上盖物业软土基坑开挖中城市轨道交通隧道变形的控制与优化  

Optimization and Control of Urban Rail Transit Tunnel Deformation in the Foundation Pit Excavation of Overhead Property

作　　者：徐永刚 狄宏规[2] 刘欢 金宏杰 于佳永 邢宇 XU Yonggang;DI Honggui;LIU Huan;JIN Hongjie;YU Jiayong;XING Yu(Ningbo Rail Transit Group Co.,Ltd.,315101,Ningbo,China)

机构地区：[1]宁波市轨道交通集团有限公司,宁波315101 [2]同济大学道路与交通工程教育部重点实验室,上海201804 [3]宁波轨道交通绿城东部置业有限公司,宁波315101

出　　处：《城市轨道交通研究》2022年第3期162-166,共5页Urban Mass Transit

摘　　要：宁波市矮潘地块项目中的上盖物业基坑存在开挖面积大、距下方城市轨道交通隧道较近等问题。因此,隧道变形控制在允许范围内是该工程的重中之重。为合理预估和控制该上盖物业基坑施工对城市轨道交通隧道结构的影响,基于Plaxis 3D软件,对软土基坑施工及辅助措施进行了优化分析。结果表明:城市轨道交通隧道上浮量主要受隧道埋深的影响,在相同基坑开挖深度下,下卧隧道埋深越大,对应的隧道上浮量越小。为减小上盖物业基坑施工引起的城市轨道交通隧道变形,宜选用基坑分步开挖及由两侧向中间开挖的施工方式,并对隧道上方土体采取加固措施;当分坑数量划为9个且施加在垫层上的临时压重应力为上方开挖土体总重应力的20%时,工程效果较好。The foundation pit of overhead property in Ningbo Aipan Plot project has problems of large excavation area and being close to the underlying tunnel.Therefore,keeping urban rail transit tunnel deformation within allowable range is the top priority.In order to reasonably estimate and control the influence of overhead property foundation pit excavation on urban rail transit tunnel structure,the foundation pit construction and auxiliary measures are optimized based on Plaxis 3D software.The results show that:the urban rail transit tunnel heave a-mount is mainly affected by tunnel depth,and the larger the tunnel depth,the smaller the tunnel heave amount.To minimize the urban rail transit tunnel deformation caused by overhead property foundation pit construction,construction plan of separate foundation pit excavation from both sides to the middle should be selected,and the auxiliary measure of soil reinforcement above the tunnel should be selected.When the number of separate foundation pits is 9 and the temporary weight compressive stress on the cushion layer is 20%of the excavated soil total weight stress,engineering outcomes are satisfying.

关 键 词：深基坑 上盖物业开发 分坑开挖 压重应力 隧道变形控制 

分 类 号：U456.32[建筑科学—桥梁与隧道工程]