提出一种由灰铸铁与钢丝绳组成的新型串联型抗风拉索用于高层隔震结构,实现风荷载作用下协同铅芯橡胶支座抗风,减少铅芯橡胶支座数量;多遇地震作用下抗风拉索退出工作,减小隔震层的等效水平刚度,以解决隔震层同时协调抗风性能与隔震性能的问题。利用有限元分析软件ETABS对设置了抗风拉索的高层隔震结构进行风荷载作用与地震作用的时程分析。分析结果表明:风荷载作用时抗风拉索拉力远小于其极限拉力设计值,抵抗水平风荷载具有足够的安全储备;多遇地震作用下拉索拉力超出其极限拉力,拉索破坏退出工作;多遇地震作用下,抗风拉索的灰铸铁达到极限拉力而破坏,钢丝绳远没达到其极限拉力,震后返修只需要更换铸铁件即可,体现了经济性;多遇地震作用下全部拉索几乎同步进入极限拉伸状态,同步退出工作;拉索退出工作后,隔震性能指标达到设计目标,整体隔震效果得到提高。
A new series type wind-resistant cable (WRC) composed of gray cast iron and steel wire rope was proposed for high-rise isolated structure. WRC can resist wind in coordination with lead rubber bearing (LRB) under the action of wind load to decrease number of lead rubber bearings. WRC quits work under frequent earthquake to reduce equivalent horizontal stiffness of the isolation layer and solve the problem of isolation layer in coordination of the wind resistant performance and isolation performance. The finite element analysis software ETABS was used to conduct the time-history analyses of high-rise isolated structure with WRC under the wind load action and seismic action. Analysis results show that under the wind load, tensile force of WRC is far less than the design value of ultimate tensile force, so it has sufficient safety margin against horizontal wind load; under frequent earthquake, WRC force is beyond the ultimate tensile force and the cable quits work; under frequent earthquake, gray cast iron of WRC reaches ultimate tensile force and fails, but steel wire rope is far beyond the ultimate tensile force, so post-earthquake repair only needs replace cast iron parts, which embodies economy; under frequent earthquake, all cables are almost simultaneously into the ultimate tensile state and synchronous exit. When the cables are out of function, indexes of isolation performance reach the design target and overall vibration isolation effect is improved.