Safety criteria for the trafficability of inundated roads in urban floodings

Abstract

The probability of unexpected urban flood hazards is steadily increasing due to global warming and climate change. Consequently, there is a growing need for safety criteria determining the trafficability of inundated roads to ensure a fast and safe evacuation of people in case of such events. In order to determine those criteria, experimental investigations on the stability of two scaled watertight vehicle models and of one prototype passenger car are conducted in a laboratory flume and a steel tank. The conducted flume experiments clearly show a dependency of vehicle stability on the flow angle, whereas the prototype experiments indicate that floating water depths are higher in prototype than in model scale, which is due to the use of a watertight vehicle model. Based on both experiments, a constant total head is proposed as decisive parameter for determining trafficability. This parameter approximates the measured stability curves and can be easily adopted in practice. Furthermore, it is in accordance with fording depths evaluated from relevant literature or by means of manufacturer inquiry. The recommended safety criteria for passenger cars and emergency vehicles are total heads of h E ¼0.3 m ¼const. and h E ¼0.6 m¼const., respectively.

Full‐scale testing of stability curves for vehicles in flood waters

“…All data were in good agreement for a range of vehicle types and sizes. For example, the data for the Nissan Patrol 4WD were in agreement with the emergency vehicle observations of Kramer et al () indicating that these two types of large vehicles may behave similarly in floodwaters. The present data for the small vehicles were in good agreement with small vehicle data from previous studies (Figure ).…”

“…All data were in good agreement for a range of vehicle types and sizes. For example, the data for the Nissan Patrol 4WD were in agreement with the emergency vehicle observations of Kramer et al (2016) FIGURE 10 Vehicle stability curves and comparison with Australian Rainfall and Runoff curves (Shand et al, 2011); use of average drag coefficient C D = 1.38 and varying friction coefficients μ indicating that these two types of large vehicles may behave similarly in floodwaters. The present data for the small vehicles were in good agreement with small vehicle data from previous studies ( Figure 11).…”

“…Shand et al (2011) provided a comprehensive summary of literature published prior to 2010 which was recently expanded by Martínez-Gomariz et al (2016). Most previous research used small-scale model cars for the assessment of vehicle stability curves (e.g., Bonham & Hattersley, 1967;Gordon & Stone, 1973;Keller & Mitsch, 1992;Kramer, Terheiden, & Wieprecht, 2016;Martínez-Gomariz, Gómez, Russo, & Djordjevi c, 2017;Shu, Xia, Falconer, & Lin, 2011;Toda, Ishigaki, & Ozaki, 2012;Xia, Falconer, Xiao, & Wang, 2013;Xia, Teo, Lin, & Falconer, 2011). The common approach in model scale research of vehicle stability has been to assume a surface friction coefficient, often μ = 0.3 (e.g., Bonham & Hattersley, 1967;Keller & Mitsch, 1992;Kramer et al, 2016), and to measure the flow conditions which displace a model vehicle.…”

Reliability-Based Estimation of Traffic Interruption Probability due to Road Waterlogging

“…The second group of research is classified in two subgroups: (a) studies of vehicle stability in flooded roads and (b) studies of wading capabilities of vehicles in flooded road with a still water regime. The studies of vehicle stability used hydrodynamic models to estimate the water depth and speed threshold than inducing (or avoiding) sliding, toppling, or floating to vehicles [26][27][28][29][30][31]. Martinez-Gomariz [32] represented in a speed-depth graph all the results existent in the literature.…”

A multi‐objective framework for analysis of road network vulnerability for relief facility location during flood hazards: A case study of relief location analysis in Bankura District, India

“…The approach involves a genetic algorithm-based approach to analyze the resilience in view of a max-min optimization problem. Kramer, Terheiden, and Wieprecht (2016) give an approach to derive safety criteria for vehicles on roads subjected to urban flood risks.…”