfaces between the layers can be either fully continuous (rough) or fully frictionless (smooth).e. i.Chapter 7 How to Modify the Databases 53 Defining the Layer properties You add the layers working from the top of your pavement system. A pop-up list will appear. Click on the New button.0. A new record will be added at the bottom of the table and the cursor will be positioned in the Thickness column. To select the Material Type. A list of available materials will now appear. and working downwards through the pavement. Enter the layer thickness. As explained in Overview of Layered System and Material Properties (on page 50). then click on the OK button. You can specify any interfaces as fully frictionless. Select the required material by clicking on the appropriate line. 1 . You can change the condition for the interface at the bottom of a given layer by clicking in the 'Interface Type' cell. all interfaces are assumed to be rough.54 CIRCLY 5. The Duplicate function lets you duplicate an existing Layered System. Then you can change the settings that need to be different. 1 Duplicating a Layered System Sometimes you may want to create a Layered System that is similar to an existing one. You will then see a form that will let you define the ID and Title of the newly duplicated Layered System: .0 User's Guide By default. You can then click on the down arrow at the right of the cell to select a 'Smooth' interface. Move the blue highlight to the Layered System that you want to duplicate: Then click the Duplicate button. Note that for a semi-infinite subgrade both 'Rough' and 'Smooth' are equivalent. After you click the OK button you will be taken to the Layered System Components table so that you can make your changes. You now choose the material type to be used.make sure that you modify the Title.5' for the Title. CBR=2. Click here to select Material Type Click on the New button.Chapter 7 How to Modify the Databases 55 The ID and Title that are provided are based on the original Layered System . you can type in 'Sub_CBR2. For this example.5'. As you can see from the example below. . the ID is used to sort the data. Click on the material type combo box as shown below to select from the available material types. Type in 'Subgrade. Click on 'Subgrade (Austroads 2004)' for the Material Type. Click the OK button. A dialog box will appear. as shown below. Adding a new Elastic Material Click on the button. Click on the Elastic Materials tab. You should now type in your ID (index) field of up to 10 characters. 56 CIRCLY 5.24 (= 0.5 νvh = νh = 0. To select a Performance Criterion make sure the checkbox next to ‘Use performance criterion’ is checked.0 Eh = 12. then click on the appropriate performance criterion. A new record will be added to the table. Then type in the moduli and Poisson's ratios as follows: Ev = 25. Click on the OK button. Select 'Anisotropic' in the column headed 'Aniso?'.0 User's Guide You will now be given an opportunity to select a Performance Criterion.5 Ev) (= ν) (= Ev/(1+ν)) The new record should be as shown below: .45 f = 17. assume VB = 12. VB = percentage by volume of bitumen in the asphalt. and Smix= mix stiffness (Elastic modulus) in MPa. Click on the material type combo box (as shown on the first screenshot in Adding a new Elastic Material (on page 55)) to select from the available material types. For this example type in 'Asph1600' for the ID. Click the OK button. so that the above equation simplifies to: N = [ 5889 / µε]5 To enter this data click on the Click on the Performance tab.856 V + 1. Vb=12. Click on the New button. button.   µ S e mix   5 where RF is the Reliability Factor µε = maximum tensile strain (in units of microstrain).9%' for the Title. The Reliability Factor is assumed to be 1. You now choose the material type to be used. Type in 'Asphalt1600 MPa. . For this example click on 'Asphalt'.Chapter 7 How to Modify the Databases 57 Adding a new Performance Criterion For this example we consider the Shell asphalt fatigue criterion:  6918(0.0 if you are using the Austroads 1992 Pavement Design Guide. Now type in your ID (index) field of up to 10 characters and the Title (up to 72 characters).9 and Smix = 1600 MPa. Otherwise the value of the Reliability Factor is automatically handled by your choice of Project Reliability (see How to Use Project Reliability (on page 80)).08)  B  N = RF  0 36 . For this example. You can move down the list by clicking on the down arrow or by dragging the slider down. Click on the button to choose between ‘Top’ and ‘Bottom’. mm/mm).0. For this example select the ‘Max. there will be a slider bar on the right hand side. As CIRCLY assumes that the fatigue relationship is of the form N = [k / ε]b .005889 and Exponent (b) will be 5.0 User's Guide A record will be added to the table and you can type in the relevant data as follows: The cursor will now be in the component field. the parameter µ (micro) must be replaced by 10-6 giving: N = [k / ε]5 So Constant (k) will be 0.e. stress or strain component to be used. Here you specify the particular displacement. The new record should be identical to the bottom row in the figure below: . The Location field defines the location (relative to a layer of this material) at which the criterion is to be applied. If there are more entries than will fit in the listbox. For this example Location should be 'Bottom'. The entries for the remaining two parameters define the fatigue relationship N = [5889 / µε]5 Note carefully that strains in CIRCLY must be specified in dimensionless units (i. Horizontal Tensile Strain’ (maximum horizontal tensile strain). length/length.. You can select the component from a dropdown list by clicking on the button.58 CIRCLY 5. To add a new material type. then click on the appropriate sub-layering scheme. You will now be given an opportunity to select a Sub-Layering scheme. To select a SubLayering scheme. . click the checkbox next to ‘use sub-layering’.Chapter 7 How to Modify the Databases 59 Adding a new Material Type You can add new material types. Click on the OK button. A dialog box will now appear and you can enter the ID (index) field of up to 10 characters and Title field (up to 72 characters). Click on the Click on the Material Types tab. You will now choose the Generic Material Type for your new Material Type: button. Click the OK button. Click New to create a new entry. If there are more entries than will fit in the listbox there will be a slider bar on the right. You can move down the list by clicking on the down arrow or by dragging the slider down. Depending on whether or not the components you need already exist. A dialog box will now appear and you can enter the ID (index) field of up to 10 characters and Title field (up to 72 characters). You can move the highlight to the vehicle that you wish to use by positioning the mouse pointer on it and clicking once. You finally select the vehicle by double clicking on it. The Spectrum Components Table will now appear. the steps required are described in the following sub-sections. A new record will be added at the bottom of the table and the cursor will be positioned in the Movements column. click on the Click on the Spectrum tab. Click the OK button. Click New to create a new entry. Adding a new Traffic Spectrum If the Traffic screen is not already active. The databases form a hierarchy: Traffic Spectrum. Load Locations. This will activate a pop-up list of possible choices. . Enter the number of vehicle movements (or passages) over the desired design life. Traffic Spectrum Components. Now define your spectrum components: Click New for each vehicle model you wish to include.60 CIRCLY 5. Load Groups. button.0 User's Guide The "Loads" and "Traffic Spectrum" Databases Introduction Four inter-related databases are used for the Traffic data. The Duplicate function lets you duplicate an existing Traffic Spectrum. You will then see a form that will let you define the ID and Title of the newly duplicated Traffic Spectrum: The ID and Title that are provided are based on the original Traffic Spectrum . Then you can change the settings that need to be different.make sure that you modify the Title. Move the blue highlight to the Traffic Spectrum that you want to duplicate: Then click the Duplicate button. .Chapter 7 How to Modify the Databases 61 Duplicating a Traffic Spectrum Sometimes you may want to create a Traffic Spectrum that is similar to an existing one. After you click the OK button you will be taken to the Traffic Spectrum Components table so that you can make your changes. 62 CIRCLY 5. Yload and θload. Yload. You can choose the origin of the 'global' coordinate system to be any point on the upper surface of the layered system and the X and Y axes as any two mutually perpendicular axes that lie in this horizontal plane. which is dealt with in Wardle (2004). In terms of the 'global' coordinate system the origin of each 'local' coordinate system is specified by Xload. Z. Z for Global coordinates and lowercase x. The orientation of the load is defined by the angle (θload) between the directions of the X-axis and the x-axis. The location of the circular load is described by a ‘global’ coordinate system. z for Local coordinates. The Z-axis in the positive direction is taken as vertically downwards. it may be taken as parallel to the X-axis so that θload is then zero. z) and has its origin at the centre of the load it describes. The 'global' system is cartesian. θ. it is possible to model more complex loads induced by breaking and turning movements of vehicles.0 User's Guide Coordinate System for Loads The most common type of load modelled in CIRCLY is a circular area over which a uniform vertical pressure is applied. Y. However. though. This load typically represents the contact of a tyre on the surface of the pavement. For loads that are symmetrical about their centre point the x-axis may have any orientation. with axes X. while 'local' coordinate systems are used to describe each of the loads. z) or cylindrical (r. Note the use of uppercase X. For loads that are symmetrical about a horizontal axis this axis is taken as the x-axis. Y. Each 'local' coordinate system may be cartesian (x. y. The location and orientation of a load are therefore specified by Xload. y. for convenience. Figure 6: Global and Local Coordinate Systems . For this example type in 'TA-DW' as the ID and 'Tandem axle with dual wheels' as the Title. The example given here is for a tandem axle with dual wheels. a Vehicle or Axle Group) Click on the button. Click on the Load Groups tab..Chapter 7 How to Modify the Databases 63 Adding a new Load Group (i. Type in your ID (index) field of up to 10 characters and a descriptive title (up to 72 characters). Click the OK button.e. . Click on the New button. A dialog box will appear as shown below. If you are using an advanced load type. Type 1 Radius Stress 92. Non-zero values give non-uniform contact pressure distributions as described in Program CIRCLY Theory and Background Manual.0 The entries should look like this: You should now specify the wheel locations.75 Exponent 0. .64 CIRCLY 5.1 0. If this parameter is zero the contact stress will be uniform.0 User's Guide A record will be added to the table and you can enter the relevant data as follows: Field name (Heading) Plot Label Rows Value TA-DW 2 Explanation Label used by legend in graphs (Up to 72 characters) Number of rows (axles) in main gear (this is the NROWS parameter described in Important Note about Damage Pulses (on page 67)) A flag to indicate type of load (1=Vertical. for other values see Program CIRCLY Theory and Background Manual) Radius of tyre contact area (mm) For Vertical loads (Type=1) use the tyre contact pressure. enter the reference stress referred to in the Program CIRCLY Theory and Background Manual. generally assumed to be the tyre inflation pressure (MPa). This is used to shift the Y-coordinates of the wheels for the combined pulse option. Important Note about Axle Locations Make sure gear number 1 has an axle on Y = 0. Theta corresponds to θLOAD in Figure: Global and Local Coordinate Systems. . and the X and Y coordinates of each wheel. Click New for each wheel and enter the gear number. click on the button.other values allow for a variation in contact pressure from wheel to wheel. If it is not the one you have just defined. It is essential that the gear numbers are correctly specified. click on the appropriate record within the Load Groups table and click on Load Locations again. dual wheels gear layout (TA-DW) shown above. as described. the entries in the table should be similar to the table below. Click on the Load Locations tab.0 ..Chapter 7 How to Modify the Databases 65 Defining Load Locations (i. Theta is only used to define the force or moment direction for non-standard loads such as braking loads. Note that the wheels making up a given gear can be in any order. click on the Load Groups tab. The scaling factor is normally 1. See the note Important Note about Axle Locations (on page 65) below for special information about defining axle locations. The gear numbers are used for calculating the centroid of gear number 1. so that the gear centroid of gear number 1 is on Y = 0 (see Important Note about Damage Pulses (on page 67) for further details).e. Check the descriptive title above the table to make sure that you are referring to the correct Load Group. For the Tandem axle. Wheel positions) If the Load Groups screen is not already active. -1320) Axle 2 Figure 7: Example wheel layout (Tandem axle.0) (165.-1320) (165.0) 0 Axle 1 X (-165. dual wheels) .66 CIRCLY 5.0 User's Guide Y Direction of Travel (-165. dual wheels). the maximum strain will generally occur under the centroid of the gear. In this case. CIRCLY then computes the damage pulse beneath the centroid of the gear due to the strain contributions for all wheels of the vehicle. and ignores the number of axles in the group. NROWS refers to the number of axles in the gear. one ‘pulse per axle’ is selected. relative to the axle spacing. For shallow pavement depths. which is specified in the ROWS column of the Load Groups section of the Loads database. as shown in the Figure below. you specify 'combined pulse for gear' and CIRCLY will automatically shift the load coordinates so that the origin is at the centroid of the gear. then multiplies the computed damage by the number of axles in the axle group (NROWS). CIRCLY relies on you to specify one set of axles at Y = 0 as shown on Figure: Example wheel layout (Tandem axle. for large depths. CIRCLY then computes the damage beneath that axle due to the strain contributions for all wheels of the vehicle. relative to axle spacing. However.Chapter 7 How to Modify the Databases 67 Important Note about Damage Pulses The damage that a given point in the pavement will experience during the passage of a multiple axle will primarily depend on the depth that the given point is below the road surface. Y Axle 1 Direction of Travel 0 X Axle 2 Figure 8: Automatic shift of Y-coordinates for ‘combined pulse for gear’ case . 0 User's Guide You must decide whether the pavement is deep or shallow relative to the axle spacing. CIRCLY automatically shifts the position of the load coordinates if you specify 'combined pulse for gear'. You specify how to deal with the gear by clicking on the button to open the Coordinates for Results screen.68 CIRCLY 5. This screen has a sub-section for specifying the locations at which results are to be computed and the method for treating the damage pulses. . Computation of the damage at intermediate depths requires judgement based on a knowledge of the strain pattern. regardless of whether CIRCLY or other analysis methods are used. Chapter 7 How to Modify the Databases 69 Coordinates for Results Click on the button. A grid of points with uniform spacing in both the x-direction and the y-direction. This screen has fields for specifying the locations for which results are to be computed and the method for treating damage pulses. Two alternative formats are available for specifying the points to be used for results calculation: An array of equally spaced points along a line parallel to the x-axis. . . 71 CHAPTER 8 Appendices . . culminating in the release of the 2001 Draft (Austroads. we use the convention that Austroads 1992 is the original Guide and that Austroads 2004 is the new Guide. The following notes assume that you are already familiar with the original Guide. The development of the new features in CIRCLY relating to the Guide was based on the April 2003 Draft. The Guide has undergone a major re-write over the last few years. For convenience.A Guide to the Structural Design of Road Pavements) was first published in 1992 (Austroads. . 2001). 1992). but the main differences with the original Guide are highlighted. These notes should be read in conjunction with Austroads 2004. No attempt is made to comprehensively describe all the features.73 Overview of Austroads 2004 Features The Austroads Pavement Design Guide (the full title is Pavement Design . The technical content of the new Guide was finalized in June 2003 and that the Guide is expected to be published in the first quarter of 2004. applying a load of 80 kN. Figure 9: Model of Standard Axle .74 CIRCLY 5. Austroads 2004 uses a full Standard Axle Loading.0 User's Guide Model of Standard Axle The Standard Axle Load consists of a dual-wheeled single axle. This figure shows the layout of the wheels and their respective positions along the CIRCLY x-axis. whereas Austroads 1992 uses only one half of the Standard Axle. 5 90 .000 Main Road: lane AADT>500 Other Roads: lane AADT<500 Project Reliability (%) 95 .000 Highway: lane AADT<2.5 85 . Austroads 2004 always uses 5 equi-thick sub-layers.95 85 .97.97.Chapter 8 Overview of Austroads 2004 Features 75 Project Reliability The Project Reliability is defined as follows (Austroads 2004): The Project Reliability is the probability that the pavement when constructed to the chosen design will outlast its Design Traffic before major rehabilitation is required. The desired project reliability is chosen by the designer.90 Material Properties Sub-layering Unbound Granular Materials Sub-layering is required for granular materials placed directly on the subgrade. In regard to these reliability procedures. Typical project reliability levels are given as follows (Austroads 2004): Road Class Freeway Highway: lane AADT>2. b The vertical Elastic modulus of the top sub-layer is the minimum of the value specified in the CIRCLY input (indicative values are given in Table 6.3 of Austroads 2004) and that determined using: EV top sublayer = EV subgrade × 2(total granular thickness / 125) . a project is defined as a portion from a uniformly designed and (nominally) uniformly constructed road pavement which is subsequently rehabilitated as an entity.95 80 . The procedure is: a Divide the total depth of unbound granular materials into 5 equi-thick sub-layers. whereas with Austroads 1992. the number of sub-layers were dependent on the thickness and elastic properties of the layers. 0 User's Guide c The ratio of Elastic moduli of adjacent sub-layers is given by:  E top granular sublayer  5 R =      E subgrade  d The Elastic modulus of each sub-layer may then be calculated from the Elastic modulus of the adjacent underlying sub-layer. a check needs to be made that the vertical Elastic modulus calculated for each sub-layer (step a) does not exceed 10 times the design CBR of each selected subgrade material within the sub-layer. The vertical Elastic modulus of the top sub-layer of selected subgrade is the minimum of 10 times the design CBR of the selected subgrade material and that determined using: 1 E V top sublayer = E V insitu subgrade × 2(total selected subgrade thickness / 150) b The ratio of Elastic moduli of adjacent sub-layers is given by:  E top selected subgrade sublayer  5 R =   E insitu subgrade     c The Elastic modulus of each sub-layer may then be calculated from the Elastic modulus of the adjacent underlying sub-layer. If this condition is not met. Selected Subgrade Materials Selected subgrade materials are a special case of unbound granular material.76 CIRCLY 5. beginning with the subgrade or upper sub-layer of selected subgrade material as appropriate. the Elastic modulus of which is known.e. combined) thickness of all selected materials is divided into five sub-layers and each assigned an Elastic modulus value according to the following guidelines: a Divide the total depth of all selected subgrade materials into 5 equi-thick sub-layers. the Elastic modulus of which is known. The total (i. d If the pavement includes more than one type of selected subgrade material. an alternative trial selected subgrade configuration needs to be selected. RF. k  N = RF  ε  b . 1 Performance Models The main change to the Performance Models is the introduction of a Reliability Factor. beginning with the insitu subgrade. Cemented Materials Suggested Reliability Factors (RF) for Cemented Materials Fatigue (Austroads 2004) Desired Project Reliability Reliability Factor (RF) 80% 4.0 97.0 90% 1. apart from the introduction of the Reliability Factor.5% 0.3 90% 2. .5 85% 2.5 Asphalt Suggested Reliability Factors (RF) for Asphalt Fatigue (Austroads 2004) Desired Project Reliability Reliability Factor (RF) 80% 2.0 97.0 95% 1.5% 0.Chapter 8 Overview of Austroads 2004 Features 77 The Performance models for Cemented and Asphalt Materials are the same as for Austroads 1992.67 Subgrade The subgrade Performance Model used in Austroads 2004 is:  9300  N =    µε  7 Note that a Reliability Factor is not used for the subgrade.7 85% 3.5 95% 1. . The design tyre pressure for pavement analysis is taken as 750 kPa (Chapter 7.0 or 4. . This Standard Axle is provided in the Load Groups database with the ID given by "ESA75Full". Austroads 2004).1 in conjunction with the original Guide.0. The following notes assume that you are already familiar with using CIRCLY 4.79 How to Use New Austroads 2004 Features The previous Section provided an Overview of the new features in the Austroads 2004 Guide. Modelling the Standard Axle The layout of the four wheels used to model the Standard Axle is shown in the earlier section (see "Model of Standard Axle" on page 74). This Section shows how to use the new Austroads features in CIRCLY 5. 0 User's Guide How to Use Project Reliability Click on the button.80 CIRCLY 5. This will bring up the following form: 2 . This will bring up the following screen: 1 1 Click the Reliability tab to switch to the Reliability form. Chapter 8 How to Use New Austroads 2004 Features 81 2 Click on Use Project Reliability Factors. 4 4 This Table shows the Reliability Factor for each Material Type. Changes to Materials The Materials database in CIRCLY is affected by the Austroads 2004 changes in three main areas: 1 Unbound Granular Materials 2 Subgrade Materials . 3 3 In the Project Reliability list. click the desired Project Reliability. Full Depth Asphalt Pavement CT = Cement Treated Pavement Description Sprayed Seal Surfaced Unbound Granular Pavement Asphalt Pavement containing a Cemented Material Subbase (pre-cracking phase) Asphalt Pavement containing a Cemented Material Subbase (post-cracking phase) Full Depth Asphalt Pavement See Appendix 8.Example 2.82 CIRCLY 5.Example 2.Post-Cracked Austroads 2004 .3 (Austroads 2004) outlines three worked examples that apply a mechanistic design procedure for flexible road pavements.3 (Austroads 2004) for full details of the parameters used.Asphalt Pavement with CT Subbase.Example 1 . Copies of these examples are provided in the CIRCLY database: CIRCLY Job Name Austroads 2004 .0 User's Guide 3 Select Subgrade Materials To ensure that pavements can be handled using either the Austroads 1992 or Austroads 2004 methods. separate Material Types are used for variants of these materials: Material Type Design Method: Unbound Granular Material Austroads 1992 Unbound Granular (Austroads 1992 sub-layering) Subgrade (Austroads 1992) n/a Austroads 2004 Unbound Granular (Austroads 2004 sub-layering) Subgrade (Austroads 2004) Subgrade (Selected Material) Subgrade Select Subgrade Material n/a = not applicable Austroads 2004 Examples Appendix 8.Example 3 .Unbound Granular Pavement Austroads 2004 .Asphalt Pavement with CT Subbase Austroads 2004 . . Pavement Design – A Guide to the Structural Design of Road Pavements.J. 2001 Austroads Pavement Design Guide (Final Draft). 2. . Austroads (2001). AP-17/92. CSIRO Australia. Geomechanics Computer Program. (Austroads: Sydney). (At the time of writing the publication number and date were not known). Austroads Publication No. Austroads Publication No. Division of Applied Geomechanics. Mincad Systems. Australia. (2004). 2004 Austroads Pavement Design Guide. Wardle. (Austroads: Sydney).83 References Austroads (1992). L. Austroads Publication. (Austroads: Sydney). Wardle. Austroads (2004). (1977).J. L. Program CIRCLY User’s Manual. No. AP-T10/01. Program CIRCLY Theory and Background Manual.