高轴压比焊接环式箍筋混凝土柱抗震性能试验

Experiments on seismic behavior of concrete columns with welding ring stirrups under high axial load ratio

通过对10根焊接环式箍筋约束高强混凝土柱低周反复荷载作用下的拟静力试验,探讨配箍率、(高)轴压比和箍筋形式对构件抗震性能的影响。主要从试件在模拟地震作用下的破坏形态、承载力、滞回特性、刚度退化等方面分析该试件的抗震性能及耗能机理.试验结果表明:在高轴压比下,焊接环式箍筋柱较普通箍筋柱具有更好的抗震性能;增大轴压比和配箍率可以提高构件的承载力;轴压比在0.8、0.9时位移延性系数为3.12~4.26,等效黏滞阻尼比为0.44~0.49,三组配箍率柱子的延性系数和耗能指标均能满足抗震设计要求;同时在轴压比达到1.0时,构件在配箍率为4.24%时也可以满足抗震要求。

This paper analyzes the seismic performance for the column of different axial load ratios,stirrup ratios and stirrup forms through the pseudo-static test under low cyclic loadings of 10 test specimens,all of which are high-strength concrete columns with welding ring stirrups.The seismic performance and energy dissipation mechanism of the tested structure is evaluated based on destroying patterns,load carrying capacity,hysteretic curves and stiffness degradation.The test results show that welding ring stirrups present better seismic behavior than ordinary forms of stirrups under high axial load ratio.The bearing capacity of the specimens are improved by increasing the axial load ratio and stirrup ratio.When the axial load ratio is 0.8 or 0.9,the ductility coefficient varies from 3.12 to 4.26 and the equivalent viscous damping ratio varies from 0.44 to 0.49,the columns of three stirrup ratio can meet the requirements of aseismic design.When the axial load ratio is 1.0,the 4.24% stirrup ratio can also meet the aseismic requirements.