泥石流冲击连续刚构桥的动力响应分析

发布时间：2018-09-04 13:52

【摘要】：泥石流是山区常见的自然灾害,特别是在我国西南地区分布相当广泛。泥石流具有爆发突然、强度大、破坏力强、范围广的特点导致泥石流灾害一旦发生后果极为严重。随着我国山区经济的发展和环境污染的加剧,公路、铁路中的桥涵等工程设施遭受泥石流灾害的概率亦随之增加。由于山区地形、地质、水文、环境等特点,对连续刚构桥型的选用也日益增多,尤其是深基、高墩、大跨度桥的桥梁,连续刚构桥型是最佳方案之一。故本文开展了泥石流冲击连续刚构桥的动力响应研究。本文首先简要介绍了泥石流的基本特性,研究了影响泥石流冲击作用的重要参数,详细分析了泥石流控制方程、流变力学模型、数值分析方法,确定了本次模拟选择的泥石流力学模型及数值分析方法。通过Ansys Workbench中计算流体动力学的CFX模块模拟了泥石流对连续刚构桥常见三种不同形式桥墩的冲击作用,得到了泥石流的体积分布情况、速度流线图和桥墩所受压力图,对泥石流冲击作用下桥墩的防护、连续刚构桥桥墩设计有着理论意义和工程参考价值。通过Ansys Workbench仿真模拟泥石流对某客运专线连续刚构桥的双向流固耦合作用,得到其变形分析、应力分析。并以泥石流冲击桥墩得到的压强作为结构的边界条件导入,再次进行模拟。对双向流固耦合和单向流固耦合的结果进行对比分析。
[Abstract]:Debris flow is a common natural disaster in mountainous areas, especially in southwest China. Debris flow has the characteristics of sudden eruption, high intensity, strong destructive power and wide range, which results in very serious consequences once debris flow disaster occurs. With the development of mountain economy and the aggravation of environmental pollution, the probability of debris flow disaster in highway, railway bridge and culvert is increasing. Due to the characteristics of terrain, geology, hydrology and environment in mountainous areas, the selection of continuous rigid frame bridges is increasing day by day, especially for bridges with deep foundation, high piers, long span bridges and continuous rigid frame bridges. Therefore, the dynamic response of debris flow impact continuous rigid frame bridge is studied in this paper. In this paper, the basic characteristics of debris flow are briefly introduced, the important parameters that affect the impact of debris flow are studied, and the control equation, rheological mechanics model and numerical analysis method of debris flow are analyzed in detail. The mechanical model and numerical analysis method of debris flow are determined. The impact of debris flow on three different types of piers of continuous rigid frame bridge is simulated by CFX module in Ansys Workbench. The volume distribution of debris flow, the velocity streamline diagram and the pressure map of bridge pier are obtained. The design of continuous rigid frame bridge pier under debris flow impact has theoretical significance and engineering reference value. The two-way fluid-structure coupling effect of debris flow on a continuous rigid frame bridge of a passenger dedicated line is simulated by Ansys Workbench, and the deformation analysis and stress analysis are obtained. The pressure obtained by debris flow impingement on the bridge pier is used as the boundary condition of the structure, and the simulation is carried out again. The results of bidirectional fluid-solid coupling and unidirectional fluid-solid coupling are compared and analyzed.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441.3;U448.23

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