Experimental and Numerical Studies on the Earthquake Response of Metal Elevated Floor

• Main Authors: Yun-HsienChen, 陳運賢
• Other Authors: G. C. Yao
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/47259611763092868627

碩士 === 國立成功大學 === 建築學系碩博士班 === 98 === Taiwan is in the Circum-Pacific seismic zone, the building structures and the non-structure components in Taiwan are exposed to high seismic risks. As the safety of the structural systems has been well improved in the recent decades, many studies have also emphasized the importance of enhancing the seismic security of the non-structural components, including the raised access floors (RAF), suspension ceilings, architectural partitions, and so on. The RAF system has been widely used in the factories, hospitals, and office buildings, for they can help arrange the piping and electrical wiring system to enhance the environmental quality. However, the reconnaissance reports revealed that the RAF system may be damaged under moderate earthquakes. Therefore, in this study, full scaled shake table tests were conducted in National Center for Research on Earthquake Engineering (NCREE) to study the dynamic behaviours of the RAF systems and to improve their seismic performances. The testing setup included a (L)x(W)x(H) RAF system with a steel frame equipment specimen located on it, and the main parameters were the weight, height to width ratio, and the restraint condition of the equipment specimen. A numerical model was also built in the SAP2000 program to analyze the behaviours of the RAF systems with different equipment under severe seismic input of 0.96g, and the analytical results were verified by the experimental data. In the experiments, the push tests were performed on the retainers of the equipment specimens to identify their mechanical properties to help establish the numerical models. Compared the shake table testing results and the numerical analysis, good agreement was observed between the two. The experimental and analytical study yielded the main findings listed as following: 1. The testing result showed that in the current practical situation in high-tech factories, the deficiencies of the RAF systems include: 1) the hook of the tension link element would deformed and lose its function, 2) pulling out of the pedestals bolts under the RAF systems may occur when vertical tension is applied to the system, and 3) the seismic forces would concentrate on the pedestals right below the equipment and unable to transmit to the whole system. 2. The SAP2000 analytical results showed that under the 0.96g seismic inputs, when the weight of the equipment on the RAF system varied from 450, 350, 300, 200, 100 to 50kg, the corresponding allowable height to width ratio were 0.5, 1.0, 1.5, 2.0, 2.5, and 50, respectively. Show as fig 1. 3. For using the 1500 type panels in the RAF systems, the shear-resistant capacity of the screws on the top of the pedestals should be larger than 1717kg. For example, the diameter of the screw should not be less than 0.736cm if it is made of A36 steel. Thus, the shear-resistant bolt can break as the panel breaks. 4. The studying result showed that to enhance the shear-resistant capacity of the screws on the top of the pedestals can improve the seismic performance of the RAF systems the most. Moreover, to strengthen the out-of-plane strength of the panels and increase their yielding displacement can further raise the seismic capacity of the RAF systems.