性能增强再生混凝土框架结构模型双向模拟振动台试验

Bi-directional analog shaking table test on performance-enhanced recycled aggregate concrete frame structure model

基于课题组前期有关性能增强再生混凝土（EC—RAC）基本材性、构件等试验结果，设计并制作了一缩尺比例为1：4的3层含有多种类再生混凝土的框架结构模型，并进行了双向模拟振动台试验研究，得到了该框架结构模型的自振频率、阻尼比、结构振型、加速度响应、位移响应、层间位移角等变化规律，结果表明：EC—RAC相较于普通RAC能够较好的控制裂缝的出现与发展，从而改善结构的延性，提高结构的整体抗震性能；随着地震烈度的逐渐增加，结构损伤累积，自振频率逐渐降低、阻尼比逐渐增大、加速度放大系数亦逐渐降低、位移幅值逐渐增大，同时位移幅值的曲线形式与结构第一振型相近，表明结构振动时以第一振型为主；模型经历了七度多遇至八度罕遇各地震作用后，层间位移角均未超过规范中所规定的1／50，上述试验结果均表明，所设计的RAC框架具有良好的抗震性能，完全满足规范中的要求。最后，参考《建筑地震破坏等级划分标准》、《建筑抗震设计规范》（GB50011-2010）等文献，同时考虑各阶段试验现象，建立了能够应用于实际RAC结构震后破坏等级定量评估的5级划分。

According to the preliminary test results for the basic material properties and components of performance- enhanced recycled aggregate concrete （EC-RAC） , a 1/4 scale frame structure model of three floors built from several types of recycled aggregate concretes was designed and manufactured. Then, the bi-directional analog shaking table test was carried out for the model to obtain the variation laws for natural frequency of vibration, damping ratio, structural vibration mode, acceleration response, displacement response and story drift. The results indicate that compared to the ordinary recycled aggregate concrete, EC-RAC can better control the occurrence and development of cracks, leading to the improved structural ductility and enhanced seismic performance of the entire structure. With the increase of seismic intensity, structural damage gradually accumulates, the natural frequency gradually descends, the damping ratio gradually ascends, the acceleration amplification factor gradually decreases, and the displacement amplitude gradually increases. Meanwhile, the curve pattern of displacement amplitude is similar to the first vibration mode of structure, indicating that the structure vibrates primarily in the first vibration mode. After experiencing various earthquake actions from frequently occurring seven-degree earthquake to rarely occurring eight-degree earthquake, the story drift does not exceed 1/50 of the stipulated value in specification.The test results show that the designed RAC frame structure possesses a good seismic resistance and completely meet the requirements in specification. Finally, with reference to The Building Grading Standards of Earthquake Damage, Code for Seismic Design of Buildings（ GB 50011-2010）and other literature and with test phenomena in various stages taken into account, A 5-grade quantitative assessment criterion for post-earthquake damage of RAC structures, which can be applied to engineering practice, was established.