On the effectiveness of rotational friction hinge damper to control responses of multi-span simply supported bridge to non-uniform ground motions
On the effectiveness of rotational friction hinge damper to control responses of multi-span simply supported bridge to non-uniform ground motions
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DOI：
10.1177/1369433216645974
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发表时间：
2016-10
影响因子：
2.6
通讯作者：
B. Shrestha;H. Hao;N. H. Ibrahim;K. Bi
中科院分区：
文献类型：
--
作者：
B. Shrestha;H. Hao;N. H. Ibrahim;K. Bi
基础隔震技术已被广泛应用于改善桥梁结构的抗震性能。使用橡胶隔振器将桥面与桥墩和桥台分离，可以显著减少传递到桥梁下部结构的地震力。然而，隔震装置也会增加桥面位移，从而增加桥面撞击和脱座损伤的可能性。此外，以往的研究表明，由于地震地震动的空间变化，孤立桥梁的冲击和脱座损伤会加剧。最近的地震表明，在大地震事件中，由于甲板的过度运动，隔震支座也可能受到破坏。本研究提出使用旋转摩擦铰阻尼器来减轻桥面大位移可能引起的损伤，特别关注冲击和脱座损伤和轴承损伤。该装置能够提供较大的滞回阻尼，并且安装该装置的成本相对经济。本文介绍了这些装置在一个典型的尼泊尔简支桥上受到空间变化的地面运动的有效性的数值研究。结果表明，转动摩擦铰阻尼器能有效地减小相对位移和冲击力，控制支座变形和桥墩漂移。研究还表明，滑移力的微小变化对装置的有效性没有显著影响；因此，在桥梁的使用寿命期间，最佳滑移力的微小变化并不保证对设备进行任何调整或更换。
Base isolation techniques have been extensively used to improve the seismic performance of the bridge structures. The decoupling of the bridge decks from the piers and abutments using rubber isolator could result in significant reduction in seismic forces transmitted to the bridge substructures. However, the isolation devices could also increase the deck displacement and thus enhance the possibility of pounding and unseating damage of bridge decks. Moreover, previous investigations have shown that pounding and unseating damages on isolated bridges exacerbate due to the spatial variation in earthquake ground motions. Recent earthquakes revealed that isolation bearing could also be damaged due to the excessive movements of decks during large earthquake events. This study proposes the use of rotational friction hinge dampers to mitigate the damages that could be induced by large displacement of bridge decks, particularly focusing on pounding and unseating damages and bearing damages. The device is capable of providing large hysteretic damping and the cost of installing the devices is relatively economical. This article presents numerical investigations on the effectiveness of these devices on a typical Nepalese simply supported bridge subjected to spatially varying ground motions. The results indicate that rotational friction hinge dampers are very effective in mitigating the relative displacement and pounding force, as well as controlling the bearing deformation and pier drift. It is also revealed that the effectiveness of the device is not significantly affected by small changes in the slip forces; thus, small variations in the optimum slip forces during the lifetime of the bridge do not warrant any adjustment or replacement of the device.