南京某公寓塔楼逆作法的结构设计与分析

Structural design and analysis of apartment tower in Nanjing using top-down construction method

南京某公寓塔楼建筑高度260m,由于项目开发进度要求,对塔楼地下室采用逆作法施工。结合现场条件、塔楼结构体系和基础方案,确定了逆作法的施工工序,并针对逆作法工况对塔楼基础和上部结构影响进行了分析。地下室采用钢管混凝土柱,基础采用钻孔灌注桩。将地下1层设定为顺作、逆作交界面,并在交界面处完成核心筒剪力墙以及外框柱的托换,并将顺作、逆作交界处的连接节点以及桩基础承台设计为后连接节点。在地下1层楼板设置4个出土口,为提高施工速度,楼面梁都采用钢梁。以上设计均建立在对塔楼基础、竖向构件及地下室楼盖进行顺作、逆作工况及正常使用工况的包络设计的基础上。结果表明,公寓塔楼逆作法施工方案技术上可行,并可有效缩短预期工期。

The building height of an appartment tower Nanjing is 260 m. Due to the requirement of the project development schedule, the basement of the apartment tower was constructed using top-town construction method. Combined with the site conditions, tower structural system and foundation scheme, the construction process of the top-down method was determined, and the influence of the top-down construction method on the tower foundation and superstructure was analyzed. The basement adopted concrete-filled steel tubular column, and the foundation adopted bored cast-in-place pile. The first underground floor was set as the interface of top-down and down-top constructions, and the transfers of corewall shear wall and outer frame column of the floor were conducted at the interface, and the connection node at the interface of top-down and down-top constructions and the pile foundation cap design were designed as the post connection node. Four excavation openings were set in the slab of the first underground floor. In order to improve the construction speed, the floor beams were all steel beams. The above designs were based on the envelope design of top-down, down-top and normal use working conditions of tower foundation, vertical components and basement slabs. The results show that the top-down construction method of the apartment tower is technically feasible and can effectively shorten the expected construction period.