Energy Dissipation Systems for Bridges

9416160 1994年1月17日的北岭地震对许多桥梁造成了严重的破坏，包括7座桥梁的灾难性坍塌。初步调查表明，一些坍塌是由于上层建筑铰链的座位宽度不足所致，尽管其中大多数是使用缆索约束装置进行改装的。该项目研究桥梁的抗震性能，以确定是否可以在桥梁铰链和其他可能的桥梁位置有效地使用耗能系统来减少地震破坏。本项目的目标是：1)广泛调查北岭地震期间桥梁铰链位置的缆索抑制器的性能；2)通过分析桥梁对地面运动的响应(包括垂直分量)，检查阻尼器作为铰链抑制器的有效性；3)检查安装在桥台和弯帽处的阻尼器作为约束装置的有效性；以及4)比较不同的阻尼器装置，包括粘滞阻尼器、粘滞阻尼器、摩擦阻尼器和钢屈服阻尼器，并推荐适合桥梁应用的阻尼器装置和安装配置。采用在北岭地震中倒塌的Gavin Canyon地道桥模型，借助于非线性分析程序NEABS进行分析。加州交通部(加州交通部)的工程师提供了他们的大力支持，以确保这项研究的结果将用于改造和他们的桥梁的新设计。加州运输公司将提供技术援助，并将为PI提供位于加利福尼亚州圣贝南多地震多发地区的一座高速公路桥，以便对本研究建议的消能系统进行现场测试。这是一个北岭地震项目。***

9416160 Feng The Northridge earthquake of January 17, 1994 caused severe damage to many bridges including the disastrous collapse of seven bridges. Preliminary investigations have shown that some collapses are due to inadequate seat widths at superstructure hinges, although most of them had been retrofitted using cable restrainers. This project investigates the seismic performance of bridges to determine whether energy dissipation systems can be effectively used at bridge hinges and other possible bridge locations for seismic damage reduction. The objectives of this project are to: 1) extensively investigate the performance of cable restrainers at bridge hinge locations during the Northridge earthquake; 2) examine the effectiveness of dampers as hinge restrainers through analysis of bridge response to the ground motion (including the vertical component); 3)examine the effectiveness of dampers installed at bridge abutments and bent caps as restraining devices; and 4) compare different damper devices including viscous, viscoeleastic, friction, and steel yielding dampers and recommend appropriate damper devices and installment configurations suitable for bridge applications. A bridge model of Gavin Canyon Undercrossing which collapsed during the Northridge earthquake will be used for the analysis with the aid of the nonlinear analysis computer code NEABS. Engineers of California Department of Transportation (Caltrans) offered their strong support to ensure the results of this research will be utilized for retrofitting and in the new design of their bridges. Caltrans will provide technical assistance and will make a highway bridge located in seismic-prone San Bernando, California, available for the PI to perform field testing of energy dissipation systems to be recommended as a result of this research. This is a Northridge earthquake project. ***