Study the Effect of Measured Heave in Single Beam Hydrographic Survey on Dredged Quantity Estimation

Abstract

Dredge quantity estimation is a critical issue in dredging projects as it has direct impact on the project process and cost. Hydrographic survey is the main tool for measuring the horizontal coordinates and vertical levels of the sea bed and subsequently quantity estimation. Heave is one of the factors that did not mentioned by “IHO Standards for Hydrographic Survey, (2008)” to be measured in its specifications. They only mentioned that for Sweep Systems (multi-transducers arrays): “Once the heave on the transducers exceeds the maximum allowable value in the uncertainty budget, sounding operations should be discontinued until sea conditions improve”.

In dredging works, some consultants insisted to use at least heave motion sensor in doing the bathymetric survey works especially for harbors dredging works in spite of the survey works will cover all aspects of IHO special order and/or order “A” classes. No previous study was done to see how the effect of Heave on the estimated dredged quantities. The current study investigates the impacts of heave on the computed dredged quantities in harbors in Damitta Port, Egypt, and the new Bobyian Seaport in Kuwait for maintenance and capital dredging works.

Keywords: Dredging works, Hydrographic Survey, Heave