TRB's National Cooperative Highway Research Program (NCHRP) Report 647: Recommended Design Specifications for Live Load Distribution to Buried Structures explores recommendations to revise the American Association of State Highway and Transportation Officials Load and Resistance Factor Design Bridge Design Specifications relating to the distribution of live load to buried structures.
The report examines development of simplified design equations (SDEs) for structural response based on three-dimensional (3D) analysis of 830 buried culverts. In addition, the report suggests guidelines for conducting two-dimensional and 3D modeling for design situations with conditions not covered by the SDEs.
Appendixes A through E for NCHRP Report 647 are only avilable online. These appendixes are as follows:
• Appendix A—3-D Numerical Analysis of Live Load Distribution: Soil Constitutive Models, Load Factoring and Comparison with Field Measurements
• Appendix B—3-D Numerical Analysis of Live Load Distribution: Model Details and Results
• Appendix C—Recommended Revision to AASHTO LRFD Bridge Design Specifications
• Appendix D.1—Parametric Study MathCAD Calculation Sheets
• Appendix D.2—Tabular Listings of Parametric Study Results
• Appendix E—Refined Analysis Guidelines