锌污染对紫色土干缩与电阻率影响的试验研究  

Experimental study on the effect of zinc pollution on drying shrinkage and resistivity of purple soil

作　　者：申纪伟 万水[1] 刘素英[2] 王正成 符俊冬[1] SHEN Ji-wei;WAN Shui;LIU Su-ying;WANG Zheng-cheng;FU Jun-dong(School of Transportation,Southeast University,Nanjing,Jiangsu 211189,China;College of Civil Engineer,Chongqing Three Gorges University,Chongqing 404100,China)

机构地区：[1]东南大学交通学院,江苏南京211189 [2]重庆三峡学院土木工程学院,重庆404100

出　　处：《岩土力学》2021年第3期656-664,共9页Rock and Soil Mechanics

基　　金：重庆市教委科学技术研究项目(No.KJQN202001230);重庆市三峡水库岸坡与工程结构灾变防控工程技术研究中心开放基金(No.SXAPGC19YB10P);国家自然科学基金(No.51878151)。

摘　　要：为探究电阻率法监测重金属污染紫色土干缩的可行性,基于二极法,选取最常见、含量最高的锌为典型污染物,分析了干缩过程中蒸发量、收缩率与电阻率受锌含量影响的变化规律,并推导了电阻率模型。结果表明:干缩过程按照蒸发量划分为常速率、变速率与残余阶段,变速率段蒸发速率呈先增加后减小的趋势,其趋势峰值随锌含量的升高而增大;锌含量越高,收缩率前期增长越慢,后期趋稳越早,最终收缩越小;电阻率先慢速后快速增长,锌含量越高,电阻率前期增长越慢,后期反而增长越快;电阻率模型由蒸发量和收缩率表示,并在一定范围内与锌含量相关。锌含量影响了不同阶段的蒸发速率,抑制了干缩变形,对电阻率的作用也越来越强,模型阐明了它们间的相互关系,为电阻率测试紫色土干缩变形提供依据。To explore the feasibility of resistivity method in monitoring the drying shrinkage of heavy metal contaminated purple soil,zinc,which is the most common and most abundant contaminant,was selected based on two-electrode method.In this study,the influence of zinc content on evaporation,shrinkage and resistivity during drying shrinkage was analyzed,and a resistivity model was deduced.The results showed that according to the evaporation amount,the drying shrinkage process can be divided into three stages:constant rate,variable rate,and residual.In the stage of variable rate stage,the evaporation rate firstly increases and then decreases,and its peak value increases with the increase of zinc content.The higher the zinc content is,the slower the shrinkage increases in the early stage;the earlier it stabilizes in the later stage,the smaller the final shrinkage is.The resistivity increase slowly at first and then rapidly.The higher the zinc content,the slower the resistivity increases in the early stage,but the faster it increases in the later stage.The resistivity model is expressed by evaporation and shrinkage,and it is related to zinc content within a certain range.The zinc content affects the evaporation rate at different stages,inhibiting the shrinkage deformation,and has an increasingly stronger effect on the resistivity.The model illustrates the relationship between them,which provides a basis for measuring the drying shrinkage deformation of purple soil through the resistivity method.

关 键 词：紫色土 干缩 锌污染 电阻率 收缩率 蒸发量 

分 类 号：TU411[建筑科学—岩土工程]