Safety Analysis And Prediction Of Existing Masonry Structure

Due to the advantage of its local materials,simple construction method and good physical properties,masonry structure was a common structure form of civil building in our country.All previous disasters show that when the wall used as the main bearing and lateral resistance members of masonry structure,the wall damaged serious.Based on this phenomenon,in order to guarantee the safety of existing masonry structure,it's particularly important to research the shear reliability index of the wall.The shear reliability index is influenced by many factors.One is formed in the process of design and construction,such as mortar strength grade,ratio of openings and aspect ratio of wall,etc.One is formed in the process of serving,such as cracking and spalling of masonry materials under internal or external loads or environmental effect.In addition to too many factors' s problems,there are exist other problems,such as the uncertainty of factors' s parameter as well as the uncertainty of calculation model of reliability analysis and so on.To solve above problems,the main contents and achievements of this paper are as follows:(1)From the perspective of building wall's shear reliability performance function,this paper desiges pseudo static tests of 6 pieces of unreinforced masonry walls one single-layer masonry structure,and studies the shear reliability index of the walls under the factors such as mortar strength grade?ratio of openings?aspect ratio of wall and the asymmetry damage of the structure.(2)In order to deal with the uncertainty of resistance parameters,Based on bayesian inference method,modifies the test compressive strength results of masonry material by it's springback and penetration results,and gets posteriori probability density functions of fired common brick and mortar.The results pointed out that this method can give a priori information and the measured information a reasonable weight,and reduce the parameters' uncertainty,which is advantageous to analyse the the safety of masonry wall.(3)The performance function of wall shear reliability are established,then calculate and analyse shear reliability index by the checking point method.The results pointed out that the shear reliability index of wall decreased when the wall have lower mortar strength grade?larger ratio of openings?larger aspect ratio or the wall damaged.(4)Generating initial samples of shear strength randomly according to the distribution of wall's parameters.Then trains the initial samples by GPR prediction model,and gets probability density functions and shear reliability index directly.Which can avoid the iterative computation and improve the computational efficiency.Comparing the shear reliability index under the GPR prediction model and the checking point method,the shear reliability index results show that the GPR prediction model agree well with checking point method,and the former is more safe on reliability analysis of masonry structure...