Scour at culvert outlets under ice cover and ice jam conditions

设计和建造公路系统的主要考虑因素之一是通过涵洞系统输送支流排水。有关涵洞出口急流冲刷的调查已进行了数十年。各种研究都考察了影响冲刷程度的许多冲刷参数，但对寒冷地区涵洞出水口设计和冲刷控制的研究还很有限。在严酷的冬季气候下，涵洞可能会完全被进水口覆盖，也可能在早春面临冰堵，这可能会导致堤坝洪水和过度冲刷。此外，由于冰盖和冰塞的附加边界，涵洞内的流场不同于明渠条件下的流场。由于冰盖和冰塞对涵洞出口的过度冲刷可能会导致堤坝泛滥，从而导致高速公路坍塌。有盖的和堵塞的涵洞入口的影响从未*在实验中解决过。此外，还没有可用的实验或数值模拟来研究覆盖条件下涵洞内的流动情况。*对冰盖和冰堵条件下涵洞冲刷进行了试验和数值研究。将评估下列目标：a)评估冰盖条件下涵洞出口冲刷的时间发展；b)建立描述冲刷过程与水流强度、涵洞形状、颗粒尺寸和边界条件的关系的关联方程；c)确定冰盖和冰塞如何改变非均匀沙中涵洞出口冲刷孔的几何形状；d)调查冰塞对涵洞出口冲刷的影响；e)开发一个数值模型来模拟矩形涵洞出口的冲刷过程。*在拟议的研究中，将在三个不同的水力水槽上进行小型、中型和大型试验。这些试验和数值模拟将产生一套经验公式，用于预测结冰条件下涵洞出口的最大冲刷深度。将汇编水利工程涵洞设计和维护的综述。冰盖和冰塞的影响将被深入讨论。这项研究将为解决涵洞出口的冲刷问题提供一个切实可行的方法。预测涵洞出口冲刷的规模和几何形状的能力是加拿大公路沿线侵蚀控制和管理的一种非常有用的评估工具。这项研究将对执业工程师和科学界有所裨益。

One of the major considerations in the design and construction of a highway system is the conveyance of tributary drainage through a culvert system. The investigation of scour by swift-flowing water at culvert outlets has been on-going for several decades. Various studies have examined many scour parameters that affect the degree of erosion; however, there is limited research on culvert outlet design and scour control in cold regions. Culverts may become fully inlet-covered in rigid winter climates and may also face ice jamming in early spring, which can result in embankment flooding and excessive scour. Additionally, due to the extra boundary imposed by ice cover and ice jam, the flow field inside the culvert is different from that under open channel conditions. Excessive scour at culvert outlets due to ice cover and ice jamming can*cause embankment flooding, which can result in highway failure. The*impact of covered and jammed culvert inlets has never been addressed*experimentally. Furthermore, there are no available experimental or*numerical simulations to investigate the flow profiles inside the*culvert under covered conditions. ***The research focuses on the experimental and numerical investigation of culvert scour under ice cover and ice jam conditions. The following objectives will be evaluated: a) to assess temporal scour development at culvert outlets under ice cover conditions; b) to establish associated equations describing the dependence of scour processes on flow intensity, culvert shape, particle grain size, and boundary conditions; c) to determine how ice cover and ice jams alter the geometry of scour holes at culvert outlets in non-uniform sands ; d) to investigate the impacts of ice jamming on the scouring at culvert outlets; e) to develop a numerical model for simulating the scour process for rectangular culvert outlets. ***In the proposed research, small scale, medium scale and large scale experiments will be conducted at three different hydraulic flumes. The experiments, together with numerical simulation, will generate a set of empirical equations that will predict the maximum scour depth at culvert outlets under ice conditions. A compilation of review on culvert design and maintenance in hydraulic engineering will occur. The ice cover and ice jam impacts will be discussed in depth. The present research will provide a practical approach to address the scouring at culvert outlets. The ability to predict the magnitude and geometry of scour at culvert outlets is an extremely useful evaluation tool in the control and management of erosion along highways in Canada. The research will be beneficial to practicing engineers and the scientific community.