A Study on Reinforcement Detailing and Retrofitting Effect of RC Squat Walls

• Main Authors: Bing-Yun Wu, 吳炳昀
• Other Authors: Shyh-Jiann Hwang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/08192482951526394057

碩士 === 國立臺灣大學 === 土木工程學研究所 === 100 === During the 921 earthquake in Taiwan, many reinforced concrete buildings were damaged or collapsed especially for low-rise school buildings. Due to the lacking of walls or the walls with too many openings, insufficient lateral load capacity was found for those damaged buildings. Therefore, how to enhance the capacity of seismic resistance in existing buildings is an important issue. Because of its large lateral stiffness and strength, shear wall can increase the lateral resistance of structural system easily. Although installing the shear wall is an effective method to enhance the capability of seismic resistance, the force transfer mechanisms and failure modes need to be further studied. In addition, the role of shear reinforcement in the squat wall also needs to be clearly defined. Furthermore, to reduce the number of reinforcement planting for the retrofitting method using shear wall is of interest. This research included a testing of six specimens of squat shear wall. Four specimens were made by simultating new construction; the other two specimens were the RC frames retrofitted with RC walls. By testing these specimens, the role of shear reinforcement and the retrofitting effect of RC squat walls can be investigated. According to test results, the lateral strength of shear wall is remained the same regardless of the amount of horizontal or vertical shear reinforcement in the wall. In addition, the specimen with 12 cm RC wall detailed using the shrinkage and temperature reinforcement can develop a sufficiently large lateral strength. The retrofitting method by planting the large size of shear reinforcement can develop the targeted strength. However, the length of lap splice of these planted shear reinforcement should be carefully designed. Strength evaluation of diagonal shear failure and sliding failure was also performed in this study. The analytic result shows the SST model is better than the ACI code in predicting diagonal shear strength of squat RC wall. In predicting the interface shear strength, the formula which suggested by Paulay and Priestly shows better performance the ACI code method.