| High-strength steel bars have high strength,good economics in the structure and good environmental performance.Promoting the application of high-strength steel bars in engineering construction is an effective means to implement the scientific development concept,implement the goal of energy saving and emission reduction,and achieve sustainable development of the construction industry.Although many scholars have done a lot of research on the bearing capacity,deformation capacity and seismic performance of high-strength steel members,the theory analysis of the seismic performance of structures with high-strength steel bars are relatively lacking.The frame-shear wall structure is widely used in practical engineering,but there are few theoretical studies on the seismic performance of such structures with high-strength steel bars,especially in the study of seismic response of such structures under bidirectional earthquake motions.Therefore,it is necessary to carry out further in-depth study on the seismic performance of high-strength reinforcement frame-shear wall structure.According to China's current design specifications and targets three fortification zones of 7 degrees(0.15g),8 degrees(0.3g)and 9 degrees(0.4g),this paper intends to disign the frameshear wall structure with HRB400,HRB500 and HRB600 steel bars as the longitudinal reinforcement which configured separately in beams,columns,and wall components.And do the elastoplastic time history analysis under the action of rare level earthquake that under bidirectional earthquake input base on OpenSEES software.And from the two aspects of overall structural displacement and component local reaction to study and summarize the regular seismic response pattern of high-strength reinforcement frame-shear wall structure and get the following conclusions:(1)The amount of steel bars in the structure is gradually reduced after the HRB500 and HRB600 high-strength steel bars are placed as the main stressed steel bars in the main forcebearing members of the structure,which adopted the "equal strength substitution".But the more sections are controlled by the minimum reinforcement ratio at the same time.The steel dosage of frame-shear wall structure reinforced with HRB500 and HRB600 steel bars under different seismic fortification intensity zones is reduced by about 10% and 15% respectively compared with the HRB400 one.(2)From the perspective of the overall seismic response of the structure,the structure has similar laws under the 7th,8th and 9th degrees.With the increase of the reinforcement level,the apex displacement and interlayer displacement angle of the structure showing a slight increase but still meet the displacement limit requirements.The shear force of the layer and the shear force distribution between the frame and the shear wall have no obvious law.Judging from the maximum interlayer displacement angle,the different reinforcement structures in the three seismic intensity zones are between the medium damage performance level and the not severe damage performance level under rare earthquakes.And the structural damage degree of different strength reinforcement is close.In general,the change of the steel bar strength has no significant effect on the overall seismic response of the frame-shear wall structure.(3)From the perspective of local seismic response of the structure,with the increase of the reinforcement level,the ratio of the maximum corner and the rotation capacity of the rod end of the member which of the same fortification intensity zone is increased,while the ductility requirement of the beam and column is reduced,and the component hinge rate is significantly reduced and the first hinge time is postponed.It shows that the structural members of HRB500 and HRB600 high-strength steel bars have a larger reserve of plastic rotation capacity,and their seismic performance is improved from the component level.In general,the high-strength reinforcement can improve the local seismic response of the frame-shear wall structure to some extent.(4)Combined with the overall and local aspects of the structure,the placement of highstrength steel in the main force-receiving members of the frame-shear wall structure does not impair the overall displacement response of the structure,and can improve the local seismic response performance of the structure to some extent.Under the rare earthquake,the structure can meet the seismic fortification target of big earthquake does not fall,indicating that the frame-shear wall structure with high-strength steel bars has good seismic performance. |
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