不排水条件下全风化花岗岩残积土工程特性与本构模型

通过土工试验对不排水剪切条件下的饱和松散砂质土的工程特性进行了探讨 ,发现其在剪切时的应力 -应变关系呈现出加工软化特性 ,土体超过峰值强度后最终达到了变形的稳定状态 .基于稳定状态概念 ,将临界土力学理论与非线性应力 -应变关系相结合 ,建立了非线性应力 -应变 -临界状态本构模型 .采用香港钻石山地区全风化花岗岩残积土的不排水三轴试验结果 ,确定了有关模型参数 ,验证了所建议本构模型的合理性

Fundamental behavior and constitutive modeling of a CDG residual soil under undrained shear

The stress strain relationships of saturated loose sandy soils under undrained shear show strain softening behaviour and soils will reach the steady state of deformation after beyond the peak shear stress. In this paper, on the basis of the concept of steady state, the fundamental theory of the critical soil mechanics and nonlinear stress strain relationship are combined together to establish the constitutive model for describing nonlinear type stress strain curves and critical states. The experimental data of undrained triaxial compression tests for a loose completely decomposed granite (CDG) residual soil from Diamond Hill Development Site Formation in Hong Kong is used to define the model parameters. The proposed constitutive model is verified by comparing the predicted results and experimental data.