软黏土主次固结划分及其模型应用

Division of Primary and Secondary Consolidation for Soft Clay and Its Model Application

现有蠕变模型计算值与实际变形量偏差较大,原因是没有合理的确定蠕变开始时刻,进而导致模型参数不符合要求。为了获得更可靠的蠕变模型,确定蠕变开始时刻,以珠海饱和软黏土为例,进行K0固结三轴排水蠕变试验,深入分析相关试验数据和主次固结理论后,发现主次固结曲线存在规律性拐点,且该点往后的变形以蠕变变形为主,同时提出一种新的方法确定该点。由试验数据可知应变与应力水平成幂函数关系、与时间成二次曲线关系,根据新方法获得的参数建立了严格意义上的蠕变模型。通过分析对比表明,该蠕变模型适合描述试验土样的蠕变特性,与试验数据吻合度高。

There is big deviation between the actual value and calculation value from existing creep model because of not determining the start moment of creep accurately ,so causing the parameters of creep model not meeting some require-ments .In order to obtain the reliable model and determine the start moment of creep ,and taking the saturated soft clay in Zhuhai for example ,the K0 consolidated triaxial drainage creep tests are conducted .Then ,through analyzing the test data and primary-secondary consolidation theory ,it is found that the primary-secondary consolidation has inflection point , and the dominated deformation after the point is creep ,so a new method is proposed to determine the point .From the test data ,it is shown that the strain presents the power function retationship with the level of stress and presents the quadratic curve retationship with time .Based on the parameters from the new method ,the strict creep model is established .The analysis and comparison results show that the model could describe the creep properties of soil samples well and have the high degree of agreement with the test data .