Rigid Pavement Design Deficiencies[刚性路面设计缺陷](PPT54).ppt

Rigid Pavement Design Deficiencies,Major shortcomings of JPCP designs based on 1972-1986 versions of the AASHTO Guide:inadequate joint load transfer,long joint spacing,erosion of base/subbase,poor subdrainageetc.Deterioration occurs earlyRehabilitation needed,Development of Supplemental AASHTO Design Procedure for JPCP,Serious deficiencies noted in 1986 AASHTO procedureStudies showed major flaws in base/subgrade support proceduresNo easy fixesImproved structural(3D finite element)model for JPCP was developed to correct deficiencies,Development,Validation,Adoption:1998 Supplemental Rigid Pavement Design Procedure,Developed under NCHRP Project 1-30(University of Illinois at Urbana-Champaign)Validated under FHWA/LTPP research study(ERES Consultants/ARA)Adopted by AASHTO as Supplementary Rigid Pavement Design Procedure(1998)FHWA/LTPP-Supplementary Rigid Pavement Design Spreadsheet(ERES Consultants/ARA),Only JPCP For Now,Jointed plain concrete pavement(JPCP),Most constructed rigidpavement Basic design procedure developed Procedure field verified,Jointed reinforcedconcrete pavement(JRCP)Continuously reinforcedconcrete pavement(CRCP),Limited field verification,1998 AASHTO JPCP Design Is Better,Improved structural modelingImproved subgrade characterizationBase course as structural layerTransverse joint spacingClimate at site is considered directlyShoulder type and slab widthJoint faulting and cracking checks,Use of LTPP Data to Verify1998 AASHTO Design,Design procedure verified using field data from LTPPInputs to 1998 AASHTO design model obtainedActual traffic log ESALs compared to predicted log W(ESALs)No significant bias found in predicting serviceability of pavements in four climatic zones,PRESENTATION OBJECTIVES,What is the Rigid Pavement Design(RPD)Software?Development of RPD SoftwareRPD Software Features and Capabilities How To Use The RPD Software Who Should Use the RPD Software and WhyHow to Get the RPD Software,Rigid Pavement Design Spreadsheet:Features,Information sheet containing spreadsheet“User Guide”,Rigid Pavement Design Spreadsheet:Features,Command buttons for easy navigation between sheets,Rigid Pavement Design Spreadsheet:Features,Command button links to reference tables,Joint spacing and edge support conditions are direct inputs,Rigid Pavement Design Spreadsheet:Features,Climatic properties are direct inputs in the supplemental rigid pavement design,Rigid Pavement Design Spreadsheet:Features,True subgrade k-value is used(not adjusted for top-of-base),Rigid Pavement Design Spreadsheet:Features,Easy links to sensitivity analysis for various design inputs,Rigid Pavement Design Spreadsheet:Features,Project data can be saved in rows and exported to the main sheets,Rigid Pavement Design Spreadsheet:Features,Sensitivity Analysis plot displays inputs held constant,Rigid Pavement Design Spreadsheet:Features,Results sheet can be viewed on screen or can be printed,Rigid Pavement Design Spreadsheet:Features,Calculation sheet shows all calculations and displays design traffic for different slab thicknesses,Rigid Pavement Design Spreadsheet:Features,Faulting Check sheet used to estimate faulting over design life for doweled and nondoweled pavements,PRESENTATION OBJECTIVES,What is the Rigid Pavement Design(RPD)Software?Development of the RPD SoftwareRPD Software Features and Capabilities How To Use The RPD Software Who Should Use the RPD Software and WhyHow to Get the RPD Software,Systems Requirements,IBM PC running:Microsoft Office 95 or 97 or Microsoft Excel 7.0,Using The RPD Software,Copy the Rigid Pavement Design(RPD)Software spreadsheet to the hard driveThe RPD software cannot be run from the floppy driveOpen the RPD spreadsheet using Microsoft Excel,Using The RPD Software,Click on Enable Macros to allow execution of spreadsheet macros,Using The RPD Software,Click on Input Form to access the main sheet,Using The RPD Software,Enter General Information for the project as shown below:,Using The RPD Software,Scroll down to enter Serviceability and PCC Properties,Using The RPD Software,Enter Base Properties,Reliability,and Standard Deviation,Click on Table 14 for friction factors for different base types,Using The RPD Software,Click on Input Form to navigate back to the main screen,Using The RPD Software,Select Pavement Type and Edge Support Condition,Enter Joint Spacing,Using The RPD Software,Enter Climatic Properties for the design region.Click on Table 15 for climatic properties for major metropolitan areas in each State.,For the first run enter the approximate subgrade k-value,Using The RPD Software,Click on Calculate Traffic for traffic calculation worksheet,Using The RPD Software,After entering traffic design inputs click Calculate,Click Export to Input Form,Using The RPD Software,Click on Calculate on the main sheet to calculate thickness for design inputs,Click on Calculate Seasonal k-Value for calculating seasonally adjusted k-value,Using The RPD Software,Enter number of months and subgrade k-value for each season.Click Calculate.,Using The RPD Software,Use the chart to estimate adjusted k-value for fill layer above the subgrade and/or rigid layer beneath the subgrade,Using The RPD Software,Click on Calculate on the main sheet to recalculate thickness for design inputs with the adjusted k-value,Using The RPD Software,Enter thickness for sensitivity analysis,Click Slab Thickness Sensitivity for sensitivity analysis of design traffic to slab thickness,Click on radial buttons for sensitivity analysis of design traffic to different design inputs,Using The RPD Software,Using The RPD Software,Using The RPD Software,Click on Faulting Check to perform checks for doweled and nondoweled faulting,Using The RPD Software,Enter dowel diameter and other design inputs for doweled pavements,Using The RPD Software,Click on FI Table or Drainage Coeff.Table for tables containing information regarding these inputs,Click Calculate to obtain estimated faulting at end of design life,Click Results to view and print results,Using The RPD Software,Enter design inputs for nondoweled faulting check and click Calculate,Click Corner Break Check to perform top-down cracking analysis,Using The RPD Software,The critical values for joint faulting can be changed by entering the appropriate values below,Using The RPD Software,On the Corner Break Check worksheet enter the built-in temperature gradient related to construction curling and moisture gradient,Using The RPD Software,Use one of six charts provided to estimate tensile stress at top of slab from total effective negative temperature differential,Using The RPD Software,The tensile stress at the top of the slab is less than the bottom up tensile stress for which the pavement is designed,Using The RPD Software,Results sheet can be viewed on screen or can be printed,Click Save Data to save the design information entered,Using The RPD Software,Enter ID for saving data and click OK,Using The RPD Software,All design information is saved in rows with the first column corresponding to the data set ID,Select appropriate row and click Export to export design information from this sheet to main sheet.This sheet can be accessed by clicking on Retrieve Data on the main sheet.,PRESENTATION OBJECTIVES,What is the Rigid Pavement Design(RPD)Software?Development of the RPD SoftwareRPD Software Features and Capabilities How To Use The RPD Software Who Should Use the RPD Software&WhyHow to Get the RPD Software,Users of the RPD Software,State and Provincial Highway EngineersConsulting Engineers,Benefits of Rigid Pavement Design Software,Provides key answers not previously addressed:How do I adequately characterize the subgrade support?What is the best base type for the conditions?What is the optimum joint spacing?Will this pavement fault or have corner breaks?,PRESENTATION OBJECTIVES,What is the Rigid Pavement Design(RPD)Software?Development of the RPD SoftwareRPD Software Features and Capabilities How To Use The RPD Software Who Should Use the RPD Software&WhyHow to Get the RPD Software,Get&Use The Software,Order software:-Through LTPP homepagewww.tfhrc.gov-Through LTPP customer serviceCall 865-481-2967,