饱和软粘土压缩变形中渗透参数的分析

Analysis of percolation parameters of saturated soft clay under compression

为探讨饱和软粘土压缩变形中渗透参数的变化,首先对软粘土中有效应力原理进行了分析。由于粘土颗粒处于非充分接触或非接触状态,经典Terzaghi有效应力原理需要作适当的修正;接着分析了粘土介质中结合水和自由水的转化规律,指出了结合水对软粘土固结过程的影响;在此基础上,分析了孔隙度和孔隙渗透率应力敏感性,并讨论给出了相关的表达式。分析结果表明:软粘土的性质与其微结构有着密切的关系,饱和状态下,随着粘土中孔隙水的不断排出,有效应力增加,孔隙结构也随着其所受的应力的改变而发生变化,造成粘土孔隙度和渗透率的变化,进而对软粘土的压缩特性和渗流形态产生影响。

In order to investigate the change of percolation parameters of saturated soft clay under compression, the effective stress principle of soft clay was analyzed firstly. The classical Terzaghi＇s effective stress principle should be modified for clay particles remaining in a non-full contact or noncontact status under saturation. The transformation rule of bound water and free water in clay was studied, and it was pointed out that the bound water had an important impact on the consolidation process of soft clay. Based on the aforementioned study, the stress sensitivity of porosity and pore permeability was discussed, and the related formula was given, too. The result showed that the property of soft clay had a close relation with its micro-structure. In the condition of being saturated, with the pore water discharging, the effective stress was increased and pore structure was transformed as the stress changes, which causes variation of clay porosity and permeability, and influenced the compression property and percolation of soft clay.