Collapse mechanism of pilotis buildings and development of displacement distribution structural system

底层架空建筑倒塌机理及位移分布结构体系开发

基本信息

批准号：
15360304
负责人：
ZHANG Fuming
金额：
$ 7.81万
依托单位：
National Research Institute for Earth Science and Disaster Prevention
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-15360304/
关键词：
Pilotis building Damage Collapse Pulse ground motion Structural control Vibration mode Seismic design

项目摘要

The object of this research is to investigate the collapse mechanism of pilotis buildings, and to develop a new structural system for preventing the collapse at the first story of buildings.In order to investigate the collapse of reinforced concrete pilotis building, a numerical integration method was developed using the correct instantaneous stiffness of elements by predicting the time increment compatible with stiffness variation. The collapse of reinforced concrete columns was discussed using fiber model at plastic hinge and considering the horizontal and vertical vibrations. It was found that column models will collapse at a smaller earthquake input level for a simultaneous input of vertical motion, the ultimate safety of buildings should be evaluated considering the 3-dimensional dynamic behaviors of vertical members. Recent near-fault earthquakes shown strong pulse-like ground motion component in velocity, explicit formulas and simplified methods are efficient to highlight the de … More structive power of ground motions. Here, earthquake motions are simplified as rectangular acceleration pulses and velocity pulses that are solely related with peak values of ground motions, and explicit formulas are obtained that give an extremely simple correlation between structural response and seismic demand with peak values of ground motion.In order to eliminate deformation concentration of building structures, Rocking Center Designated (RCD) Mechanism is proposed to control the vibration modes. Firstly, the dynamic characteristics of this new structure were investigated, and its seismic design method was proposed. The effectiveness and advantages were discussed for design of new buildings and for retrofitting of existing buildings. To confirm the vibration properties of this new structure, Small shaking table tests were carried out to confirm the function of RCD mechanism for displacement distribution. Test results shown that the vibration mode of the main structure varies according to the rocking center of RCD mechanism. If the rocking center is under the ground level, then the first vibration mode will be predominant, and will be solely decided by the rocking radius geometrically, and the story forces are effectively relocated by RCD mechanism. This new structure system is expected to meet different performance needs for distributing the first mode displacement, and to choose the most suitable structural member for strength, deformation and energy consumption. Less

本研究的目的是研究底层架空建筑的机理，并开发一种新的防止建筑物首层倒塌的结构体系。为了研究钢筋混凝土底层架空建筑的倒塌，开发了一种数值积分方法通过预测与刚度变化相适应的时间增量，使用正确的单元瞬时刚度，使用塑性铰处的纤维模型讨论了钢筋混凝土柱的倒塌，并发现柱模型在较小的情况下会倒塌。同时发生的地震输入电平在输入垂直运动时，应考虑垂直构件的三维动态行为来评估建筑物的最终安全性，最近的近断层地震在速度中表现出强烈的脉冲状地震动分量，明确的公式和简化的方法可以有效地突出垂直运动的影响。此处，地震运动被简化为仅与地震动峰值相关的矩形加速度脉冲和速度脉冲，并获得了明确的公式，给出了结构响应与地震动之间极其简单的相关性。地震需求为了消除建筑结构的变形集中，提出了摇摆中心指定（RCD）机构来控制振动模式。首先，研究了这种新型结构的动力特性及其抗震设计方法。讨论了新建筑设计和现有建筑改造的有效性和优点，为了确认这种新结构的振动特性，进行了小型振动台试验，以确认 RCD 机构的位移分布测试功能。结果表明，振动模态主体结构根据RCD机构的摇摆中心而变化，如果摇摆中心在地面以下，则第一振动模式将占主导地位，并且将仅由几何上的摇摆半径决定，并且楼层力被有效地重新分配。这种新的结构体系有望满足分布第一模态位移的不同性能需求，并选择最合适的结构构件的强度、变形和能耗。