桂林地区碱污染红黏土力学效应弱化试验  

Experiment of the mechanical effect weakening for alkali polluted red clay in Guilin

作　　者：牟春梅[1,2] 韦瑜玺 张岩 MU Chun-mei;WEI Yu-xi;ZHANG Yan(College of Civil and Architectural Engineering Engineering, Guilin University of Technology, Guilin 541004,China;Guangxi Key Laboratory of Geomechanics and Geotechmical Engineering, Guilin University of Technology, Guilin 541004,China)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004

出　　处：《桂林理工大学学报》2019年第2期376-382,共7页Journal of Guilin University of Technology

基　　金：国家自然科学基金项目(41867039);广西自然科学基金项目(2017GXNSFAA198213);广西高校科学技术研究重点项目(KY2015ZD055)

摘　　要：为了研究碱污染对红黏土力学性质的影响,使用氢氧化钠(NaOH)溶液对桂林雁山红黏土进行浸泡,考虑碱浓度(0、 4%、 8%、 12%)和养护时间(1、 7、 14 d)双因子因素,通过室内直剪试验和固结试验,分析碱污染对桂林雁山红黏土力学性质的变化。试验结果表明:随着碱浓度及养护时间的增加,红黏土的抗剪强度、黏聚力、内摩擦角减小;浸泡后红黏土的孔隙比增大,压缩系数增大,压缩模量减小。碱-土相互作用是导致桂林地区碱污染红黏土力学效应弱化的根本原因,其相互作用导致红黏土颗粒间的胶结物被溶解后又重新生成絮状物,使其原本稳定的结构状态发生改变。In order to study the effect of alkali pollution on the mechanical properties of red clay, sodium hydroxide (NaOH) solution was used to immerse the red clay in Yanshan, Guilin. Based on the double factors of alkali concentration (0, 4%, 8%, 12%) and time (1, 7, 14 d), the direct shear test and consolidation test were carried out. The effect of alkali pollution on the mechanical properties of red clay in Guilin was analyzed. The results show that the shear strength, cohesion and internal friction angle of red clay decrease with the increase of alkali concentration and time.The compression coefficient increases and the compression modulus decreases because of the porosity ratio of red clay increase after soaking. Analysis of test results finds out that the alkali-soil interaction is the fundamental cause in weakening the mechanical effect of alkali contaminated red clay in Guilin area.The interaction results in the dissolution of the binder between red clay particles and the formation of flocculants,and changes the original stable state of the structure.

关 键 词：碱污染 红黏土 力学效应 弱化 桂林 

分 类 号：TU411.3[建筑科学—岩土工程]