深基坑施工对临近既有车站结构变形的影响

Influence of deep foundation pit construction on deformation of adjacent subway station

为了研究基坑开挖过程对紧邻既有车站结构及周边环境的影响,依托福州北站南广场某深基坑工程,通过现场实测与数值建模的方法对紧邻既有车站及基坑的位移变形进行分析。结果表明:当开挖至坑底时,紧邻既有车站一侧的基坑围护结构变形比其他侧小50%~70%;基坑围护结构角点处距基坑中心较远且呈三角结构,对变形具有良好的削弱作用;当开挖至坑底时,应加强对围护结构中下部位的监测;距基坑围护75 m范围内,基坑对既有车站竖向变形影响最大,大于75 m范围则对水平方向变形影响突出。

In order to obtain the influence of foundation pit excavation to the adjacent existing station structure and surrounding environment,the displacement of the adjacent existing station and foundation pit was analyzed by field measurement and numerical calculation based on a deep foundation pit project in the south square of Fuzhoubei station.The results show that when the excavation reached the bottom of the pit,the deformation of the enclosure structure adjacent to the existing station is 50%-70%less than the other side.The corner of the enclosure structure of the foundation pit is far away from the center of the foundation pit and it is a triangle structure,which has a good resistance for the deformation.When the foundation pit is excavated to the bottom of the pit,the monitoring of the middle and lower parts of the enclosure structure shall be strengthened.In the range of 75 m from the foundation pit,the vertical deformation of the existing station is mostly affected by the foundation pit,and the horizontal deformation is affected more than 75 m.