某各层弱相关悬挂结构抗震设计

Seismic design of a suspension structure with weakly related of each floor

某高层连体结构采用各层弱相关的悬挂结构体系,悬挂区偏置于结构一侧,在屋顶设置单侧悬挑转换桁架,主桁架悬挑约15.5m,9~16层各自独立地悬挂于转换桁架上。该结构存在扭转、凹凸、楼板不连续、尺寸突变、构件间断5种不规则项,属于特别不规则的超限高层建筑。为了减小屋顶转换桁架的内力和优化截面,悬挂部分的连接体楼板未执行《高层建筑混凝土结构技术规程》(JGJ 3—2010)关于板厚的规定,楼板应力分析结果表明楼板能够可靠地传递水平力,在连接体及挑空区设置水平交叉支撑作为保证水平力可靠传递的加强措施。针对结构特点,提出了合理的抗震措施,采用多种软件(YJK、MIDAS Building、SAUSAGE)对结构进行小震、中震、大震下的计算分析,结果表明在大震作用下屋顶桁架及钢拉杆能保持弹性,整体结构能够满足C级抗震性能目标要求。

A high-rise connected structure adopts a weakly related of each floor suspension structure system.The suspension area is offset to one side of the structure,and single-side cantilever transfer trusses are set on the roof.The main truss cantilever about 15.5m,and the 9~16th floors are independent suspended on the transfer trusses.It is a special irregular high-rise out-of-code building with five out-of-code items,such as torsional irregularity,concave convex irregularity,floor slab discontinuity,dimension mutation and component discontinuity.In order to reduce the force and optimize the section of the transfer truss,slab thickness of the connected structure did not carry out the relevant provisions of Technical specification for concrete structures of tall building(JGJ 3-2010).The result of the floor stress analysis shows that the slab can reliably transmit horizontal forces,and horizontal cross brace was set up as a strengthening measure to ensure the reliable transmission of horizontal force.According to the characteristics of the structure,reasonable anti-seismic measures were put forward,and a variety of softwares(YJK,MIDAS Building,SAUSAGE)were used to calculate and analyze the structure under frequent earthquake,fortification earthquake and rare earthquake.The results show that transfer trusses and the steel tie rod could maintain elasticity,and the whole structure could meet the requirements of the C-level seismic performance requirements.