自复位RC框架柱脚节点在不同轴压比下的抗震性能试验研究

Experimental Study on the Seismic Behavior of Self-Centering RC Frame Column Base Joints Under Different Axial Compressive Ratios

自复位RC框架柱脚节点将无黏结预应力钢筋与新型金属消能阻尼器结合,在保证结构足够的承载力和耗能能力的前提下,能有效减小传统框架结构水平地震作用下产生的残余变形.对2个采用了新型可更换阻尼器的自复位RC框架柱脚节点进行了低周往复荷载抗震试验,对比分析了不同轴压比下框架柱脚节点的受力机制、滞回曲线、耗能能力、复位能力等性能.试验结果表明:自复位RC框架柱脚节点的耗能主要来自阻尼器的屈服耗能,不同轴压比下该框架柱脚节点的耗能能力大致相当;高轴压比导致框架柱产生轻微的塑性变形,从而使残余变形增大,相应的复位能力略有降低.

Self-centering(SC)RC frame column base joints can effectively reduce residual drift under horizontal seismic action with unbonded prestressed reinforcements and energy-dissipating dampers,in which unbonded prestressed reinforcements are compared with traditional RC frame and energy-dissipating dampers provide the energy dissipation capacity.Two specimens of SCRC frame column base joints with a new type of replaceable damper were designed and tested under cyclic horizontal loading.The mechanical behavior,hysteretic curve,energy dissipation capability,and SC capacity of the SCRC frame column base joints with different axial compression ratios were investigated.The energy dissipation capacities of the SCRC-frame column base joints with different axial compression ratios were found to be nearly the same because they were provided by the dampers.Moreover,the residual drift of the SCRC frame column base joints with high axial compression ratio is large and the SC capacity is slightly reduced.