为研究近接地铁隧道高层建筑施工对既有隧道稳定性的影响,以重庆市某近接地铁隧道高层建筑为例,利用大型有限元计算软件Midas-GTS建立三维有限元计算模型并开展数值模拟.数值模拟中采用的施工工序与实际工程一致,着重分析高层建筑施工各个阶段围岩变形,衬砌位移、内力的变化规律.研究结果表明:建筑物修建对左线隧道影响显著大于右线隧道;隧道衬砌最大变形出现在基坑开挖阶段,最大水平、竖向位移分别为1.45、3.64 mm;由于建筑物与隧道斜交,左、右线隧道最大位移出现断面有所不同,但均出现在距模型正面40 ～60 m范围内;衬砌内力随建筑物施工呈先减小后增大的趋势,基坑开挖阶段左隧道衬砌内力较隧道开挖完成时降低了15.5％.研究结果可为类似工程提供一定的依据和指导.%In order to study the influence to stability of existing tunnel by subway tunnel adjacent high building construction,this paper takes certain subway tunnel adjacent high building in Chongqing as instance,sets up a 3D finite element model by using the finite element calculation software Midas-GTS and carries out numerical simulation.The construction process in numeric simulation is the same with that of the project practice.The variation law of surrounding rock deformation,lining displacement and internal force in all stages of high building construction is analyzed emphatically.Results show:The influence of building construction on left tunnel is significantly greater than that of right tunnel;The maximum deformation of tunnel lining occurs in excavation stage of foundation pit,the maximum horizontal and vertical displacement are 1.45 and 3.64 mm respectively;Due to the skewing of the building and the tunnel,the maximum displacement of the left and right line tunnels is different,but all appear in the range of 40 ～ 60 m from the front of the model;The internal force of the lining decreases first and then increases with the construction of the building.The internal force of the left tunnel lining is reduced by 15.5％ when the tunnel excavation is completed.The results of study may provide certain reference and instruction to future similar projects.
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