摘要
层间隔震的隔震层下部结构类似于抗震体系,其在近场脉冲型地震下易产生弹塑性变形,且隔震层易发生过大变形而导致其上部结构倾覆失稳,这些不利影响需深入探讨。本文对比分析在有、无速度脉冲型地震激励下层间隔震结构的弹性和弹塑性反应,探讨速度脉冲对隔震层变形、隔震结构塑性铰分布所产生的影响,提出在隔震层增设粘滞阻尼器形成层间混合隔震方案,分析其对隔震层的限位保护效果及其对隔震结构非线性反应的减震效果。结果表明:在有速度脉冲型近场地震作用下,隔震层下部结构的峰值层间剪力与峰值层间位移角比原抗震结构有不同程度的增大,隔震层最大变形比无速度脉冲型地震下的最大变形有显著增加,远超越了隔震支座容许变形值。层间混合隔震能有效控制隔震层上部结构、下部结构的非线性地震反应与隔震层最大变形,避免隔震支座破坏而导致上部结构倾覆失稳倒塌。
The substructure of mid-story isolation is similar to seismic resistant system. It probably generates elastic-plastic deformation and excessive deformation of isolation layer would occur under near-field pulse-like ground motion. The excessive deformation of isolation layer would destroy the isolation bearings, and would further lead to the overturning collapse of superstructure. All these adverse influences need to be investigated. Comparative analysis are carried out for the e（astic and elastic-plastic seismic responses of mid-story isolation under ground motions with velocity pulse and without velocity pulse, and the influences on deformation of isolation layer and distribution of plastic hinge are discussed. Mid-story hybrid isolation which had viscous dampers installed on the isolation story are developed. Then the effects on limiting deformation of isolation layer and reduction of nonlinear response are studied. The results show that the peak inter-story shear force and peak inter-story drift ratio of the substructure are greater in some extent than those of original seismic resistant structure subjected to ground motions with velocity pulse, and that maximum deformation of isolation layer obviously increases than that under ground motions without velocity pulse and is beyond the allowable deformation of isolation bearings. The results also indicate that mid-story hybrid isolation can significantly reduce the nonlinear responses of the substructure and superstructure of the mid-story isolation system, and can reduce the maximum deformation of isolation layer to avoid superstructure overturning collapse caused by isolation bearings destruction.
出处
《建筑科学》
CSCD
北大核心
2015年第1期115-121,共7页
Building Science
基金
国家自然科学基金资助项目(51378124
51108083)
福建省自然科学基金资助项目(2013J01169)
福建省教育厅项目(JK2012035)
福建工程学院科研项目(GY-Z11069)
关键词
层间隔震
近场脉冲型地震
混合隔震
非线性反应
隔震层限位
mid-story isolation
near-field pulse-like ground motion
hybrid isolation
nonlinear response
limitingdeformation of isolation layer
