基于数值模拟的高速公路S型曲线积水规律分析

Analysis of Water Accumulation Characteristics on S-Curve of Highway Based on Numerical Simulation

S型曲线由于特殊的线型几何特征形成了易积水的路面区域,对于积水规律的掌握有利于在设计和建造阶段提前预防和处理积水路段的危害。该文基于计算流体力学软件Fluent,结合计算流体力学分析中基于欧拉-拉格朗日方法的欧拉液膜模型EWF(Eulerian Wall Film),针对精细化处理的典型S型曲线双向多车道道路模型进行模拟计算。模拟包含了几何特征与降雨量等不同变量因素,得出了积水的水膜厚度以及流速分布规律。模拟结果表明:在降雨阶段,S型曲线横坡坡度0%~1%路段为积水路段,横坡坡度1%~2%路段为易积水路段,横坡坡度大于2%的路段积水情况受到降雨强度影响;在排水阶段,S型曲线横坡坡度0%~1%路段为排水困难路段,横坡坡度1%~2%路段为排水不畅路段,横坡坡度大于2%的路段排水顺畅,在排水时间结束时,路面在不同的几何条件和降雨条件下均能将积水排除至水膜厚度小于2 cm,横坡的大小与渐变影响了积水的横向分布与纵向分布,横向呈现中间高两边低、横断面上标高大的位置水膜厚度小和标高小的位置水膜厚度大的水膜厚度分布规律,总体呈现S型的分布规律;水膜流速在积水阶段呈现纵向上中间低两边高、水膜厚度大则水膜流速大的水膜厚度分布规律,在排水阶段则为纵向上中间高两边低的水膜流速分布规律。道路宽度影响了降雨落到路面的积水总量,进而对积水水膜厚度产生了影响;超高缓和率则主要使得积水路段、易积水路段增长,从而影响了积水分布的范围。

The S-curve pavement formation is susceptible to waterlogging due to its distinctive linear geometric characteristics.Therefore,the mastery of the waterlogging pattern is beneficial for the prevention and management of the hazards associated with waterlogged road sections,particularly in the design and construction phases.Using computational fluid dynamics software Fluent and the Eulerian Wall Film(EWF)which is based on the Eulerian-Lagrange method in computational fluid dynamics analysis,this paper carried out simulation calculations on the the typical S-curve bidirectional multilane road model with refinement treatment.The simulation included different variables,such as geometric features and rainfall,and obtained the film thickness and flow velocity distribution of the ponded water.The simulation results indicate that during the rainfall stage,0%to 1%of the cross slope of the Scurve represents a waterlogged road section,1%to 2%of the cross slope represents a waterlogged road section,and the waterlogging situation of the road section with a cross slope exceeding 2%is influenced by the intensity of rain⁃fall.During the drainage stage,a cross-slope of 0%~1%on the S-curve represents a challenging road section,while a cross-slope of 1%~2%indicates a poorly drained road section.A cross-slope of more than 2%indicates a road section that is smoothly drained.The drainage of the road section at the end of the drainage time can remove the wa⁃ter film to less than 2 cm under different geometric conditions and rainfall conditions.The dimensions and gradient of the cross slope influence the lateral distribution of water as well as the longitudinal distribution.As the drainage stage progresses,the water film thickness distribution law changes to a longitudinal high in the middle and low on both sides with the overall distribution of S pattern,while the water film flow rate distribution law becomes longitudi⁃nal low in the middle and high on both sides.The width of the roadway exerts a significant influence on the total amount of water that falls onto the roadway from rainfall.This,in turn,affects the water film thickness.The ultrahigh retardation rate primarily increases the number of road sections that are waterlogged or prone to water damage,thereby influencing the range of water distribution.