广州西塔巨型斜交网格平面相贯节点试验研究

Experimental study on plannar intersecting connections used in obliquely crossing mega lattice of the Guangzhou West Tower

广州西塔主塔楼高432m,结构形式采用钢管混凝土巨型斜交网格外筒和钢筋混凝土内筒构成的筒中筒结构。斜交网格外筒由不同角度的钢管混凝土柱斜向相贯而成,为了实现节点承载力大于构件承载力的强节点设计原则,提出了两种节点构造形式:加强板+衬板节点和法兰板节点。为了验证两种节点构造的合理性,了解节点实际受力的工作性状、破坏机理和承载能力,进行了8个比例为1∶5.5的节点模型试验,设计并制作了能承受20000kN的自平衡钢结构加载架,采用两个10000kN千斤顶对相贯节点的柱端施加轴向力。结果表明两种构造形式的节点均表现出了约束混凝土的特点,均可满足西塔主塔楼结构设计承载力的要求,具有较高的安全性。相对法兰板节点,加强板+衬板节点对核心混凝土约束作用较大,力学性能较好。

The Guangzhou West Tower is an ultrahigh-rise building with a height of 432m, with the structural pattern of a reinforced concrete core tube enclosed by an outer lattice tube made of obliquely crossing concrete filled steel tubular （CFST） columns. To assure that the capacities of connections exceed those of structural components, two details of the eonneetions were proposed and studied. One connection type was reinforcing plate with lining board and the other was connection with flange plates. Eight 1 ： 5.5 scale models were tested using a specially designed selfbalancing equipment with two 10000kN capacity jacks and pinion rack, in order to verify the rationality of the details and to investigate the performance, capacity and failure mechanism. Test results indicate that the connections exhibit the characteristic of confined concrete. The connections are validated to meet the design requirement of the Guangzhou West Tower, with sufficient loading capacity. Compared with the connections with flange plates, the connections with reinforcing plate plus lining board have larger confining effects on concrete core and thereby better mechanical behaviors.