李广平, 常中华. 2011: 马河崩塌堆积体结构特征与稳定性评价. 工程地质学报, 19(4): 588-593.
    引用本文: 李广平, 常中华. 2011: 马河崩塌堆积体结构特征与稳定性评价. 工程地质学报, 19(4): 588-593.
    LI Guangping, CHANG Zhonghua. 2011: THE STRUCTURAL CHARACTERISTIC AND THE STABILITY ANALYSIS OF MAHE COLLAPSE BODY. JOURNAL OF ENGINEERING GEOLOGY, 19(4): 588-593.
    Citation: LI Guangping, CHANG Zhonghua. 2011: THE STRUCTURAL CHARACTERISTIC AND THE STABILITY ANALYSIS OF MAHE COLLAPSE BODY. JOURNAL OF ENGINEERING GEOLOGY, 19(4): 588-593.

    马河崩塌堆积体结构特征与稳定性评价

    THE STRUCTURAL CHARACTERISTIC AND THE STABILITY ANALYSIS OF MAHE COLLAPSE BODY

    • 摘要: 马河崩塌体堆积边坡坡度陡峭,起伏变化大,钻孔勘探难以准确查明边坡松散覆盖层厚度、边坡下伏基岩起伏情况及其风化发育程度。选用地震散射剖面的物探方法探明了马河崩塌堆积体结构特征,并采用多种极限平衡法(Bishop、Janbu、Morgenstern-Price)计算和对比基覆界面的安全系数,评价马河崩塌堆积体在三种不同工况下(自然工况、地震工况、降雨工况)的稳定性。得出结论为:马河崩塌堆积体的地质结构可分为三层:靠近地表为厚度为30~40m左右的松散覆盖层,未胶结; 中间为厚度10~15m的中-强风化层,节理裂隙发育; 40~50m以下为完整性较好的基岩,波速在2500m s-1以上。对地震和降雨2种不利工况进行了稳定性评价:在地震工况下,崩塌体可沿着覆盖层底界面或者风化层底界面发生失稳破坏; 在降雨工况下,崩塌体可沿着风化层底界面发生失稳破坏。

       

      Abstract: This paper mainly researches the structural characteristic and the stability analysis of Mahe collapse body.First of all,the range of slope and changing shape in landscape orientation restraint the application of drilling exploration.It is difficult to figure out the loose coverage thickness,fluctuating bedrock beneath and situation of developing weathered layer exactly.Hence,this paper adopts SSP(Seismic Scatter Profile)method to explore the structural characteristic of Mahe collapse body.Furthermore,this paper evaluates the stability of Mahe collapse body under three conditions(natural condition、earthquake condition and rainfall condition)by using various LEM(Bishop、Janbu、Morgenstern-Price)and then calculating and comparing the safety factors of discontinuity between bedrock and coverage.Finally,this paper concludes that the geological structure of Mahe collapse body is approximately sorted into three layers.The upper layer close to surface is loose coverage with a thickness about 30~40mm,not cementitious; The medium layer is a medium to strong weathered layer with a thickness about 10~15mm,weathered strongly,fractured intensively; The bottom layer is a relatively intact rock mass under 40~50m depth with a wave velocity above 2500m s-1; As to stability evaluation,there are two unstable conditions:the collapse body may occur failure along the bottom boundary of coverage or weathered layer under earthquake condition,while the collapse body may also occur failure along the bottom boundary of weathered layer under rainfall condition.

       

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