Abstract：At present, we usually take the soil test samples used in the project on the site and process them into a standard sample in the laboratory, then we freeze samples without pressure and carry out the three axis strength tests. But in the actual engineering, the soil is often frozen under pressures, and few of us have studied the strength differences between the two conditions. There are also few studies on the strength of three axis under different loading methods, so it is necessary to study the stress strain characteristics of Nanjing silty clay under different confining pressures, different consolidation methods and different stress paths. The results show that the maximum axial stress is linearly increased with the confining pressure, and the growth rate of remolded silty clay is larger than that of raw silty clay. The consolidation way has great influence on the friction angle, and less influence on cohesion. The friction angle of frozen remolded silty clay ranged from 21.94 to 28.22. The strength of the isobaric drainage consolidation followed by freezing specimen will be greatly improved; the strength and elastic modulus are affected by the stress path, and the strength and elastic modulus of loading stress path are greater than the unloading stress path. On the basis of Duncan-Chang model, we have established a new model considering the influence of the confining pressures. The damage ratio of the original silty clay and silty clay consolidated by isobaric drainage before freezing, consolidated by isobaric undrained before freezing and consolidated after freezing are 0.87, 0.89, 0.93 and 0.87, respectively.
张雅琴 杨 平 江汪洋 张 婷. 粉质黏土冻土三轴强度及本构模型研究[J]. 土木工程学报, 2019, 52(S1): 8-15.
Zhang Yaqin Yang Ping Jiang Wangyang Zhang Ting. Study on triaxial strength and constitutive model of frozen silty clay. 土木工程学报, 2019, 52(S1): 8-15.
