The Strengthening Model And Theoretical Research Of Primary And Secondary Schools After The "5·12" Wenchuan Earthquake

Masonry structure has a high damage rate in earthquake, because of the low bearing capacity of tensile, shear, and bending resistance. In the"5·12"Wenchuan Earthquake, tremendous losses has been caused to China, and houses in the affected area are badly destroyed, especially the buildings of primary and middle school, majority of which is brick masonry structure. Because these buildings have the bigger standard width, smaller lateral rigidity, especially for the sngle buildings with natural lighting, longitudinal and transverse main wall, corridor at one side, large windows on both surfaces. Under the action of earthquake, lots of cracks appeared in walls, which made some houses had become dangerous buildings, considering the process of safety testing and appraisal and strengthening design, implement the guidelines of"focus on prevention", the project of seismic appraisal and reinforcement must do to the work isn't up to the standard of requirements.Reliable and effective methods are usually taken to strengthening the concrete walls in the reinforcement of masonry structures, which is major following the experience. In this paper, the reinforcement modes of concrete walls in typical are studied to supply some reference to similar researches. The main achievements can be summarized as follows:1.Finite model was established to simulate a load-bearing masonry wall, and the shear resistances of the structure are also studied before and after the concrete walls are reinforced. Meanwhile, the simulated results match well with the theory results, in about ten percent error. The finite model established by ansys to investigate the masonry structure is reasonable.2.Based on the base shear method, the errors results to study the seismic behavior of the whole structure are compared from the simplified method with the ansys finite method and the pkpm computing method. It is found that the ansys finite method produces error (sometimes are very large) easily in many cases, and even makes mistakes. The results of the pkpm computing method are more credible compared with the other two methods, which convinced the research of pkpm in the calculation of the seismic behavior of the whole structure before and after reinforcement.3.Based on the"stiffness converted model"of the masonry structure, the relative parameters of the strength level of wall materials after reinforcement are converted and input to the structure design software PKPM. The structures after and before strengthened are assessed. The reinforcement results are judged with comprehensive aseismic capacity index. The seismic behaviors of structures in different reinforcement mode are studied, and the third mode is proved the reasonable one.4.Based on the destroying status of structures, under the premise of reasonable reinforced mode, the reliability index of the structures after and before reinforcements are studied to ensure the structure after reinforcement are safe which meet the minimum requirements of Unified Standard for Reliability Design of Building Structures. Taking the whole structure as research object, the whole model was established by using ansys to analysis the modal of houses. It is found that the structure stiffness after the reinforcement improved greatly vary with before the reinforcement.