Seismic design of unseating prevention system for bridges

桥梁防脱系统抗震设计

基本信息

批准号：
15360247
负责人：
IZUNO Kazuyuki
金额：
$ 3.39万
依托单位：
Ritsumeikan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15360247/
关键词：
unseating prevention system shock absorber seismic design of bridge capacity design cable conservation of energy deformation limit collision between girders 落橋防止システム耐震設計運動方程式摩擦緩衝材道路橋

项目摘要

All road bridges in Japan have been fitted with a seismic unseating prevention system to prevent bridge girders from falling during an earthquake. In the current design of Japanese highway bridges, the necessary strength of the system is prescribed to be 1.5 times the reaction force for the dead load of the bridge girder. In other words, the capacity is stipulated in terms of the dead load alone, with no consideration of the dynamic response of the bridge system.With the emergence of the seismic unseating prevention system as an important issue in Japan, much research has been conducted in recent years. However, most studies have focused on specific factors in bridge collapse such as cable capacity, while research on the design procedure for the unseating prevention system itself remains limited. The bridge unseating prevention system has been designed based on theoretical considerations under many assumptions because it is difficult to evaluate the operation of the system during an actual earthquake. It is necessary to ensure that the system functions adequately during earthquakes.In this study, the design of connecting devices for preventing bridge girders from becoming unseated during strong seismic motion is extended to include consideration of the velocity response of the bridge. The demand strength and cross-sectional area of the connecting cable are derived based on conservation of energy considerations. The demand capacity of the connecting cable is also defined for the worst case that the girder falls from the pier. The installation of shock absorber with optimum stiffness based on its deformation limit and the cable stiffness is found to reduce both the stress on the cable and the required cross-sectional area.

日本的所有道路桥都装有地震脱落预防系统，以防止桥梁在地震期间掉落。在当前的日本高速公路桥梁的设计中，该系统的必要强度是桥梁载荷死负荷的1.5倍。换句话说，仅凭死负荷就规定了能力，而没有考虑桥梁系统的动态响应。随着地震屈服预防系统的出现是日本的重要问题，近年来已经进行了许多研究。但是，大多数研究都集中在桥梁塌陷中的特定因素上，例如电缆的容量，而对预防系统的设计程序本身仍然有限。在许多假设下，基于理论考虑的桥梁预防系统是基于理论考虑的，因为在实际地震期间很难评估系统的运行。有必要确保系统在地震期间充分发挥作用。在这项研究中，连接设备的设计用于防止桥梁在强烈的地震运动期间脱颖而出，以包括考虑桥梁的速度响应。连接电缆的需求强度和横截面面积是根据能源考虑的保护得出的。连接电缆的需求能力也被定义为梁从码头掉落的最坏情况。基于其变形极限和电缆刚度的最佳刚度的休克吸收器的安装可减轻电缆的应力和所需的横截面区域。