摘要
本工程位于杭州市拱墅区地铁2号线边,场地内分布有1层老地下室,需拆除原有地下室改建为2层地库,基坑开挖范围内以淤泥质粉质黏土为主,基坑位于中心城区,邻近主要市政道路,且西侧道路下为运营地铁,周边环境非常复杂,拆复建期间要确保周边环境特别是运营地铁安全,基坑变形控制和环境保护是本工程需考虑的重点。本工程邻近地铁一侧基坑采用800厚地下连续墙结合1道钢筋混凝土支撑和2道带轴力补偿系统钢支撑,其余范围采用咬合桩结合2道钢筋混凝土内支撑,远离地铁A区大坑设置钢筋混凝土栈桥,邻地铁侧B区坑内采用高压旋喷桩抽条加固。实际施工过程中发生了地铁隧道变形超控制值、南侧污水干管渗漏、地墙和桩基施工遇地下障碍清障难等事故,可为类似软土地基基坑设计、施工、基坑变形控制、地铁保护监测、采用有限元风险软件预测地铁变形和地铁设施的保护与修复提供参考。
This project is located near Metro Line 2 in Gongshu District,Hangzhou City.There is an old basement distributed in the site,and the original basement needs to be demolished and rebuilt into a two-story basement.The soil in excavation range of the foundation pit is dominated by silt and silty clay.During the demolition and reconstruction,the surrounding environment should be ensured,especially the safety of subway operation.Hence the deformation control of foundation pit and environmental protection are the key points to be considered in this project.The foundation pit close to the subway side supported by 800-thick underground continuous wall combined with 1 reinforced concrete support and 2 steel support with axial force compensation system,the rest of the pit was supported by the piles combined with two reinforced concrete internal bracing.Reinforced concrete trestle bridge was used in A division,which is far from the subway.High pressure rotary jet pile pumping reinforcement was used in B division.During the actual construction process,accidents such as subway tunnel deformation exceeding the control value,leakage of the southern sewage main pipe,difficulty in clearing underground obstacles during the construction of ground walls and pile foundations happened.This can provide reference for the design,construction,deformation control of foundation pits on soft soil foundations,subway protection monitoring,prediction of subway deformation using finite element risk software,and protection and repairment of subway facilities.
作者
陈俊辉
许磊
岑仰润
CHEN Jun-hui;XU Lei;CEN Yang-run(Hangzhou Geotechnical Engineering and Surveying Research Institute with Limited Liability,Hangzhou 310012,Zhejiang,China)
出处
《地基处理》
2023年第S01期20-33,共14页
Journal of Ground Improvement
关键词
软土
清障
旁侧基坑
变形超控
隧道监测
地铁隧道
有限元分析
soft soil
clearing the barrier
adjacent excavation
deformation super control
tunnel monitoring
subway tunnel
finite element analysis
作者简介
陈俊辉(1983—),男,江西南昌人,本科,高级工程师,主要从事地铁安全评估及岩土设计工作。E-mail:470671261@qq.com。
