Dynamic Response of Dilute to Viscous Channelized Debris Flow on Pipeline Crossing

Abstract

Abstract This study aims to experimentally investigate the dynamic response of dilute to viscous debris flows on pipeline crossing. The debris flow impact mechanism, front flow depths, and front velocities were measured and analyzed using pressure transducers, ultrasonic sensor, and high-speed cameras in a 9-degree inclined flume. The experimental findings revealed that dilute debris flows were characterized by turbulent and rapid flow regimes that produced splashing phenomena. In contrast, viscous debris flows exhibited relatively slow flow velocities, leading to the impact of the pipe via run-up or layered phenomena. Significant variations in flow depths, frontal velocity, and impact pressures were observed due to wavelike and layered phenomena from dilute to viscous debris flows. Front flow depths were substantially increased while front velocities and impact pressures were decreased with an increment of solid volume fraction (αs). The calculated dimensionless number confirmed the similarity of experimental results with those observed in natural phenomena and other experimental studies. Further, for dilute debris flows, dimensionless impact pressure was a power function of Froude number (Fr), while for viscous debris flows, it was a power function of both Froude (Fr) and Reynold number (Re).