RISC - A MECHANISTIC METHOD OF RIGID PAVEMENT DESIGN

Abstract

This paper deals with the development and verification of a stress analysis model (RISC) and the use of this model in a program for the design of rigid pavements. RISC is the result of coupling finite element plate theory with multi­layer elastic layer theory and consists of a two­layer rigid slab resting on a semi-infinite t0.ree-layer elastic solid foundation. The features of RISC include variable thickness of slabs, the effects of curling, warping, voids and parti­al contact, the effect of load transfer across joints and cracks by specifying either dowel bars, aggregate interlock, or load or shear transfer efficiency, the ability to analyze up to nine slabs in any configuration, and the ability to determine the stresses in both rigid layers as well as anywhere in the subbase and subgrade layers. Model verification includes comparison with known solutions whenever possible; however, since this model is an extension beyond the scope of existing theories, qualitative comparisons are also included. The pavement design program uses RISC for stress analysis; however the input requirements have been drastically simplified for the convenience of the user. The output includes the expected design life.