一维回弹试验中卸载条件下的负超孔隙水压力响应  

Responses of negative excess pore water pressure under unloading in one-dimensional swelling tests

作　　者：林城福 雷国辉[1,2] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学岩土工程科学研究所,江苏南京210098

出　　处：《岩土力学》2017年第12期3613-3618,3626,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金项目资助(No.51278171;No.51578213);中央高校基本科研业务费专项资金项目资助(No.2017B20614)~~

摘　　要：针对卸载条件下的孔隙水压力(简称孔压)响应问题,通过一维加载压缩和卸载回弹试验,研究了不同卸载量和卸载速率对孔压变化的作用影响,并基于Terzaghi一维固结理论建立了线性加载和卸载条件下孔压响应的预测方法,结合固结-渗透联合试验测定的压缩和回弹条件下的固结系数,评估了该类预测方法对于卸载条件下孔压响应预测的适用性。结果表明,卸载产生的负超孔压随着卸载量和卸载速率的增加而增加,在卸载初期,超孔压减小速率较快,之后则以近似恒定的速率减小,而基于Terzaghi一维固结理论建立的孔压预测方法并不完全适用于分析卸载过程中的这类孔压响应特性。One-dimensional compression and swelling tests are carried out to investigate the responses of pore water pressure under unloading. Effects of various magnitudes and rates of unloading on changes of pore water pressure are analyzed. Based on Terzaghi＇s one-dimensional consolidation theory, a calculation method is proposed for predicting the pore water pressure responses under linearly loading and unloading conditions. Coefficients of consolidation under compression and swelling are measured by consolidation and permeability combined testing. The applicability of the proposed calculation method to the pore water pressure responses under unloading conditions is evaluated. The results show that negative excess pore water pressure increases with the increases of magnitude and rate of unloading. At the beginning of unloading, excess pore water pressure reduces at a relatively high rate. This is followed by a reduction of excess pore water pressure at an approximately constant rate. However, this type of pore water pressure response behavior cannot be satisfactorily modelled by the calculation method established based on Terzaghi＇s one-dimensional consolidation theory.

关 键 词：一维固结 回弹 卸载量 卸载速率 负超孔压 

分 类 号：TU472.3[建筑科学—结构工程]