Local Scour in Front of Quay Wall Caused by Bow Thruster and its Countermeasure using Filter Units

摘要

This study is intended to investigate local scour in front of a quay walland its generation mechanism. Hydraulic model experiments have beenconducted to investigate the local scour in front of quay wall. Also,countermeasures against local scour using armor stones and filter unitsare investigated based on the experiment. To consider the mechanismof local scour, numerical simulation has been conducted. Thenumerical computation method employed in this study includes a flowsimulation inside seabed and dynamic response of seabed like sedimenttransport. Time variation of pore pressure obtained in the experimentsindicates the generation of local liquefaction due to strong flow and itsresponse of seabed, and this may encourage the local scour.Experimental results clearly show that armoring by filter units iseffective to reduce the local scour.