Experimental and Numerical Studies on Reinforced Concrete Framed Shear Walls

• Main Authors: Fu-Pei Hsiao, 蕭輔沛
• Other Authors: Yaw-Jeng Chiou
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/f7z95f

博士 === 國立成功大學 === 土木工程學系碩博士班 === 92 === 　　The Chi-Chi earthquake in Taiwan (September 21, 1999) induced severe damage of school buildings. The investigations on the failure of buildings show that these damage buildings are mainly caused by shear failure of short column, insufficient walls, and too small column cross-section. RC shear wall has been widely used as an efficient earthquake resistant structure. Its structural analysis and test have been studied by many researchers. The adoption of RC shear walls for buildings sounds valuable earthquake resistant structures. 　　Shear walls have been recognized as efficient earthquake resistance elements. Framed shear walls are extensively used as the components of earthquake resistance buildings. However, the conventional shear walls, which the reinforcements are in vertical and horizontal directions, frequently possess pinching effect in the load-displacement curves. The improvement of conventional shear wall to reduce the pinching effect sounds an essential research. 　　The structural behavior of reinforced concrete framed shear walls were studied by the large-scale tests. Twenty-seven specimens subjected to reversed cyclic lateral loading have been tested, and the OpenSees (Open System for Earthquake Engineering Simulation) finite element model is adopted to analyze the experimental results. These specimens include framed shear walls with opening, high-, middle-, low-rise framed shear walls, pure frames, pure walls, and high seismic performance framed walls. The parameters of steel ratio and layout of reinforcement of walls were investigated by the high seismic performance framed walls. The reinforcements of high seismic performance walls were designed with 45° reinforcements, 45° and boundary vertical reinforcements, and hybrid conventional and 45° reinforcements. 　　The seismic performance of repaired reinforced concrete framed shear walls with opening is quantitatively investigated in this study. Ten large-scale repaired framed wall specimens subjected to reversed cyclic lateral loading had been tested. According to the failure mechanism of the prototype specimens, three specimens were repaired with epoxy and the other specimens were repaired by various methods, such as enlargement of the column size, addition of wing walls adjacent to the boundary columns, jacket addition to the joints of beam-column, and use of steel bracings on the wall. 　　The experimental results showed that the failure of high-rise shear walls is flexural; their ductility factors are greater than those of low-rise shear walls; their displacements are also greater. The middle-rise shear walls failed by a combination of both flexure and shear. The experimental results also show that the crack load, yield load, and limit load are superior for specimens with higher concrete strength and frame with wall. The numerical solutions agree well with the experimental results. 　　The results show that the pinching effect, which frequently existed in the conventional shear walls, is remarkably improved in the new design high seismic performance walls. The larger steel ratio in the shear walls with 45° reinforcements induces less pinching effect. The structural behavior is highly dependent on the layout of reinforcements of walls. The new design shear wall possesses high potential to improve the seismic performance of buildings, and the proposed numerical model will be a fundamental of model-based simulation of concrete structures.