龙滩天湖特大桥桥址古滑坡堆积体安全评价  

Safety Assessment of Ancient Landslide Accumulation at the Site of Longtan Tianhu Bridge

作　　者：李世明 陈云生 张国发[2] 孙冠华[3] LI Shiming;CHEN Yunsheng;ZHANG Guofa;SUN Guanhua(Guangxi Communications Design Group Co.,Ltd.,Nanning 530029,China;Guizhou Tansportation Plannning Survey and Design Institute of Co.,Ltd.,Guiyang 550001,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,Cina)

机构地区：[1]广西交通设计集团有限公司,广西南宁530029 [2]贵州省交通规划勘察设计研究院股份有限公司,贵州贵阳550001 [3]中国科学院武汉岩土力学研究所岩土力学与岩土工程国家重点实验室,湖北武汉430071

出　　处：《安全与环境工程》2021年第6期118-126,共9页Safety and Environmental Engineering

摘　　要：龙滩天湖特大桥位于龙滩水库库区,特大桥跨越红水河。桥位区山体坡脚有基岩出露,不良地质条件主要为南丹岸存在大型古滑坡堆积体,该古滑坡堆积体主要由粉质黏土混碎石、碎石土和强风化砂岩组成,局部发育架空空洞。采用极限平衡法和三维严格极限平衡法,对古滑坡堆积体开展了三种工况下(自然边坡、自然边坡+暴雨和自然边坡+地震荷载)的稳定性分析与评价。结果表明:(1)在自然边坡和自然边坡+地震荷载工况条件下,边坡均处于稳定状态;(2)在自然边坡+暴雨工况条件下,尽管边坡处于稳定状态,但表层结构松散的覆盖层及强风化岩体可能会发生浅层滑塌,应注意防护。Longtan Tianhu Bridge is located in the reservoir area of Longtan Reservoir.The bridge crosses the Hongshui River.The bedrock is exposed at the foot of the mountain slope in the bridge site area,and the main unfavorable geological condition is the existence of a large ancient landslide accumulation on Nandan’an.The ancient landslide accumulation is mainly composed of silty clay mixed with gravel,gravel soil and strongly weathered sandstone,and some overhead cavities.This paper uses the limit equilibrium me-thod and three-dimensional rigorous limit equilibrium method to analyze and assess the stability of the ancient landslide accumulation.Three working conditions are considered which are natural slope,natural slope+rainstorm,and natural slope+seismic load.The results are as follows:(1)under the conditions of natural slope and natural slope+earthquake load,the slope is in stable state;(2)under the condition of natural slope+rainstorm,although the slope is in stable state,shallow collapse may occur in the loose overburden layer of surface structure and strongly weathered rock mass,and attention should be paid to protection.

关 键 词：古滑坡堆积体 稳定性分析 安全评价 龙滩天湖特大桥 

分 类 号：X4[环境科学与工程—灾害防治] P642.22[天文地球—工程地质学]