Study on the Multi-Scale Evolution Mechanism of Shear Bands and Cobweb Effect in Solidified Silt Considering Strain Rate

The strain rate is a critical element influencing soil strength and the development characteristics of shear bands, which are essential for soil landslides. In order to accurately study the development of shear bands in stabilized silt, digital imaging technology (DIC) combined with triaxial tests was used to study the effects of strain rate on the mechanical properties of stabilized silt and the development mechanism of shear band. Experimental results indicate the following: (1) A strength prediction model incorporating curing agent dosage and curing age was developed, effectively characterizing the strength development law of solidified silt. The optimal dosage of the curing agent was determined to be 8% based on the UCS results. There is an obvious hysteresis effect of peak strain at high strain rate. (2) The degree of strain softening is sensitive to the change in strain rate and curing agent content, and it is positively correlated with strain rate and curing agent content. (3) The “cobweb effect” of the stabilized silt shear band at low strain rate is proposed, which can accurately explain the development law of the stabilized silt shear band. (4) Compared with the maximum strain of 0.04 mm/min, the maximum strain on the shear band decreased by 16.1% and 61.8%, respectively, at 0.4 mm/min and 4 mm/min, and the thickness of the shear band was inversely proportional to the maximum strain on the shear band.