Analysis On Seismic Damage Of School Buildings

Schools are densely populated,and students’ ability to escape risks is weak.Strong earthquakes can cause mass casualties easily.The result of multiple earthquake damage show that the vulnerability of school buildings,especially teaching buildings,is significantly higher than that of ordinary residential buildings.It is very important to explore the mechanism of seismic damage of school buildings.Their seismic capacity need to be improved ensure the safety of teachers and students.In this paper,through the actual seismic damage investigation,model experiment and theoretical analysis,a new understanding of the seismic damage mechanism of school buildings is obtained,which is expected to provide reference for the seismic design and reinforcement of school buildings.The main work of this paper includes:1.Sorted out and summarized the earthquake damage data of school buildings since the Wenchuan earthquake.Analyzed the failure phenomena and characteristics of different structural forms of school buildings under the action of earthquake,and pointed out that eccentric and brittle were prone to defects of school buildings;2.Took a teaching building of Shuanghe middle school in Changning earthquake as an example to explore the failure mechanism of multi-storey corridor frame structure.The results show that the same longitudinal lateral displacement occurs in each vertical component driven by the floor slab.The weak brittle（small stiffness,poor ductility）component and the hard brittle（large stiffness,poor ductility）component are first to reach “deformation saturation” under the earthquake load,which leads to the collapse of the structure.3.Through shaking table model tests and three groups of quasi-static comparative experiments,the collapse process of the structure under earthquake action was reproduced.At the same time,the structure relationship and destruction mode of different vertical components under the horizontal reciprocating load were studied.The "deformation saturation" mechanism of structural earthquake disaster was further verified.The above research shows that the reason for the damage or collapse of school buildings is not empty.However,due to the “internal force condensation” of vertical hard and brittle components under seismic action,the first “deformation saturation”occurs brittle failure,and causes the overall damage and even collapse of the structure at last.Only by balancing the stiffness and increasing the ductility of the members can we reduce “internal forces concentration” and avoid the collapse of the structure due to the “deformation saturation” of the components.