| Previous earthquake investigations show that 95% of the disaster losses are mainly caused by structural damage.However,the potential risks of earthquake disaster-bearing bodies are innumerable,which has become the key shortboard restricting the improvement of earthquake disaster prevention and control capacity in China.The new generation of Seismic ground motion parameters zonation map of China(GB18306-2015)improves the seismic fortification standards of most cities and towns,cancels the nonfortified areas,and adjusts the seismic fortification grade and site characteristic period of 2860 cities and towns.Whether the anti-seismic capacity of all kinds of buildings built in different ages meets the requirements of current codes,whether there are hidden dangers and risks of earthquake disasters,and how to identify and prevent them scientifically are urgent problems to be solved.RC frame structures are widely used in public buildings such as teaching buildings,hospitals,factories and shopping malls because of their flexible spatial arrangement and good seismic performance.Therefore,this paper takes RC frame structure teaching building as the research object,studies and establishes a fuzzy comprehensive evaluation method of seismic capacity considering the influence of multiple factors,which can provide theoretical and technical support for earthquake disaster risk investigation and seismic reinforcement of buildings in China.The following work has been accomplished in this paper:Firstly,the current evaluation methods of structure earthquake-resistance capability are briefly introduced.By analyzing the typical seismic damage of reinforced concrete frame structures,the main factors affecting the seismic performance of frame structures are summarized.Based on the prototype of double-span and multi-span corridor frame structure teaching building,five kinds of analysis conditions are set up,including fortification intensity,site condition,regularity degree,material strength and number of stories.Then,using SAP2000 structural analysis software,Pushover analysis is carried out on the different working conditions of teaching buildings to obtain the maximum interstory displacement angle and damage state of the structure under different seismic intensity.The influence rules of five factors including fortification intensity,site type,rule degree,material strength and number of stories,on the seismic capacity of the structure are analyzed and summarized,which is the evaluation system of seismic capacity.The determination of weights of influencing factors provides objective basis.Then,a fuzzy comprehensive evaluation model of seismic capacity of reinforced concrete frame structure teaching building is established.The main factors affecting the seismic capacity of the frame structure are taken as the base floor,and specific classification indexes are set up.The evaluation results are expressed by the seismic damage index fuzzy set.By means of fuzzy analytic hierarchy process(FAHP),combined with the weight coefficients of existing methods for earthquake damage prediction of frame structures and the results of Pushover analysis under different conditions of influencing factors,the weight coefficients of influencing factors are objectively and subjectively synthetically weighted,and the membership relationship between influencing factors and earthquake damage index in common intensity areas of moderate and strong earthquakes(degree VI~X)is given by means of fuzzy mathematics.Finally,the weighted average of the weighted coefficients of the influencing factors and the single factor evaluation matrix is used to obtain the evaluation results of the seismic capacity of the structure.The model is used to evaluate three teaching buildings of frame structure in Ya'an City,Sichuan Province.The evaluation results are consistent with the actual earthquake damage in Lushan earthquake,and the reliability of the method is verified. |
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