【摘要】 研究砌体加层隔震结构体系下部结构出现损伤后的抗震性能,重点关注隔震层上部、下部结构频率比变化对下部结构响应的影响。采用随机振动理论推导加层隔震体系与加层非隔震体系下部结构加速度响应均方值比,给出了下部结构加速度响应均方值比随频率比的变化规律,分析表明对于加层隔震结构,出现损伤前隔震效果明显,但随着下部结构刚度的不断退化,加层隔震体系下部结构的地震响应会超过加层非隔震结构体系。对加层隔震和加层非隔震结构进行了振动台试验研究,对比试验模型损伤前后各楼层加速度反应,分析其损伤前后减震效果的变化,试验结果表明,初始加层隔震模型地震响应明显小于加层非隔震模型,但随着加层隔震结构下部砌体的不断损伤,加层隔震体系的减震效果逐渐降低,下部结构甚至出现了加速度反应被放大的不利现象,试验现象和数据与理论分析结果吻合良好。在加层隔震结构的分析和设计中必须考虑下部结构出现损伤后对结构的不利影响。更多还原

【Abstract】 The increasing frequency ratio of a super-sub structure has a great influence on aseismic performance of the substructure of the isolated masonry with an added storey.The Root-Mean-Square(RMS) ratio of the substructure response in an isolation structure and a no-isolation one is developed by random vibration theory.The variation law of the RMS ratio of the substructure acceleration with the different frequency ratios is analyzed.The results show the isolated structure has a good aseismic performance before it damaged.But the seismic response of substructure is increased with the stiffness degeneration.The acceleration response of the isolated structure can exceed the no-isolated structure.A shaking table test for an isolated structure with added storey and a no-isolated structure with an added storey was carried out.The variation of damping effect was analyzed by the comparison with the floors acceleration responses between sound and damaged structure.The experiment shows that the acceleration responses of an initial isolated model were smaller than that of a no-isolated model.But the damping effect of the isolated structure was reduced with the damage of the substructure and the acceleration responses were even exaggerated.The results show a good agreement with theoretical conclusions.The negative influence of the damaged substructure must be considered in the design for the isolated structure with an added storey.更多还原