Analysis on dynamic eccentricity effect and torsional performance of steel reinforced concrete frame with special-shaped column

Abstract

Based on the seismic simulation shaking table test of steel reinforced concrete frame model with special-shaped column, the lateral-torsional vibration response, dynamic eccentricity effect and nonlinear torsion response law of the model structure are studied. The results show that, under the action of three-way earthquake, the Y-direction and X-direction horizontal torsion coupling phenomena occur in the high-order vibration mode of the model structure, and the accidental eccentric torsion has a light influence on the seismic performance of the special-shaped column structure which does not exceed the height limit. The nonlinear torsion analysis shows that the inter-storey displacement angle of the model structure is affected by floor position, eccentricity and ground motion intensity. As the eccentricity and seismic intensity increases, the inter-storey torsion Angle of the model structure increases constantly. In case the relative eccentricity is less than or equal to 0.5 and the peak acceleration is less than or equal to 0.62g, then the amplitude of the inter-storey torsion Angle of the model increases slightly; In case the relative eccentricity is more than 0.5, then the lateral-torsional coupled effect of earthquake response of the structure is obvious, and the influence of eccentricity on torsion effect of the model structure is more obvious. The results show that steel reinforced concrete frame with special-shaped column has good ductility and torsion resistance.