急流槽出口冲刷机理与影响因素试验研究

The Experimental Study on Mechanism andInfluencing Factors of the Local Scour of Chute Outlet

在山区公路排水系统中,急流槽作为路基排水设施之一,占有相当的比例。急流槽出口铺砌末端垂裙处常发生局部冲刷破坏。在室内试验基础上,从二元水流和动力学角度,分析了局部冲刷形成机理,并讨论了局部冲刷深度的影响因素,得出流量、河床质的组成和出口消能形式为主要影响因素。提出按最优水力原理设计出口断面,可通过改变下游河床质为粗粒式、采用铺砌或消力池加挑坎等消能形式,减小出口局部冲刷深度。这些措施可用于公路排水设计及急流槽养护中。

Chute that is one of the facilities of the highway dainage occupies a certainty proportion in highway drainage system in Mountain. In the highway engineering in mountainous area, washout by flood of chute happens frequently in ditch outlet. On the base of doing the hydraulic model test, this paper analyzed the forming mechanism of the local scour of chute exit, discussed the influencing factors and educed what are flux, the compose of riverbed matters and the form of chute outlet affect mainly on the local scour depth of chute outlet. This paper put forward the optimal hydrauic principle of designing chute outlet, the measures which changing the riverbed matters and the form of dissipation energy. The points can be used in the design and maintain of chute.