本文選題：隨機(jī)有限斷層法　切入點(diǎn)：地震動(dòng)　出處：《南昌航空大學(xué)》2015年碩士論文

【摘要】：工程中常用時(shí)程分析法研究結(jié)構(gòu)在地震作用下的反應(yīng)。人工合成的加速度時(shí)程在結(jié)構(gòu)振動(dòng)分析中不可或缺。隨機(jī)有限斷層法因在模擬高頻地震動(dòng)方面有著獨(dú)到的優(yōu)勢,常應(yīng)用于實(shí)際工程中。在加速度時(shí)程模擬過程中,隨機(jī)有限斷層法采用的震源參數(shù)對模擬結(jié)果有很大的影響,往往因?yàn)椴煌芯空咚P(guān)注的角度不同,所采用的震源參數(shù)也會(huì)有所不同,從而得到不同的結(jié)果。比如應(yīng)力降的取值將影響地震動(dòng)的幅值,kappa因子對高頻地震動(dòng)會(huì)有影響,斷層的走向、傾角、場址類別以及場址的位置等都會(huì)影響所合成的地震動(dòng)。此外,隨機(jī)有限斷層法在模擬近場基巖地震動(dòng)時(shí),在某些頻段存在能量偏低的現(xiàn)象。本文采用隨機(jī)有限斷層法模擬近場基巖地震動(dòng),計(jì)算模擬加速度時(shí)程的能量在各個(gè)頻段分布,通過對模擬時(shí)程與實(shí)際地震近場基巖記錄的能量在頻域的分布情況的對比分析,找出兩者間的差異;采取調(diào)整某些頻段的能量分布的方法,以實(shí)現(xiàn)調(diào)整后的模擬近場基巖地震動(dòng)與實(shí)際記錄時(shí)程相符或更為接近的目的。主要的研究內(nèi)容如下:1)以美國工程強(qiáng)震中心數(shù)據(jù)庫中的近場基巖場地的加速度記錄為數(shù)據(jù)基礎(chǔ),運(yùn)用傅氏變換得到記錄的能量分布曲線,分析能量在頻域的分布特征以及能量與震級(jí)和震源距的關(guān)系,揭示了水平向和豎向地震動(dòng)時(shí)程的能量分布規(guī)律。2)利用基于隨機(jī)有限斷層法的EXSIM模擬程序,探討了震源參數(shù)—kappa因子、應(yīng)力降、方位角和斷層傾角等對模擬加速度時(shí)程的幅值、反應(yīng)譜和能量分布曲線的影響規(guī)律。3)提出了一種基于能量的改進(jìn)隨機(jī)有限斷層法。該法通過調(diào)整能量在頻域的分布比例,得到與實(shí)際地震記錄更為逼近的模擬地震動(dòng)時(shí)程。分別以具有豐富近場基巖地震記錄資料的美國北嶺地震及汶川地震為例,選取合理的震源模型和震源參數(shù),模擬得到了近場基巖地震動(dòng)時(shí)程。通過對比分析模擬地震動(dòng)與實(shí)際記錄在能量分布、加速度峰值和反應(yīng)譜等方面的差異,以驗(yàn)證改進(jìn)方法的合理性和可行性。
[Abstract]:Time history analysis is commonly used in engineering to study the response of structures to earthquake. Synthetic acceleration time history is indispensable in structural vibration analysis. Stochastic finite fault method has unique advantages in simulating high frequency ground motion. In the process of acceleration time history simulation, the focal parameters used by stochastic finite fault method have great influence on the simulation results, often because different researchers pay attention to different angles. For example, the magnitude of the stress drop will affect the amplitude of the ground motion and the kappa factor will have an effect on the high frequency ground motion, the strike of the fault, the angle of inclination, The type of site and the location of the site will affect the synthetic ground motion. In addition, the stochastic finite fault method is used to simulate the near-field ground motion of bedrock. There is a phenomenon of low energy in some frequency bands. In this paper, stochastic finite fault method is used to simulate near-field bedrock ground motion, and the energy distribution of simulated acceleration time history is calculated in each frequency band. By comparing and analyzing the distribution of energy in the frequency domain between the simulated time history and the actual seismic near field bedrock record, the difference between them is found out, and the method of adjusting the energy distribution in some frequency bands is adopted. In order to achieve the objective that the adjusted simulation of near-field bedrock ground motion is consistent with or closer to the actual recorded time history, the main research contents are as follows: 1) based on the acceleration records of the near-field bedrock site in the American Engineering strong earthquake Center Database, The energy distribution curve recorded by Fourier transform is used to analyze the distribution characteristics of energy in frequency domain and the relationship between energy and magnitude and focal distance. The energy distribution of horizontal and vertical ground motion is revealed. 2) using the EXSIM simulation program based on stochastic finite fault method, the amplitude of focal parameter -kappa factor, stress drop, azimuth angle and fault dip angle on the simulated acceleration time history is discussed. This paper presents an improved stochastic finite fault method based on energy, which adjusts the distribution of energy in frequency domain by adjusting the distribution ratio of energy in frequency domain. The time history of simulated ground motion, which is more approximate to the actual seismic record, is obtained. Taking the North Ridge earthquake and Wenchuan earthquake with abundant near-field bedrock seismic records as examples, a reasonable focal model and source parameters are selected. In order to verify the rationality and feasibility of the improved method, the difference of energy distribution, acceleration peak value and response spectrum between the simulated ground motion and the actual record is analyzed by comparing the time history of near-field bedrock ground motion.
【學(xué)位授予單位】：南昌航空大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P315.9

【參考文獻(xiàn)】

相關(guān)期刊論文 前8條

1 李啟成;景立平;李中寧;;用經(jīng)驗(yàn)格林函數(shù)法和隨機(jī)方法模擬盧龍地震的比較[J];地震工程與工程振動(dòng);2009年02期

2 易桂喜;龍鋒;張致偉;;汶川M_S8.0地震余震震源機(jī)制時(shí)空分布特征[J];地球物理學(xué)報(bào);2012年04期

3 �，�;周紅;俞言祥;;汶川地震強(qiáng)地面運(yùn)動(dòng)模擬[J];地震學(xué)報(bào);2012年02期

4 ;Improvements of corner frequency and scaling factor for stochastic finite-fault modeling[J];Earthquake Engineering and Engineering Vibration;2010年04期

5 孫曉丹;陶夏新;;基于動(dòng)力學(xué)拐角頻率的汶川主震近場地震動(dòng)隨機(jī)合成[J];土木工程學(xué)報(bào);2013年S2期

6 張翠然;俞言祥;陳厚群;呂紅山;李敏;;基于汶川和蘆山地震的沙牌壩址地震動(dòng)輸入研究[J];水力發(fā)電學(xué)報(bào);2014年03期

7 盧育霞,石玉成;1988年肅南地震近場地面運(yùn)動(dòng)的隨機(jī)模擬[J];巖石力學(xué)與工程學(xué)報(bào);2003年S2期

8 陶夏新;陳富;孫曉丹;;強(qiáng)地震動(dòng)隨機(jī)合成中震源譜模型的改進(jìn)[J];巖土工程學(xué)報(bào);2012年03期

相關(guān)碩士學(xué)位論文 前1條

1 史家平;地震動(dòng)合成方法比較與研究[D];大連理工大學(xué);2008年

，

本文編號(hào)：1662644