Abstract:
The microstructure, soil-water characteristics, accumulative plastic strain (
εp) and resilient modulus (
MR) of a compacted Heilongjiang clay are compared. The specimens are imposed with three different moisture (wetting-drying, WD) and temperature (freeze-thaw, FT) paths (i.e., WD-FT, FT-WD and interlaced FTWD histories). The experimental results show that: (1) After moisture-temperature (M-T) actions, the structural pores develop while the textural ones shrink, which leads to reduction in the water retention capacity and increase in the desaturation rate. After M-T effects are stabilized, the microstructure and soil-water characteristics of the specimens with different M-T paths become similar. (2) Under at high moisture content (
w),
εp and
MR are more sensitive to moisture changes (including
w and suction
s). After FT cycles,
εp becomes more sensitive while
MR becomes less sensitive to moisture changes. (3) After M-T effects, the
MR-
s relationships are nonlinear while the
MR-
w relationships are linear. The different M-T paths do not generate differences in
εp and
MR when the M-T effects are stabilized. (4) A model based on the mechanics of unsaturated soils is used to rationally predict the variation of
MR with
w and
s for the specimens with different M-T paths.