Author(s): Jaehak Jeong; Randall J. Charbeneau
Linked Author(s):
Keywords: Sheet flow; Hydraulics; Urban drainage; Curvilinear coordinates; Kinematic wave boundary conditions; Diffusion wave modeling
Abstract: Curved highway segments often use superelevation transitions to help balance centrifugal forces on vehicles. Such transitions have regions with near-zero pavement cross-slope as the pavement cross-section rotates from negative to positive grade. This condition promotes extended stormwater runoff drainage path lengths and may result in excessive splash from vehicles and hydroplaning. A critical concern is the effects of longitudinal slope on stormwater drainage through superelevation transitions. The overall goal of this study is to provide design guidance on minimum longitudinal slope at superelevation transitions through application of numerical simulation of highway runoff. For drainage of roadway surfaces, regions with near-zero slope constitute ‘irregular topography’. Specific issues addressed in this manuscript include 1) automatic development of a curvilinear grid using standard output from roadway design software, 2) formulation of a finite-volume diffusion wave model for highway runoff, 3) development of kinematic wave-based boundary conditions, and 4) applications of the resulting simulation model.
Year: 2007