Analysis On The Collapse Resistant Capacity Of Masonry Structure Under Earthquake

It is shown from seismic damage in history that masonry structures collapsed toomuch in strong earthquakes, causing enormous casualties and property losses. Based ona large number of material about seismic damage of masonry structures, the papersummarizes some factors which influence the anti-collapse capacity of masonrystructures. It gives several measures which can improve the anti-collapse capability ofmasonry wall with ring beam and constructional column by analyzing and discussing itscollapse mechanism. Researches on anti-collapse performance of masonry structure fordifferent space volume has been done, which is significant for estimating the masonrystructure anti-collapse performance and forecasting seismic damage in majorearthquake.The main works have been done as below:（1）According to organizing a large number of materials about seismic damage,the seismic damages of masonry structures are summarized. Depending on differentusing function the teaching building with large space and the residential building withsmall space are analyzed to analyse and discuss the collapse mechanism of masonrywall.（2）The finite element software is selected reasonably and a systematic studyabout finite element analysis and software using is done. By comparing the constitutiverelationship of masonry, concrete and rebar from relevant literatures, separately, then getthe appropriate constitutive relationship applied to this study.（3）To check the rationality of reliability of modeling, a simple two-storiesstructural model of masonry is devised by using the ABAQUS. The modal calculation isconducted. It illustrates that the imitation is reliable by analyzing the mode shape andnatural vibration period.(4)36different space volume masonry structures are designed and analyzed byABAQUS software. Modal analysis and dynamic time-history analysis are carried outto each modal, to compare the natural vibration period, mode of vibration, tensiondamage cloud diagram and average value of damage parameters.(5) Damages of36modals are summarized, so propose anti-collapseperformance space characterization index, and get the relational graph of spacecharacterization index and damage level, and make frequency analysis and difference analysis about space characterization index.The main outcomes according to the studies above are as follows:(1) It gives several measures which can improve the anti-collapse capability ofmasonry wall with ring beam and constructional column by analyzing and discussing itscollapse mechanism.(2) By model building and analysis using the ABQUS, it conducts the modalcalculation of masonry structure. It checks that the imitation is reliable by analyzing themode shape and natural vibration period.(3) After comparing Modal analysis and time-history analysis results, it finds thatthe larger apace volume is, the more severe damage is.(4) By means of analyzing characterization index, its critical value for differentdamage level can be obtained, in7degree and8degree major earthquake separately. Itillustrates the rationality of the characterization index by analyzing its difference.