既有地铁隧道上覆深大基坑中抗拔桩优化分析  

Optimization Analysis of Anti-Pulling Piles in Deep Foundation Pit Overlying Existing Subway Tunnel

作　　者：陈涵宇 彭丽云[1] 刘兵科 陶畅 CHEN Hanyu;PENG Liyun;LIU Bingke;TAO Chang(School of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044;Beijing Construction Civil Engineering Co.,Ltd.,Beijing 100015)

机构地区：[1]北京建筑大学土木与交通学院,北京100044 [2]北京建工土木工程有限公司,北京100015

出　　处：《北京建筑大学学报》2025年第1期82-91,共10页Journal of Beijing University of Civil Engineering and Architecture

基　　金：国家自然科学基金项目(42172299)。

摘　　要：为解决深大基坑开挖过程中,其下方既有地铁隧道产生较大位移的问题并探究最优抗拔桩方案,基于北京某体育场改造复建项目,采用数值模拟结合监测分析的方法,利用MIDAS软件对基坑施工进行模拟,将计算结果与监测数据对比以验证模型的正确性和计算参数的合理性;在此基础上对抗拔桩桩长、桩径和桩间距进行单因素优化,随后对上述因素对既有隧道变形的影响进行显著性分析,针对最显著的2个因素进行多因素优化分析。结果表明:基坑开挖过程中,地表土体先隆起后沉降,既有地铁隧道则呈隆起;针对抗拔桩,单因素影响下最优方案为原设计桩长减小2 m、桩径不变或桩间距增加1 m;桩间距和桩长对既有隧道位移影响较显著,桩径影响不显著;提出的多因素计算模型能够较准确地反映抗拔参数与既有隧道最大位移的关系且预测能力较好;三维曲面投影得到的桩长和桩间距的关系,能用来判断工程中既有隧道的安全。In order to address the issue of large displacement of the existing subway tunnel under a deep foundation pit during excavation and explore the optimal anti-pulling pile scheme,a numerical simulation method combined with monitoring and analysis was employed in the reconstruction project of a stadium in Beijing.The foundation pit construction was simulated using MIDAS software,and the calculated results were compared with monitoring data to validate the model and parameters.Single factor optimization of pile length,diameter,and spacing was conducted,followed by significance analysis of their impact on existing tunnel deformation.Multi-factor optimization analysis was then performed based on the most significant factors.Results indicated that during foundation pit excavation,soil on the surface rose and then sank,while the subway tunnel rose.For the pull-out piles,the optimal scheme involved reducing pile length by 2 m and maintaining pile diameter or increasing spacing by 1 m under single factor influence.Pile spacing and length had significant effects on tunnel displacement,while diameter did not.The proposed multi-factor model accurately reflected the relationship between uplift parameters and maximum tunnel displacement,with good predictive ability.The relationship between pile length and spacing obtained from 3D surface projection can be used to assess tunnel safety in this project.

关 键 词：深大基坑 数值模拟 抗拔桩优化 既有隧道 

分 类 号：TU753[建筑科学—建筑技术科学] U45[建筑科学—桥梁与隧道工程]