为探究超宽坑中坑降水与开挖过程中基坑变形和地下水的变化特征，采用实测分析方法对围护结构侧移、地表沉降、周边建筑物沉降及地下水与潮汐水之间的关系进行分析。同时，利用ABAQUS有限元软件建立考虑潮汐补水的三维流固耦合模型，研究基坑降水和开挖过程中地下连续墙的侧移规律，并验证分段降水控制和换撑措施对墙体变形的控制效果。主要结论如下： 1)基坑开挖过程中，围护结构最大侧移为29.5 mm，南北墙顶均向坑外侧移，地表沉降最大为29.4 mm，立柱、周边建筑物竖向位移量均小于6.5 mm； 2)潮汐补水和降雨导致南北两侧坑外水位降落分别约-1.0 m和-1.5 m； 3）在坑中坑降水和开挖深坑阶段，采用分段降水控制和钢支撑换撑使墙体最大侧移减小约29%和21%。
Herein, to investigate the characteristics of
dewatering, excavationinduced deformation, and groundwater
variation in an ultrawide pitinpit in the Binhai avenue renovation project in Shenzhen, China,
deflection of retaining structures, settlement of surfaces and surrounding
structures, and correlation between groundwater and tidal water are analyzed
using a field monitoring method. Moreover, a threedimensional
fluidsolid coupling model is established considering
tidal water replenishment using the ABAQUS finite element software to explore
the development characteristics of underground diaphragm wall deflections
during dewatering and excavation processes. The model validates the control
effect of the staged dewatering control method and steel bracing change scheme
on wall deformation. The following conclusions are drawn: (1) During the
excavation process, the maximum wall deflection is 29.5 mm and the north and
south wall tops move outward. Further, the maximum surface settlement is 29.4
mm, and the vertical displacements of columns and surrounding structures are
<6.5 mm. (2) Tidal water replenishment and rainfall lead to a water level
drop of approximately 〖WTBZ〗-〖WT５《TNR》〗1.0 m in
the north and 〖WTBZ〗-〖WT５《TNR》〗1.5 m in
the south outside of the pit. (3) During the dewatering and excavation phases,
the staged dewatering control method and steel bracing change scheme reduce the
maximum wall deflection by ~29% and 21%, respectively.
