泥石流弯道超高实验研究

发布时间：2018-04-27 06:15

本文选题：清水 + 泥石流　；参考：《成都理工大学》2017年硕士论文

【摘要】：泥石流是一种典型的山区地质灾害,破坏性强。泥石流形成过程复杂,爆发突然,流速快,运动惯性大,直进性强,因此在泥石流通过弯道时,弯道凹岸泥深增大,冲刷作用强,容易在弯道处出现较大的超高并产生巨大的破坏。当弯道沟岸有足够的超高时,泥石流可能会有强烈的冲刷作用或截弯取直,破坏弯道上的防护建筑物及弯道附近的建筑物(公路、铁路、居民建筑等)。因此,研究泥石流弯道超高规律及最大超高位置对保护人民的生命和财产安全有着不可忽视的意义。前人对泥石流的弯道超高研究,针对泥石流流速与弯道曲率半径的研究较多,对泥石流性质以及泥石流超高位置的研究较少。本文通过影响因素分析并简化出影响泥石流弯道超高的几个重要因素,如泥石流流速、弯道曲率半径、泥石流性质(屈服应力和密度),通过控制变量法研究不同因素对泥石流超高及泥石流最大超高位置的影响。然后通过一系列实验研究得到计算模型并通过野外验证,得出主要结论如下:(1)通过多组不同清水流速及不同曲率弯道半径实验,经数据分析,得出了清水弯道超高公式h = (BV2)/(Rg),与前人理论推导公式吻合,验证了实验方法的可靠性。(2)通过影响因素分析,并结合前人研究确定了泥石流弯道超高的影响因素:泥石流流速、弯道曲率半径、弯道宽度,而泥石流性质对弯道超高也有很大影响,其中屈服应力对其影响最大,容重和弯道宽度对其也有一定影响,无量纲化的的屈服应力(由屈服应力、弯道宽度、容重和重力加速度计算得到)与超高成正比。经过多组不同流速、不同弯道曲率半径、不同屈服应力的泥石流实验,得到了泥石流弯道超高计算公式K=4.3×(τ/(ρgB))0.2,经野外数据验证,适用性较好。(3)通过多组不同清水流速及不同曲率弯道半径实验,得到了清水最大弯道超高位置公式:θ = 90×(V2)/(Rg),并经前人实验数据验证,吻合度较高。验证了实验方法的可靠性。(4)通过影响因素分析,确定了泥石流最大弯道超高位置的影响因素:泥石流流速、弯道曲率半径、弯道宽度,而泥石流性质对最大弯道超高位置也有很大影响,其中屈服应力对其影响最大,密度和弯道宽度对其也有一定影响,无量纲的屈服应力与泥石流最大弯道超高位置成正比。通过多组不同流速、不同弯道曲率半径、不同屈服应力的泥石流实验,得到了泥石流最大弯道超高位置的计算θ=20+AV2/Rg=20+56×V2/Rge80τ/(ρgB),经野外数据验证,适用性较好。本文通过研究泥石流弯道超高及最大超高位置与泥石流流速、弯道曲率半径、泥石流性质(屈服应力和密度)之间的规律,从而为现实生活中的工程建筑、公路铁路选址、排导槽修建等提供参考依据,以达到减轻或避免由于泥石流灾害造成的损失。
[Abstract]:Debris flow is a typical geological hazard in mountainous area. The formation process of debris flow is complicated, sudden eruption, fast velocity, large inertia of movement and strong directness, so when the debris flow flows through the bend, the mud depth in the concave bank of the bend increases and the scour effect is strong. Easy to appear at the corner of the larger super-high and cause great damage. When the bend bank is high enough, the debris flow may have strong scouring effect or cutting straight, destroying the protective building on the bend and the building near the bend (highway, railway, residential building, etc.) Therefore, it is of great significance to study the ultra-high rule and maximum super-high position of debris flow bend to protect people's life and property safety. There are many researches on the flow velocity and curvature radius of the debris flow, but less on the nature of the debris flow and the ultra-high position of the debris flow. This paper analyzes and simplifies several important factors that affect the ultra-high bend of debris flow, such as the velocity of debris flow, the radius of curvature of bend, The influence of different factors on the superhigh and maximum ultrahigh position of debris flow is studied by means of controlling variable method in order to study the properties of debris flow (yield stress and density). Then, through a series of experiments, the computational model is obtained and verified in the field. The main conclusions are as follows: (1) through the experiments of several groups of different water flow velocity and different curvature curve radius, the data are analyzed. The super-high formula h = BV _ 2 / R _ (g) of clear water bend is obtained, which coincides with the formula derived from previous theories, and verifies the reliability of the experimental method. (2) through the analysis of influencing factors, and combining with the previous studies, the influence factors of super high velocity of mud-rock flow are determined: the velocity of debris flow. The curvature radius, the width of the bend, and the nature of debris flow have great influence on the ultra-high bend, among which the yield stress has the greatest influence, the bulk density and the bend width also have some influence on it, and the dimensionless yield stress (from the yield stress) The width of the bend, bulk weight and gravity acceleration are calculated) in direct proportion to the height. Through several experiments of debris flow with different velocity, curvature radius and yield stress, the formula K _ (4.3) 脳 (蟿 ~ (r) (蟻 g B) _ (0.2)) is obtained, which is verified by field data. Through many experiments of different water flow velocity and different curvature curve radius, the formula of super-high position of the maximum curve of clear water is obtained: 胃 = 90 脳 V _ 2 / R _ (g), and verified by previous experimental data, the degree of agreement is high. The reliability of the experimental method is verified. (4) through the analysis of the influencing factors, the influencing factors of the superhigh position of the maximum bend of the debris flow are determined: the velocity of debris flow, the radius of curvature of the bend, the width of the bend, The nature of debris flow also has a great influence on the position of the maximum bend, in which yield stress has the greatest influence, density and bend width also have a certain influence on it. The dimensionless yield stress is directly proportional to the ultra-high position of the maximum bend of the debris flow. Based on the experiments of debris flow with different velocity, curvature radius and yield stress, the calculation of 胃 ~ (20) AV2/Rg=20 ~ (56) 脳 V2/Rge80 蟿 _ (r) (蟻 V2/Rge80 蟿 ~ (r) for the maximum bend of debris flow is obtained, which is verified by field data, and its applicability is good. In this paper, the relationship between the ultra-high and maximum ultra-high position of debris flow bends and the velocity of debris flow, the radius of curvature of bend, the nature of debris flow (yield stress and density) is studied, so as to be the site selection of engineering construction and highway and railway in real life. In order to reduce or avoid the loss caused by debris flow disaster, the construction of drainage channel can provide reference basis.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.23

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