MJS套打钻孔灌注桩施工扰动变形特性研究  

Optimization Analysis of Deformation Characteristics of Construction Disturbance of MJS Set Bored Pile

作　　者：李平[1,2] 马向前 陈育民[1,2] 刘光辉 李焱 Li Ping;Ma Xiangqian;Chen Yumin;Liu Guanghui;Li Yan(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,P.R.China;College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,P.R.China;Nanjing Shangtie Local Railway Development Co.,Ltd.,Nanjng 210003,P.R.China;Jiangxi Academy of Water Science and Engineering,Nanchang 330029,P.R.China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学土木与交通学院,南京210098 [3]南京上铁地方铁路开发有限公司,南京210003 [4]江西省水利科学院,南昌330029

出　　处：《地下空间与工程学报》2025年第2期620-628,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(41977240);江西省水利厅科技项目(202325ZDKT16)。

摘　　要：针对狭小密闭空间内深基坑开挖支护难的问题,研发了高压喷射注浆系统(Metro Jet System,MJS)止水帷幕套打钻孔灌注桩的微扰动支护方案。以海安火车站站房扩建项目三期深基坑工程为例,应用Plaxis 3D有限元分析软件建立三维数值计算模型,对MJS止水帷幕在不同喷浆压力、喷浆范围、桩径大小和施工顺序工况下对临近既有建筑物桩基的变形影响进行了优化分析。结果表明:随着MJS桩喷浆压力系数的增大,既有桩基等深度处水平变形位移呈线性增长;随着MJS桩喷浆范围的减小,施工对临近既有桩基的变形影响沿桩深方向均有所减小;既有桩基变形位移随MJS桩径大小呈非线性变化;考虑多桩不同施工顺序的影响,从中间往两边对称的施工方法对临近既有桩基的累积变形量最小。研究成果可为类似狭小密闭空间内基坑开挖支护提供经验。A micro-disturbance support technique using MJS waterproof wall set drilling and grouting piles has been designed to tackle the challenge of difficult excavation and support of deep foundation pits in narrow and confined spaces.Employing the Plaxis 3D finite element analysis software,a 3D numerical calculation model was established based on the third phase of the deep foundation pit project of the Hai'an railway station expansion project in order to optimize the impact of the MJS waterproof wall on the deformation of the pile foundation of adjacent existing buildings under various working conditions,including grouting pressure,grouting range,pile diameter,and construction sequence.The results indicate that the horizontal deformation displacement at the depth of existing pile foundations increases linearly with the MJS pile grout pressure coefficient;the deformation effect on adjacent existing pile foundations decreases along the pile depth direction with the reduction in MJS pile grout range;the deformation displacement of existing pile foundations changes non-linearly with the MJS pile diameter;considering the effect of different construction sequences of multiple piles,the symmetric construction method from the middle to both sides has the least cumulative deformation on the nearby existing pile foundation,which can provide experience for the excavation and support of the foundation pit in similar narrow and confined spaces.

关 键 词：密闭深基坑 微扰动支护 变形特性 优化分析 

分 类 号：TU94[建筑科学—建筑技术科学]