ABSTRACT

A novel three-dimensional (3D) seismic isolator combining the quasi-zero stiffness (QZS) system in the vertical direction with the friction pendulum system in the horizontal direction is presented and applied to a moderately tall building model. The isolation system dynamic properties are first assessed in vertical and rotational directions separately using a simplified 3D model based on an equivalent analytical method with the frequency-amplitude functions and displacement transmissibility curves. The effectiveness of the 3D isolation system is then verified through numerical time history analysis of a tower building with a bottom podium modeled in OpenSees including a new numerical element representative of the 3D isolators implemented in the software. A comparison of the dynamic response is made between a fixed-base model, a 2D isolated model with friction pendulum bearings in the horizontal direction only, and the novel 3D isolated model. The input excitations consist of strong earthquake shaking and low-amplitude field recorded metro vibration. Results demonstrate that the 3D isolator can effectively reduce the seismic actions in three directions compared with the fixed based model and the 2D isolated model. The overturning movement can be controlled within safe limits under maximum considered earthquakes. In addition, the 3D isolators can significantly decrease human discomfort from high frequency environment vibration.

摘要

提出了一种结合垂直方向准零刚度（QZS）系统和水平方向摩擦摆系统的新型三维（3D）隔震器，并将其应用于中等高层建筑模型。首先使用基于频率-幅度函数和位移传递率曲线的等效分析方法的简化 3D 模型分别在垂直和旋转方向上评估隔离系统动态特性。然后通过在 OpenSees 中建模的带有底部裙楼的塔楼的数值时间历史分析验证 3D 隔离系统的有效性，包括在软件中实施的代表 3D 隔离器的新数值元素。在固定基础模型之间进行动态响应的比较，仅在水平方向具有摩擦摆轴承的 2D 孤立模型，以及新颖的 3D 孤立模型。输入激励包括强烈的地震震动和低振幅场记录的地铁振动。结果表明，与固定基础模型和二维隔震模型相比，3维隔震器可以有效减少三个方向的地震作用。在考虑的最大地震下，倾覆运动可以控制在安全范围内。此外，3D 隔振器可以显着降低高频环境振动带来的人体不适感。结果表明，与固定基础模型和二维隔震模型相比，3维隔震器可以有效减少三个方向的地震作用。在考虑的最大地震下，倾覆运动可以控制在安全范围内。此外，3D 隔振器可以显着降低高频环境振动带来的人体不适感。结果表明，与固定基础模型和二维隔震模型相比，3维隔震器可以有效减少三个方向的地震作用。在考虑的最大地震下，倾覆运动可以控制在安全范围内。此外，3D 隔振器可以显着降低高频环境振动带来的人体不适感。