非对称配钢型钢混凝土柱受剪机理及承载力研究

Shear mechanism and bearing capacity study of steel reinforced concrete columns with unsymmetrical steel reinforcement

为揭示非对称配钢型钢混凝土柱的受力特点和破坏机理,考虑剪跨比、轴压比、体积配箍率以及拉结筋等4个影响因素,对12个T形配钢型钢混凝土柱进行了水平低周往复荷载试验。对水平低周反复荷载和恒定轴向荷载作用下试件的受力过程和破坏特征进行了研究,结果表明:非对称配钢型钢混凝土柱具有较好的滞回性能和耗能性能,其破坏形态主要有弯曲破坏、剪切斜压破坏和剪切粘结破坏三类。通过实测型钢腹板和箍筋的荷载-应变滞回曲线,分析了试件在不同阶段的受力状态,基于破坏机理和力学分析推导了T形配钢型钢混凝土柱发生剪切斜压破坏和剪切粘结破坏时的受剪承载力计算公式,计算结果与实测值符合较好。

To investigate mechanical characteristics and failure mechanism of steel reinforced concrete （SRC） columns with unsymmetrical steel reinforcement, 12 columns with T-shaped steel reinforcement were tested under low cyclic loads considering the influence of shear span ratio, axial compression ratio, stirrup ratio and presence of cross tie. Loading process and failure characteristics under low cyclic loads and constant axial loads were studied. It is shown that the columns have good hysteretic characteristics as well as dissipation capacity and the failure patterns of the SRC columns with unsymmetrical steel reinforcement contains bending failure, shear-bond failure and shear compression failure. Based on the analysis of the load-strain hysteretic curves of steel web and stirrups, different mechanism states of specimen in different stages were analyzed. And according to the mechanical analysis and failure mechanism results, the calculation formula of shear capacity was established under the modes of shear compression failure and shear-bond failtlre. The results of formulas agree well with the test data.