吕梁山区马兰黄土抗剪强度参数的区域变化规律及其影响因素试验研究  

Regional Variation and Influencing Factors of Shear Strength Parameters of Malan Loess in Lüliang Area

作　　者：洪勃 唐亚明 冯卫 陈新建[3] 冯凡 周永恒 尹春旺 HONG Bo;TANG Yaming;FENG Wei;CHEN Xinjian;FENG Fan;ZHOU Yongheng;YIN Chunwang(Xi’an Center of China Geological Survey/Northwest China Center for Geoscience Innovation,Xi’an 710054,Shaanxi,China;Institute of Geological Survey,China University of Geosciences(Wuhan),Wuhan 430074,Hubei,China;School of Geological Engineering and Geomatics,Chang’an University,Xi’an 710054,Shaanxi,China)

机构地区：[1]中国地质调查局西安地质调查中心/西北地质科技创新中心,陕西西安710054 [2]中国地质大学(武汉)地质调查研究院,湖北武汉430074 [3]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《西北地质》2023年第2期272-282,共11页Northwestern Geology

基　　金：陕西省重点产业创新链(群)项目“基于大数据的地质灾害机理及风险评估关键技术研究与应用”(2019ZDLSF07-07-02);中国地质调查局地质调查项目“吕梁山区城镇地质灾害调查”(DD20160276);“晋陕黄土高原河曲-韩城段灾害地质调查”(DD20190642)联合资助。

摘　　要：为探索吕梁山区原状马兰黄土抗剪强度参数区域上的变化规律,以该地区29个区县94个取样点的马兰黄土为研究对象,通过直剪试验及其影响因素试验,分析区内马兰黄土抗剪强度参数的空间变化规律,及其抗剪强度参数c、φ与天然含水率、天然干密度、增湿含水率、含盐率等影响因素的变化规律。结果表明:在水平地域上,抗剪强度参数c、φ表现为东高西低、南高北低;在垂直空间上,表现为从表层向下黏聚力逐渐增大、内摩擦角逐渐降低的趋势;吕梁山东、西两侧原状马兰黄土抗剪强度参数c、φ受天然含水率、天然干密度的影响较小,离散程度较大;在天然状态条件下,随着含水率的增加,黏聚力c与增湿含水率具有良好的负指数函数关系,内摩擦角φ与增湿含水率呈负线性关系;在同一含水率条件下,含盐率与抗剪强度参数c、φ具有正相关关系;与含盐率相比,增湿含水率对c、φ的影响作用更为显著。该研究可为该地区马兰黄土地层的工程建设及防灾减灾工作提供基础和必备条件。Taking the undisturbed Malan loess from 94 sampling points in 29 counties in Lüliang Area as the research object,the undisturbed Malan loess was subjected to direct shear tests and undisturbed loess wetting water content and salt content shear tests to reveal the loess in the area.The regional distribution of loess shear strength parameters in the area is revealed,and the influencing factors of undisturbed Malan Loess shear strength parameters are analyzed.The results show that in the horizontal area,the shear strength parameters c andφof the undisturbed Malan loess in the Lüliang area are higher on the east side than on the west side;in the vertical space,the correlation between c andφand the sampling depth is low.The experiment of influencing factors also reveals that c,φhave discrete distribution with natural water content and natural dry density.Under the condi-tion of wetting water content,undisturbed Malan loess c has a good exponential function relationship with wet-ting water content,φhas a linear negative correlation with wetting water content,and salinity has a positive cor-relation with c andφ.The effect of salt content on increasing internal friction angle is more obvious than that of cohesion.Compared with salt content,moisture content has a more significant effect on c andφ.This research provides the foundation and necessary conditions for solving the geological disasters in the Loess Plateau of western Shanxi Province.

关 键 词：马兰黄土 黏聚力 内摩擦角 增湿含水率 含盐率 吕梁山区 

分 类 号：P642.3[天文地球—工程地质学] P642.4[天文地球—地质矿产勘探]