Base isolated/damping platforms for seismic protection of essential equipment - Hinge-Bearing Platform

One isolation platform, consisting of four hinge-bearings supporting one horizontal steel frame that in turn supports a mass that simulates the self-weight of a piece of equipment was tested. Each hinge-bearing consists of an elastomeric bearing atop of a hinge joint. The hinge joint acts as an articulation connecting the elastomeric bearing and load cells that in turn are connected to the shake table. The hinge-bearing isolation system was provided by Seismic Foundation Control Inc. To simulate the equipment weight, steel plates and concrete blocks totaling 72.7 kips are supported by the horizontal frame (8 feet long x 8 feet wide). 5 channel load cells were placed under each isolator to record the axial and shear forces. The test program consists of white noise excitation, single directional and bi-directional sinusoidal excitations and three-directional earthquake ground and floor motions. The floor motions intend to replicate floor accelerations recorded in multi-story buildings under historic earthquake shaking.

本研究针对一款隔震平台开展试验测试：该平台由四个铰支座(hinge-bearing)支撑一水平钢框架，钢框架再承载用于模拟单台设备自重的配重块。每个铰支座均由设于铰节点(hinge joint)上方的弹性支座(elastomeric bearing)组成，该铰节点作为铰接连接件，连接弹性支座与荷载传感器(load cells)，荷载传感器再与振动台(shake table)相连。该铰支座隔震系统由Seismic Foundation Control Inc.提供。为模拟设备自重，尺寸为8英尺×8英尺的水平框架承载总重72.7千磅的钢板与混凝土块。每个隔震支座下方均布设5通道荷载传感器，以采集轴向与剪力荷载数据。本次试验涵盖白噪声激励、单向与双向正弦激励，以及三向地震地面运动与楼层运动四类工况；其中楼层运动工况旨在复现历史地震作用下多层建筑内实测得到的楼层加速度响应。