建筑物下方地铁车站中洞法施工的力学效应  

Mechanical Effect of Construction by Center Drift Method for Subway Station under Building

作　　者：汪成兵[1] 邵普 周宁[1] WANG Chengbing;SHAO Pu;ZHOU Ning(Research Institute of Highway of Ministry of Transport,Beijing 100088,China)

机构地区：[1]交通运输部公路科学研究院,北京100088

出　　处：《中国铁道科学》2018年第4期14-21,共8页China Railway Science

基　　金：国家自然科学基金资助项目(51278233)

摘　　要：以北京某地铁车站为工程背景,采用1∶20大比例模型试验与数值模拟的方法,对地面3层框架结构建筑物下方地铁车站中洞法施工的力学效应进行研究,模型试验结果与数值模拟结果吻合较好。结果表明:地表及建筑物顶部沉降、地表水平位移在中洞开挖支护期间最大,侧洞开挖支护期间次之,而中洞二衬期间最小;施工完成后,车站拱底水平应力、垂直应力、侧壁附近水平应力减小,侧壁附近垂直应力增加;建筑物立柱下部垂直应力变化值较上部大,外侧横梁水平变化值比中间横梁大;中洞开挖支护完成时围岩塑性区主要分布在建筑物基础附近的围岩及侧洞未开挖土体,随着施工的进行建筑物基础下方围岩塑性区向车站方向进一步发展,车站施工完成后围岩塑性区发展到车站边界。Taking a subway station in Beijing as the engineering background,the mechanical effects of construction by center drift method for subway station under a three-storey frame structure building above ground were studied through 1∶20 large scale model test and numerical simulation.The results of model test agreed well with the results of numerical simulation.Results show that the settlement of ground surface and at the top of building as well as the horizontal displacement of ground surface are the largest during the excavation and support of the middle hole,followed by those during the excavation and support of the side hole,while those are the smallest during the secondary lining construction of the middle hole.After the completion of construction,the horizontal and vertical stresses at the arch bottom of station decrease.The horizontal stress near the side wall also decreases,but the vertical stress near the side wall increases.The vertical stress at the lower part of building column changes more obviously than that at the upper part of building column.The horizontal change value of the lateral beam is larger than that of the intermediate beam.The plastic zone of the surrounding rock is mainly distributed in the surrounding rock near the building foundation and the unexcavated soil of the side hole after the excavation and support of the middle hole.As the construction goes on,the plastic zone of the surrounding rock under the building foundation develops further towards the station.After the completion of station construction,the plastic zone of the surrounding rock develops to the station boundary.

关 键 词：地铁车站 地面建筑物 中洞法 施工力学效应 模型试验 

分 类 号：U231.4[交通运输工程—道路与铁道工程]