摘要
降雨作用下土坡基质吸力随时空而变化,直接影响土坡的瞬态稳定性分析。为研究降雨作用下土坡电导性能与基质吸力的时空变化与联系,通过人工降雨滑坡物理模型试验,将电阻率作为监测量与常规的含水率、基质吸力相结合,并在边坡模型上种植马尼拉草,研究植草边坡在均匀降雨、前小后峰和前峰后小这3种动态降雨模式下的入渗特征。研究结果表明:动态降雨模式下,降雨强度变化对土体电阻率和含水率均能产生影响,但都存在一定滞后性。降雨前边坡土体基质吸力、电阻率较高,随着深度的增加逐渐递减。降雨后表层土体基质吸力、电阻率出现较大跌幅,分布上呈现由浅层到深层逐渐增大态势。结合Keller改进的Archie拓展模型与VG模型,得到基于电阻率的残积土基质吸力计算模型,并用试验数据进行验证,结果较为合理,为非饱和残积土基质吸力的测量提供一种快速便捷的方法。研究成果有助于探究非饱和残积土边坡在不同降雨模式下的渗流特征,揭示了降雨作用下坡残积土的电导性能演化规律与基质吸力空间分布特征。
In order to study the temporal and spatial changes and relations between the conductivity of soil slope and matrix suction under the action of rainfall,a physical model test of artificial rainfall landslide was conducted,in which the resistivity was used as the monitoring quantity,combined with the conventional water content and matrix suction,and Manila grass was planted on the slope model to explore the infiltration characteristics of grass slope under three dynamic rainfall modes:uniform rainfall,front small back peak,and front peak back small.The results show that under the dynamic rainfall mode,the change of rainfall intensity can affect the resistivity and water content of soil,but there is a certain lag.Although the response time of soil matric suction is different under different rainfall patterns,the variation trend of soil matric suction is similar.Before rainfall,the matrix suction and resistivity of slope soil are higher,and gradually decrease with the increase of depth.After the rainfall,due to water infiltration,the matric suction and resistivity of surface soil decreased greatly,and the distributions on the slope have showed a trend of increasing gradually from shallow layer to deep layer.A prediction model of residual soil matric suction based on resistivity was obtained,combined with Keller’s improved Archie model and VG model,which was verified by experimental data,and the results were reasonable.This model adds a new way for indirect measurement of residual soil matric suction.The research results are helpful to explore the seepage characteristics of unsaturated residual soil slope under different rainfall modes,and reveal the evolution law of the electrical conductivity and spatial distribution characteristics of matric suction of residual soil slope under rainfall,which is of theoretical and practical significance for stability analysis,monitoring and early warning of residual soil slope under typhoon and rainstorm.
作者
林昀昭
简文彬
陈瑞敏
康浩隆
章德生
LIN Yunzhao;JIAN Wenbin;CHEN Ruimin;KANG Haolong;ZHANG Desheng(Institute of Geotechnical and Geological Engineering,Fuzhou University,Fuzhou 350108,China;Fujian Key Laboratory of Geohazard Prevention,Fuzhou University,Fuzhou 350108,China)
出处
《自然灾害学报》
CSCD
北大核心
2024年第1期139-150,共12页
Journal of Natural Disasters
基金
国家自然科学基金项目(U2005205,41861134011)。
关键词
滑坡
降雨
残积土
电阻率
基质吸力
入渗
landslide
rainfall
residual soil
resistivity
matrix suction
infiltration
