深基坑水平封底在富水深厚砂层的加固效果  

Reinforcement Effect of Horizontal Bottom Sealing of Deep Foundation Pit in Water-rich and Deep Sand Layer

作　　者：尚桌 葛忻声[1] 王菁悦 张念 SHANG Zhuo;GE Xinsheng;WANG Jingyue;ZHANG Nian(College of Civie Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学土木工程学院,太原030024

出　　处：《太原理工大学学报》2022年第4期786-792,共7页Journal of Taiyuan University of Technology

基　　金：山西省回国留学人员科研资助项目(2020038)。

摘　　要：对于位处富水深厚砂层中的深基坑,在开挖过程中可能出现涌水涌砂等施工安全问题。采用基底封底配合降水减压是保证基坑安全开挖的常用措施。以太原某地铁车站区间明挖法施工工程为背景,采用有限元软件进行基坑开挖过程的流固耦合分析和对比,并结合现场监测数据,研究了不同封底形式和降水对基坑的变形影响。结果表明:封底加固能有效减小地连墙最大侧位移、地表最大沉降和基底最大隆起,相比未加固,变形量减少约50%;同一加固厚度,从基底开始加固效果更好;封底加固区与地连墙组成的新支护体系配合井点降水能很好地控制地下水渗流和基坑变形。For deep foundation pit with rich water and deep sand layer,construction safety problems such as water and sand gushing may occur during excavation.Base sealing with well point dewatering is a common measure to ensure the safety of foundation pit excavation.This paper is based on an open-cut construction project of a metro station in Taiyuan.The fluid-structure coupling analysis and comparison of foundation pit excavation process were carried out by using finite element software.Combined with the field inspection data,the influence of different bottom sealing forms and dewatering on the deformation of foundation pit was studied.The results show that the bottom sealing reinforcement can effectively reduce the maximum lateral displacement of diaphragm wall,the maximum surface settlement,and the maximum uplift of basement.The amount of deformation is reduced by about 50%compared with that without reinforcement.With the same reinforcement thickness,the reinforcement effect is better starting from the basement.The new support system composed of bottom sealing reinforcement zone and diaphragm wall can control the seepage of groundwater and the deformation of foundation pit well with the well point dewatering.

关 键 词：深基坑 水平封底 砂性土层 注浆加固 基坑降水 

分 类 号：TU472[建筑科学—结构工程]