软粘土卸载特性计算模型研究

本文从三个方面对软粘土的卸载特性进行了理论研究。采用太沙基一维固结理论，编制了内嵌固结计算的修正剑桥模型程序．对软粘土卸载强度进行了分析。推导了基于修正剑桥模型的孔压表达式并编制了相应的程序对软粘土的卸载孔压特性进行了研究，结果显示，在伸长条件下．孔压先由零逐渐发展到负的最大值．然后又逐渐减小至零。突破零位后，发展成为正孔压并最后达到正的最大值。围压越大，产生的负孔压的极值越大，最终的正孔压越小。将传统边界面模型的线弹性卸载过程改进为弹塑性．建立了软粘土的边界面广义弹塑性模型，从而使边界面模型可用于分析软粘土卸载过程中的塑性变形问题。理论分析结果与试验进行了比较验证，证明理论研究方法是可行的。

Unloading Characteristic Research of Soft Clay

The characteristic of soft soil in unloading condition was studied in three aspects. By the program for embedded consolidation calculation and modified cam-clay model, the soft soil strength in unloading condition was analyzed. The water pressure expression was deduced based on the modified cam clay model, and the water pressure characteristic was studied upon numerical program. The research indicates that, the water pressure changes from zero to the largest negative point and relates with confining pressure. The elastic unloading is replaced by elasto-plastic, then the boundary surface model can be used to analyze the plastic deformation of soft clay during unloading process. The labor test result indicates the theory research method is feasible.