考虑应力历史的饱和黏土一维固结渗透试验研究  

Experimental study on 1-D consolidation permeability of saturated clay considering stress history

作　　者：张乐[1] 党发宁[1] 高俊 丁九龙 ZHANG Le;DANG Faning;GAO Jun;DING Jiulong(State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi'an University of Technology,Xi'an 710048)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,西安710048

出　　处：《水力发电学报》2021年第4期84-96,共13页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金(51979225;51679199);水利部公益性行业科研专项(201501034-04)。

摘　　要：为研究固结应力比和应力历史对饱和黏土一维固结渗透的影响,利用GDS三轴仪进行了一系列一维固结-渗透联合试验。研究结果表明,在不同固结应力比相同应力历史条件下,正常固结和超固结饱和黏土在一维固结渗透过程中试样的渗透系数和孔隙比均随固结应力比的增大而减小,试样的最终压缩量均随固结应力比的增大而增大。在相同固结应力比不同应力历史条件下,超固结饱和黏土的最终压缩量小于正常固结饱和黏土。将固结应力σ与土层自重应力σcz的差值σdv与试样最终压缩量sf进行拟合,得出应力差值σdv与各固结应力下的最终压缩量sf间呈良好的线性关系。通过研究发现,同时考虑固结应力比和应力历史对饱和黏土一维固结渗透的影响是有必要的,同时在得到土体自重应力后可较为准确地预测土体最终压缩量。A series of one-dimensional consolidation permeability tests were carried out using the GDS triaxial apparatus to study the influence of consolidation stress ratio and stress history on the characteristics of saturated clay.The results indicate that the permeability coefficient and void ratio of normal-and over-consolidated saturated clay decrease with the increase in consolidation stress ratio under different consolidation stress conditions with the same stress history.And the final compression of the specimens increases with consolidation stress ratio.Under the same consolidation stress ratio but different stress history conditions,the final compression of over-consolidated saturated clay is smaller than that of normal consolidated saturated clay.In addition,the differenceσdv between consolidation stressσand gravity stressσcz is fitted to the final compression sf of the specimen,and a good linear relationship between these two parameters is obtained for each consolidation stress.This study finds that for saturated clay,it is necessary to consider simultaneously the influence of both consolidation stress ratio and stress history on its 1-D consolidation and permeability,and the final compression can be accurately predicted if knowing its gravity stress.

关 键 词：固结应力比 应力历史 饱和黏土 一维固结渗透 

分 类 号：TU411[建筑科学—岩土工程]