Design of Sheet Piled Quay Walls Taking into Account Scour of Bottom Caused by Ships
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Vol. 54, No. 3, September, 2020
DESIGN OF SHEET PILED QUAY WALLS TAKING INTO ACCOUNT SCOUR OF BOTTOM CAUSED BY SHIPS V. I. Shabanov,1 P. A. Garibin,2 and N. D. Belyaev3 Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 4, April 2020, pp. 25 – 29.
The analysis of the current state of issues related to scour of the bottom and foundations of hydraulic structures under the influence of jets from ship propulsor is presented. The possibility of using an alternative approach to ensuring safety during the operation of thin quay walls by immersing the sheet pile to a greater depth with the creation of a reserve for possible scour has been revealed. Keywords: design; mooring facility; sheet piled quay wall; ship propulsor; scour; scour protection.
mersion. Removal of this material due to scour increases the load on the flexible wall, which can lead to its excessive deformation and, in its turn, damage and/or destruction. In addition, scouring behind the sheet pile wall is also a dangerous mechanism. Hypothetically, when the scour reaches the bottom of the sheet pile wall, the filling material can be partially washed out, which will lead to sagging of the coating or the berth decking with damage to any equipment and structures located on its surface. However, for the majority of sheet piled quay walls, the bottom elevation of sheet piles significantly exceeds the possible scour depth [3, 4]. Published papers on this topic began to appear in the second half of the 20th century due to the occurrence of emergency situations, the causes of which were scour under the impact of ship propulsors on the bottom and foundations of hydraulic structures [5 – 7]. Most of the papers on the topic under consideration were published in the PIANC (Permanent International Association of Navigation Congress) periodicals, in which, in 2015, Guidelines for Protecting Berthing Structures from Scour Caused by Ships were issued [4]. Data on the issue under consideration are also given in some foreign regulations on related topics, for example, in those that relate to issues connected with the design of berthing facilities [8, 9]. There are no Russian methods or regulatory documents for the design of berths taking into account the possible bottom scour [3]; at the same time, the projects traditionally develop protective measures near the quay walls or impose restrictions on the ships sailing conditions [10]. To protect the bottom from scour near the foundations of the mooring facilities, various coverings are used [3, 4, 10, 11]: rockfill blanket; impregnated stone coverings; fabricated concrete block mats; concrete plates; fabric mattresses with
The issue of scour of the bottom near hydraulic structures has acquired great urgency in connection with the increase in the water transport intensity [1 – 3]. The mooring and departure from the berth of a modern freighted marine vessel of large draught are accompanied by a significant force impact of water on the bottom of the water area. Disturbances in the flow violate the dynamic equilibrium of the
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