黄土边坡失稳的降雨入渗预警阈值  

Rainfall infiltration threshold for loess slope instability

作　　者：马强 李郑淼 解家毕[1] 乔楠 张启义[1] 张顺福[1] 刘昌军[1] 郑慧洋[2] MA Qiang;LI Zhengmiao;XIE Jiabi;QIAO Nan;ZHANG Qiyi;ZHANG Shunfu;LIU Changjun;ZHENG Huiyang(China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Beifang Investigation,Design&Research Co.,Ltd,Tianjin 300222,China)

机构地区：[1]中国水利水电科学研究院,北京100038 [2]中水北方勘测设计研究有限责任公司,天津300222

出　　处：《南水北调与水利科技（中英文）》2022年第1期152-159,共8页South-to-North Water Transfers and Water Science & Technology

基　　金：国家重点研发计划项目(2017YFC1501202)。

摘　　要：选取陕西省延安市宝塔山地区作为主要研究对象,结合实测数据,利用非饱和土力学有限元计算方法对宝塔山西部边坡进行数值模拟,初步得出宝塔山西部滑体可以诱发坡体滑坡的降雨入渗阈值为24 h累计雨量100 mm。本研究为开展饱和-非饱和黄土边坡在降雨入渗影响下的稳定性分析提供一定的参考。With the growth of the infiltrated water amount,the loess matrix suction will decrease,and lead to the reduction of slope shearing strength that lets the slope under an unstable condition and prone to occur landslides or other geotechnical disasters.The variation of the seepage field as one of the important influence factors of slope stability has been widely agreed with the majority of geotechnical scholars.However,most of the simulation analyses were limited to experimental or hypothetical simulation due to the lack of real monitoring data.According to the measurement of loess property in both southern and western slopes,the Geo-Studio software was selected to study and analyze the impact of rainfall seepage on loess slope stability in Baota Mountain.Based on four kinds of geotechnical data("slow shear","triaxial","effective",and"total stress"),the stability of the western slope of Baota Mountain was analyzed and simulated under different rainfall scenarios.By comprehensively comparing the results simulated by four kinds of loess parameters,the influence of rainfall infiltration on slope stability was relatively lower with"total stress"and"slow shear"parameters.When the rainfall over 100 mm in 24 h,the slope stability decreased abruptly under the condition of"triaxial"and"effective".The"triaxial"test can strictly control the drainage conditions and can obtain the effective shear strength indexes of the soil through the pore water pressure.The base of Baota Mountain is generally stable,and the possibility of having large landslides is relatively lower.However,the potential risk of slope collapse disaster still existed on the Baota Mountain.Under extreme climatic conditions,where the accumulated rainfall exceeded 100 mm in 24 h,the surface loess on the slope will be supersaturated,and then prone to have small/medium-scaled collapse.It is recommended to take relevant measures to manage the risk slope of Baota Mountain from the perspective of how to prevent slope erosion and reduce rainfall infiltration on the slop

关 键 词：延安宝塔山 边坡稳定 Geo-Studio 降雨入渗 模拟分析 

分 类 号：TV143[水利工程—水力学及河流动力学] P642[天文地球—工程地质学]