主-余震作用下框架-核心筒错层隔震结构地震响应分析

Seismic response analysis of a frame-core tube staggered story isolation structure under mainshock-aftershock sequences

新型错层隔震结构是基础隔震和层间隔震体系发展而来的一种新型隔震结构。强主震发生后会伴随着大量的余震出现,余震会使结构造成更大损伤。研究新型错层隔震结构分别在单独主震和主-余震作用下结构的变形与损伤,采用ETABS有限元软件建立某24层框架-核心筒结构模型进行非线性时程响应分析。结果表明:主-余震作用下,新型错层隔震结构的核心筒损伤主要集中在框架隔震层和核心筒隔震层之间,框架的塑性铰集中在框架隔震层以下部分,框架隔震层角柱支座的滞回曲线饱满且比核心筒隔震层角部隔震支座耗能好。新型错层隔震结构的最大隔震层位移均出现在框架隔震层。在余震作用下,新型错层隔震结构的损伤会显著增加。框架隔震层以上框架部分和以下框架部分以及核心筒的损伤分别增加8%、10%和19.80%。余震对隔震层的影响更大,框架隔震层和核心筒隔震层的层间位移分别增加78.70%和60.54%。

The new staggered story isolation structure is a novel seismic isolation structure developed from the base isolation structure and the inter-story isolation structure. A large mainshock may trigger numerous aftershocks, which may cause greater damage to the structure. In this paper, the deformation and damage of the new staggered story isolation structure under the action of a single mainshock and mainshock-aftershock sequences were analyzed. The finite element software ETABS for nonlinear time-history response analysis was used to establish a 24-story frame-core tube structure model. Results show that the damage on the core tube of the structure under mainshock-aftershock sequences is concentrated between the frame isolation layer and the core tube isolation layer. The plastic hinge of the frame is concentrated below the frame isolation layer. The hysteretic curve of the corner column bearing of the frame isolation layer is full, and its energy dissipation effect is better than that of the core tube isolation layer. The maximum displacement of the isolation layer of the new staggered story isolation structure occurs in the frame isolation layer. Under the aftershocks, there is a significant increase in the damage to the new staggered floor isolation structure. Under aftershocks, the damage of the new staggered story isolation structure obviously increases. The damage to the frame part above and below the frame isolation layer increases by 8% and 10%, respectively, and the damage to the core tube increases by 19.80%. Aftershocks have a greater impact on the isolation layer, and the inter-story displacement of the frame isolation layer and the core tube isolation layer increases by 78.70% and 60.54%, respectively.