循环荷载作用下非对称配钢型钢混凝土柱性能退化试验

Experiment of performance deterioration of shape steel reinforced concrete columns with unsymmetrical steel reinforcing under cyclic load

通过24根T形、L形配钢型钢混凝土柱低周反复加载试验,对水平低周反复荷载和恒定轴力作用下非对称配钢型钢混凝土柱的强度、刚度退化规律进行研究.基于试验结果建立三线型刚度退化模型,对刚度退化规律进行数学描述,分析轴压比、剪跨比、配箍率以及拉结筋等因素的影响.结果表明,剪跨比越小,强度衰减和刚度退化越明显;轴压比越大,强度衰减越快;轴压比越小,刚度退化越快;提高配箍率可以延缓试件强度衰减,但对刚度退化影响不大;配置拉结筋对试件的强度和刚度退化有一定的抑制作用;所提出的刚度退化模型能较好地反映试件在地震作用下的滞回性能.

The strength and stiffness degradation patterns of unsymmetrical shape steel reinforced con- crete columns under low-cyclic horizontal load and constant axial compression were investigated by means of low-cycle repeated loading test of shape steel reinforced concrete columns with 24 T-shaped and L- shaped steel reinforcing. Based on the test results, trilinear stiffness degradation model was established to describe the degradation pattern mathematically. The influencing factors such as shear span ratio, axial compression ratio, stirrup ratio, and cross ties were analyzed. The result indicated that columns with low- er shear span ratio would possess more obvious strength and stiffness degradation. Higher axial compres- sion would lead to quicker strength attenuation and slower stiffness degradation. Larger stirrup ratio could delay the strength attenuation, but affect the stiffness degradation hardly. The presences of cross tie would have certain positive effect to restrain the strength and stiffness degradation. The proposed stiffness degradation model could well reflect the hysteretic behavior.