Seismic Performance Analysis Of Rocking Single-span RC Frame Structure Based On OpenSees

The conventional seismic design method is based on the conception of ductility seismic design,which is at the expenses of the lost of component failure or structure failure,leading to expensive maintenance costs or serious damaged.The seismic fortification of “No Collasping With Strong Earthquake” has' t satisfied the requirements of modern society.Single-span RC frame structure(SS-RCFS)has been seriously damaged or collapsed in previous earthquakes.In this paper,A new seismic design methods was proposed,basing on the characteristics of single-span RC frame structure and the mechanism of structure rocking shock absorbing.The column base of single-span RC frame structure was placed in cup-shaped foundation.The frame column is connected with the cup-shaped foundation through rubber,and the metallic dampers was arrangement at the top of foundation,allowing superstructure limit uplift relate to foundation at cyclic loading--Rocking single-span RC frame structure(RSS-RCFS).In this constitution,the model of rocking single-span RC frame structure was established by the finite element software OpenSees.The curve of column uplift,the curve of horizontal displacement?inter-story displacement angle,maximum acceleration,story shear force and the ratio of base shear between SS-RCFS with RSS-RCFS was obstracted by elasto-plastic time-history analysis.The influence of intensity of ground motion?structure aspect ratio and the yield strength of metallic dampers to structure seismic performance were studied.The research contents and main conclusions are as follows:1.The principle of wave-chose was certain,then two long-period ground motions and three short-period ground motions were choose for this study.The reason of put forward rocking single-bay RC frame structure,the establishment of the model and the certain method of relative design parameters was introduced.2.The influence of intensity of ground motion to rocking single-span RC frame structure was studied by numerical analysis.The results showed that: as the increase of the intensity of ground motion,the vertical displacement response and horizontal displacement response of RSS-RCFS column base increased obviously;The vertical displacement response and horizontal displacement response at the action of long-period ground motion is more stronger than the action of short-period ground motion,and the discipline of displacement response of column base was not founded.Relative to single-span RC frame structure,the inter-story displacement angle,maximum acceleration and story shear force of rocking single-span RC frame structure was decreased obviously,and the ratio of base shear between SS-RCFS withRSS-RCFS decreased.It's explain that the seismic performance of RSS-RCFS is increased as the increasement of the intensity of ground motion,but seismic reduction efficiency is different for different ground motion.3.The column uplift response,inter-story displacement angle and story shear force of rocking single-span RC frame structure when structure aspect ratio equal to 2.29,2.86 and3.45 was studied.The result shows that: as the increase of structure aspect ratio,the column uplift response of RSS-RCFS increased obviously.Relative to SS-RCFS,the inter-story displacement angle of RSS-RCFS,the ratio of base shear between SS-RCFS with RSS-RCFS decreased.It's explain that the seismic performance of RSS-RCFS increased,as the structure aspect ratio increase.4.The uplift of column base,inter-story displacement angle and story shear force of RSS-RCFS was studied,when the yied strength of metallic dampers equal to 100 Mpa and235Mpa.The result shows that: the uplift of the column base is more obvious,and the inter-story displacement angle and the story shear force are smaller,when the yield strength of the metal damper is 100 Mpa.It have better seismic performance,but the effect is not obvious.