The Study On The Analysis Method Of The Collapse Performance Of Masonry Structure

When the masonry structure is in use, some factors such as construction, environment or accident may lead to a sudden failure of the structure and the quitting of wall piece may cause unknown safety hazards or even collapse for the rest of the structure. So the collapse resistance design is very important in the design and reinforcementof masonry structure. This paper firstly uses the design software SAP2000 to pushover analysis the anti-collapse design of masonry structures. Due to The complexity of masonry structure,SAP2000 only can analyze the elastic stage, and it cannot analyze the elastic-plastic stageof real masonry structures. But for the frame structure, the analysis of SAP2000 software is mature enough. The first step of the paper is to study to replace the masonry structure with equivalent frame structure model.Thetheoretical basis of the replacement is equation of stiffness and it consists of three parts:axial stiffness、shear stiffness and bending stiffness.After equating the masonry structure with a frame structure, use the SAP2000 to establish two models of masonry structures and then have a contrast of the floor displacement in elastic stage between these two models with the equated frame structures. Then compared the displacement in elastic stage and first three order vibration mode of the cycle between the final masonry structure model and the equated frame structures model. Finally, the papercame to the conclusion that the equation between the two kinds of models is accurate enough and reasonable.The second part of the paper is to choose the demolition method in collapse resistance design guidelines GSA2003 of US public affairs administration for Pushover analysis. Considered the structural model we chose select the corner wall, vertical wall and outside wall as the dismantled components.After the Pushover analysis of dismantling the wall, we can found that under a given earthquake load, most of the plastic hinges appeared in the first floor and the second floor other than other floors. Most of the yielded plastic hinges in the first and second floor appeared in the four corner walls, external walls, and the walls around dismantled walls. Through the analysis of the demolition of the wall, we can get the importance and collapse order of masonry structures in different locations. When designing and reinforcing ordinary masonry structures, the analysis results can provide important guidance to the judgment and attachment of the importance to the walls inkey parts and the walls which collapse first.