【摘要】：黃土邊坡穩(wěn)定性的評價一直以來是巖土工程界研究的熱點課題，但由于黃土強度參數(shù)變異性大，取值較為困難，致使邊坡穩(wěn)定性評價的確定性方法難以獲得可靠的結(jié)果。本文利用黃土空間變異性與相關(guān)性的特點，研究了其垂向自相關(guān)距離，采用Monte-Carlo模擬的隨機有限元法，對甘泉地區(qū)的黃土高邊坡穩(wěn)定系數(shù)和失效概率進(jìn)行了系統(tǒng)研究，詳細(xì)分析了自相關(guān)距離對失效概率和穩(wěn)定系數(shù)的影響。取得的研究成果如下： （1）分析了甘泉地區(qū)的工程地質(zhì)條件，收集了黃陵-延安高速公路工程報告中黃土實驗數(shù)據(jù)，對物理力學(xué)指標(biāo)做了統(tǒng)計，并對該區(qū)強度參數(shù)概型分布進(jìn)行了分析，結(jié)果表明該區(qū)所有地層的c、值都接受對數(shù)正態(tài)分布。以靜探實驗結(jié)果為基礎(chǔ)數(shù)據(jù)，分別利用遞推空間法、空間均值法和空間趨勢法計算了該區(qū)的黃土參數(shù)的自相關(guān)距離，發(fā)現(xiàn)空間均值法和遞推空間法側(cè)摩阻力計算所得結(jié)果基本是錐尖阻力計算結(jié)果的2倍左右。以錐尖阻力數(shù)據(jù)用以上三種方法求得的相關(guān)距離范圍為0.76—2.85m，以側(cè)摩擦阻力數(shù)據(jù)求得的相關(guān)距離范圍為0.64—6.32m。 （2）通過研究巖土參數(shù)自相關(guān)距離對可靠度分析結(jié)果的影響，認(rèn)為當(dāng)邊坡失效概率小于38.0%時，隨著自相關(guān)距離的增大，失效概率增大，意味著土坡越均勻，會增加邊坡不穩(wěn)定性，而強度隨深度變化劇烈的土坡，能一定程度提高邊坡穩(wěn)定性。反之，當(dāng)邊坡失效概率大于38.0%時，隨著自相關(guān)距離的增大，失效概率減小，意味著強度隨深度變化劇烈的土坡，會增加邊坡不穩(wěn)定性，均勻土坡則一定程度上提高邊坡穩(wěn)定性。工程中采用均質(zhì)土坡或分成2-3個大層將不均勻的黃土高邊坡地層簡化進(jìn)行穩(wěn)定性評估，對穩(wěn)定性差的邊坡，將高估邊坡的穩(wěn)定性，獲得冒險的結(jié)果。而對于較穩(wěn)定的邊坡，，則會低估邊坡的穩(wěn)定性，獲得保守的結(jié)果。
[Abstract]:The evaluation of loess slope stability has always been a hot topic in geotechnical engineering. However, because of the large variability of loess strength parameters, it is difficult to obtain reliable results by the deterministic method of slope stability evaluation. Based on the characteristics of spatial variability and correlation of loess, the vertical autocorrelation distance of loess is studied in this paper. The stability coefficient and failure probability of high loess slope in Ganquan area are studied systematically by using the stochastic finite element method simulated by Monte-Carlo. The influence of autocorrelation distance on failure probability and stability coefficient is analyzed in detail. The research results are as follows: (1) the engineering geological conditions in Ganquan area are analyzed, the loess experimental data of Huangling-Yan'an expressway engineering report are collected, and the physical and mechanical indexes are counted. The results show that the values of c and C of all strata in this area accept logarithmic normal distribution. The autocorrelation distance of loess parameters in this area is calculated by using recursive space method, spatial mean method and spatial trend method based on the results of static exploration experiments. It is found that the results obtained by the spatial mean method and the recursive space method are about 2 times of the calculated results of the cone tip resistance. The range of correlation distance is 0.76-2.85musing the data of cone tip resistance and 0.64-6.32m. (2) the reliability of autocorrelation distance of geotechnical parameters is studied by studying the autocorrelation distance of geotechnical parameters. The impact of the analysis, It is considered that when the slope failure probability is less than 38.0, the failure probability increases with the increase of autocorrelation distance, which means that the more uniform the soil slope is, the more unstable the slope will be, and the soil slope whose strength varies sharply with the depth. It can improve slope stability to some extent. On the contrary, when the slope failure probability is greater than 38.0, with the increase of autocorrelation distance, the failure probability decreases, which means that the soil slope whose strength varies sharply with the depth will increase the slope instability, and the even soil slope will improve the slope stability to some extent. In engineering, homogeneous soil slope or 2-3 layers are used to simplify the formation of uneven loess high slope for stability evaluation. The slope with poor stability will overestimate the stability of slope and obtain risky results. For a more stable slope, the stability of the slope is underestimated and conservative results are obtained.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU444;TU43

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 倪萬魁,韓啟龍;黃土土性參數(shù)的統(tǒng)計分析[J];工程地質(zhì)學(xué)報;2001年01期

2 張茂省;李林;唐亞明;薛強;孫萍萍;程秀娟;;基于風(fēng)險理念的黃土滑坡調(diào)查與編圖研究[J];工程地質(zhì)學(xué)報;2011年01期

3 張亞國;張波;李萍;李同錄;;基于點估計法的黃土邊坡可靠度研究[J];工程地質(zhì)學(xué)報;2011年04期

4 高大釗;巖土工程設(shè)計安全度指標(biāo)及其應(yīng)用[J];工程勘察;1996年01期

5 李鏡培,高大釗;土性指標(biāo)的變異特性研究[J];中國港灣建設(shè);2001年06期

6 高德彬,倪萬魁,梁偉;基于Monte-Carlo模擬的公路黃土高邊坡可靠性研究[J];公路交通科技;2005年S2期

7 李萍;王秉綱;李同錄;;自然類比法在黃土路塹邊坡設(shè)計中的應(yīng)用研究[J];公路交通科技;2009年02期

8 朱位秋,任永堅;基于隨機場局部平均的隨機有限元法[J];固體力學(xué)學(xué)報;1988年04期

9 楊軍;;邊坡穩(wěn)定性分析方法綜述[J];山西建筑;2009年04期

10 黃僑;孫廣婧;;有限元可靠度方法在橋梁工程中的應(yīng)用[J];交通科技與經(jīng)濟(jì);2006年06期

相關(guān)博士學(xué)位論文 前2條

1 吳振君;土體參數(shù)空間變異性模擬和土坡可靠度分析方法應(yīng)用研究[D];中國科學(xué)院研究生院（武漢巖土力學(xué)研究所）;2009年

2 顏斌;洛川剖面黃土的結(jié)構(gòu)性及其力學(xué)特征研究[D];長安大學(xué);2010年

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