地铁车站深基坑开挖影响分析

Influence Analysis of Deep Foundation Pit Excavation of Subway Station

国内外基坑坍塌事故时有发生,其中不乏在开挖中的地铁车站深基坑。根据合肥市某地铁车站深基坑项目,利用MIDAS/GTS软件建立3D模型,研究地铁车站深基坑在开挖过程中对围护结构变形、地表沉降以及基坑底部隆起的影响规律。结果表明:地铁车站深基坑在开挖会对围护结构变形、地表沉降以及基坑底部隆起产生一定的影响,随着基坑开挖越深,影响越大,这种影响在一定的范围内。在基坑中部位置即深度约为12m处,围护结构水平位移达到最大值;周围地表沉降最大值出现在距离基坑Y方向边缘距离约为10m的位置;基坑底部隆起最大值出现在距离基坑中部距离约2m的位置。

Foundation pit collapse accidents occur frequently at home and abroad,including the deep foundation pit of subway station under excavation.According to the deep foundation pit project of a subway station in Hefei,a 3D model is established by using MIDAS/GTS software to study the influence of deep foundation pit excavation on the deformation of retaining structure,ground settlement and uplift of foundation pit bottom.The results show that:the excavation of deep foundation pit of subway station will have a certain impact on the deformation of retaining structure,ground settlement and the uplift of foundation pit bottom.The deeper the foundation pit is excavated,the greater the impact,and the impact is within a certain range.In the middle of the foundation pit,that is,the depth is about 12 m;the horizontal displacement of the retaining structure reaches the maximum;the maximum settlement of the surrounding ground surface appears at the position about 10 m away from the y-direction edge of the foundation pit;the maximum uplift of the bottom of the foundation pit appears at the position about 2 m away from the middle of the foundation pit.