本文選題：黃土 + 震陷�。� 參考：《中國地震局蘭州地震研究所》2017年碩士論文

【摘要】：黃土震陷是地震作用下黃土的大孔隙結構產(chǎn)生崩潰性破壞而引發(fā)的地震災害,具體表現(xiàn)為地面塌陷和黃土滑坡等。歷史上因強烈地震引發(fā)的黃土震陷災害帶來了生命和財產(chǎn)的極大損失。黃土震陷問題已經(jīng)引起了人們的重視,目前評價黃土震陷的方法主要是室內(nèi)實驗測試不同深度的震陷系數(shù),利用分層總和法計算震陷量。本文在前人研究的基礎上,通過對蘭州新區(qū)及周邊地區(qū)大量剪切波速、含水率和震陷實驗資料的統(tǒng)計分析,給出了利用剪切波速和含水率雙指標評價黃土震陷的方法。通過研究,本論文取得了以下幾方面結論:1.選取了剪切波速和含水率兩個獨立的參數(shù)組成評價震陷的參數(shù)體系,分析了剪切波速和含水率與震陷系數(shù)的關系。在一定含水率條件下,隨著剪切波速的增大震陷系數(shù)減小。在一定剪切波速情況下,隨著含水率的增大震陷系數(shù)增大;并且剪切波速越大,隨著含水率的增大震陷系數(shù)增長的越緩慢。2.分析了剪切波速和含水率在震陷過程中的相互關系,提出天然震陷能力的概念。通過分析二者與震陷系數(shù)的關系,得出剪切波速反映著非飽和土體的強度特征和絕對變形量及含水率影響非飽和土體的強度特征和絕對變形量的釋放的觀點。在此基礎上,提出表征黃土潛在震陷能力的概念—天然震陷系數(shù),其與剪切波速呈正相關,含水率對天然震陷系數(shù)影響較小,但含水率對震陷過程的完成有著明顯的影響。3.在預測黃土震陷方面,通過剪切波速擬合公式和含水率擬合公式得到兩個震陷系數(shù),通過對兩個系數(shù)進行比較后,得出場地的實際震陷系數(shù),再進行黃土場地震陷量的預測。在這種方法的指導下,可能存在兩種工況:第一種工況,當由含水率擬合公式計算得到的震陷系數(shù)小于天然震陷系數(shù),此時黃土的潛在震陷能力沒有得到完全釋放,實際震陷系數(shù)由含水量擬合公式計算。第二種工況,當依據(jù)含水率擬合公式計算得到的震陷系數(shù)大于天然震陷系數(shù),此時黃土的潛在震陷能力得到完全釋放,實際震陷系數(shù)由剪切波速擬合公式計算,即天然震陷系數(shù)。4.利用剪切波速和含水率雙指標對蘭州新區(qū)黃土震陷特性進行了評價,并與室內(nèi)震陷試驗結果對比驗證。結果表明,預測結果與室內(nèi)震陷試驗預測結果基本相符。本論文的研究成果為黃土震陷評價提供了較好的思路,具有較大的工程意義。
[Abstract]:Loess earthquake subsidence is a kind of earthquake disaster caused by the collapse of the pore structure of loess caused by earthquake, which is manifested as ground collapse and loess landslide. In history, great losses of life and property were caused by the earthquake subsidence disaster of loess caused by strong earthquake. People have paid more attention to the problem of loess seismic subsidence. At present, the evaluation method of loess seismic subsidence is mainly to test the seismic subsidence coefficient of different depth through laboratory experiments, and to calculate the seismic subsidence by using the method of stratified summation. On the basis of previous studies, this paper presents a method for evaluating loess seismic subsidence by means of statistical analysis of a large number of shear wave velocity, water content and seismic subsidence experimental data in Lanzhou New area and its surrounding area. Through the research, this paper has obtained the following several aspects of conclusion: 1. Two independent parameters of shear wave velocity and water content are selected to evaluate seismic subsidence. The relationship between shear wave velocity and water content and seismic subsidence coefficient is analyzed. Under certain water content, the seismic trapping coefficient decreases with the increase of shear wave velocity. In the case of certain shear wave velocity, the seismic trapping coefficient increases with the increase of water content, and the larger the shear wave velocity, the slower the seismic trapping coefficient increases with the increase of water content. The relationship between shear wave velocity and water content in the process of seismic subsidence is analyzed, and the concept of natural seismic trapping ability is put forward. By analyzing the relationship between the shear wave velocity and the seismic subsidence coefficient, it is concluded that the shear wave velocity reflects the strength characteristics of unsaturated soil and the effect of absolute deformation and moisture content on the strength characteristics and release of absolute deformation of unsaturated soil. On this basis, the concept of natural seismic subsidence coefficient, which represents the potential seismic subsidence ability of loess, is put forward, which is positively related to shear wave velocity, and water content has little effect on natural seismic subsidence coefficient, but water content has obvious influence on the completion of seismic subsidence process. In the aspect of predicting loess seismic subsidence, two seismic subsidence coefficients are obtained by shear wave velocity fitting formula and water content fitting formula. After comparing the two coefficients, the actual seismic subsidence coefficient of the site is obtained, and then the earthquake subsidence of loess field is predicted. Under the guidance of this method, there may be two conditions: first, when the seismic subsidence coefficient calculated by the water content fitting formula is less than that of the natural seismic subsidence coefficient, the potential seismic subsidence capacity of loess is not completely released. The actual seismic subsidence coefficient is calculated by the fitting formula of water content. In the second case, when the seismic subsidence coefficient calculated by water content fitting formula is larger than that of natural seismic subsidence coefficient, the potential seismic subsidence capacity of loess is completely released, and the actual seismic subsidence coefficient is calculated by shear wave velocity fitting formula. That is, natural seismic subsidence coefficient. The seismic subsidence characteristics of loess in Lanzhou New area were evaluated by using the double indexes of shear wave velocity and water content, and the results were compared with the results of indoor seismic subsidence test. The results show that the predicted results are in good agreement with the results of indoor seismic subsidence test. The research results of this paper provide a good idea for evaluation of loess seismic subsidence and have great engineering significance.
【學位授予單位】：中國地震局蘭州地震研究所
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU444;TU435

【參考文獻】

相關期刊論文 前10條

1 王峻;王強;楊寶平;鐘秀梅;王謙;王平;柴少峰;;基于含水率變化的黃土場地震陷評價預測[J];巖石力學與工程學報;2015年10期

2 李為樂;黃潤秋;裴向軍;張曉超;張遠明;;基于Google Earth的1920年海原8.5級大地震地質災害研究[J];災害學;2015年02期

3 田文通;王蘭民;孫軍杰;徐舜華;劉琨;孫昱;;黃土動力變形研究進展與可能突破方向[J];蘭州大學學報(自然科學版);2014年05期

4 孫軍杰;王蘭民;陳秀清;孫昱;;黃土抗剪強度定量影響其動殘余變形過程的試驗研究[J];地震工程與工程振動;2014年S1期

5 王強;吳志堅;王平;;西北地區(qū)典型河谷城市巖土體剪切波速的特征分析[J];水文地質工程地質;2014年01期

6 鄧津;王蘭民;張振中;孫軍杰;鐘秀梅;;我國黃土的微結構類型與震陷區(qū)域劃分[J];地震工程學報;2013年03期

7 孫軍杰;田文通;徐舜華;劉琨;王蘭民;牛富俊;;概率性分析在黃土場地動力沉降評價中的應用[J];巖土力學;2013年08期

8 董林;夏坤;鄭龍;;甘肅地區(qū)波速測試中的問題分析[J];震災防御技術;2013年01期

9 董林;王峻;夏坤;王謙;;剪切波速判別方法對黃土液化判別適用性研究[J];世界地震工程;2012年04期

10 王強;孫軍杰;王蘭民;;黃土震陷研究及相關問題探討[J];中國地震;2012年04期

相關博士學位論文 前1條

1 袁中夏;黃土動殘余變形的特性與機理研究[D];中國地震局工程力學研究所;2010年

相關碩士學位論文 前6條

1 朱強偉;壓實黃土強度特性試驗研究[D];長安大學;2014年

2 邵顯顯;黃土濕陷過程中微觀結構的動態(tài)變化研究[D];蘭州大學;2014年

3 譚芳;基于參數(shù)等級劃分模糊處理的黃土震陷災害概率分析[D];西安建筑科技大學;2010年

4 程小勇;含水量對黃土強度的影響試驗研究[D];中國地質大學;2009年

5 侯云亮;西安地區(qū)黃土地基剪切波速與工程特性相關性的研究[D];長安大學;2007年

6 駱亞生;中國典型黃土動力特性及其參數(shù)的試驗分析[D];西安理工大學;2000年

，

本文編號：1922130