Preliminary Study On Seismic Damage Prediction Method Of Masonry Structure Considering The Effect Of Ring Beam And Structional Column

Masonry structure has many advantages,such as wide distribution of raw materials,low cost and good fire resistance.It has a long history in China and is widely used in urban and rural buildings such as residential buildings and office buildings.At the same time,the brittleness of masonry structure in resisting horizontal earthquake action can not be ignored.It is found that the earthquake damage of masonry structure is very serious through the investigation of engineering damage in the earthquake field.With the deep research in engineering field,the seismic capacity of masonry structure can be effectively improved by setting ring beam and structural column in masonry structure.Scientific and effective earthquake damage prediction of masonry structure can provide technical support for its vulnerability analysis and earthquake prevention and disaster reduction planning.However,most of the previous seismic damage prediction methods of masonry structures are based on the seismic damage data of unfortified masonry structures,which need to be further improved to meet the development needs of society.Therefore,it is necessary to modify the original method in order to make the results of earthquake damage prediction more accurate.Firstly,the existing methods for predicting seismic damage of masonry structures at home and abroad are divided into six categories and summarized,and their advantages and disadvantages are analyzed.Based on the Yin Zhiqian's deterministic method for vulnerability analysis of masonry stucture(referred to as "Yin method"),which is widely used in vulnerability analysis of masonry stucture,the principle and application process of this method are described in detail.It is pointed out that the method needs to be further modified,and a new correction coefficient-structural column correction coefficient is introduced,which lays a theoretical foundation for the following work.Secondly,the paper introduces the development of masonry structure in China and its advantages and disadvantages.Through the detailed analysis of the earthquake damage,the failure law and failure mechanism of the masonry structure are revealed.At the same time,the working principle of ring beam and structional column is briefly introduced,and the corresponding relationship between the number of constructional column and the actual seismic damage is derived by comparing the phenomenon of earthquake damage of masonry structure with or without protection.Finally,the plane layout of Xuankou middle school teachers' dormitory(the southwest)is selected as the prototype,and the working conditions are set strictly according to the layout requirements of ring beam and structional column in GBJ11-89,GB50011-2001 and GB50011-2010.The finite element software Abaqus was used to analyze the time-history,obtaining the maximum displacement angle of each working condition,and the variation law with the number of layers,intensity of fortification and PGA was analyzed.Through the mathematical relationship,the corresponding relationship with the earthquake damage index is found,and combined with the results calculated by the "Yin method",the structural column correction coefficient is finally obtained,which takes into account three factors,namely,the number of storeys of the structure,the fortification intensity and the intensity of the earthquake encountered.The changing law of the correction coefficient is discussed to supplement the original correction coefficient.At the same time,the corresponding empirical formula is fitted.Finally,the examples of earthquake damage are selected to verify the accuracy of the modified "Yin method".The results show that the modified coefficient can reflect the effect of the ring beam and structional column on the seismic performance of masonry structure The purpose of revising the "Yin method" has been achieved.