Fluid mud properties and nautical depth estimation: A case study in navigation channel of Duyen Hai Port, Vietnam

Duyen Hai Port, Tra Vinh province, Vietnam, was used in January 2016, bringing great benefits to the economic development of the Mekong River Delta. In recent years the navigation channel to the port has faced serious sedimentation, which has become a major obstacle for the larger vessel to reach the port. For the safety of port operations, it is necessary to dredge with a relatively large volume and considerable cost. However, fluid mud in the navigation channel and ports induced many difficulties for vessels entering the port and maintenance dredging. This paper presents the fluid mud properties and nautical depth estimation based on observation data of rheology by RheoTune probe and bathymetries measured by multi-frequency echo sounding. Based on the analysis and comparison of water depth at 91 measurement locations, the paper proposed to apply the echo-sounding at 33 kHz and 200 kHz frequencies for measuring the bathymetry in a fluid mud bed. Density, yield stress, and viscosity were selected as combination criteria to determine the nautical depth for the Duyen Hai port and the navigation channel.