【摘要】：研究區(qū)地處龍門山中段,山高谷深、岸坡陡峭,且地質(zhì)構(gòu)造復雜,新構(gòu)造運動強烈。大量分布著花崗巖、花崗閃長巖等高強度巖石,這些巖石裂隙發(fā)育,巖體破碎,在遭受強烈震動以后,引發(fā)了不同規(guī)模的崩塌和滑坡,大量崩滑堆積體堆積在斜坡的不同部位,改變了斜坡的微地貌特征,影響震后斜坡的匯水條件,導致研究區(qū)形成了多種成因模式和運動特征不盡相同的坡面型泥石流。給災區(qū)人民的生命財產(chǎn)和交通安全造成嚴重的影響。因此,開展對震后坡面型泥石流的研究,對減災防災有重要意義。論文取得的成果及結(jié)論如下:(1)、地震以后坡面型泥石流的活動增強,臨界降雨量降低,表現(xiàn)出明顯的高頻性、群發(fā)性和類型多樣性,具有突發(fā)性強、破壞性大、季節(jié)性強的特點。(2)、根據(jù)物源的類型和物源堆積狀況的不同,將研究區(qū)的坡面型泥石流分為以下7類:1)、高位滑坡堆積體-揭底-側(cè)蝕型:①、高位滑坡堆積體以中、小型滑坡堆積體為主,堆積位置較高。②、溝道縱比降相對較大,呈“陡-緩-陡”的階梯狀。③、泥石流運動速度快、沖擊力大、破壞性強、運移距離遠。④、侵蝕方式為:揭底侵蝕+側(cè)向侵蝕。2)、大型滑坡堆積體-沖切-溯源侵蝕型:①、滑坡堆積體大多分布在坡腳處,多為厚層或巨厚層堆積體。②、整個滑坡堆積體穩(wěn)定性較好,淺表層固體物質(zhì)松散,穩(wěn)定性較差。③、泥石流的動能較小,運動速度較低。④、侵蝕方式為:拉槽沖切+溯源侵蝕。3)、坡腳崩塌堆積體侵蝕型:在暴雨作用下,崩塌堆積體淺表松散物質(zhì)呈片狀啟動。泥石流流速較慢,侵蝕能力較弱,溝道寬且淺。4)、高位崩塌堆積體侵蝕型:崩塌堆積體堆積部位較高,以中、小型堆積體為主,穩(wěn)定性較差。物源具有一定的隱蔽性,流體運動速度快、破壞力強、危害性大。5)、溝內(nèi)高位崩塌堆積體侵蝕型:泥石流具有間歇性期,在非暴雨期間,固體物質(zhì)累積在溝道高處緩坡平臺處;在暴雨期間,坡面徑流沖刷松散固體物質(zhì)形成泥石流。泥石流運動速度快,破壞力強,規(guī)模較小,爆發(fā)頻率高。6)、滑坡型坡面型泥石流:①、多為小型淺層溜滑。②、滑坡體的位能是泥石流轉(zhuǎn)化過程中主要動力來源。③、滑坡轉(zhuǎn)化形成為泥石流是一個連續(xù)快速的過程,中間沒有間斷。④、流體運動過程中運動阻力較大。7)、崩塌型坡面型泥石流:可以分為兩類:①、崩塌體直接轉(zhuǎn)化為坡面型泥石流,過程如下:巖體崩塌撞擊碎屑化流動堆積。②、崩塌體運動過程中擾動堆積體形成泥石流,過程如下:崩塌碰撞侵蝕流動堆積。③、物源多為震裂巖體,沒有明顯的匯水區(qū)域、流體容重大、規(guī)模較小、溝道細長,縱比降大、運動速度快。(3)、本文建立了以立方體為稀性坡面型泥石流粗顆粒的基本模型,提出了立方體模型的滑移、翻轉(zhuǎn)(包括繞邊翻轉(zhuǎn)、繞支點翻轉(zhuǎn)及嵌固繞邊翻轉(zhuǎn))等啟動方式。并推導得出了粗顆粒啟動平均流速公式,采用陳奇伯的實驗數(shù)據(jù)加以驗證,計算結(jié)果較吻合。(4)、采用能量守恒定理和動量守恒定理,討論不同質(zhì)量的粗顆粒之間的碰撞過程,并以此分析流體運動過程中粗顆粒的運動特征。(5)、結(jié)合水力學基本原理和粗顆粒啟動條件研究內(nèi)容,探討了泥石流粗顆粒啟動條件與降雨強度之間的關(guān)系,為坡面型泥石流的監(jiān)測提供一定的理論基礎(chǔ)。
[Abstract]:The study area is located in the middle section of the Longmen mountain. Yamadaka Tani is deep, the bank slope is steep, and the geological structure is complex and the new tectonic movement is strong. A large number of high strength rocks, such as granite and granodiorite, are distributed in large quantities. These rocks are fractured and rock masses are broken. After the strong vibration, different scales of landslides and landslides are triggered, and a large number of landslide deposits are stacked in slanting. The different parts of the slope change the microgeomorphic features of the slope and influence the water confluence of the post - earthquake slope, which leads to the formation of a variety of genetic patterns and different slope type debris flows in the study area. The results and conclusions obtained in this paper are as follows: (1) after the earthquake, the activities of the slope debris flow are enhanced and the critical rainfall is reduced, showing obvious high frequency, group and type diversity, with sudden strong, destructive and seasonally strong characteristics. (2) according to the type of source and the accumulation of material sources In the same way, the slope debris flow in the study area is divided into 7 categories: 1), the high landslide accumulation body and the bottom side erosion type: (1) the high landslide accumulation body is mainly the small landslides accumulation body, and the accumulation position is high. The erosion mode is: exposure erosion + lateral erosion.2), large landslide accumulation - scouring and traceability erosion type: (1) most of the landslide deposits are distributed at the foot of the slope, mostly thick layer or thick layer accumulation body. 2. The stability of the whole landslide accumulation is good, the shallow surface solid material is loose and the stability is poor. The movement speed is low. (4) the erosion mode is the erosion pattern of the slotting and the traceability erosion.3) and the slope foot collapse accumulation. Under the action of the rainstorm, the shallow surface loose material of the collapse accumulation is flaky. The debris flow velocity is slow, the erosion ability is weak, the channel wide and the shallow.4), the high collapse accumulation body erosion type: the accumulation part of the collapse accumulation body is higher in the middle, The small accumulation body is mainly, the stability is poor. The source has a certain concealment, the fluid movement speed is fast, the destructive force is strong, the dangerous.5), the debris flow has the intermittent period, during the non rainstorm, the solid substance accumulates in the high slope platform of the channel height, and the sloping runoff scour loose solid during the rainstorm. Debris flow is formed by debris flow. Debris flow has fast speed, strong destructive force, small scale, high frequency of.6), and landslide type slope debris flow: (1) small and shallow skating. (2) the potential energy of the landslide body is the main source of power in the process of debris flow transformation. The collapse type slope type debris flow can be divided into two types: (1) the collapse body is divided into two types: (1) the collapse body is transformed directly into the slope type debris flow, and the process is as follows: rock mass collapse and debris flow accumulation. The main source is the rock mass, and there is no obvious area of the rock mass, there is no obvious water area, the fluid volume is important, the size is small, the channel is slender, the longitudinal ratio decreases and the movement speed is fast. (3) the basic model of the coarse particles with the cube as the lean slope is established in this paper, and the slip of the cube model is put forward, including the reversal of the winding, the reversal of the branch point and the embedding. The formula of starting average velocity of coarse particles is derived, and the formula of average velocity of starting of coarse particles is derived. The results are verified by Chen Qibo's experimental data. (4) the energy conservation and momentum conservation theorems are used to discuss the collision process between coarse particles of different mass and to analyze the transport of coarse particles in the process of fluid motion. (5) the relationship between the starting condition of the coarse particles and the rainfall intensity is discussed in accordance with the basic principle of hydraulics and the starting condition of coarse particles, which provides a theoretical basis for the monitoring of the sloping debris flow.
【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P642.23

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