砂砾地层小净距多孔顶管先后顶进叠加扰动效应分析  

Analysis of superposed disturbance effects of successive construction of multiple pipe-jacking with small spacing in sand and gravel strata

作　　者：刘维正[1,2] 张思宇 陈旺 彭焱锋[3] LIU Weizheng;ZHANG Siyu;CHEN Wang;PENG Yanfeng(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-Speed Railway Construction Technology,Changsha 410075,China;China Railway Tunnel Group No.2 Engineering Co.Ltd.,Sanhe 065201,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075 [3]中铁隧道集团二处有限公司,河北三河065201

出　　处：《中南大学学报(自然科学版)》2025年第1期138-155,共18页Journal of Central South University:Science and Technology

基　　金：湖南省建设科技计划项目(KY202108)。

摘　　要：为研究小净距多孔顶管施工叠加扰动效应,依托南昌市丹霞路综合管廊工程,建立三孔顶管的三维数值模型,探究左→右→中、右→左→中、中→左→右、中→右→左、左→中→右、右→中→左这6种不同施工顺序对土体与管片受力变形的影响规律。综合考虑地表沉降、土体水平位移、管片受力变形,比选出最优施工顺序,并基于此顺序分析三孔顶管引起的土拱效应,以地表沉降与管片变形为判别依据对扰动影响进行分区,同时结合现场监测数据验证模拟结果的准确性,揭示砂砾地层顶管施工时地层受力变形规律。建立地表沉降、管片变形分别与管径、管净距、埋深的经验关系,给出砂砾地层多孔顶管施工的强、中、弱影响分区界限。研究结果表明:间隔式施工比相邻顶管连续施工造成的叠加扰动小,最优顺序为依次施工外侧大直径顶管、小直径顶管及中间顶管,其地表沉降、土体水平位移、管片受力和变形较最不利值分别减少12.2%、24.4%、12%和13.6%;在顶进过程中,地表最大沉降发生在顶管轴线上方并不断叠加变大,第1孔顶管引起的地表最大沉降占最终沉降峰值的50%~70%,沉降槽宽度逐渐增大至单孔时的1.75倍;三孔顶管两侧土体水平位移不断叠加变大,两顶管中间土体水平位移较小且受施工顺序影响较大;后行管顶进会使先行管上方的土拱继续发展,中间顶管上方的土拱效应程度最强;土压力的最大增幅与降幅分别为69.5%和40.9%,顶管上方4.5 m以上土体几乎不受应力释放与土拱效应的影响。To study the superimposed disturbance effect of small clear distance multiple pipe-jacking construction,a numerical model of three pipe-jacking was established based on the Danxia Road comprehensive pipe gallery project in Nanchang City.The influence of six different construction sequences,namely left→right→middle,right→left→middle,middle→left→right,middle→right→left,left→middle→right,right→middle→left,on the stress and deformation of soil and pipe segments was explored.Taking into account surface settlement,deep horizontal displacement of soil,stress and deformation of segments,the optimal construction sequence was selected.Based on this sequence,the soil arching effect caused by three pipe-jacking was analyzed,and the disturbance impact zoning was carried out based on the discrimination of surface settlement and pipe segment deformation.At the same time,the accuracy of the simulation results was verified by combining field monitoring data,revealing the deformation law of the strata during the pipe-jacking construction in gravel stratum.Finally,empirical relationships were established between surface settlement and segments deformation,as well as diameter,clear distance,and burial depth,respectively.The impact zone boundaries for the strong,medium,and weak impacts of multiple pipe-jacking construction in gravel stratum were given.The results show that interval construction causes less superimposed disturbance than continuous construction of adjacent pipe jacking.The optimal sequence is to sequentially construct the outer large-diameter pipe jacking,small-diameter pipe jacking,and middle pipe jacking.The surface settlement,soil horizontal displacement,stress and deformation of segment are reduced by 12.2%,24.4%,12% and 13.6%,respectively,compared to the most unfavorable values.During the jacking process,the maximum surface settlement occurs above the axis of the pipe-jacking and continuously increases.The maximum surface settlement caused by the first pipe-jacking accounts for about 50% to

关 键 词：多孔顶管 施工顺序 叠加扰动 数值模拟 影响分区 现场监测 

分 类 号：U456[建筑科学—桥梁与隧道工程]