【作者】 齐琼； 巨玉文； 董震；

【Author】 Qi Qiong;Ju Yuwen;Dong Zhen;Department of Architecture and Civil Engineering,Taiyuan University of Technology;

【机构】 太原理工大学建筑与土木工程学院；

【摘要】 通过对山西西部黄土地质灾害的调查研究和土样的直接剪切强度试验,从宏观降雨气象特征和细观土体强度劣化规律两个方面分析了该地区黄土地质灾害的诱发原因。分析结果表明,降雨是山西西部地区诱发黄土地质灾害的外因,土体抗剪强度随含水量的增大而降低是内因;该地区由降雨诱发的黄土地质灾害占灾害总数的75%以上,连续性强降雨、暴雨及冻融变化是诱发灾害的主要因素。强度试验结果表明,该地区灾害处的黄土抗剪强度随着含水量的增大显著降低,并存在两种规律性关系:其一是随着含水量的增大,土体的黏聚力与含水量呈现反比下降关系,内摩擦角呈增大趋势,前者的变化幅度大于后者;其二是在含水量达到塑限之前,土体的黏聚力随着含水量的增大显著下降,当含水量超过塑限后黏聚力基本不再变化,内摩擦角随含水量的增大变化不大。综合分析后建议当土体中含水量超过塑限时即可作为地质灾害的预警参考值。更多还原

【Abstract】 Through the investigation of Loess geological disasters in western of Shanxi and direct soil shear strength test,and according to analysis on both fronts of the macroscopic characteristics of rainfall and microscopic characteristics of soil strength degradation law,the causes of the loess geological disasters were summarized.The analysis results suggested that the external factor is rainfall to precipitation-induced loess geological disasters in western Shanxi,and the internal factor is that the shear strength of soil decrease with the increases of water content.Rain-induced geological disasters happened more than 75%of the total number of disasters in the area.Continuous heavy rains,rainstorm and freeze thawing are the major factors to induce disasters.The results of direct soil shear strength have shown that at the disaster area the shear strength of loess reduced with the water content increases significantly,and there are two regular relationships.The first is with the increases of water content the soil cohesion will downward as an inverse relationship and the internal friction angle tend to increase,but the former’s amplitude of variation is greater than the latter.The second is before the water contenting reached the plastic limit,the cohesion of the soil decreased significantly with water content increases,the moisture content would even out when it exceeds the plastic limit,and the internal friction angle increases little with the change of water content.After a comprehensive analysis,it suggests that the water content in the soil can be used as an early warning of geological disasters reference value when the water content exceed the plastic limit.更多还原