Study the Effect of Bottom Erosion from Ships at Thin Berths

Abstract

The analysis of the current state of issues related to the erosion of the bottom and construction of foundations of port hydraulic structures under the influence of hydraulic jets from ship engines is presented. The most common structures made of sheet piles and methods of fixing the soil on the bottom in front of berths and the causes of erosion are considered. Standard construction solutions and problems associated with their implementation are analyzed. The possibility of using an alternative approach to ensuring safety in the operation of thin mooring walls by sinking the sheet pile to a greater depth with the creation of a reserve for possible erosion is revealed. A container ship with dimensions corresponding to the Arctic shuttles that are used in ports and waters of the Northern Sea Route has been accepted as a settlement ship. Methods for calculating the erosion flow rate for soils composing the bottom of the water area and methods for determining the depth of erosion from the action of ship engines with different power are proposed. As part of the study, two options were developed and compared: the first is a standard one with the bottom fixed by building structures, the second option involves a deeper immersion of sheet piles to the depth of possible erosion. The recommended sequence of calculations of the area of bottom erosion at the berth and the depth of erosion from the action of ship engines is proposed. A container ship with a DWT 35000 is accepted as the settlement ship. The cost-effectiveness of the thin sheet pile wall option with the proposed erosion protection in the form of deeper pile immersion exceeds traditional methods by at least 30%.KeywordsBerth structureSheet pile wallsErosion of bottom soilErosion protectionNorthern Sea Route