Wetting deformation characteristics of granite residual soils and the micro-mechanism

This article investigated the influences of initial conditions on the wetting deformation characteristics of granite residual soils. The wetting deformation decreased with the increasing initial water content. Increasing the degree of compaction contributed to swelling deformation, while increasing the vertical pressure contributed to compression deformation. A regression model for predicting the wetting strain was established. The bimodality pore size distribution was characteristic of and tended to be uniform after wetting. Small pores increased while large pores decreased with the increasing initial water content. Large pores decreased while small pores rarely varied with the increasing degree of compaction. Increasing initial water content promotes the uniformity of the pore size distribution, which reduces the wetting deformation. For soil samples with high degree of compaction, the compression deformation resulting from large pores remains limited as the vertical pressure increases, so they exhibit swelling deformation because of hydrophilic minerals.