發(fā)布時(shí)間：2018-03-10 02:35

  本文選題：坡面泥石流　切入點(diǎn)：變形過(guò)程　出處：《重慶交通大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：坡面泥石流是我國(guó)山區(qū)公路沿線(xiàn)的重要地質(zhì)災(zāi)害,主要受降雨控制。本文在國(guó)家自然科學(xué)基金項(xiàng)目“坡面泥石流精細(xì)演化機(jī)制研究”(編號(hào)41071017)資助下,對(duì)模型試驗(yàn)結(jié)果進(jìn)行數(shù)值模擬研究,取得如下成果:(1)分析了坡面泥石流的形成影響因素,主要研究了地形條件和水源條件對(duì)坡面泥石流形成過(guò)程的影響。地形條件是坡面泥石流發(fā)生的控制因素,它決定了泥石流發(fā)生后的破壞形式。水文條件主要是降雨的作用,降雨是坡面泥石流發(fā)生的主要誘發(fā)因素,它改變斜坡巖土體的水文地質(zhì)條件,而且降雨也是坡面泥石流形成的必備條件,它不僅為泥石流的形成提供豐富的水源,降雨還為泥石流的運(yùn)動(dòng)提供動(dòng)力作用。(2)孔隙水壓力的增長(zhǎng)與累積降雨量有著密不可分的關(guān)系,累計(jì)降雨量增長(zhǎng)越快,孔隙水壓力增長(zhǎng)幅度反而小。以實(shí)驗(yàn)中5號(hào)點(diǎn)為例,在相同的降雨量情況下,在降雨歷時(shí)8h試驗(yàn)中的,累積降雨量平均增長(zhǎng)速度為12.5mm/h,孔隙水壓力從-0.00433Mpa增長(zhǎng)到0.0041Mpa,增長(zhǎng)幅度為0.00843Mpa。在降雨歷時(shí)4小時(shí)試驗(yàn)中,累積降雨量平均增長(zhǎng)速度為25mm/h,孔隙水壓力從-0.00619Mpa增長(zhǎng)到0.0031Mpa,增長(zhǎng)幅度為0.00919MPa。(3)依照模型試驗(yàn)的尺寸和數(shù)據(jù),采用ANSYS14.5中FLUENT模塊結(jié)合大變形模擬的數(shù)值模擬方法,對(duì)降雨誘發(fā)坡面泥石流的演化過(guò)程作了數(shù)值模擬,通過(guò)模型的建立、參數(shù)的設(shè)置、網(wǎng)格的劃分、邊界條件的設(shè)定和模型計(jì)算等步驟,得到了坡面泥石流的變形云圖和變形數(shù)據(jù)。通過(guò)對(duì)部分點(diǎn)的變形分析,得到了土體單元的變形規(guī)律,通過(guò)對(duì)剖面的分析,得到了整個(gè)坡面土體的整體變形規(guī)律,通過(guò)對(duì)整個(gè)坡面變形的分析,得到了坡面泥石流在降雨作用下的變形趨勢(shì)。通過(guò)對(duì)比分析了模型試驗(yàn)和數(shù)值模擬兩種情況下,坡面在降雨作用下的變形趨勢(shì)基本相同。(4)模擬了不同坡度下坡面泥石流土體的變形過(guò)程,得到不同坡度下,坡體的變形云圖和變形數(shù)據(jù)。通過(guò)對(duì)不同坡度下坡體的變形云圖的分析,發(fā)現(xiàn)坡度越大,土體變形越大,且隨著坡度的增大,坡體后緣土體的變形增長(zhǎng)較快,而前緣土體變形增長(zhǎng)較慢。
[Abstract]:Slope debris flow is an important geological hazard along highway in mountainous area of China, which is mainly controlled by rainfall. This paper is supported by the project of National Natural Science Foundation "study on fine evolution mechanism of slope debris flow" (No. 41071017). The numerical simulation results of the model test results are obtained as follows: 1) the factors affecting the formation of debris flow on the slope are analyzed. This paper mainly studies the influence of terrain condition and water source condition on the forming process of debris flow on slope surface. Terrain condition is the controlling factor of debris flow on slope surface, which determines the failure form of debris flow after occurrence, and the hydrological condition is mainly the function of rainfall. Rainfall is the main inducing factor of debris flow on slope, which changes the hydrogeological condition of slope rock and soil, and it is also the necessary condition for the formation of debris flow on slope. It not only provides abundant water for the formation of debris flow. The increase of pore water pressure is closely related to the accumulated rainfall. The faster the accumulated rainfall, the smaller the increase of pore water pressure. Under the same rainfall condition, the average growth rate of cumulative rainfall was 12.5 mm / h, and the pore water pressure increased from -0.00433Mpa to 0.0041Mpa. the increase was 0.00843Mpa. in the 4-hour rainfall experiment, the average growth rate of cumulative rainfall was 12.5mm / h, and the pore water pressure increased from -0.00433Mpa to 0.0041Mpa. The average growth rate of accumulated rainfall is 25mm / h, the pore water pressure increases from -0.00619Mpa to 0.0031Mpa. the increase range is 0.00919MPa.m3) according to the size and data of the model test, the numerical simulation method of FLUENT module combined with large deformation simulation in ANSYS14.5 is adopted. The evolution process of slope debris flow induced by rainfall is numerically simulated. Through the establishment of model, the setting of parameters, the division of grid, the setting of boundary conditions and the calculation of model, etc. The deformation cloud map and deformation data of debris flow on slope surface are obtained. Through the deformation analysis of some points, the deformation law of soil element is obtained, and the integral deformation law of the whole slope soil is obtained by analyzing the profile. Through the analysis of the deformation of the whole slope surface, the deformation trend of debris flow on the slope surface under the action of rainfall is obtained. The deformation trend of slope surface under rainfall is basically the same. 4) the deformation process of debris flow soil under different slope degrees is simulated, and the deformation process of debris flow soil is obtained under different slope degrees. The deformation cloud map and deformation data of slope body. By analyzing the deformation cloud map of slope body with different slope degrees, it is found that the larger the slope degree is, the larger the deformation of soil is, and with the increase of slope, the deformation of soil in the back edge of slope body increases rapidly. However, the deformation of the front soil increased slowly.
【學(xué)位授予單位】：重慶交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：P642.23

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 劉菲;唐紅梅;;工程棄渣型坡面泥石流形成過(guò)程試驗(yàn)[J];重慶交通大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年S1期

2 劉成;徐剛;黃彥;孔圓圓;程中玲;楊娟;;激發(fā)坡面泥石流形成的降水因素探討——以重慶北碚地區(qū)為例[J];水土保持通報(bào);2007年01期

3 劉成;徐剛;;坡面泥石流活動(dòng)與降水之間的關(guān)系初探——以重慶北碚地區(qū)為例[J];水文地質(zhì)工程地質(zhì);2006年04期

，

本文編號(hào)：1591414