Development of Menshin(Repair-Free)Bridge Piers

免修桥墩的开发

基本信息

批准号：
11650478
负责人：
KAWASHIMA Kazuhiko
金额：
$ 2.3万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650478/
关键词：
Seismic Design Bridge Bridge Pier Smart Material Ductility High Damping Rubber Lateral Confinement New Construction 塑性ヒンジ長実験新技術地震

项目摘要

This research was conducted for aiming to develop a new reinforced concrete bridge pier that is free from damage under the near-field ground motions. Current practice to enhance the ductility capacity of a reinforced concrete bridge pier consists of providing larger amount of ties for lateral confinement of concrete at the plastic hinge region. The lateral confinement enhances the ultimate strain of concrete, which in turn increase the ductility capacity. However no matter how the lateral confinement is provided, once plastic deformation occurs at the plastic hinge region, it may be required to be repaired after an earthquake.The basic ideal of this research is to replace the concrete at the plastic hinge region with a material that is stable under large cyclic load excursion in the plastic range. The material should be sustainable for long-term use, and stable for natural environmental condition. In the current research, we developed a new reinforced concrete piers that satisfies the following two requirements ;(1)high ductility with drift of 4%, and(2)repair-free after cyclic excursion with displacement up to 4% driftWe used the high damping rubber for such a purpose. After clarifying the conditions required for the rubber layer, its effectiveness was verified by a series of cyclic loading test. Eight 1.35m high reinforced concrete piers with a 40cm x 40cm cross section were constructed, and rubber layers with various parameters such as the anchor to the concrete, steel plates on and bottom of the rubber layer, and shear key, were provided for the replacement of concrete in the plastic hinge region. An analysis using the fiber element was conducted to clarify the test results.It was found from the investigation that the damage-free pier based on the above concept is feasible. The use of rubber layer anchored to concrete with shear key is proposed for implementation.

这项研究的目的是开发一个新的钢筋混凝土桥码头，该桥梁在近场地面运动下没有损坏。当前的实践以增强钢筋混凝土桥码头的延展性能力，包括在塑料铰链区域提供更大的关系以将混凝土横向限制。横向限制增强了混凝土的最终应力，从而增加了延展性能力。但是，无论如何提供横向限制，一旦塑料变形发生在塑料铰链区域，就可能需要在地震后修复。这项研究的基本理想是用塑料区域稳定的材料替换塑料区域的混凝土。该材料应具有可持续的长期使用，并且对于自然环境状况稳定。在当前的研究中，我们开发了一种新的钢筋混凝土墩，满足以下两个要求；（1）延迟性高4％，以及（2）循环偏移后无修理，位移后无修理，最多4％漂移使用了高阻尼橡胶来实现此类目的。在阐明橡胶层所需的条件后，通过一系列循环加载测试验证了其有效性。构建了八个具有40厘米x 40厘米横截面的高钢筋混凝土墩，并提供了带有各种参数的橡胶层，例如固定层和橡胶层的固定板和剪切键的钢板，以及剪切钥匙，用于更换塑料铰链区域的混凝土。进行了使用纤维元件进行分析以阐明测试结果。从调查中发现，基于上述概念的无损害码头是可行的。提出了用剪切键锚定在混凝土上的橡胶层用于实施。