Seismic Research On Reinforced Masonry Structure Of Primary And Secondary School Buildings

In2008, the devastating earthquake was happened in WenChuan, the most serious ones were schoolhouses of masonry structure. In June of2009, the safety engineering of primary and secondary school buildings was launched formally across the country, and the seismic fortification category of primary and secondary schools improved from standard fortification to key fortification. At present, large numbers of masonry structure in primary and secondary school are built in the last century, In addition, according to the influence of environment and artificial factors, the seismic behavior of primary and secondary school buildings in service are decreased constantly, and will not satisfy the current code requirements. Therefore, seismic analysis need to construct on the existing primary and secondary school masonry structure buildings, and checking the seismic performance of reinforced structures hasimportant application value. The main contents are as follows,This paper introduces the characteristics of earthquake damage of masonry structure building and analyzes the reasons for this phenomenon. The common reinforcement method of masonry structure and the scope of application of the methods are discussed. Taking the gallery type masonry structure building in the Inner Mongolia Autonomous Region, Baotou City as an example, strengthening the teaching building is used the double reinforced concrete wall. The antiseismic checking calculation for the structure before and after reinforcement uses the dentification of reinforcement (JDJG) module of the PKPM design software. Both the vertical and horizontal comprehensive seismic capability index of each floor structure after reinforcement and wall resistance effects are more than1. The results meet the requirements of specification.Elastic analysis of the non strengthening project uses the mode decomposition response spectrum method with SAP2000finite element software. Its purpose is to get the internal force distribution of masonry teaching building. The concrete contents includes the following aspects: the shear of the lower part of the structure is greater than the upper shear; the wall between windows and window wall are the weak part of the structure; shear in the stairwell wall is larger than any other walls. The internal force distribution of the corridor of the longitudinal wall and cross wall near the corridor is complicated.By using the interlayer displacement angle of the performance index, it can evaluate the action of earthquake for the teaching building of frequent earthquake and rare earthquake performance.The results show when the structure is placed in the8degree earthquake, maximum drift angle is1/1872in Y direction,it is greater than1/2500to the maximum inter storey displacement angle, that does not meet the requirements of minor earthquake fortification. The structure of double thickness concrete wall is100mm,120mm,140mm. X direction are respectively1/12376,1/13774and1/15060to the maximum inter storey displacement angle, Y are respectively1/6329,1/7042and1/7692, were less than1/2500. which can meet the performance requirement of normal use. By using the method of Pushover analysis and the reinforcement of structure seismic performance evaluation of rare earthquake of8degrees, found the structure without reinforcement, the capacity spectrum curve and the demand curve does not intersect, does not meet the requirements of no collapse under rare earthquake fortification. Using the structure of double thickness concrete wall which is100mm,120mm,140mm. X direction are respectively1/1064,1/1261and1/1594to the maximum inter storey displacement angle, Y direction are respectively1/901,1/1188and1/1449, that are less than1/250. The performance level meets the safety requirements.