本文選題：滑體顆粒　切入點(diǎn)：運(yùn)動(dòng)特性　出處：《蘭州大學(xué)》2015年碩士論文

【摘要】：滑體運(yùn)動(dòng)包含滑體崩落、滑動(dòng)、滾動(dòng)、坡面撞擊回彈以及滑體顆粒之間相互碰撞等多種作用形式,運(yùn)動(dòng)過程與滑體顆粒的力學(xué)特性、物理參數(shù)以及邊坡特性等多種因素有關(guān)。目前,相關(guān)研究大多是基于滑體的形成機(jī)理,而對(duì)其滑后運(yùn)動(dòng)特性的研究相對(duì)較少。因此,本論文基于離散單元法對(duì)滑體下滑的運(yùn)動(dòng)進(jìn)行仿真,著重對(duì)滑體在流向內(nèi)物體前的堆積特性及其對(duì)擋墻所造成的沖擊作用等進(jìn)行分析。主要研究工作如下：首先,建立了滑體運(yùn)動(dòng)及其對(duì)流向內(nèi)受災(zāi)體沖擊的二維離散單元模型�；诨w下滑過程中不同時(shí)刻的空間形態(tài),分析了其下滑過程中的基本運(yùn)動(dòng)特性。同時(shí),通過統(tǒng)計(jì)滑體滑動(dòng)過程中對(duì)流向內(nèi)物體不同高度處的沖擊作用,分析了滑體沖擊結(jié)束后的靜態(tài)堆積特性；最后分析了滑體顆粒間的摩擦系數(shù)、堆積區(qū)域長(zhǎng)度以及邊坡坡角對(duì)滑體下滑后的最大堆積力的影響規(guī)律,并進(jìn)一步討論了這些參數(shù)對(duì)滑體靜態(tài)堆積形態(tài)的影響。其次,基于顆粒流理論,建立了一個(gè)簡(jiǎn)單的斜面滑體顆粒對(duì)擋墻的動(dòng)態(tài)沖擊模型。通過分析滑體在斜面滑動(dòng)過程中的動(dòng)力學(xué)行為及其能量耗散特征,給出滑體在整個(gè)沖擊過程中對(duì)擋墻沖擊作用的時(shí)空演化規(guī)律,得到的動(dòng)態(tài)沖擊力與已有實(shí)驗(yàn)結(jié)果定性一致。針對(duì)不同滑體顆粒的初始構(gòu)型,討論了最大動(dòng)態(tài)沖擊力的分布特征。在此基礎(chǔ)上,分析了滑體顆粒摩擦系數(shù)、滑體的斜面滑動(dòng)距離以及邊坡坡面粗糙度等參數(shù)對(duì)擋墻所受最大沖擊力的影響�？傊�,通過對(duì)滑體運(yùn)動(dòng)過程中的動(dòng)力學(xué)特性及其對(duì)受災(zāi)體及擋墻的沖擊作用研究,一方面可以為工程建設(shè)中邊坡防護(hù)結(jié)構(gòu)的設(shè)計(jì)建造提供相關(guān)理論支持。另一方面可以探究顆粒群體與連續(xù)結(jié)構(gòu)之間的復(fù)雜作用過程,這對(duì)從微觀層面研究滑體運(yùn)動(dòng)的動(dòng)力學(xué)特性是一個(gè)有益的嘗試。
[Abstract]:The motion of sliding body includes many kinds of action forms, such as caving, sliding, rolling, bumping and springback of slope, and collision between particles of sliding body, and so on, and the movement process and the mechanical properties of the particles of sliding body. Physical parameters and slope characteristics are related to many other factors. At present, most of the related studies are based on the formation mechanism of sliding body, but there are few researches on its motion after sliding. Based on the discrete element method, this paper simulates the sliding motion of sliding body, focusing on the analysis of the stacking characteristics of the sliding body before the flow direction of the body and its impact on the retaining wall. The main research work is as follows: first of all, A two-dimensional discrete element model of sliding body motion and its impact on the body affected by the flow direction is established. Based on the spatial morphology of the sliding body at different times, the basic motion characteristics of the sliding body are analyzed. The static stacking characteristics of the sliding body after the end of the impact are analyzed by statistics of the impact action of the sliding body on different heights of the body in the flow direction. Finally, the friction coefficient between the particles of the sliding body is analyzed. The influence of the length of the stacking region and the slope angle on the maximum stacking force of the sliding body is discussed, and the influence of these parameters on the static stacking shape of the sliding body is discussed. Secondly, based on the particle flow theory, In this paper, a simple dynamic impact model of inclined sliding body particles on retaining wall is established. The dynamic behavior and energy dissipation characteristics of sliding body during slope sliding are analyzed. The temporal and spatial evolution of the effect of sliding body on the impact of retaining wall during the whole impact process is given. The obtained dynamic impact force is qualitatively consistent with the existing experimental results. The distribution characteristics of maximum dynamic impact force are discussed. On the basis of this, the influence of parameters such as the friction coefficient of sliding particles, slope slip distance and slope roughness on the maximum impact force on the retaining wall is analyzed. The dynamic characteristics of the sliding body and its impact on the affected body and retaining wall are studied. On the one hand, it can provide theoretical support for the design and construction of slope protection structure in engineering construction, on the other hand, it can explore the complex process between particle group and continuous structure. This is a useful attempt to study the dynamic characteristics of sliding body motion from the micro level.
【學(xué)位授予單位】：蘭州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P642.2

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本文編號(hào)：1669042