本文選題：地震可靠度 + 響應(yīng)極值　； 參考：《大連理工大學(xué)》2014年碩士論文

【摘要】：20世紀(jì)50年代以來,國內(nèi)外在強地震區(qū)建造的土石壩日漸增多。今后幾十年,特別是在中國,將有更多的土石壩在強地震區(qū)興建,從而使這一工程的抗震技術(shù)日益受到關(guān)注。 土石壩的抗震設(shè)計存在大量的不確定性,包括土性參數(shù)的不確定性、計算模型參數(shù)的不確定性、模型尺寸的不確定性以及地震荷載的不確定性等等,以往的設(shè)計中,工程設(shè)計人員常常把實際工程中的這些不確定性歸結(jié)為一個確定性的安全系數(shù)上,對于靜力計算通常會預(yù)留出較富裕的安全儲備,但對于隨機性很強的地震作用,安全系數(shù)很高的土石壩可能因為一次地震作用就出現(xiàn)永久性的破壞,這與地震動的峰值加速度、卓越周期以及持時都有很大關(guān)系。 本文基于傳統(tǒng)定值設(shè)計法的不足,考慮地震動的隨機性,用可靠度指標(biāo)評價土石壩的安全程度。同時,文中對比了多種傳統(tǒng)可靠度計算方法,認為以往的可靠度分析方法主要分為靜力和動力兩類,靜力可靠度方法多用來解決材料參數(shù)以及方法本身的不確定性,對于地震動的隨機性,往往不能獨立使用；動力可靠度方法主要是基于隨機振動首次超越概率理論提出的可靠度計算公式,這種方法應(yīng)用理論多、難度大、成果較少且計算過程復(fù)雜。鑒此,本文引用了一種解決土石壩地震可靠度的簡便思路—響應(yīng)極值分布法,通過考察土石壩地震響應(yīng)極值的概率分布,給出了土石壩在一系列符合某場地地震統(tǒng)計特性的地震動作用下結(jié)構(gòu)直觀的失效概率和可靠度指標(biāo)。在此思路基礎(chǔ)上,本文做了以下幾項工作： (1)通過時域和頻域內(nèi)雙重非平穩(wěn)性的地震動模型,人工合成了大量峰值加速度滿足某種分布規(guī)律的隨機地震波,考察了某些土石壩地震響應(yīng)(壩頂加速度反應(yīng)、加速度放大倍數(shù)、壩坡安全系數(shù)、壩體豎向永久變形)的概率分布,分析了地震參數(shù)(震級、震中距)對這些響應(yīng)分布的影響情況。 (2)將壩坡最小安全系數(shù)的分布擬合為概率密度函數(shù),計算了土石壩壩坡地震作用下的失效概率和可靠度指標(biāo),列出了最小安全系數(shù)不同的臨界值下土石壩的失效概率參考值。 (3)將土石壩壩頂豎向永久變形量的分布擬合為概率密度函數(shù),計算了土石壩由于震陷而導(dǎo)致的失效概率和可靠度指標(biāo),用《水利水電工程結(jié)構(gòu)可靠度設(shè)計統(tǒng)-標(biāo)準(zhǔn)》中可靠度指標(biāo)的參考值,對土石壩給出危險性評價。
[Abstract]:Since the 1950s, more earth-rock dams have been built in the strong earthquake area at home and abroad. In the next few decades, especially in China, more earth-rock dams will be built in strong earthquake areas, which makes the seismic technology of this project receive more and more attention. There are a lot of uncertainties in seismic design of earth-rock dam, including uncertainty of soil parameter, uncertainty of calculation model parameter, uncertainty of model size and uncertainty of seismic load, etc. Engineering designers often attribute these uncertainties to a deterministic factor of safety. For static calculations, they usually reserve a richer safety reserve, but for highly random earthquakes, A high safety factor earth-rock dam may be permanently destroyed by an earthquake, which is closely related to the peak acceleration of the ground motion, the excellent period and the duration of the earthquake. Considering the randomness of ground motion, the reliability index is used to evaluate the safety of earth-rock dam. At the same time, compared with many traditional reliability calculation methods, the former reliability analysis methods are mainly divided into static and dynamic methods, and static reliability methods are used to solve the uncertainty of material parameters and the method itself. The dynamic reliability method is mainly based on the reliability calculation formula proposed by random vibration first transcendence probability theory. The results are less and the calculation process is complicated. In this paper, a simple method to solve the seismic reliability of earth-rock dams, the response extremum distribution method, is introduced, and the probability distribution of seismic response extremum of earth-rock dams is investigated. The structural failure probability and reliability index of earth-rock dam under a series of ground motions which accord with the seismic statistical characteristics of a certain site are given. On the basis of this idea, this paper has done the following work: In this paper, a large number of random seismic waves with peak acceleration satisfying a certain distribution law are synthesized by using the time-domain and frequency-domain double nonstationary ground motion models. The seismic response of some earth-rock dams (the acceleration response of the dam top) is investigated. The probability distribution of acceleration magnification, safety factor of dam slope and vertical permanent deformation of dam body is analyzed. The influence of seismic parameters (magnitude, epicentral distance) on these response distributions is analyzed. (2) the distribution of minimum safety factor of dam slope is fitted as probability density function, the failure probability and reliability index of earth-rock dam slope under earthquake action are calculated, and the reference values of failure probability of earth-rock dam under different critical values of minimum safety factor are listed. The distribution of vertical permanent deformation at the top of earth-rock dam is fitted as probability density function, and the failure probability and reliability index of earth-rock dam due to earthquake subsidence are calculated. Based on the reference value of reliability index in structural reliability design of water conservancy and hydropower engineering, the risk assessment of earth-rock dam is given.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TV641;TV312

【參考文獻】

相關(guān)期刊論文 前10條

1 李鵬祥;;隨機抽樣中必要樣本容量的確定[J];赤峰學(xué)院學(xué)報(自然科學(xué)版);2009年09期

2 劉立平,雷尊宇,周富春;地震邊坡穩(wěn)定分析方法綜述[J];重慶交通學(xué)院學(xué)報;2001年03期

3 歐進萍,牛荻濤,杜修力;設(shè)計用隨機地震動的模型及其參數(shù)確定[J];地震工程與工程振動;1991年03期

4 鄒德高;徐斌;孔憲京;;釘結(jié)護面板對高土石壩壩坡地震穩(wěn)定性影響研究[J];大連理工大學(xué)學(xué)報;2009年05期

5 董娣;周錫元;閆維明;徐國棟;楊潤林;;地震動不確定性及其影響因素的初步分析[J];地震研究;2006年02期

6 楊海菲;楊仕教;曾晟;;巖土工程可靠度計算方法研究[J];水利與建筑工程學(xué)報;2008年02期

7 王國體,陳名昭,周新宇,寇明國;土坡穩(wěn)定可靠度指標(biāo)分析[J];合肥工業(yè)大學(xué)學(xué)報(自然科學(xué)版);2002年03期

8 桂勁松,康海貴;結(jié)構(gòu)可靠度分析的響應(yīng)面法及其Matlab實現(xiàn)[J];計算力學(xué)學(xué)報;2004年06期

9 蘇成;徐瑞;;非平穩(wěn)隨機激勵下結(jié)構(gòu)體系動力可靠度時域解法[J];力學(xué)學(xué)報;2010年03期

10 陳菊香;卓建平;盧坤林;;考慮地震隨機性的土坡可靠度分析[J];水電能源科學(xué);2010年02期

相關(guān)博士學(xué)位論文 前1條

1 謝桂華;巖土參數(shù)隨機性分析與邊坡穩(wěn)定可靠度研究[D];中南大學(xué);2009年

，

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