Compaction and shear performance of lime-modified high moisture content silty clay
Yunfang Shi, Shengang Li, Tianbiao Zhang, Jinning Liu, Ji‐Tao Zhang
Abstract
In subgrade engineering, silty clay often deforms and fails due to poor strength and water stability. This study investigates the compaction and shear properties of high-moisture-content silty clay modified by quicklime. Through compaction tests and direct shear tests, the effects of different lime admixture levels and curing conditions on the compaction and shear properties of the modified soil were analyzed. The results show that the maximum dry density of the modified soil decreases linearly with the lime admixture, while the optimal moisture content increases quadratically with the lime admixture. Excessive lime admixture cannot effectively improve the optimal moisture content of the modified soil, the compaction performance of the modified soil is optimal when the lime admixture is 7 %. The incorporation of lime significantly improves the cohesion and internal friction angle of the soil. Cohesion increases with the lime admixture, while the relationship between the internal friction angle and lime admixture is not significant. Curing conditions have a significant impact on the mechanical properties of the modified soil. Under low lime admixture, immersion curing conditions significantly deteriorate the shear strength of the modified soil, while under high lime admixture (7 %, 9 %), the modified soil exhibits good water stability. Moreover, the modified soil exhibits better shear strength and water stability under higher vertical stress. The research findings reveal the mechanical and deformation characteristics of lime-modified silty clay and provide important guidance for its practical engineering application.