Anti-Collapse Performance of Out-Jacketing Frame for Adding Stories Around an Existing Building under Rarely Occurred Earthquake

Based on the characteristics of nonuniform lateral rigidity of separated out-jacketing frame for adding stories around an existing building,the collapsed law of prestressed reinforced concrete,prestressed steel reinforced concrete and huge steel reinforced concrete out-jacketing frame is studied,and relative design suggestions under current codes and standards are proposed.According to the previous study,the seismic performance indexes of three types of out-jacketing such as period,laws of plastic hinges occurring and elasto-plastic story draft ratio,are observed by a practical project,and it is demonstrated that the prestressed steel reinforced concrete out-jacketing frame behaves as the good seismic performance and moderate cost of construction and it should be spread for application.