CANDE: a versatile soil—structure design and analysis computer program

Abstract

This paper introduces CANDE, a new computer program for the structural design, analysis, and evaluation of buried culverts or other soil—structure interaction problems. Structures composed of corrugated steel, corrugated aluminium, reinforced concrete, and structural plastic may be designed and/or analysed for incremented soil loading and live loading. Both the soil mass and structure are incorporated into an incremental, static, plane-strain formulation and solved by a chosen solution level. There are three solution levels corresponding to successive increases in analytical power. Level 1 is a closed form elasticity solution, whereas levels 2 and 3 are based on the finite element method. Level 2 employs a completely automated finite element mesh generation scheme suitable for most culvert installations, thus no special knowledge of finite element mesh construction is required for this level. Level 3 applies to an arbitrary soil—structure configuration, but requires a user-defined finite element mesh topology. The solution level concept permits the user to choose a degree of rigour and cost commensurate with the worth of a particular project and confidence in input parameters. Analytical modelling features include incremental construction, nonlinear soil models, structural models for ductile yielding and cracking, and special interface models for frictional sliding, debonding and rebonding. Example applications demonstrate the results of: frictional interfaces between culvert and soil, comparing predicted and experimental data, and investigating parameters of long-span soil structures.