Fundamental study on failsafe structural systems against large earthquakes using uplift mechanism

本研究旨在探讨一种使用提升机制的失效安全结构体系的可能性和效率，使建筑物即使在更大的地震反应效应下也能比用顺序抗震设计规范估计的更安全。以往的研究表明，在剧烈地震运动下，伴随着隆升运动的摇晃振动可以降低建筑物的震害。拟议的脂肪1英里。系统就是建立在这些知识的基础上的。该体系在一定的地震输入水平下表现出固定柱基础体系的地震响应特性，但一旦地震输入水平超过极限，系统就会发生摇晃。震动引起的隆升响应将抑制地震输入对结构的上升。首先，对建筑结构的抬升机理进行了介绍，研究项目如下：1)利用提升机制的钢框架体系2)柱底恢复力特性使钢框架提升其次，为了制定更合适的摇摆结构抗震性能评价方法，进行了以下研究项目。3)摇晃结构的地震侧向力分布4)地震时楼板倾斜对摇晃结构室内物体的影响最后，基于简化建筑结构模型的地震反应分析，研究了以下研究项目。(5)采用上扬机制的故障保险系统对强烈地震地震动的有效性。通过这些研究，提出了一些用于摇摆结构的框架体系和构件，并定量分析了上扬响应特性。验证了所提出的故障安全系统对强震的有效性。当我们将该系统应用于高纵横比的建筑物时，它可以提供优越的抗震性能，几乎等同于带有迟滞阻尼器的被动振动控制系统。

This study aims to investigate possibility and efficiency of a failsafe structural system using uplift mechanism to make buildings safety even against larger earthquake response effects than those estimated with ordinal seismic design codes. Previous studies have cleared that rocking vibration accompanied with uplift motion might reduce the seismic damage of buildings subjected sever earthquake motions. The proposed fat-1mi. system is based on this knowledge. This system shows seismic response characteristics of a fixed column base system under certain seismic input leveL But it starts rocking once the seismic input level exceeds the limit. Uplift response due to the rocking will restrain ascent of seismic input to the structures.Firstly, to introduce uplift mechanism to building structures, the following research items were studied.1) Steel frame systems utilizing uplift mechanism2) Restoring force characteristics of column bases to make steel frames upliftSecondary, to develop more appropriate seismic performance evaluation methods for rocking structures, the following research items were studied.3) Seismic lateral force distribution of rocking structures4) Effect of floor incline during an earthquake to indoor objects in rocking structures Finally, the following research item was studied based on earthquake response analyses using simplified building structural models.5) Efficiency of the proposed failsafe system using uplift mechanism against sever earthquake ground motionsThrough these studies, some frame systems and structural members for rocking structures were proposed and uplift response characteristics were analyzed quantitatively. And the efficiency of the proposed failsafe system against sever earthquakes was confirmed. When we apply this system to buildings with a high aspect ratio, it can provide them superior seismic performance, which is almost equal to that of passive vibration control systems with hysteresis dampers.