地铁明挖车站下穿越既有建筑物的局部暗扩挖施工关键技术  

Key Technology of Local Underground and Enlarged Excavation Construction of Subway Open-Cut Station Underpassing Existing Buildings

作　　者：刁国君 何昕 Diao Guojun;He Xin(Road and Bridge Engineering Co.,Ltd.,China Railway Tunnel Group Co.,Ltd.,Tianjin 300308,China;Transportation College,Jilin University,Changchun 130025,China)

机构地区：[1]中铁隧道局集团路桥工程有限公司,天津300308 [2]吉林大学交通学院,长春130025

出　　处：《吉林大学学报(地球科学版)》2025年第2期536-549,共14页Journal of Jilin University:Earth Science Edition

基　　金：吉林省科技发展计划项目(20240304126SF)。

摘　　要：针对成都地铁某明挖车站局部穿越既有建筑物的复杂工程挑战,通过综合对比分析和有限元模拟,采用了局部暗扩挖的施工策略。提出了明暗挖分界点的科学判定方法,并深入探讨了沉降控制、暗挖初期支护和二次衬砌等施工关键技术的多个方面,包括施工前的降水处理、地表注浆加固与数值模拟分析,以及施工中的超前支护、开挖步骤控制和二次衬砌结构施工等。结果表明:相较于传统的明挖法,暗挖扩挖技术能显著降低拆迁难度,工程成本投入减少约1.04亿元,施工周期缩短2个月;施工成功的关键在于精确确定明暗挖分界点,建议该分界点设在结构腋角外侧,距离房屋基础3 m处,同时结合袖阀管地表注浆与管井降水等措施有效控制地表沉降。施工过程中,需根据暗挖隧道跨度及围岩特性灵活选择施工方法,妥善处理初期支护结构节点,确保二次衬砌施工与初期支护结构破除的有效衔接,并高度重视施工监测的应用。Addressing the complex engineering challenges of a excavated metro station in Chengdu that partially traverses existing buildings,this study adopted a localized undercut and expansion excavation strategy through comprehensive comparative analysis and finite element simulation.The research proposed a scientific method for determining the boundary between open and undercut excavation,and delved into various aspects of key construction technologies such as settlement control,primary support for undercut excavation,and secondary lining,including pre-construction dewatering,ground surface grouting reinforcement,and numerical simulation analysis,as well as advanced support during construction,excavation sequence control,and secondary lining structure construction.The research results indicate that,compared to the traditional open-cut method,the undercut and expansion excavation technique can significantly reduce demolition difficulties,It has significantly cut the investment in project costs by approximately 104 million yuan and shortened the construction period by two months.The key to successful construction lies in accurately determining the boundary between open and undercut excavation,which is recommended to be set outside the structural haunch and 3 m away from the building foundation.Meanwhile,combining sleeve valve pipe ground surface grouting with tube well dewatering measures can effectively control ground surface settlement.During construction,it is necessary to flexibly select construction methods based on the span of the undercut tunnel and the characteristics of surrounding rocks,properly handle the nodes of the primary support structure,ensure effective connection between secondary lining construction and the removal of the primary support structure,and attach great importance to the application of construction monitoring.

关 键 词：地铁 穿越既有建筑物 局部暗扩挖 数值模拟 暗挖法 明挖法 明暗挖分界点 沉降 

分 类 号：TU455[建筑科学—岩土工程]