- 摘 要
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（華東建筑設計研究院有限公司， 上海 200041）
［摘要］針對超高層結(jié)構(gòu)在罕遇地震彈塑性分析中發(fā)現(xiàn)的位移響應振動周期相對于彈性結(jié)果出現(xiàn)“縮短”的現(xiàn)象，從概念和理論角度進行原因分析。結(jié)果表明，結(jié)構(gòu)位移響應由穩(wěn)態(tài)振動和瞬態(tài)振動疊加而成的基本特征是發(fā)生周期“縮短”的必要前提條件，地震波頻譜特征與結(jié)構(gòu)自由振動周期的相互關(guān)系以及結(jié)構(gòu)阻尼的衰減效應共同導致了位移響應周期的變化。明確了易于發(fā)生周期“縮短”的一般條件。通過理想彈性算例對分析結(jié)論進行驗證。對發(fā)生周期“縮短”的案例補充震后模態(tài)分析，論證剛度退化的程度。最終形成對結(jié)構(gòu)總體剛度退化進行評估的合理化建議。
［關(guān)鍵詞］罕遇地震； 位移響應； 剛度退化； 周期縮短； 穩(wěn)態(tài)振動； 瞬態(tài)振動
中圖分類號：TU318， TU973文獻標識碼：A文章編號：1002-848X(2020)18-0091-05
Cause analysis of “shortening” of displacement response period for super high-rise structure under rare earthquake
AN Dongya
(East China Architectural Design & Research Institute Co., Ltd., Shanghai 200041, China)
Abstract:Aiming at the phenomenon that the vibration period of displacement response of super high-rise structure is “shortened” in the elasto-plastic analysis compared with the elastic result under rare earthquake, the reason analysis was carried out from the concept and theoretical point of view. The result shows that the basic feature of the displacement response of the structure, which is the superposition of steady-state vibration and transient vibration, is the necessary prerequisite for the occurrence of “shortening” phenomenon，and the relationship between the spectrum characteristics of seismic wave and the period of free vibration of structure，as well as the damping effect of the structure together lead to the change of the displacement response period. The general conditions for "shortening" of vibration period were clarified. The analysis conclusions were verified by some ideal elasticity analysis cases. The post-earthquake modal analysis was supplemented for the case of displacement period "shortening" to demonstrate the degree of stiffness degradation. Finally, reasonable suggestions for the evaluation of the overall stiffness degradation of the structure were formed.
Keywords:rare earthquake; displacement response; stiffness degradation; shortening of vibration period; steady-state vibration; transient vibration
*“上海超高層建筑設計工程技術(shù)研究中心”建設項目（14D22252800）。
作者簡介：安東亞，博士，高級工程師，Email:dongya_an@arcplus.com.cn。
