Integrated Navigation Effects/Impacts Modeling System

Hydrodynamics generated by moving deep-draft vessels create significant impacts to navigation safety and other users in the waterway. An integrated numerical modeling system has been developed to assist Ports in evaluating navigation issues such as squat effects on the maneuvering and berthed vessels, forces on berthed vessels and shoreside structures, and other impacts such as shoreline erosion and water quality. Vessels maneuvering in confined waterways of arbitrary configurations subject port structures and other vessels to varying forces and moments, which change in time due to speed and location in the waterway, as well as changes in waterway configuration. Accurate prediction of hydrodynamics and forces in real waterways with variable depths, channel widths, and ambient currents are essential to improve port efficiency and for optimizing navigation channel and mooring design. The Vessel Hydrodynamics Longwave Unsteady (VH-LU) modeling system was developed as part of a complete coastal engineering modeling system, and incorporates into the vessel hydrodynamics code a wide array of coastal ambient forces and processes which provide an integrated evaluation of navigation processes and impacts in real port settings. The modeling system has been previously validated for hydrodynamic calculations using field water level and velocity measurements as well as for berthed vessel loading using laboratory measurements. The present paper presents two test cases of evaluation of passing vessel forces on berthed vessels from the Port of Los Angeles, CA and Port of Tampa, FL. In both cases, numerical modeling and analysis results reveal completely different results than empirical methods due to irregular passing vessel and waterway conditions. This paper also describes model enhancements for prediction of moving and berthed vessel sinkage (squat) in arbitrary channels, with validation performed using empirical methods. Squat calculations are compared with empirical/laboratory data for a wide variety of conditions and example squat calculations of transit through complex channels are provided as an example of the variability of squat during arrival and departure into ports. Squat example calculations are also provided for situations where vessels pass each other in complex waterways.