K_0状态超固结软黏土蠕变性状的试验和理论研究

Experimental and Theoretical Study on Creep Properties of Overconsolidated Soft Clay under K_0 State

为了研究软黏土K_0应力状态下土体的蠕变规律,对湖州软黏土进行了K_0状态下三轴蠕变试验,从竖向应变和剪切应变2方面对试验结果进行分析,在竖向应变分析中,采用"陈氏法"对试验结果进行处理,得到了超固结比对次固结系数的影响规律;在剪切应变分析中,采用Hu-Xie一维剪切蠕变等效时间模型对试验数据进行了归纳。研究结果表明:超固结软黏土竖向应变的次固结系数随超固结比的增大呈指数型减小,超载预压法能有效减小工后次固结沉降; Hu-Xie模型在超固结土的剪切应变计算中具有较好的适用性。

In order to study the creep characteristics of soft soil in K0 stress state,the triaxial creep tests in K0 stress state are conducted for Huzhou soft clay.The test results were analyzed from both vertical strain and shear strain.In the analysis of the vertical strain test results,the effect of overconsolidation ratio on the secondary consolidation coefficient was obtained by processing the test results by"Chen's method".In the analysis of shear strain test results,the Hu-Xie one-dimensional shear creep equivalent time model was used to summarize the test data.The results show that the secondary consolidation coefficient of the vertical strain of overconsolidated soft clay decreases exponentially with the increase of the overconsolidation ratio,which means the overload preloading method can effectively reduce the post consolidation settlement.The results also show that the Hu-Xie equivalent time-line model can properly calculate the shear strain of the soil under any loading path,which indicates that the Hu-Xie model has good applicability in the calculation of shear strain in overconsolidated soil.