碎屑流对拦挡结构的动力冲击研究

发布时间：2018-05-05 02:12

本文选题：碎屑流 + 冲击力　；参考：《西南科技大学》2015年硕士论文

【摘要】：本文利用碎屑流模型实验和PFC2D颗粒流数值计算的方法,对碎屑流冲击挡土墙的动力特征进行了研究。通过研究发现,碎屑流运动时既有摩擦运动机理又有碰撞运动机理,在不同体积、坡度下随着流体厚度、冲击角度的改变,两种机理的相互转化对碎屑流冲击力有显著的影响,分析研究了碎屑流冲击力与影响因素间的关系;碎屑流冲击挡墙时不同高度上冲击力呈现非线性变化的特征,通过分析冲击力的这种变化跟土拱效应有关,因此利用离散元软件PFC2D进行数值计算,验证土拱效应的存在,结果显示在碎屑流冲击过程中颗粒间、颗粒与底板间、底板与挡墙间存在冲击拱,冲击拱能够改变冲击力的迹线影响挡墙上的冲击力;最后,利用PFC2D数值计算了不同结构形式、不同颗粒形状、不同底板系数等因素对碎屑流冲击力的变化,对碎屑流冲击做进一步讨论和分析。
[Abstract]:In this paper, the dynamic characteristics of debris flow impingement on retaining wall are studied by using the model experiment of clastic flow and the numerical method of PFC2D particle flow. It is found that there are both frictional and collisional motion mechanisms in the debris flow movement. With the change of fluid thickness and impact angle at different volume and slope, the mutual transformation of the two mechanisms has a significant effect on the impact force of the debris flow. The relationship between the impact force of debris flow and the influencing factors is analyzed, and the nonlinear variation of impact force at different heights is observed when the debris flow impacts on the retaining wall, which is related to the soil arch effect through the analysis of the impact force. Therefore, numerical calculation with discrete element software PFC2D is used to verify the existence of soil arch effect. The results show that there are impact arches between particles, between particles and bottom plates, and between floor plates and retaining walls during the impact of debris flow. The impact arch can change the trace line of impact force to influence the impact force on the retaining wall. Finally, the impact force of debris flow is calculated by using PFC2D numerical calculation, such as different structure form, different particle shape, different floor coefficient and so on. The impact of debris flow is discussed and analyzed further.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.2;TU476

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