北京东直门交通枢纽基坑工程设计施工技术

Design and Construction Technology of Foundation Excavation of Beijing Dongzhimen Transportation Hub

北京东直门交通枢纽位于高楼林立的市中心,基坑施工时,紧邻2栋16层塔楼部位采用地下连续墙和预应力锚杆支护;毗邻市政道路部位采用降水井、护坡桩和预应力锚杆支护;紧邻地铁隧道并与隧道同时施工区段采用深桩加预应力锚杆支护,并做地下连续墙止水帷幕;建筑基坑调整加深地段相应调整锚杆长度并增加1排锚杆;按照建筑一级基坑实施监测。结果表明,锚杆轴力和桩顶位移满足要求,支护结构安全。

Dongzhimen Transportation Hub locates in center of Beijing which is crowded with high-rise buildings. Various supporting and waterprofing methods are.adopted according to surrounding and geological conditions, such as supporting with diaphragm wall and prestressed anchors at parts adjacent to two tower buildings with 16 storeys, supporting with slope protection piles and prestressed anchors compounding with dewatefing wells at parts adjacent to urban roads, supporting with deep piles and prestressed anchors and underground continuous wall waterproof curtain at parts near subway tunnel when the tunnels and the foundation excavation are constructed at the same time, adjusting anchors length and increasing a row of anchors where the foundation excavation is deeper. The foundation excavation is monitored according to first grade standards. Monitoring results show that the axial stresses and displacement of pile top can satisfy requirements, and the supporting structure is safe.