Seismic Response Observation of Super High-Rise Buildings Throughout their Construction Stage and Development of Long-Stroke Shaking Table for Tracing Long-Period Floor Response

本研究以超高层建筑施工期的大量观测数据为基础，研究了超高层建筑的基本动力特性。为了了解不同楼层数的结构相似建筑物之间结构反应的差异，可以在施工期间对单个建筑物进行观测，因为当不同楼层数完成时，地震可能在整个施工期发生。在这项研究中，观察到了三座超高层建筑。我们阐明了自振周期与建筑高度近似成正比，而阻尼比则成反比。对于具有小阻尼的长周期建筑，当自振周期接近土的优势周期时，对于长周期地震动而言，建筑的地震反应会得到极大的放大。这一现象是从两个观测…解释的多而简单地分析了一个单自由度系统。自振周期和阻尼比的变化是从一座47层建筑在建时的微震记录中获得的。对于第一阶和第二阶振型，自振周期几乎与建筑物高度成线性增加，而阻尼比则分散在0.5%左右。这个阻尼值与钢材本身的材料阻尼值相对应。为了促进超高层建筑对抗预测的大地震引起的长周期地面运动的对策，有必要通知结构设计者和建筑物业主，建筑物可能因共振而遭受意外的大响应。为了确保结构设计者和建筑物业主意识到这种风险，他们有必要体验楼层响应量。然后，他们将了解室内区域安全措施的必要性以及增加阻尼器以减少响应的重要性。由于用于驱动工作台的动态致动器的位移限制，传统的振动台不能再现这种运动。为了再现超高层建筑的反应，我们开发了一种新的振动台，名为“三重L振动器”，意为“长冲程长周期直线振动器”。这一想法的创新之处在于使用了两个伺服电机，从两侧拉动连接到钢轨上的振动台上的绳索，如图13和照片2所示。与普通的振动台相比，该系统不需要很大的空间或特殊的电源。该表再现了高达3米的位移幅度、5米/S的速度和2G的加速度。使用这张表，人们可以很容易地体验到各种建筑在不同的土壤条件下的任意反应。较少

In this research project, the fundamental dynamic properties of super high-rise buildings are investigated based on a large quantity of data observed during their construction stage. To understand the differences in structural response between structurally similar buildings with different numbers of floors, observations can be carried out in a single building during its construction, as earthquakes are likely to occur throughout the construction period when different numbers of floors have been completed. In this research, three super high-rise buildings have been observed. We clarify that the natural period is approximately proportional to the building height, while the damping ratio is inversely proportional. In the case of long-period buildings with small damping, when the natural period is close to the predominant period of soil, the seismic response of the building is enormously amplified for long-duration seismic ground motion. This phenomenon is explained from both observations … More and a simple analysis of a system with one degree of freedom. The changes in natural periods and damping ratios were obtained from microtremor records for a 47-story building while under construction. The natural period increases almost linearly with building height, both for the first and second modes, while the damping ratio is scattered around 0.5%. This damping value corresponds to the material damping of the steel itself.To promote countermeasures for super-high-rise buildings against long-period ground motions arising from predicted massive earthquakes, it is necessary to inform structural designers and building owners that buildings might suffer from an unexpectedly large response due to resonance. To ensure that structural designers and building owners are aware of this risk, it is necessary for them to experience the amount of floor response. They will then understand the necessity of safety measures for indoor areas and the importance of the addition of dampers to reduce the response.Conventional shaking tables are unable to reproduce this movement because of the displacement limit of the dynamic actuator used to drive the table. We developed a new shaking table named the 'Triple-L shaker,' which stands for he 'Long-stroke Long-period Linear shaker,' to reproduce the response of super-high-rise buildings. The innovation in this idea is the use of two servo-motors that pull the rope connected to the shaking table on the rail from both sides, as shown in Figure 13 and Photo 2. Compared with ordinary shaking tables, this system doesn't require a large space or special power supplies. The table reproduces amplitudes of displacement of up to 3 m, velocities of 5m/s, and acceleration of 2G. Using this table, people can easily experience the arbitrary response of various buildings upon different soil conditions. Less