考虑楼板大开洞及大质量比附属设施的结构抗震性能实例研究

对某楼板大开洞且具有大质量附属设施的复杂钢筋混凝土厂房结构开展抗震性能实例研究。楼板大开洞会导致构件缺少有效的楼板约束,从而使构件发生显著的横向振动,最终构件在双向弯矩等复合内力作用下发生破坏,必须采用分布塑性铰纤维模型对该重要现象进行精细模拟,并应在设计中重点关注该类构件的横向抗弯承载力。大质量比附属设施作为非传统质量调谐阻尼器(TMD),可采用Tsai和Lin建议的简化公式进行参数优化,从而能显著减小主结构的动力响应。对于覆盖面积较大的多点弹簧支撑附属设施,必须有效考虑扭转效应导致的加速度放大,同时不能忽略大质量比对附属设施楼层反应谱的衰减作用。

CASE STUDY ON STRUCTURAL SEISMIC BEHAVIOR CONSIDERING LARGE SLAB OPENINGS AND AUXILIARY FACILITIES WITH LARGE MASS RATIOS

A case study was carried out on the seismic behavior of a complex reinforced concrete(RC) plant structure with large slab openings and an auxiliary facility with large mass ratio. The absence of effective slab constraints for the structural members can be observed in structures with large slab openings, leading to evident transverse vibration. As a result, the structural members fail under the combination of bi-directional moments and other internal forces. A fiber beam-column element with distributed plasticity approach should be used to elaborately capture this significant phenomenon, and much attention should be paid to the transverse flexural capacity of such structural members. The simple formula suggested by Tsai and Lin can be applied to optimize the parameters of the large mass auxiliary facility as a non-conventional tuned mass damper(TMD) to evidently reduce the dynamic response of the main structure. For the auxiliary facility covering a relatively large area with multiple supports, the acceleration amplification effect due to the torsion of auxiliary facility should be considered, and the evident decreasing of the floor response spectrum due to large mass ratios should not be neglected.