摘要
密实度、含水率是影响膨胀土边坡稳定性的关键物理参数,其与土体波速、电阻率参数密切相关,揭示膨胀土物理力学特性参数的声-电响应特征对评价膨胀土边坡的稳定性具有重要意义。对不同含水率、密实度的膨胀土土样开展了声波和电阻率测试。研究结果表明:含水率一定时,土体波速随密实度增加而增大,当含水率为40%,密实度≥80%时,波速趋于稳定;当密实度一定时,含水率≥35%和≤25%试样的波速出现交叉现象,此时无法单独通过波速判断土体含水率与密实度的大小;当密实度或含水率不变时,膨胀土含水率或密实度与电阻率呈负相关,即含水率或密实度越大,电阻率值越小;当含水率≥45%时,电阻率变化值基本趋于稳定,此时电阻率的变化无法有效表征含水率或密实度的大小。由于依靠单一参数来评价膨胀土的含水率和密实度存在局限性,为此,提出了采用波速-电阻率的综合参数分析方法,该方法可以提高膨胀土含水率识别的准确性。研究成果对膨胀土边坡稳定性评价研究具有借鉴指导作用。
Compactness and moisture content, closely related with soil wave velocity and resistivity, are the key parameters affecting stability of expansive soil slopes.It is significant to evaluating stability of expansive soil slopes through studying the acoustic-electrical response of key above mentioned parameters of expansive soil slopes.This paper reveals the acoustic-electrical response characteristics of expansive soil with different compactness and moisture contents through a series of laboratory tests.When retaining a certain water content, the wave velocity of soil increases with the increase of compactness, however when the water content is 40% and the compactness is ≥ 80%, the change of wave velocity tends to be stable;When the compactness is a certain value, and the water content is ≥35% or ≤25%, the wave velocity curves cross with each other, in this condition the water content and compactness can not be evaluated simply by the wave velocity.When the compactness(water content)remains unchanged, the water content(compactness)is negatively correlated with the change of resistivity, that is, the larger the water content or compactness is, the smaller the resistivity value is;When the water content is greater than 45%, the resistivity value basically tends to be stable, at this time, the resistivity can not effectively represent the water content and compactness.In view of the limitations of using a single test method to evaluate the moisture content and compactness of expansive soil, we suggest using wave velocity and resistivity comprehensively to analyze physical features of expansive soil, which can improve the identifying accuracy on water content and compactness of expansive soil.
作者
张智
周黎明
徐涛
付代光
ZHANG Zhi;ZHOU Liming;XU Tao;FU Daiguang(Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan 430010,China;Changjiang Geophysical Survey Co.,Ltd.,Wuhan 430010,China;Key Laboratory of Geomechanics and Engineering of MWR,Changjiang River Scientific Research Institute,Wuhan 430010,China)
出处
《人民长江》
北大核心
2022年第10期183-188,共6页
Yangtze River
基金
国家重点研发计划项目(2017YFC1501203)
湖北省重点研发计划项目(2020BCA083)。
关键词
膨胀土
含水率
密实度
声波波速
电阻率
expansive soil
water content
compactness
acoustic velocity
resistivity
