Seismic Upgrading of Clustered Wooden Houses by Damping Connection to Seismic Core Structure

本研究的目的是提出一种用于城市防灾的集群木结构房屋抗震改造方法。相邻的两个或多个木制房屋通过粘性或滞回阻尼器相互连接或连接到钢或钢筋混凝土建筑等抗震核心结构。这种阻尼连接使耗能得到提升，从而降低地震反应，从而达到城市防灾的目的。研究结果表明：(1)采用粘性阻尼器连接时，刚度和强度均小于抗震核心结构的木结构的地震响应随连接阻尼器阻尼系数的增大而单调减小。而当基本阻尼系数达到1.0左右时，地震反应的减振效果几乎达到上限。(2)在滞回阻尼器连接情况下，木结构的地震反应减小效果强烈依赖于输入地震的强度或频率特征，即滞回阻尼器的最佳性能将强烈依赖于输入地震。(3)粘性阻尼器连接建筑物的基本阻尼系数可以用“刚性结构连接”概念近似估计。基于这一概念，在连接建筑中相对较软的建筑通过阻尼器连接刚性结构的假设下，计算了基本阻尼系数。通过带阻尼器连接的比例结构模型振动台试验，验证了该方法的有效性。

The objective of this research is to propose a seismic retrofitting method of clustered wooden houses for urban disaster prevention. Adjacent two or more wooden houses are connected by viscous or hysteretic dampers to each other or to seismic core structure such as steel or reinforced concrete building. Such damping connection causes upgrading of energy dissipation and results in reduction of seismic response, and leads to urban disaster prevention.The findings of this research are stated as follows:(1)In the case of viscous damper connection, seismic response of wooden building with smaller stiffness and strength than seismic core structure decreases monotonically as damping coefficient of the connection damper increases. However, the reduction effect of seismic response reaches almost upper bound when the fundamental damping factor reaches about 1.0.(2)In the case of hysteretic damper connection, the reduction effect of seismic response of wooden building strongly depends on strength or frequency characteristic of input earthquake, i.e., optimum property of hysteretic damper for damping connection will strongly depends on input earthquake.(3)The fundamental damping factor of connected buildings by viscous damper can be approximately estimated by concept called "connection to rigid structure." Based on this concept, the fundamental damping factor is calculated under assumption that relatively soft building in connected buildings is connected to rigid structure by damper.The efficiency of the proposed seismic reinforce method is demonstrated through shaking table tests on scaled structure models with damper connection.