低净空下地铁车站深基坑施工对高架桥桩变形影响研究  

Study on the Influence of Deep Foundation Pit Construction of Subway Station on Viaduct Pile Deformation under Low Clearance

作　　者：袁国发 施液峰 张婷[2] 杨平[2] 袁华崧 黎兴望 魏领先 YUAN Guofa;SHI Yefeng;ZHANG Ting;YANG Ping;YUAN Huasong;LI Xingwang;WEI Lingxian(China Railway Second Bureau Fifth Engineering Co.,Ltd.,Chengdu 610031,China;College of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]中铁二局第五工程有限公司,成都610031 [2]南京林业大学土木工程学院,南京210037

出　　处：《三峡大学学报(自然科学版)》2025年第3期81-88,共8页Journal of China Three Gorges University:Natural Sciences

基　　金：国家自然科学基金项目(51709088)。

摘　　要：针对苏州轨道交通8号线采莲路站下穿既有轨道交通2号线高架桥深基坑工程,开展紧邻既有高架桥低净空下地铁车站深基坑施工数值模拟研究,并与实测结果进行对比,验证数值模拟方法的合理性.基于数值计算,研究围护结构、支撑体系参数和隔离桩设置等因素对桥桩变形的影响及变形控制措施.结果表明:可通过优化围护结构、支撑体系参数控制紧邻基坑的桥桩变形.影响程度为:围护结构厚度>围护结构材料(弹性模量)>钢支撑预加轴力,本基坑工程围护结构在原有厚度基础上增加至1.1倍、弹性模量选用35 GPa(C30混凝土)、钢支撑预加轴力65%以上更能有效控制桥桩变形.隔离桩结构参数是控制高架桥桩变形的关键因素,影响程度为:隔离桩与墩台距离>隔离桩深度>隔离桩材料>隔离桩厚度,低净空条件下优先选取钻孔灌注桩作为隔离桩,应设置于与既有高架桥墩相距4.5 m处,深度建议取基坑开挖深度1.4倍,厚度设置为0.55 m.In view of the deep foundation pit project of the viaduct of the existing rail transit line 2 under the Cailian Road station of Suzhou Rail Transit Line 8,the numerical simulation study of the deep foundation pit construction of the subway station under the low clearance of the existing viaduct was carried out,and the rationality of the numerical simulation method was verified by comparing it with the measured results.Based on the numerical results,the effect factors such as enclosure structure,support system parameters,and isolation pile setting on the deformation of bridge piles and deformation control measures were studied.The results show that the deformation of the bridge piles adjacent to the foundation pit can be controlled by optimizing the parameters of the enclosure structure and the support system.The influence degree is as follows:the thickness of the enclosure structure>the material of the enclosure structure(elastic modulus)>the pre-applied axial force of the steel support.When the thickness of the enclosure foundation pit structure is 1.1 times of the original design,the elastic modulus is 35GPa(C30 concrete),and the pre-applied axial force of the steel support is over 65%of full scale,the deformation of the bridge pile can be effectively controlled.The structural parameters of the isolated pile are the key factors to control the deformation of the viaduct pile,and the degree of influence is:the distance between the isolated pile and the pier abutment>the depth of the isolated pile>the material of the isolated pile>the thickness of the isolated pile.The bored pile should be preferentially selected as the isolation pile under low clearance conditions,which should be set at a distance of 4.5 m from the existing viaduct pier.The isolation pile depth is recommended to take 1.4 times of the pit excavation depth,and the thickness is set to 0.55 m.

关 键 词：低净空 地铁深基坑 围护结构 隔离桩 桥桩变形 

分 类 号：TU473[建筑科学—结构工程]