基于修正压力场理论的型钢超高强混凝土柱受剪承载力研究

为分析型钢超高强混凝土柱受剪机理，并准确计算其受剪承载力，基于修正压力场理论提出型钢超高强混凝土柱的受剪承载力计算模型。该模型通过柱端部截面中心正应变ε0来考虑轴力、弯矩和剪力的相互作用，并通过关键参数混凝土主压应力角θ和平均纵向应变εx来反映剪跨比、轴力以及配箍对柱受剪承载力的影响。推导出型钢超高强混凝土柱受剪承载力的计算式，并分析其两种剪切破坏形式。通过两组型钢超高强（高强）混凝土柱的低周反复试验结果对该受剪模型进行验证。研究表明：模型能合理考虑轴力、弯矩和剪力的相互作用，反映剪跨比、轴力和箍筋对受剪承载力的影响；模型计算所得受剪承载力与试验值吻合较好。

Shear strength of steel reinforced high strength concrete columnsbased on modified compression field theory

An effective model based on modified compression field theory was proposed for estimating shear strength and analyzing shear mechanism of steel reinforced high strength concrete columns. Centroidal strain of the end cross-section was employed for considering the axial-flexure-shear interaction and effects of shear span ratio, axial force and stirrups on shear strength of columns were considered through the angle of inclination of principal stress and the average strain in longitudinal direction according to the proposed model. Then shear design formulas were developed and the two shear failure modes of steel reinforced high strength concrete columns were analyzed based on the model. At last, the proposed model was validated by comparing predictions of the model with experimental results of steel reinforced high strength concrete columns subjected to constant axial forces and reversed cyclic horizontal loads. The results indicate that, the model considers the interaction of axial, flexural and shear mechanisms, and reflects the effects of shear span ratio, axial load and stirrups on shear strength rationally.