双洞隧道地铁运行引起的软土地基振动及孔压研究  

Study on Vibration of Soft Soil Foundation and Pore Pressure Induced by Subway Operation in Twin Tunnels

作　　者：丁峰 程扬 钱春宇 宋春雨[1] 陈龙珠[1] DING Feng;CHENG Yang;QIAN Chunyu;SONG Chunyu;CHEN Longzhu(School of Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;School of Human Settlements and Civil Engineering,Xi’an Jiaotong University,Xi’an 710049,China;China Jikan Research Institute of Engineering Investigations and Design,Co Ltd,Xi’an 710043,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]西安交通大学人居环境与建筑工程学院,陕西西安710049 [3]机械工业勘察设计研究院有限公司,陕西西安710043

出　　处：《土木工程与管理学报》2024年第5期71-77,共7页Journal of Civil Engineering and Management

基　　金：国家自然科学基金(51678361)。

摘　　要：建立双洞隧道的三维有限差分模型,通过车轨耦合计算得到地铁运行中隔振器的力时程,以集中力的形式施加到地铁轨道对应的节点上,分析探讨了软土地基中振动加速度和超静孔隙水压力的变化规律及影响范围等。结果表明:左侧隧道和右侧隧道振动及孔隙水压力的变化基本一致,在地铁的一次相向运行过程中,软土地基的地表竖向振动加速度在两隧道中心处出现最大值,在距隧道中心轴约25 m处存在地表振动加速度放大现象,在距隧道中心轴150 m外,地表加速度峰峰值衰减至2 gal以下。软土地基中的超静孔隙水压力随着远离隧道而快速减小,在距隧道中心轴80 m外,超静孔隙水压力便衰减至100 Pa以下。白天地铁运行过程中,超静孔隙水压力出现较平稳的振荡,晚间地铁停运后,超静孔隙水压力出现一定程度下降,且随着地铁的反复运行下降幅度减小。A three-dimensional finite difference model was established for soft foundation involving a twin tunnels system.By coupling the vehicle-track system,the time-history forces of the isolators during subway running were calculated and applied to corresponding nodes along the subway tracks in FDM in form of concentrated excitations.The variation law and influence range of vibration acceleration and excess pore water pressure in soft soil foundation were investigated and discussed.The results show that the distributions of vibration and pore pressure on both the left and right sides of the tunnels are generally consistent.During the simultaneous bidirectional subway running,the maximum vertical vibration acceleration on the ground surface occurs near the symmetrical line of the projections of two tunnels.There is a phenomenon of amplification of vibration acceleration of ground surface at a distance of about 25 m from the center axis of the tunnel,while the peak-to-peak values of ground acceleration attenuates to below 2 gal at a distance of 150 m from the center axis of the tunnel.Excess pore pressure in the soft soil foundation rapidly decreases with distance from the tunnel.At a distance of 80 m from the center axis of the tunnel,the excess pore water pressure decays to below 100 Pa.During the operations of subway from morning through midnight,excess pore pressure exhibits relatively stable oscillations.However,after the subway stops running during late night,there is a certain degree of decline in excess pore pressure,and the rate of decline decreases with repeated subway operations.

关 键 词：双洞隧道 软土地基 数值模拟 振动响应 超静孔隙水压力 

分 类 号：U231[交通运输工程—道路与铁道工程] U451[建筑科学—桥梁与隧道工程]