深基坑开挖对邻近既有建筑变形影响范围的研究

Study on the Scope of Influence of Deep Foundation Excavation on the Deformation of Adjacent Existing Buildings

目前特大城市的城市更新项目越来越多,在已有建筑物周边的深基坑工程越来越多。基坑开挖对周边建筑物的影响范围越来越值得重视,基坑开挖的影响范围确定在工程中非常重要,这样可以在工程初期设置监测观测及并根据监测结果采取相应的加强措施。基坑开挖的影响范围与土层信息、地形地势、房屋建筑基础及基坑的阻水情况有关。根据不同的工程案例数值模拟结果与实际监测结果进行对比。结果表明,基坑开挖影响范围在填土层或砂层,在0.8~1.3倍基坑深度范围内对天然基础的建筑物变形影响最大。其中若已有建筑物在周边设置阻水设施(无水补给)时,变形较正常情况(有水补给时)要增大3~5倍。

At present,there are more and more mega cities and more and more deep foundation pit projects around existing buildings.The influence range of foundation excavation on the surrounding buildings deserves more and more attention.It is very important to deter-mine the influence range of foundation excavation in the project,so that monitoring and observation can be set up at the early stage of the project and corresponding strengthening measures can be taken according to the monitoring results.The influence range of foundation excava-tion is related to the information of soil layer,topography,building foundation and water blockage of foundation pit.The numerical simula-tion results are compared with the actual monitoring results according to different engineering cases.The results show that the influence range of pit excavation is in the fill layer or sand layer,and the greatest influence on the building deformation of natural foundation is in the range of 0.8~1.3 times of pit depth.The deformation is 3~5 times larger than the normal situation(with water recharge)if the existing build-ing is installed with water blocking facilities(without water recharge)in the surrounding area.