软土和砂土复合地层超深地连墙槽壁稳定性研究  

Research on slot wall stability of ultra⁃deep diaphragm wall in soft soil and sandy composite strata

作　　者：石文广 卢春雨 石波 王山平 张涛 SHI Wenguang;LU Chunyu;SHI Bo;WANG Shanping;ZHANG Tao(Guangdong Yuehai Yuedong Water Supply Co.,Ltd.,Jieyang 522000,Guangdong,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,Hubei,China;Sinohydro Bureau 7 Co.,Ltd.,Chengdu 610081,Sichuan,China)

机构地区：[1]广东粤海粤东供水有限公司,广东揭阳522000 [2]中国地质大学(武汉)工程学院,湖北武汉430074 [3]中国水利水电第七工程局有限公司,四川成都610081

出　　处：《工程建设》2025年第1期30-36,共7页Engineering Construction

基　　金：中国水利水电第七工程局有限公司科技攻关项目(GSSC-科研-2023-001)。

摘　　要：软土地层超深地连墙基槽深度大,土层强度低、稳定性差,成槽时间长,槽壁稳定性难以控制,施工过程中失稳风险高。本文以“韩江-榕江-练江水系连通后续优化工程”中的GX12号超深地连墙工作井为依托,采用验证后的数值模拟方法研究深厚软土和砂土复合地层中地下水埋深、泥浆参数和砂土渗透性等因素对超深地连墙槽壁稳定性的影响规律。结果表明:1)槽壁水平位移和地表沉降随原始地下水位埋深的增大而减小,并逐渐趋于稳定;原始水位为-1.28、-10.28 m时,槽壁水平位移分别为33、18 mm,减小约46%,地表沉降减小约57%;2)槽壁水平位移和地表沉降随泥浆重度或泥浆液面高度的增加而减小;当泥浆容重小于12.5 kN/m^(3)时难以满足槽壁稳定性要求,从12.5 kN/m^(3)增加至13.0 kN/m^(3)时,槽壁水平位移减小约68%,地表沉降减小约55%;泥浆液面高度从2.5 m降至1.5 m时,槽壁水平位移增加300%,地表沉降增加304.5%;建议泥浆容重不低于12.5 kN/m^(3),泥浆液面高度不低于2.0 m;3)承压含水层为粉砂、细砂、中砂、粗砂4种工况下,粉砂的变形最小,细砂最大,水平位移相差约50%,地表沉降相差约53%。The ultra⁃deep diaphragm wall of the soft soil layer has a large depth of base slot,low soil strength,poor stability,long slotting time,difficult to control the stability of the slot wall,and high risk of instability in the construction process.Based on the GX12 ultra⁃deep diaphragm wall working well in the“Hanjiang⁃rongjiang⁃lianjiang river system connectivity follow⁃up optimization project”,the verified numerical simulation method is used to study the influence law of groundwater depth,mud parameters and sand permeability on the stability of the ultra⁃deep diaphragm wall in the deep soft soil and sandy composite strata.The results show that:1)The horizontal displacement and surface settlement of the slot wall decrease with the increase of the depth of the original groundwater level,and gradually tend to be stable.When the original water level is-1.28 and-10.28 m,the horizontal displacement of the slot wall is 33 mm and 18 mm,respectively,which is reduced by about 46%,and the surface settlement is reduced by about 57%;2)The horizontal displacement of the slot wall and the surface settlement decrease with the increase of the slurry gravity or the height of the slurry level.When the slurry gravity is less than 12.5 kN/m^(3),it is difficult to meet the stability requirements of the slot wall,and when the slurry increases from 12.5 kN/m^(3) to 13.0 kN/m^(3),the horizontal displacement of the slot wall decreases by about 68%,and the surface settlement decreases by about 55%.When the slurry level height decreases from 2.5 m to 1.5 m,the horizontal displacement of the slot wall increases by 300%and the surface settlement increases by 304.5%.It is recommended that the slurry gravity should not be less than 12.5 kN/m^(3),and the height of the slurry level should not be less than 2.0 m;3)Under the 4 working conditions of silt,fine sand,medium sand and coarse sand in the confined aquifer,the deformation of silt is the smallest,the fine sand is the largest,the horizontal displacement difference is about 50%,

关 键 词：地连墙 水平位移 沉降 槽壁稳定性 数值模拟 

分 类 号：TU476[建筑科学—结构工程]