Experimental Study on Dynamic Shear Modulus Characteristics of Unsaturated Silt Soils in the Yellow River Delta

To study the dynamic deformation characteristics of unsaturated silt in the Yellow River Delta, undrained cyclic loading tests were carried out on silt in the Yellow River Delta using the KTL dynamic triaxial apparatus. The effects of effective confining pressure σ_3, consolidation ratio k_c, and relative density D_r on the dynamic shear modulus ratio of unsaturated silt were analyzed. The results show that under the same dynamic shear strain, the dynamic shear modulus G of silt increases with the increase of effective confining pressure σ_3, consolidation ratio k_c, and relative density D_r. The influence of confining pressure on the maximum dynamic shear modulus can be described by both linear and nonlinear models, along with the parameter values of these models under different consolidation ratios. The H-D hyperbolic model was used to analyze the G/Gmax of the pulverized soil by regression analysis. Results show that the H-D hyperbolic model can well describe the relationship between G/Gmax and γ_c of unsaturated silt soil in the Yellow River Delta. A preliminary exploration of their developmental patterns was conducted.