多层承压水地层盖挖基坑钢管柱竖向变形和对结构影响的研究  

Study on Vertical Deformation of Steel Pipe Column and Influence on Main Structure of Cover Excavation Pit in Multi-layer Confined Water Stratum

作　　者：何华飞 王富强 郭飞 宋健平 崔向阳 He Huafei;Wang Fuqiang;Guo Fei;Song Jianping;Cui Xiangyang(Beijing Municipal Engineering Group Co.,Ltd.,Beijing 100089,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京市政建设集团有限责任公司,北京100089 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《市政技术》2024年第5期63-68,共6页Journal of Municipal Technology

基　　金：国家重点研发计划项目(2018YFC0808705);北京市政建设集团有限公司重大科技研发计划项目(2022-01)。

摘　　要：钢管柱是盖挖法施工中地下结构的主要竖向承载构件。在基坑开挖卸载与基坑底部地下水的共同作用下,钢管柱会产生竖向变形,并在地下结构中产生附加应力,进而影响结构安全。因此,以北京城市副中心交通枢纽深基坑为研究背景,首先提出了有利于控制钢管柱竖向变形的基坑开挖方案,然后采用数值模拟方法分析了基坑开挖与不同降水方案对钢管柱竖向变形的影响,确定了适用的降水方案;在施工过程中还对钢管柱竖向变形进行了监测,再将实测的钢管柱竖向变形等效为强制位移,计算了钢管柱竖向变形所产生的附加内力,并将附加内力和原始内力进行叠加,分析了最不利工况下钢管柱竖向变形对地下结构安全性的影响。The steel pipe column is the main vertical bearing member of underground structure constructed by cover excavation method.Under the combined action of excavation unloading and underground water at the bottom of foundation pit,the steel pipe column will produce vertical deformation,produce additional stress in underground structure and affect the structure safety.Therefore,based on the deep foundation pit of the transportation hub of Beijing Municipal Administrative center,firstly,the excavation scheme of the foundation pit which is conducive to controlling the vertical deformation of the steel pipe column is proposed.Then,the effects of foundation pit excava-tion and different dewatering schemes on the vertical deformation were analyzed by numerical simulation method to determine the suitable dewatering scheme;The vertical deformation was monitored during the construction process.Then,the measured vertical deformation was equivalent to the forced displacement.The additional internal force generated by the vertical deformation was calculated.The additional internal force and the original internal force were superimposed.The influence of the vertical deformation on the safety of the underground structure was analyzed under the most unfavorable conditions.

关 键 词：盖挖基坑 承压水 降水方案 基坑开挖步序 钢管柱 变形 附加应力 

分 类 号：TU753[建筑科学—建筑技术科学]