预制再生混凝土框架模型模拟地震振动台试验

Shaking Table Test on Precast Recycled Aggregate Concrete Frame Structure Model

摘要:

选用不同地震波，通过模拟地震振动台对首例1/4缩尺再生粗骨料取代率为100%的预制再生混凝土框架模型进行了3种地震波输入试验.通过白噪声扫描得到了该模型结构的自振频率、结构振型、阻尼比等动力特性，研究了加速度、楼层剪力、位移动力反应，记录了结构在试验中的开裂等现象.试验分析表明，随着地震动峰值强度的增加，模型呈现自振频率下降、阻尼比增大、加速度放大系数逐渐降低、楼层剪力逐渐增大的趋势；在弹塑性阶段后期，后浇节点刚度退化迅速，层间位移明显增大.采用层间位移作为评估标准，对预制再生混凝土框架的抗震能力进行了评价，表明预制再生混凝土框架抗震性能良好，但应采取必要措施加强梁柱节点的耗能能力.

Abstract:

A one fourth scaled precast concrete frame structure model, which was made of recycled aggregate concrete(RAC) with 100% replacement percentage of recycled coarse aggregate, was tested on the shaking table with 3 different seismic wave inputs. Dynamic characteristics such as natural frequency, vibration mode, damping ratio were assessed through white noise scanning. Acceleration, inter storey shear force and displacement dynamic response were investigated. Damage phenomenons during the test were described in detail. The test analysis indicates that the natural frequency descends, the damping ratio ascends and the acceleration amplifying factor decreases gradually, the inter storey shear force increases gradually with the increase of seismic intensity. In the later elasto plastic stage, the deterioration of joint stiffness is quite rapid and the inter storey drift is much larger obviously. The inter storey drift is adopted as the index to evaluate the seismic performance of the precast RAC frame structure, which shows that the precast RAC frame structure has good seismic performance and some measures should be taken to enhance the energy dissipation of the beam column joint if it is applied to practice.