地震下RC空心墩弯-剪数值模型及混合试验验证OA北大核心CSTPCD

Seismic action on reinforced concrete hollow-section medium-high piers often results in bending-shear failure.However,studies on numerical simulation for their coupled bending-shear be-havior are not yet fully developed.Addressing the issue that current shear models in bending-shear se-ries models do not consider the characteristics of hollow sections,this paper proposes a method for modifying the shear model based on key parameters and verifies it through hybrid testing.By focusing on parameters such as the shear span ratio of the pier,post-cracking shear stiffness of the concrete,equivalent cross-section area,effective height of the pier,and the inclination angle of the concrete di-agonal cracks in the pier,this paper proposes a modification method for the key parameters of the shear model.Based on the corrected cracking shear strength,cracking shear displacement,ultimate shear capacity,and its corresponding shear displacement and shear failure displacement,a trilinear skeleton curve establishment method suitable for simulating the shear performance of hollow piers was proposed.By combining the shear model with a bending model based on fiber elements,a numerical model for the coupled bending-shear response of hollow piers was established.Comparison with the hybrid test results of a hollow high-pier bridge validated the numerical simulation method through the physical test results of the pier substructure.Results showed that the bending-shear hysteretic curves provided by the numerical model matched well with the experimental curves under real seismic loading paths.The proposed model can accurately simulate the bending-shear hysteretic behavior of hollow piers under actual earthquake loading conditions.