Seismic strengthenoing of existing old buildings with viscous damping devices

本研究的重点是开发合理的和低成本的方法，利用粘滞阻尼器的高阻尼性能，以提高地震稳定性的既有旧木屋，造成了大量的死亡人数在1995年兵库县南部地震。木结构的机械弱点是其脆弱的特性，特别是在许多连接处对抗张力。因此，我们的目标是在房子里分配一些小尺寸的油阻尼器。阻尼器设计成仅利用截止阀和减压阀来显示压缩阻力。阻尼器的规格已经确定，现在可以在商业基础上获得。已经证实，阻尼器的工作相当不错，以防止甚至地震不足的房屋倒塌时，受到非常强烈的地面运动。延伸的结构系统设置有固体基底，该固体基底被允许在铺在垫基础上的高聚合物片材上滑动。该系统的效果不如普通基础隔震系统，但它可以将顶层的最大加速度降低到400- 500 cm/s^2。还开发了一种用于防止建筑物和房屋的某些特定部分损坏集中的联动油阻尼器。通过全尺寸动力加载或振动台试验，这些结构系统的可用性得到了证实。利用扩展归一化特征环模型描述了各种木结构房屋的荷载-挠度关系，研究了这些结构体系的地震反应特性。分析表明，模型的初始阻尼特性对结构在强地震动作用下的最大位移影响较大。因此，本文还对建筑结构和房屋的阻尼系数进行了识别。

Our study was focused on development of rational and low cost method, taking advantage of high damping property of viscous dampers, to increase seismic stability of existing old wooden houses which caused a great deal of death tolls during 1995 Hyogoken Nanbu Earthquake. Mechanically weak points of wood structures are their fragile properties, especially against tension, at numbers of connections. So, we aimed at distributing a number of small size oil dampers in the house. Dampers are so designed as to exhibit compressive resistance only making use of stop and relief valves. Specifications of the damper were identified and now available on commercial basis. It has been confirmed that dampers work fairly well to prevent even seismically inadequate houses from collapse when subject to very strong ground motions. An extended structural system is provided with a solid base which is allowed to slide on the high polymer sheet spread over a mat foundation. The system is not that effective as normal base-isolation system, but it was found to be able to reduce the maximum acceleration of the top floor to be as low as 400-500cm/s^2. Also developed was a linked oil damper which works to prevent damage concentration to some specific part of the buildings and houses.Availability of those structural systems was confirmed through full scale dynamic loading or shaking table test. Seismic response behaviors of those systems are also studied making use of an original Extended Normalized Characteristic Loop model to represent load-deflection relations of a variety of wooden houses. It came to the light in this analysis that original damping property of the model affects much the maximum displacement when subject to strong ground motions. Therefore, identification of damping factor of building structures and houses are also conducted.