One Dimensional Computer Analysis of Simultaneous Consolidation and Creep of Clay

Abstract

This dissertation describes the development and verification of a general purpose computer program, CONSOL97, for analysis of one dimensional consolidation of multi-layered soil profiles. The program uses an elasto-visco-plastic model that can simulate both consolidation and creep in a single consistent analysis. The finite element program uses standard oedometer test data to model stress-strain-time relationships, and the effect of strain rate on preconsolidation stress observed in the laboratory and in the field. Validation of the computer program by simulating standard oedometer tests is described and the applicability of the program in predicting field behavior is examined.

The oedometer test simulations indicate good agreement with stress-strain and strain-log time test results during loading. Unloading behavior produces excessive rebound. Well-instrumented field tests at Väsby, Sweden, Skå-Edeby, Sweden and Berthierville, Canada indicate that elasto-visco-plastic CONSOL97 analyses produce better predictions of field behavior than conventional elasto-plastic models. CONSOL97 results were in good agreement for the Väsby and Berthierville test fills but underestimated displacements and pore pressures near the center of the normally consolidated clay layer beneath the Skå-Edeby test fill.