进洞高程对黄土隧道洞口衬砌和仰坡动力响应的影响  

Influence of portal elevation on lining and slope dynamic response of loess tunnel portal section

作　　者：孙纬宇 严松宏[1,3] 汪精河 欧尔峰 梁庆国[1,2] SUN Weiyu;YAN Songhong;WANG Jinghe;OU Erfeng;LIANG Qingguo(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Road&Bridge and Underground Engineering of Gansu Province,Lanzhou Jiaotong University,Lanzhou 730070,China;Engineering Laboratory of Mechanics Application of Railway Transportation of Gansu Province,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]兰州交通大学甘肃省道路桥梁与地下工程重点实验室,甘肃兰州730070 [3]甘肃省轨道交通力学应用工程实验室,甘肃兰州730070

出　　处：《世界地震工程》2019年第2期24-30,共7页World Earthquake Engineering

基　　金：国家自然科学基金项目(编号41562013,51268030);兰州交通大学青年科学基金项目(2017020)

摘　　要：针对黄土边坡与隧道洞口段衬砌的相互作用问题,运用数值模拟的方法分析了以不同进洞高程进洞时黄土隧道洞口段衬砌的动力响应特征和洞口仰坡的动力稳定性。结果表明:进洞高程越大,洞口段隧道衬砌的位移响应与内力响应越大;随着进洞高程的增大,坡面位移放大系数在减小,不同进洞高程进洞时坡面位移放大系数均呈先增大后减小再增大的变化趋势。在0.2~0.6H时变化最为剧烈,0.4H左右时位移放大系数达到了最大值;不同进洞高程进洞时坡面中心和水平方向距离隧道结构1.5D处的坡面位移放大系数变化趋势基本一致,其大小关系为:纯边坡位移放大系数<有隧道结构中面位移放大系数<距隧道1.5D位移放大系数;随着进洞高程的增大,剪应变增量和坡面位移均在减小,坡面的稳定性在增强。该研究可为黄土地区隧道进洞高程的选择提供一定的参考。In view of the interaction between loess slope and tunnel portal lining,the dynamic response characteristics of loess tunnel portal and the dynamic stability of entrance slope at different tunneling altitude on slopes are analyzed by numerical simulation method.The results show that:the higher of the tunneling altitude on slope,the greater of displacement response and internal force response of the tunnel structure;the magnification coefficient of the slope displacement gradually decreases with the increase of the tunneling altitude on slope;the amplification coefficient of the slope displacement are increases first,then decreases,finally increases again at different tunneling altitude on slopes,and the change is most serious at 0.2H^0.6H and reaches the maximum value about 0.4H;there are the same variation trend of the amplification coefficient at the center of the slope and at the distance of 1.5D from the tunnel in the horizontal direction.For the amplification coefficient,it shows that the slope without tunnel is the smallest,the center of the slope is the medium,and distance from the tunnel of 1.5D in the horizontal direction is the largest.The shear strain increment and slope displacement decrease with the increase of tunneling altitude on slope,meanwhile the slope stability is strengthening.The research results can provide some references to the selection of tunneling altitude on slope in loess area.

关 键 词：进洞高程 黄土隧道 动力响应 洞口仰坡 坡面稳定性 

分 类 号：U452[建筑科学—桥梁与隧道工程]