Experimental study on scour at unpaved road shoulder

¹ Department of Civil Engineering, Universitas Jenderal Soedirman, Purwokerto, Indonesia
² Dept. Hydraulic and Ocean Engineering, National Cheng Kung University, Tainan, Taiwan

^* Corresponding author: wahyu.widiyanto@unsoed.ac.id

Abstract

Scour is often found along the shoulder of the road, especially the shoulder without pavement in suburban and rural areas. This can reduce the function of the road shoulder and increase the risk of traffic accidents. The mechanism and form of scour have not been widely discussed and need to be studied to improve road safety aspects. This study aims to investigate scour occurrence along the unpaved road shoulders. An experiment was conducted in the laboratory by creating a physical model to simulate the scouring process at unpaved road shoulder. The laboratory test used varying rainfall intensities, slopes, and sediment diameters. Results show that the scour depths are influenced significantly by those three factors. Scour depths resulting in 25% longitudinal slope is around twice deeper than these in 0% longitudinal slope. The scour depth in border between the paved road lane and the unpaved road shoulder is deeper than other part of the shoulder. It shows that the location is a susceptible-part to scouring.