Observation Earthquake Response and Pseudo-dynamic Tests on Semi-rigid Partial-strength connectipns with Steel Structure

本研究项目研究了由高强度螺栓和角钢或端板组成的半刚性部分强度梁柱连接，并对引入此类连接或半刚性柱底座的各种试验结构进行了循环加载试验和拟动力试验。此外，还开发并建造了一个名为“钢秋千”的钟摆式天文台，其中一个 15000 公斤的质量悬挂在刚性钢框架上，并且可以在钟摆和框架之间插入建筑构件样本。观测站内还安装了用于地震监测的受迫振动试验系统和数据采集系统。这种半刚性框架一般存在中震时变形过大的缺点，可能需要适当的加固。对监测现场现有的柔性抗弯框架进行了拟动力试验。低屈服点钢剪力板阻尼器用于加固模式结构。现场过去事件中记录的几次地面运动被用作伪动力测试中的输入激励。 （这些事件的观察时间为1985年10月4日、1986年6月24日、1987年12月17日和1996年9月11日。）根据试验结果检查了阻尼器的响应缓解效果。对于半刚性柱底座，矩形空心型钢柱由由地脚螺栓和底板组成的裸露柱底座支撑，并安装在摆式观测台中，以观察中度地震时的刚度和阻尼。经过初步振动试验后，于2001年开始进行地震监测，成功记录了柱基对18个事件的响应。根据这些试验和监测数据，研究了在设计过程中如何对各种半刚性连接进行适当的分类，并提出了评估屈服强度、最大强度、刚度和变形能力的简单方法。提出了具有半刚性部分强度连接的钢结构的适当设计程序，包括与阻尼器等其他抗震元件的组合。较少的

Semi-rigid partial-strength beam-to-column connections composed from high-strength bolts and angles or endplates were studied in this research project Cydic loading tests and pseudo-dynamic tests were performed on various test structures inducting such a type of connections or semi-rigid column bases. Furthermore, a pendulum-type observatory termed 'steel swing' was developed and constructed, where a 15000kg mass was hung from a rigid steel frame and a specimen of building element can be inserted between the pendulum and the frame. Forced vibration test system and data acquisition system for seismic monitoring are also installed in the observatory.Such semi-rigid frames have a disadvantage in general of too large deformation during moderate earthquakes, and appropriate stiffening may be needed. Pseudo-dynamic tests were performed on an existing flexible moment resisting frame that was built in the monitoring field. Low-yield-point steel shear panel dampers were used to stiffen the mode … More l structure. Several ground motions recorded in the past events at the site were used as input excitations in the pseudo-dynamic tests. (The events were observed on October 4, 1985, on June 24, 1986, on December 17, 1987, and on September 11, 1996.) The effects of response mitigation by the dampers were examined from the test results. As for semi-rigid column bases, a rectangular hollow section steel column was supported by an exposed column base that consists of anchor bolts and a base plate, and installed in the pendulum-type observatory to observe stiffness and damping during moderate seismic events. Seismic monitoring was started in 2001 after preliminary vibration tests, and responses of column base to eighteen events were successfully recorded.Based on these test and monitored data, how to classify various semi-rigid connections suitably in the design procedure was studied, and also a simple method for evaluating yield strength, maximum strength, rigidity, and deformation capacity were proposed. An appropriate design procedure of steel structures with semi-rigid partial-strength connections was proposed including a combination with other earthquake resisting elements such as dampers. Less