槓桿黏彈性制震壁之發展與實驗驗證及其在高科技廠房之應用評估

Abstract

高科技廠房除了須確保在大地震作用下廠房結構安全外，小地震乃至環境微小振動作用下對於製程設備的影響更須加以控制，因此，本研究發展一「速度型 + 位移型」消能裝置─槓桿黏彈性制震壁(Lever Viscoelastic Wall Damper, LVEW)，不僅可提高小地震作用下黏彈性阻尼器之消能效率，在不同等級地震力作用下具不同的消能機制而適用於任何等級地震。小地震作用下，藉由槓桿放大層間側位移使黏彈性阻尼器承受數倍層間側位移的剪變形而消散地震能量；大地震作用下，由限位裝置限制黏彈性阻尼器位移，保護黏彈性材料不因大變形而產生永久損壞，同時，摩擦阻尼器開始滑動而消散地震能量。本文主要將推導一系列公式，由單一黏彈性阻尼器擴展至整體槓桿黏彈性制震壁，供工程師設計使用，接著，以此理論公式設計兩組實尺寸試體進行動態與靜態實驗，實驗結果除了驗證裝置可依據層間側位移大小的不同切換黏彈性阻尼器與摩擦阻尼器作用外，樞軸與螺栓孔間隙更影響其消能效率，因此，試體2將針對此因素稍作修改，在進行相同實驗程序後與試體1相比可提升位移放大倍率與消散能量。 為了瞭解槓桿黏彈性制震壁對高科技廠房提供之耐震效益，本研究選取南部科學園區高科技廠房與新竹科學園區標準廠房，使用PISA3D結構分析軟體依據實際廠房結構建立非線性數值模型，同時，針對台南高科技廠房進行微振動監測與系統識別以了解其受震反應及驗證模型可信度，接著，將槓桿黏彈性制震壁(LVEW)與一般不具位移放大機制之黏彈性制震壁(VEW)加入至原構架模型中，藉由模態分析、非線性靜力側推分析與動力歷時分析評估其耐震性能，其中地震歷時部分，選取八組臺灣與世界各地強地動紀錄(含臺灣2016/02/06美濃地震)，分別調整至尖峰地表加速度0.035 g、DBE與MCE三種等級地震，在阻尼器提供相同最大力量條件下，配置LVEW與VEW分析結果差異不大，與原構架相比均可降低最大層間側位移、殘餘層間側位移及樓層加速度受震反應，不同之處在於槓桿黏彈性制震壁可大幅減少黏彈性材料使用面積而降低成本。

High-tech factory should ensure structural safety during strong earthquakes and control the impact of environmental vibration to make the process equipment operate normally. In this paper, a new type of seismic energy dissipation device: lever viscoelastic wall damper (LVEW) which consists of a velocity-dependent damper and a displacement-dependent damper had been developed for the first time. It’s able to improve the efficiency of energy dissipation during weak earthquakes and has corresponding mechanism for different level of earthquakes. First, for weak earthquake (e.g., below design basis earthquake level), the viscoelastic damper is subjected to a interstory displacement amplified by lever to dissipate seismic energy. Second, for strong earthquake (e.g., above design basis earthquake level and equal to maximum considered earthquake level), the viscoelastic damper is restricted by stopper in order to avoid larger deformation and permanent damage. Meanwhile the friction device slide to dissipate seismic energy. The main purpose of this paper is to derive a series of formula from viscoelastic component to whole device. Next, we designed two full-scale specimens according to theoretical formula and conducted a dynamic and static test to validate its performances. The test results shown that the device operated as expected. In addition, the gap between pivot and blot hole had a great influence on efficiency of energy dissipation, thus the hysteresis energy and amplification factor of displacement were both decreased. To solve above problems, we modified some design detail in specimen 2, then its efficiency improved observably. In order to evaluate the seismic performances and effects of lever viscoelastic wall damper (LVEW) in actual buildings, a high-tech factory in Tainan, Taiwan and a high-rise building in Hsinchu, Taiwan were selected and modeled by PISA3D with installing of LVEW and typical viscoelastic wall damper (VEW). Also, vibration monitoring was conducted in high-tech factory to obtain its dynamic response under earthquake excitation and make sure model’s reliability. Furthermore, from nonlinear dynamic time history analysis, LVEW and VEW both provided well seismic effects in reduction of maximum interstory drift, residual interstory drift and maximum story acceleration of original frames only if both devices have the same maximum force. However, it is to be observed that LVEW used much fewer viscoelastic material than VEW to achieve same effect.