本文選題：離散元 + PFC　； 參考：《中國地質(zhì)大學(北京)》2017年碩士論文

【摘要】：2014年8月3日,云南省昭通市魯?shù)榭h發(fā)生6.5級地震,造成牛欄江紅石巖村附近右岸山體發(fā)生滑塌,并阻塞牛欄江,形成堰塞湖,淹沒了上游的紅石巖水電站首部樞紐。本文以紅石巖地震滑坡為例,基于離散元顆粒流軟件PFC對該滑坡的運動過程進行了模擬,對滑坡的啟動機制、運動路徑、運動速度和堆積范圍等進行分析和探討,主要工作內(nèi)容和成果有:(1)針對PFC建立滑坡模型前處理方面較弱的問題,以2014年地震觸發(fā)的紅石巖滑坡為例,以Brick填充法為基礎(chǔ)從獲取地形數(shù)據(jù)、確定滑體和滑床區(qū)域、建立滑體和滑床幾何模型、生成顆粒模型四個步驟出發(fā),提出基于數(shù)字等高線地形圖建立PFC二、三維復雜滑坡模型的前處理方法,為今后基于PFC的滑坡運動過程模擬提供幫助。(2)采用PFC單軸壓縮模擬試驗對巖體力學細觀參數(shù)進行標定,通過單因子變量法開展平行粘結(jié)模型下細觀參數(shù)對試樣的彈性模量、抗壓強度和泊松比三個宏觀特性影響的定性與定量分析,分析結(jié)果便于快速開展單軸壓縮模擬試驗并確定PFC模擬滑坡所需的材料細觀參數(shù)。(3)分別建立紅石巖滑坡的PFC~(2D)和PFC~(3D)模型,施加地震荷載,對其運動過程進行模擬,較好地反演了紅石巖地震滑坡的運動過程和堆積特征,同時監(jiān)測滑體顆粒的速度和位移,顆粒最大運動速度為48.9m/s,表明紅石巖滑坡屬于高速巖質(zhì)滑坡,二、三維模擬得到堆積體形態(tài)相近,呈現(xiàn)前緣層狀堆積,后緣混雜堆積的特點。(4)通過二、三維模擬對比分析,二維模擬滑坡總歷時較短為60s,三維模擬中顆粒隨機碰撞較多,導致顆粒速度較小,能量耗散更明顯,堆積體混雜程度更高,雖然二維模擬有計算速度快的優(yōu)勢,但是三維模擬更能反映滑坡的運動路徑、堆積范圍、堆積厚度等,模擬效果更好。
[Abstract]:On Aug. 3, 2014, a magnitude 6.5 earthquake occurred in Ludian County, Zhaotong City, Yunnan Province, causing the collapse of the right bank near the Niulan Jiang Hongshi Rock Village, blocking the Niulan River, forming a barrier lake, and flooding the first part of the upstream Hongshiyan Hydropower Station. In this paper, based on the discrete element particle flow software PFC, the motion process of the Hongshi rock earthquake landslide is simulated, and the starting mechanism, motion path, velocity and accumulation range of the landslide are analyzed and discussed. The main work contents and results are as follows: (1) aiming at the problem of weak pre-treatment in the establishment of landslide model by PFC, taking the red rock landslide triggered by the 2014 earthquake as an example, taking the Brick filling method as the basis to obtain the topographic data, the sliding body and sliding bed area are determined. The geometric model of sliding body and sliding bed is established, and the particle model is generated. The pre-processing method of PFC 2 and 3 D complex landslide model based on digital contour topographic map is proposed. To provide help for the simulation of landslide motion process based on PFC in the future. The PFC uniaxial compression simulation test is used to calibrate the meso-parameters of rock mass mechanics, and the elastic modulus of the specimen under the parallel bond model is carried out by the single factor variable method. The qualitative and quantitative analysis of the influence of three macroscopic characteristics of compressive strength and Poisson's ratio, the analysis results are convenient for the rapid development of uniaxial compression simulation test and the determination of material mesoscale parameters required by PFC to simulate landslide. By applying seismic load and simulating its motion process, the movement process and accumulation characteristics of Hongshi rock earthquake landslide are well inversed, and the velocity and displacement of sliding particles are monitored at the same time. The maximum movement velocity of particles is 48.9 m / s, which indicates that the Hongshi landslide belongs to high speed rock landslide. Second, 3D simulation shows that the accumulation body is similar in shape, showing the characteristics of front edge stratiform accumulation and posterior edge mixed accumulation. The total duration of 2D simulated landslide is shorter than 60 s. In 3D simulation, there are more random collisions of particles, which results in smaller particle velocity, more obvious energy dissipation, and higher mixing degree of accumulative bodies, although 2D simulation has the advantage of fast calculation speed. But 3D simulation can better reflect the movement path, accumulation range and thickness of landslide.
【學位授予單位】：中國地質(zhì)大學(北京)
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：P642.22

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本文編號：1912851