Influence of Stress Path on Mechanical Behavior of Saturated Silty Clay Under K₀ Consolidation

With a rapid development of economy in China in the past decades, some existing transportation system (e.g., highways, railways or airports) has been confronted with widening and rebuilding. In the process of roadway widening or rebuilding, subsoil would experience different stress paths due to excavation or backfilling. Thus the effect of stress path on mechanical properties of subsoil shall be considered in design. This paper presents a series of triaxial tests to investigate the influence of stress path on the mechanical properties of saturated silty clay. Soil samples were drilled from the area of the modern tram line in Suzhou high-tech district. The soil samples were prepared by remolding and consolidating under K₀ condition. The soil behavior under four types of stress paths and the drainage conditions (i.e., drained and undrained conditions) were investigated. The results show that the saturated silty clay performed a strain hardening characteristic in an undrained condition irrespectively of the stress path. Under the drained condition, the Poisson ratio of soil varied in different stress paths. The development of pore pressure in soil had two patterns, i.e., the stable mode and the attenuation mode after reaching the peak value. The drainage conditions (i.e., drained and undrained conditions) had great influence on the initial tangent modulus of saturated silty clay under different stress paths.