| Earthquakes are among the most powerful natural disasters which bring about great harm to human being. A damaging earthquake will cause huge economic and social loss on human society. Even the national security and social stability would be under threat. China is one of the most powerful earthquake activity and serious earthquake disaster countries in the world. This paper makes a study of the seismic response of truss arch under the strong earthquakes. The Analysis can improve the insufficient in the phase of elastic design. A defense mechanism which to answer the earthquake load for such system will set up effectively. The method of existing seismic design and performance-based seismic design shall be compared. Ensure structure will not collapsed when earthquake, especially the rare earthquake. So the structure can assume the function of earthquake shelters. It also analyzes the different seismic response that dissimilar section form under the earthquake effects. The structural design will have more rational choices of cross section shape in the different structure. When an earthquake comes, the buildings can protect the safety of lives and properties of the people. So this study has enormous economical value and social value.In this paper, the elasto-plastic dynamic analysis on the steel spatial arch truss with90m span and0.25rise-span ratio is carried out under earthquake wave with SAP2000,Based on the seismic design performance,to discuss the different amount, ductility index and failure modes of the steel when the structure have the the different section form.1、In elastic design stage,Select the section follow some rule,the top boom and lower boom control strength stress ratio near1.0, the chose of Web members control the bar of slenderness ratio,And then analysis the structure modal,to get the natural period of vibration and mode of vibration of the steel spatial arch truss,Understand the stiffness,quality distribution degree and the order modes of vibration form of steel tube arches of the truss。2、This article through to build three different section forms of steel arch truss model,respectively is poured triangle section, are triangle section, trapezoidal section.Choose three different seismic wave (Shanghai artificial wave, Hollywood wave, LWD wave) to analyze different section of the form of the steel tube arches of truss in wave under the action of dynamic response。3、Use the PUCHOVER to analysis three models, With the analysis to get the internal force and deformation of the structure,,And with the earthquake demand or directly estimate the structural performance point, Approximate get anti-seismic performance of structure under the action of seismic,Thus to achieve the aseismic property for the evaluation.0In this paper the main conclusion that are as follows:1、In the sane span and rise-span ratios condition, the steel quantity of trapezoidal section is the largest, the numerical value of the pour triangle section and regular triangle section are close。2、No matter what kind of the section,the the structure of vertical stiffness is less than level stiffness,the vertical displacement response is the structure of the main displacement response,the vertical deformed capacity and energy-dissipation capacity are all smaller than the horizontal deformed capacity and energy-dissipation capacity。3、Three different section forms of steel arch truss model,No matter what kind of waves, the ductility coefficients are good,The results show that its failure mode under the earthquake action is elasto-plastic dynamic buckling,accord with the application needs need,This shows that in the sane span and rise-span ratios condition,the force performance of structure is similar,the different kinds plays unimportant role to bearing capacity of of section forms of steel arch truss。4、With the time-history and PUCHOVER analysis, the structure is designed according to frequent earthquake of8°,bar stress control in the1.0or so,Structure can resist the shock of intermediate level of8°, but not enough to resist action of the rarely met earthquake。... |
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