Experimental studies of the flow-front and drag forces exerted by subaqueous mudflow on inclined base

Submarine slides are one of the most complex geotechnical problems causing serious damages to the seabed environment. Damages may lead to imminent destruction of offshore facilities such as platform and subsea pipeline. Mud sediment was the most susceptible of subsea material involved in the event. The completeness of field investigation is very limited; therefore, laboratory experiment is implemented in view of modeling the dynamics movement at the time of submarine slides occurs. The current experiment was conducted by generating the mudflow in water ambient over an inclined base to observe the flow-front structures of the mudflow. As facility to investigate the drag force exerted by mudflow, additional pipe model was positioned at certain flow distance. Mud models were prepared from mixtures of 10–35 % by weight of kaolin and water. Mudflow observations were limited to 3.5-m run-out distance with an exemption for 35 % KCC since this percentage stopped flow at 2.3-m flow distance. The role analysis of destructive flow was developed by the determination of drag force coefficient exerted by mudflow incorporating the Reynolds number. Velocity analysis indicates that all flows were defined as initial flow since they have only one phase of slumping phase. With respect to head-flow height and densimetric Froude number, the general form of velocity propagation formula provided the satisfactorily results in tracing mudflow velocity observation of laboratory experiment. Furthermore, the higher percentage of KCC exerted the higher drag force than the lower one. Copyright Springer Science+Business Media Dordrecht 2013