摘要
以单侧反包式加筋土路堤为研究对象,基于塑性极限分析上限法并引入土体剪切强度折减系数,考虑拉筋拉断和拔出2种破坏模式,给出了路堤边坡稳定性分析方法,并推导了相关计算公式。在此基础上给出了基于路堤稳定性加筋土等效为纯土体时的准黏聚力计算方法,并采用工程实例分析拉筋极限拉力、拉筋竖向间距、填土内摩擦角、拉筋长度、路堤高度及顶面荷载对准黏聚力的影响。结果表明:拉筋极限拉力、拉筋长度、拉筋间距、填土内摩擦角对准黏聚力的影响相对较大;传统方法与本文方法得到的准黏聚力计算值之比往往大于2;传统方法确定的准黏聚力值易过高估计路堤边坡的稳定性,一般不宜用于路堤边坡稳定性分析。
Taking the geosynthetics-reinforced embankment with a wrap-around facing as the research object,based on the upper bound method of plastic limit analysis and the soil shear strength reduction coefficient,two failure modes of tension and pull-out were considered,the stability analysis method of embankment slope was given,and the relevant calculation formula was derived.On this basis,the calculation method of quasi-cohesion based on embankment stability was given when reinforced soil is equivalent to pure soil.The influence of ultimate tension of rebar,vertical spacing of rebar,internal friction angle of fill,length of rebar,height of embankment and top load on quasi-cohesion were analyzed by engineering examples.The results show that the ultimate tensile force,the length and the spacing of the rebar and the friction angle of the soil have great influence on the quasi-cohesion,and the ratio of the calculated value of the traditional method to that of the present method is usually greater than 2.The quasi-cohesion value determined by the traditional method is easy to overestimate the stability of the embankment slope,it is generally not suitable for the stability analysis of the embankment slope.
作者
肖世国
闫清卫
刘航
XIAO Shiguo;YAN Qingwei;LIU Hang(Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 610031,China;MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道建筑》
北大核心
2020年第10期78-82,共5页
Railway Engineering
基金
国家自然科学基金(51578466)
中铁二院工程集团有限责任公司科研项目(KYY2018110(18-20))。
关键词
铁路路基
准黏聚力
极限分析
加筋土路堤
边坡稳定性
railway subgrade
quasi-cohesion
limit analysis
geosynthetics-reinforced embankment
slope stability
