本文關鍵詞： 速度脈沖識別 速度脈沖特性 標定譜 地震動輸入 隔震結構　出處：《中國地震局工程力學研究所》2015年碩士論文　論文類型：學位論文

【摘要】：近三十年發(fā)生的幾次大地震給人類造成了巨大的人員傷亡和經濟損失,引起了科學家對近斷層地震動的關注。其中,地震動速度脈沖作為近斷層地震動特征之一,因其具有幅值大、周期長、包含長周期高能量及對結構影響大等特點備受各國學者關注。在研究近斷層地震動速度脈沖時,首先需要識別出含速度脈沖的地震動,其次是對速度脈沖型地震動的工程特性進行研究,最后研究其對隔震結構的影響。本文針對上述三個問題展開研究,主要內容和結論如下:1.通過對前人定性和定量識別速度脈沖方法的總結,簡要介紹了Baker(2007)、ShahiBaker(2014)定量識別速度脈沖方法,提出改進的經驗模態(tài)分解(EMD)方法識別速度脈沖,并從理論上和實例上進行了對比。研究發(fā)現(xiàn),EMD方法較其它兩種方法,沒有嚴苛的應用范圍,本身自適應性強的特點擴大了它的應用范圍,可以作為識別速度脈沖的一種參考和補充方法。2.通過對臺灣集集地震含速度脈沖和不含速度脈沖兩種地震動的三要素研究發(fā)現(xiàn),速度峰值PGV、速度反應譜峰值所對應的周期Tpsv、能量持時Tp最能反映兩種地震動之間的區(qū)別。含與不含速度脈沖PGV的比值平均值為2.21;含與不含速度脈沖的Tpsv的比值大多分布在1-2.66之間,其平均值為1.68。含脈沖地震動的能量持時要比不含脈沖的短,大約是不含脈沖地震動能量持時的0.69倍,含脈沖的地震動在很短的時間內能量累計要比不含脈沖的大。3.采用雙參數(shù)標定法和最小二乘法分段擬合方法對臺灣集集地震中的8組數(shù)據(jù)進行反應譜標定。通過研究其標定譜特征參數(shù)特征周期Tg、平臺段高度βmax、衰減指數(shù)γ發(fā)現(xiàn),在平均周期1.16 s之后,含脈沖的標定譜幅值大于不含脈沖的,并且平均是其1.98倍。因此規(guī)范中的設計譜需要考慮含速度脈沖的地震動對其影響。4.歸納總結了前人研究地震動速度脈沖對結構影響時選取地震動輸入的原則:(1)滿足同源性:即地震動時程來自于同一次地震、具有相同的震中距、相同的場地條件;(2)反應譜相似性;(3)每類時程數(shù)量不得少于8組;(4)盡量保持震中距范圍基本一致。5.采用基于小波分析Baker提取速度脈沖方法,將選取的1999年臺灣集集地震中30條FN方向含脈沖的地震動分解為Orig分量(沒有進行小波分析的原始地震動)、Pulse分量(提取出來的脈沖)和Resid分量(原始地震動提取脈沖后剩余的不含脈沖分量);將Orig作為含脈沖的地震動、Resid作為不含脈沖的地震動輸入6層框架隔震結構中,采用有限元分析軟件ETABS對其進行非線性時程分析,研究含與不含速度脈沖的地震動對隔震結構的影響。通過研究結果,為保證隔震結構設計的可靠性,提出如下建議:(1)在距離震中比較近的區(qū)域內應考慮含速度脈沖的地震動對隔震結構的影響;這個“比較近的區(qū)域”建議為距震中80 km內;(2)當與擬建場地條件相似的含速度脈沖地震動記錄數(shù)量比較少時,脈沖影響系數(shù)取1.34-1.60之間的放大系數(shù)。
[Abstract]:Several large earthquakes occurred in recent thirty years has caused huge casualties and economic losses to human, causing scientists to near fault ground motions. The pulse for near fault ground motion characteristics of ground velocity, because of its large amplitude, long cycle, long cycle and high energy including the characteristics of structure influence by many scholars in different countries. In the study of velocity pulse of near fault ground motions, first need to identify with velocity pulse ground motions, followed by the research on engineering characteristics of pulse type ground motion for speed, finally to study its effect on isolated structure. Based on the above three issues, the main content and the conclusions are as follows: 1. based on the previous qualitative and quantitative method of pulse recognition speed up, briefly introduced the Baker (2007), ShahiBaker (2014) quantitative recognition speed pulse method, the improved empirical mode State decomposition (EMD) method to identify the velocity pulse, and from the theoretical and practical examples are compared. It is found that the EMD method is compared with the other two methods, the scope of application not harsh, self adaptability features to expand its scope of application, can be used as a reference and supplement method.2. recognition speed pulse the set containing velocity pulse and without seismic velocity pulse study three two seismic elements found on the Taiwan set, PGV peak velocity, velocity response spectrum corresponding to the peak period of Tpsv, the Tp can reflect the difference between the two seismic energy duration. The ratio with and without the velocity pulse of the average PGV 2.21 with and without Tpsv; the ratio of velocity pulse is mostly distributed in between 1-2.66, the average value of 1.68. with pulse duration of ground motion energy than does not contain short pulses, is about 0.69 times without seismic energy pulse duration, Impulsive ground motions in a very short period of time than the accumulative energy without pulse high.3. using two parameter calibration method and least squares fitting method set 8 sets of data in the earthquake response spectrum calibration of Taiwan. Through the research on the calibration of spectral characteristic parameters of characteristic period Tg, platform height beta Max gamma attenuation index found that after an average period of 1.16 s, with amplitude greater than the free spectrum calibration pulse, and the average is 1.98 times. So the design specifications of the spectrum to consider containing velocity pulse ground motions on the impact of.4. summarizes the velocity pulse on the structural effects of selected ground motion input principle previous studies of ground motion: (1) meet homology: ground motions from the same earthquake, with the same epicentral distance, the same site conditions; (2) the response spectrum similarity; (3) the number of each class is not less than 8; (4) as Keep the epicentral distance scope consistent.5. using wavelet analysis Baker extraction method based on velocity pulse, will be selected in 1999 Taiwan set 30 FN in the direction of seismic ground motion is decomposed into impulsive Orig components (no original seismic wavelet analysis), Pulse (pulse component extracted) and Resid (component extraction after the pulse remaining free pulse component of the original ground motion); Orig as impulsive ground motions, Resid as free pulse ground motion input 6 layer frame isolated structure, using finite element analysis software ETABS, the nonlinear time history analysis, research with and without vibration effects on the velocity pulse. Isolated structure. Through the research results, in order to ensure the reliability of isolation structure design, put forward the following suggestions: (1) considering the velocity pulse ground motions on isolated structures in the shadow region should be relatively close to the epicenter The near area is recommended to be within 80 km away from the epicenter. (2) when the number of records with velocity pulse ground motion similar to the site conditions is relatively small, the amplification coefficient of 1.34-1.60 is between the impulse influence coefficient.

【學位授予單位】：中國地震局工程力學研究所
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P315.9;TU352.11

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本文編號：1496879