软土地区深大基坑开挖变形控制关键技术

Key Technology for Deformation Control of Deep and Large Foundation Excavation in Soft Soil Area

杭州环城北路—天目山路提升改造工程01标某明挖基坑地处城市交通要道,基坑两侧建(构)筑物繁多,且基坑开挖跨度大、距离长,使得基坑开挖对周围建(构)筑物影响风险增大。采用分区开挖法,即平面方向分段、纵向放坡,将基坑分为若干小段的方法进行基坑开挖。现场监测数据结果表明,地下连续墙水平位移、地表沉降、邻近建(构)筑物变形均小于对应变形控制指标,表明在软土地区进行深大基坑开挖,分区开挖是控制变形的有效方法。

Hangzhou Huancheng North Road-Tianmushan Road Upgrading and Reconstruction project 01 bid section open excavation foundation excavation is located in the urban traffic artery.There are many buildings on both sides of the foundation excavation,and the excavation span is large and the distance is long,which makes the foundation excavation risky to the surrounding structures.In order to effectively reduce the impact of foundation excavation construction period on surrounding buildings,the partition excavation method is adopted,that is,the plan direction is segmented and the longitudinal slope is adopted to divide the foundation excavation into several small sections.The results of field monitoring data show that the horizontal displacement,surface settlement and deformation of adjacent buildings of diaphragm walls are less than the corresponding deformation control indexes,which indicates that the partition excavation is an effective method to control the deformation of deep and large foundation excavation in soft soil area.