注浆-冻结联合工法加固地铁隧道地表融沉特性研究  

Study on the characteristics of surface thaw settlement of subway tunnel reinforced by grouting-freezing combined construction method

作　　者：金修伟 鹿庆蕊[1] 李栋伟 陈士军[1] 洪进锋 王秋哲 JIN Xiuwei;LU Qingrui;LI Dongwei;CHEN Shijun;HONG Jinfeng;WANG Qiuzhe(School of Civil and Architectural Engineering,East China University of Technology,Nanchang 330013,China;School of Construction Engineering and Management,Jiangsu Vocational College of Commerce,Nantong 226000,Jiangsu,China;Jiangxi Academy of Water Resources Sciences,Nanchang 330029,China)

机构地区：[1]东华理工大学土木与建筑工程学院,江西南昌330013 [2]江苏商贸职业学院建筑工程与管理学院,江苏南通226000 [3]江西省水利科学院,江西南昌330029

出　　处：《冰川冻土》2024年第4期1440-1452,共13页Journal of Glaciology and Geocryology

基　　金：核资源与环境国家重点实验室开放基金项目(NR1930);国家自然科学基金项目(52168044);江西省教育厅科技项目(GJJ2200702);南通市自然科学基金青年基金项目(JC2023026)资助。

摘　　要：在地铁隧道修建过程中若遇到复杂不良地质,单一工法有时无法将冻胀融沉位移控制在预期范围内,而采用注浆-冻结联合工法施工,能够有效控制土体融沉位移的施工参数。本文以广州地铁三号线某折返线隧道冻结工程为背景,隧道所处地层为砂质黏土地层,采用有限元数值分析软件,建立水热力耦合模型分析地铁隧道冻胀融沉位移场的发展规律,并与实测数据进行对比验证了模型可靠性,建立不同注浆半径的地铁隧道模型。通过对比其注浆控制效果,得出该法能够控制地表融沉位移的最佳注浆半径,并在此基础上研究了不同水泥掺量对土体融沉位移的影响,进一步得出能够有效控制土体融沉位移的施工参数。结果表明,采用水泥预加固-人工冻结联合工法施工,注浆半径选取4~5 m对融沉的控制效果最佳,注浆半径在4 m以上时土体融沉位移的效率开始有了明显的减弱。水泥掺量大于9%时,改善土体融沉位移的效率开始提高;而水泥掺量达到12%以后,改善土体融沉竖向位移的效率变缓。注浆半径设定在4 m,水泥掺量设定为12%,此时与原施工方案对比,自然解冻末期地表融沉量减小了73%。本研究的设计参数可为其他类似工程施工提供理论依据。Artificial freezing method and grouting reinforcement method are two commonly used methods in subway tunnel construction.However,in the process of subway tunnel construction,if a complex bad geology with high water content,low soil strength and high compressibility is encountered,a single construction method sometimes cannot achieve the expected effect.Some experts and scholars have proposed to combine the two construction methods to reinforce the soil by grouting first and then freezing for complex strata.However,there is a lack of theoretical research and engineering experience in the field of subway tunnel construction.Based on this,this paper relies on a turn-back line tunnel project of Guangzhou Metro Line 3,and adopts the research method of numerical simulation.The thermal parameters and mechanical parameters measured in the laboratory test are substituted into the finite element numerical analysis software.Based on the basic theory of hydrothermal coupling,a two-dimensional finite element model is established,and the reliability of the model is verified by the measured data of the project.The development of the thaw settlement temperature field in the actual construction process of the subway tunnel is analyzed,and the development law of the surface thaw settlement displacement field is obtained,and then the best construction scheme to suppress the surface thaw settlement displacement is obtained,the main conclusions of this paper are as follows:The development of natural thawing freeze-thaw settlement displacement field gradually changes with the passage of natural thawing time.In the early stage of natural thawing,the soil began to gradually thaw.At this time,the maximum vertical displacement of thaw settlement is located on both sides of the central line above the tunnel,while the maximum displacement of soil thaw settlement below the tunnel is-39 mm,which is located below the waist of both sides of the tunnel.This displacement is much smaller than the thaw displacement above the tunnel.After 200 days o

关 键 词：联合工法 融沉 水泥掺量 注浆半径 数值模拟 砂质黏土 

分 类 号：U455[建筑科学—桥梁与隧道工程]