杭州世纪中心西天窗索夹抗滑移试验研究

Anti⁃sliding experiment study on cable clamp of west sunroof in Hangzhou Century Center

索夹是预应力索结构中拉索与其他构件连接的重要节点构件,若索夹和拉索之间发生滑移,会产生较大的预应力损失,甚至改变结构的受力性能。杭州世纪中心西天窗采用箱形桁架+钢索结构,其结构特殊性决定了拉索在施工张拉和施工完成后的状态不同,即施工张拉时要求拉索对索夹是可相对滑移的,而施工完成后需要锁定拉索和索夹的相对位置,不允许发生滑移。通过拉索施工张拉、高强螺栓紧固力衰减、索夹顶推三个阶段的全过程模拟试验确定了索夹与拉索之间的摩擦力情况。试验结果表明,在拉索施工张拉阶段,索夹对索体产生的摩擦力较小,通过锌板垫层能够有效降低铸钢索夹节点处的摩擦损失,保证拉索张拉过程中索力的有效传递;高强螺栓终拧后12h内会产生不可忽视的紧固力损失;使用阶段索夹的抗滑移承载能力能够确保索夹节点安全。

The cable clamp is an important joint member connecting the cable with other components in the prestressed cable structure.If there is a slip between the cable clamp and the cable,there will be a great loss of prestress and the mechanical performance of the structure will even be changed.The west sunroof in Hangzhou Century Center uses box truss+steel cable structure.The particularity of the structure determines the different state of the cable during the tensioning construction and after construction.In other words,the cable is required to slide relative to the cable clamp during tensioning construction,and the relative position of the cable and the cable clamp is required to be locked after construction,so that sliding is not allowed.The friction between the cable clamp and the cable is determined by simulating the whole process of the three stages of the cable tensioning construction,the attenuation of the fastening force of the high strength bolt and the jacking of the cable clip.The test results show that the friction of the cable clamp on the cable body is small during the tension stage of the cable construction,and the friction loss at the joint of the cast steel cable clamp can be effectively reduced by using the zinc plate cushion,so as to ensure the effective transmission of cable force during the tension process.The fastening force loss can not be ignored within 12 hours after the final screw of high strength bolt.The anti-slip bearing capacity of the cable clamps can ensure the structural safety of the cable clamp nodes.