深圳地铁大运枢纽站施工关键技术分析

Crucial Construction Technologies for Shenzhen Metro Dayun Hub Station

深圳地铁大运枢纽为地铁3、14、16号线和城际33号线换乘枢纽,采取先施工地下部分保证地铁开通运营,后施工上盖物业部分,最终形成大运枢纽站城一体化地标项目。在大运枢纽地下空间开发中存在对运营车站和高架桥保护、超净空大直径桩基施工、新建车站超深基坑开挖、交通核盖挖逆作法施工、已运营车站屋顶大型钢结构改造等技术难题。通过交通疏解、电子雷管爆破、注浆加固、现场监测、盖挖逆作、BIM技术模拟分段吊装及有限元模拟验算等方法,确保大运枢纽地下工程和运营高架车站改造顺利施工。结果表明:1)采用注浆加固对3号线高架车站进行保护,桥墩最大沉降仅为4.33 mm;2)采用盖挖逆作法施工控制已建车站结构变形,交通核区域周边地表最大沉降为28.19 mm,最大水平变形为22.19 mm。

Shenzhen Metro Dayun Hub Station is a transfer hub among Metro Lines 3,14,16,and Inter-city Line 33.The underground part shall be constructed first to ensure the operation of the metro,and then the property part shall be constructed to form the landmark project of the integration of the Grand Transport Hub Station and City.In the development of underground space,there are some technical problems,such as the protection of operating station and viaduct,the construction of large-diameter pile foundation with super clearance,the excavation of super-deep foundation pit in new station,the top-down construction of traffic core,and the transformation of large steel structure on the roof of existing station.Therefore,technical measures such as traffic dredging,electronic detonator blasting,grouting reinforcement,field monitoring,top-down construction method,section hoisting simulated by building information modeling technology,and finite element simulation and checking calculation are adopted to ensure the smooth construction of the underground engineering of Dayun hub and the transformation of operational elevated station.The results show that the maximum settlement of pier is only 4.33 mm after grouting reinforcement of elevated station of Line 3;the top-down construction method is adopted to control the structural deformation of the built station,resulting in maximum surface settlement around the traffic core area of 28.19 mm and the maximum horizontal deformation of 22.19 mm.