软土地层地铁车站超深地下连续墙槽壁稳定性分析  

Analysis of Metro Station Ultra-deep Diaphragm Wall Trench Wall Stability in Soft Soil Stratum

作　　者：叶如 王毅 曹昱 雷宇 相龙胜 周俊宏 YE Ru;WANG Yi;CAO Yu;LEI Yu;XIANG Longsheng;ZHOU Junhong(Construction Branch of Ningbo Rail Transit Group Co.,Ltd.,315101,Ningbo,China;Zhejiang Huazhan Research and Design Institute Co.,Ltd.,315012,Ningbo,China;CCCC Tunnel Engineering Co.,Ltd.,100102,Beijing,China;Ningbo Regional Railway Investment and Development Co.,Ltd.,315101,Ningbo,China)

机构地区：[1]宁波轨道交通集团有限公司建设分公司,宁波315101 [2]浙江华展研究设计院股份有限公司,宁波315012 [3]中交隧道工程局有限公司,北京100102 [4]宁波市市域铁路投资发展有限公司,宁波315101

出　　处：《城市轨道交通研究》2025年第3期118-122,共5页Urban Mass Transit

摘　　要：[目的]复杂地质和超深开挖条件下,地下连续墙成槽施工过程中槽壁的稳定性是目前工程界研究的难点和重点。为掌握宁波地铁7号线宁慈路站东侧WE-15幅76 m超深地下连续墙槽段施工时槽壁塌孔原因,需对该工程进行针对性分析并提出解决方案。[方法]利用PLAXIS 3D有限元软件模拟地下连续墙成槽施工过程,研究软土地层中地下连续墙施工过程中的槽壁稳定性特征及其主要影响因素,与现场超声波检测结果相结合验证模型的准确性。[结果及结论]槽壁水平位移的发展主要集中在成槽前期,即开挖至(4)2b粉质黏土层阶段,其原因是宁波地区第(4)层土层含粉砂性比较重,成槽抓斗反复抓土过程中会扰动泥浆,对槽壁形成卸力和冲击,在泥浆护壁上形成吸附孔隙,外围地下水极易涌入槽内,并带动局部粉砂涌入槽内,容易引发局部塌孔;成槽结束时槽壁水平位移最大值为18.18 mm,位于地面以下25 m处,与实际塌孔位置接近;泥浆重度和加固措施对槽壁稳定性具有显著影响,通过提高泥浆重度和对槽壁进行加固均能有效控制槽壁水平位移。[Objective]Under complex geological and ultra-deep excavation conditions,maintaining trench wall stability during diaphragm wall construction remains a critical challenge in engineering research.To identify the causes of trench wall collapse during the construction of the 76 m ultra-deep diaphragm wall trench section(WE-15)on the east side of Ningci Road Station of Ningbo Metro Line 7,it is necessary to carry out targeted analysis and propose corresponding solutions.[Method]The PLAXIS 3D finite element software is used to simulate the diaphragm wall trenching process,investigating the stability characteristics of trench walls in soft soil stratum and their key influencing factors.The accuracy of the model is validated by comparing the simulation results with on-site ultrasonic detection data.[Result&Conclusion]The horizontal displacement of the trench wall primarily occurs in the early stage of trenching,specifically when excavating the④2b silty clay layer.The reason is that the fourth soil layer in Ningbo region contains a high silt content,and repeated excavation with a trenching grab disturbs the slurry,leading to uploading and impact effects on the trench wall.This process creates adsorption pores in the slurry wall,allowing groundwater to easily flow into the trench and carry local silt deposits,thereby increasing the risk of localized collapse.At the end of trenching,the maximum horizontal displacement of the trench wall is 18.18 mm,occurring at a depth of 25 m below ground level,closely aligning with the actual collapse location.The stability of the trench wall is significantly influenced by slurry density and reinforcement measures,and both increasing slurry density and reinforcing the trench wall effectively control horizontal displacement.

关 键 词：地铁车站 地下连续墙 槽壁塌孔 槽壁水平位移 槽壁加固 

分 类 号：U231.3[交通运输工程—道路与铁道工程]