考虑卸荷带和岩体软化特性的某桥址边坡稳定性研究  

Slope Stability Analysis of a Bridge Site Considering Unloading Zone and Rock Softening Characteristics

作　　者：杜杰贵 严松 李继兴 夏艺峰 DU Jiegui;YAN Song;LI Jixing;XIA Yifeng(Zhaotong Yizhao Expressway Project Headquarters,Zhaotong,Yunnan 657000,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Zhaotong Yizhao Expressway Investment and Development Limited Company,Zhaotong,Yunnan 657000,China)

机构地区：[1]昭通市宜昭高速公路项目指挥部,云南昭通657000 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [3]中国科学院大学,北京100049 [4]昭通市宜昭高速公路投资开发有限公司,云南昭通657000

出　　处：《水利与建筑工程学报》2021年第2期12-18,共7页Journal of Water Resources and Architectural Engineering

基　　金：云交科教[2020]74号“基于原位测试关键技术的山区高速公路高边坡风险评价体系与防治措施研究”。

摘　　要：为了综合分析卸荷带以及凝灰岩泥化夹层对某桥址边坡稳定性的影响,通过不同岩体强度加权计算得到凝灰岩及其泥化带综合强度,结合现场勘察结果,对凝灰岩及其泥化夹层的分布取上限值、平均值和下限值并确定了卸荷带岩体强度参数。在对岩质边坡破坏模式分析的基础上计算了自然工况、地震工况、桥基荷载作用工况、桥基荷载和地震荷载共同作用工况四种不同条件下桥基所在典型边坡的稳定性状况。结果表明:自然工况和地震工况下,桥址边坡最危险滑面的剪入位置为前缘卸荷带,桥基荷载作用下边坡滑面剪入口移至中缘桥基所在位置;桥基荷载作用工况相较于自然状况,桥基处坡体稳定性降幅最大达到23%,最小安全系数为1.526,大于工程边坡稳定性规定的1.350,综合判断该桥址边坡稳定。In order to comprehensively analyze the influences of unloading zone and tuff argillaceous intercalation on slope stability of a bridge site,the comprehensive strength of tuff and its argillaceous zone is obtained by weighted calculation of different rock mass strength.The upper limit value,average value and lower limit value are taken for the distribution of rock mass in unloading zone.Based on the analysis of failure mode of rock slope,the stability of typical slope of bridge foundation under natural condition,earthquake condition,bridge foundation load action condition,bridge foundation load and earthquake load combined action condition are calculated.The results show that under natural and seismic conditions,the most dangerous sliding surface of bridge site slope is at the front unloading zone,and the shear entrance of slope sliding surface moves to the position of middle edge bridge foundation under bridge foundation load;compared with natural condition,the maximum decrease of slope stability at bridge foundation is 23%and the minimum safety factor is 1.526,which is greater than 1.35 specified in engineering slope stability,the slope stability of the bridge site is judged comprehensively.

关 键 词：边坡稳定性 极限平衡法 卸荷带 岩体软化 安全系数 

分 类 号：U442.2[建筑科学—桥梁与隧道工程]