软土结构性分析与扰动评价

Evaluation of Structure and Disturbance of Soft Ground

结构性软土一般具有明显的结构屈服应力,外界扰动导致软土地基的结构屈服应力减小、压缩性增加.在分析软土压缩变形过程中的孔隙比及应力变化特征的基础上,采用五段折线表示扰动结构性软土的压缩曲线,并在此基础上提出虚拟前期固结压力的概念.通过对结构性软土扰动状况进行定量化分析,利用对数形式结合虚拟前期固结压力定义软土的扰动度,使扰动度的定义与e-lgp曲线相结合进而利于土体扰动强度和变形的计算分析,并指出扰动结构性软土地基的沉降计算应合理考虑土体形成过程中的欠固结问题.工程算例显示笔者的计算方法能够合理的预测扰动软土的最终沉降.

There is an obvious yield stress for structural soft soil,and external disturbances result yield stress decrease and compression increase.Five-section line was used to simulate the compression curve of disturbed soil,and virtual pre-consolidation pressure was put up after the varied characteristics of pore ratio and stress were analyzed in the process of deformation.Disturbed degree of soft soil that defined of logarithmic form was closely connected with e-lgp curve,and thus conductive to strength calculation and deformation analysis of disturbed soil.Engineering practice showed that inadequate consolidation of soft soil should be considered when disturbance degree was calculated,and this method in the assay could reasonably predict the ultimate settlement of disturbed soil.