NCHRP 24-41 Defining the Boundary Conditions for Composite Behavior of Geosynthetic Reinforced Soil (GRS) Structures research objectives were to determine the boundary conditions for composite behavior of GRS abutments as a function of, but not limited to, vertical spacing of soil reinforcements, reinforcement type (geotextiles and geogrids) and characteristics, and backfill properties. The research resulted in development of proposed revisions to the AASHTO LRFD specifications. The final report, NCHRP 24-41 Defining the Boundary Conditions for Composite Behavior of Geosynthetic Reinforced Soil (GRS), Appendix A: SI Conversion Factors; Appendix B: Additional Data from Field Component; and Executive Summary NCHRP 24-41 are available from this project webpage. Also available, NCHRP Web-Only Document 260, Proposed Refinements to Design Procedures for Geosynthetic Reinforced Soil (GRS) Structures in AASHTO LRFD Bridge Design Specifications, an adaptation of Chapter 8 of the full report which discusses proposed design refinements for Section 11.10 of the AASHTO LRFD Bridge Design Specifications.