零距离“环抱”形基坑开挖对既有地铁车站轨向变形的影响分析  

Impact Analysis of Zero-distance"Ring"Shaped Foundation Pit Excavation on Track Deformation of Existing Metro Stations

作　　者：刘书 LIU Shu(Shanghai Urban Construction Design and Research Institute(Group)Co.,Ltd.,Shanghai 200125,China)

机构地区：[1]上海市城市建设设计研究总院(集团)有限公司,上海200125

出　　处：《建筑施工》2021年第5期942-944,961,共4页Building Construction

摘　　要：以上海临港新城某地下空间为背景,研究分析了软土地区既有地铁车站零距离“环抱”水平扩建过程中基坑开挖引起的竖向变形特性。结果表明:由于采用合理的分区分块对称开挖,车站结构的竖向位移明显大于水平位移;底板最大隆起值发生在与开挖基坑紧连的车站端部等轨向变形的独特特征。通过对比分析车站不设桩、抬高区局部设桩、全长设桩3种控制措施方案,验证了工程实践采用的控制地铁车站轨向不均匀变形措施的有效性。计算结果也为此类工程基坑设计、施工方案的进一步优化提供了参考。Taking an underground space in Shanghai Lin-gang Special Area as the background,the vertical deformation characteristics caused by the excavation of the foundation pit during the horizontal expansion of the existing metro station with zero distance"ring"in the soft soil area are studied and analyzed.The results show that the vertical displacement of the station structure is significantly larger than the horizontal displacement due to the symmetrical excavation with reasonable subdivided blocks;the unique characteristics of track deformation such as the maximum uplift value of the bottom slab occurs at the end of the station immediately connected with the excavated pit.The effectiveness of the measures adopted in engineering practice to control the uneven deformation in rail direction of metro station is verified by comparing and analyzing three control measures schemes,which are no piles at station,local piles at elevated area and full-length piles.The calculation results also provide a reference for further optimization of foundation pit design and construction plan of such projects.

关 键 词：软土 地铁车站 “环抱”开挖 竖向变形 轨向不均匀变形 

分 类 号：TU753[建筑科学—建筑技术科学]