新建地铁密贴下穿既有地铁结构施工关键技术研究  

RESEARCH ON KEY TECHNOLOGY OF CONSTRUCTION OF NEW SUBWAY CLOSELY STICKING UNDER EXISTING SUBWAY STRUCTURE

作　　者：白守兴 Bai Shou-xing(BCEG Civil Engineering Co.,Ltd.,100015,Beijing,China)

机构地区：[1]北京建工土木工程有限公司,北京100015

出　　处：《建筑技术》2024年第8期925-928,共4页Architecture Technology

摘　　要：新建地铁密贴下穿既有地铁隧道结构易引起既有结构的变形,进而影响地铁正常运营,因此下穿既有隧道结构的施工面临极大的技术难度和安全风险。依托北京地铁3号线主体结构平顶密贴下穿既有2号线东四十条站工程,形成了一种针对平顶直墙的PBA施工工法,并总结了类似新建地铁密贴下穿既有地铁结构的施工关键技术。通过深孔注浆预加固土体,分布对称台阶法同步施工,施作初期支护及背后注浆填充,跳孔施工钻孔桩并采用丝杠支顶,及时施作二次衬砌等,实现未开挖土体预加固和既有结构的补强,达到控制结构沉降变形目的。Under the existing structure of the new subway may cause the deformation of the existing subway tunnel structure,and even affect the normal operation of the subway,so the construction is faced with great technical difficulty and safety risk.Based on the project of Dongsi Shitiao Station of line 2 of Beijing Subway line 3,the paper introduces in detail the construction process of flat roof straight wall PBA construction method,and summarizes the key technologies of construction of new subway line 3 close sticking under existing subway structure.Pre-reinforcement of unexcavated soil mass and reinforcement of existing structure can be achieved through deep-hole grouting,synchronous construction with symmetrical step method,initial support and backfilling,borehole construction with screw support,and secondary lining in time,etc.,so as to control settlement and deformation of structure.

关 键 词：新建地铁 既有地铁车站 近接施工 平顶直墙PBA工法 

分 类 号：TU74[建筑科学—建筑技术科学]