Seismic Performance Study On Solid-web Steel Reinforced Concrete Frame With Special-shaped Columns

As a new type of structural form,steel-reinforced concrete special-shaped column structure inherits the advantages of high bearing capacity and good seismic performance of SRC structure,overcomes the shortcomings of ordinary concrete special-shaped column structure,and expands the applicable range of special-shaped column structure,making it highly resistant to earthquakes.Better use in fortification areas and high-rise buildings.At present,the research on the component level of SRC shaped columns is systematic,and has achieved certain scientific research results.However,there are few researches at the structural level,mainly focusing on the experimental research of planar frames.The research on spatial frame structure is extremely rare.In the early stage,the research group completed the low-cycle reciprocating test of the three SRC shaped column plane frame,and had a preliminary understanding of the seismic performance of the SRC shaped column frame.The unidirectionality of the force of the plane frame limits the variation of the load path.The number of hyperstatic times of the space frame is larger than that of the plane frame,and the excess constraint is internally distributed after the component is partially destroyed.The spatial characteristics of the structure make the reduction of the local bearing capacity compensated by the change of the load path.Therefore,the planar frame does not fully reflect the structural failure characteristics and seismic performance.In order to further deepen the understanding of the SRC special-shaped column frame and understand the synergy between the various frame structures,this paper uses the pseudo-static test method to conduct a seismic performance test on a two-span,two-span,five-story SRC space-shaped column frame.Through the seismic performance test of the SRC space-shaped column frame,the failure mode,strain and hysteresis curve of the model structure under low-cyclereciprocating load are obtained,and the bearing capacity,ductility,energy dissipation performance,stiffness degradation,displacement angle and Mechanical properties such as strength decay were analyzed.The results show that the damage is mainly concentrated in the three-frame frame along the loading direction.The damage of the three-frame frame in the vertical loading direction is slight;the middle frame yields and forms the plastic hinge before the edge frame;the damage degree of the side frame is larger than that of the middle frame;SRC The space-shaped column frame beam yields before the column,which satisfies the seismic design requirements of the "strong column weak beam";the hysteresis curve is anti-symmetric,the ductility and collapse resistance are better than the general reinforced concrete frame,and it has better energy consumption.performance.Through the OpenSees program simulation space framework,the finite element results and experimental results are compared and analyzed,and the two have a good agreement.Based on this,the beam-column bending moment-curvature curve and strain of the finite element model are analyzed,and the failure mechanism is obtained.By comparing the seismic performance of the space frame and the corresponding plane frame,the cooperative working mechanism of the space frame is analyzed.The asymmetry of the section and the thin and narrow columnar limbs make the special-shaped column have obvious bidirectional bending action,which leads to the strong sensitivity of the special-shaped column frame structure in the horizontal load direction.Based on this,under different loading angles The finite element model with different axial compression ratios and different column length to width ratios is established to study the SRC spatial special-shaped column frame,and the influence law of each parameter is obtained.