TIME-DEPENDENT DEFORMATIONS IN CLAY SOILS. PROCEEDINGS OF THE ELEVENTH INTERNATIONAL CONFERENCE ON SOIL MECHANICS AND FOUNDATION ENGINEERING, SAN FRANCISCO, 12-16 AUGUST 1985

The time-dependent behavior of compressible soils, including both hydro-dynamic lag and creep effects, is an important problem in geotechnical practice. Time-dependent behavior can be an important design consideration, particularly with respect to earthen embankments, which impose relatively large foundation loads and often traverse deep deposits of highly compressible soils requiring staged construction procedures. Previous numerical models of time-dependent soil behavior under other than one-dimensional conditions have considered either hydro-dynamic lag or undrained creep separately. In this paper, a recently developed numerical model that accounts for both hydro-dynamic lag and creep effects is introduced. This model is used to analyze the behavior of the I-95 test embankment, outside of Boston, Massachusetts, USA. Results of the analysis indicate that undrained deviatoric creep can be a major contributor to embankment foundation deformations and that an immediate/delayed consolidation model may yield the same results as a primary/secondary consolidation model if the volumetric creep rate is slow enough. For the covering abstract of the conference see IRRD 287689. (Author/TRRL)