超高A型桥塔横向地震破坏模式及其控制策略  

Damage control strategy with additional energy dissipation components and seismic failure modes for super tall A-shape tower under transverse earthquake

作　　者：谢文[1] 孙钰苗 孙利民[2] 

机构地区：[1]宁波大学建筑工程与环境学院,浙江宁波315211 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《自然灾害学报》2018年第1期127-136,共10页Journal of Natural Disasters

基　　金：国家自然科学基金(51608282;91515101-5;91315301-5);浙江省自然科学基金(LY15E080011)~~

摘　　要：以一座超大跨斜拉桥中的超高A型桥塔为对象,采用非线性时程分析方法并引入Park损伤准则和截面曲率延性系数准则,分析横向地震作用下超高A型桥塔的地震损伤与破坏模式,研究横向极端地震作用下附加耗能构件数量、布置间距和材料屈服应力等对超高A型桥塔地震损伤的控制效果。结果表明:在横向极端地震(PGA=1.0 g)作用下,桥塔与上横梁交接处以及塔底附近几乎同时发生损伤甚至破坏,出现双塑性铰的破坏模式,因而从设计上难以利用桥塔屈服后的塑性性能,应在抗震设计中引起足够重视;与原超高A型桥塔相比,附加耗能构件的数量、布置间距以及材料屈服应力均可有效改善其地震损伤,尤其是通过参数优化后的附加耗能构件能完全有效控制超高桥塔的地震损伤,使其满足损伤控制目标。Nonlinear time history analyses were performed to study the seismic damage and failure modes of a super tall A - shape tower subjected to various ground motion intensities in the transverse direction. Then a proposed damage control strategy, using sacrificial energy dissipation components installed between both tower shafts at the top regions, was studied to mitigate the seismic damage and improve the collapse resistant capacity of the super tall tower. The parameter sensitivity analyses influences of the sacrificial energy dissipation components, such as installing space and yield stress of material, were performed to determined optimal parameters on the seismic damage and fail- ure modes of the super tall tower under extreme ground motion （ PGA = 1.0 g） in the transverse direction. The re- sults show that the super tall tower experiences an unexpected failure mode with double plastic hinges confined to the tower top and bottom regions, indicating the seismic performance and stiffness after the super tall tower yielding may not further resist the dead load and earthquake load during earthquake. The proposed damage control strategy can significantly reduce the seismic damage of the super tall tower, especially, this control strategy with optimal parameters of the sacrificial components can successfully control the seismic damage of the super tall tower and make the super tall tower satisfy damage control targets according to the seismic damage criteria.

关 键 词：超高桥塔 牺牲耗能构件 地震损伤 破坏模式 地震损伤准则 极端地震 

分 类 号：X9[环境科学与工程—安全科学] U442.55[建筑科学—桥梁与隧道工程]