Experimental study of local scour around submerged cylinders supported by a skirted mudmat in steady current

Research output: Chapter in Book/Conference paperConference paper

Abstract

In this paper, local scour around a cylindrical subsea structure supported by a skirted mudmat foundation is explored experimentally. The experiments consider various geometries defined in terms of the height of the subsea structure relative to its diameter h1/D1, and the diameter of the mudmat relative to the structure D2/D1. The experimental results indicate that the scour development process can be categorized into two modes depending on h1/D1 and D2/D1. In one mode local scour develops immediately at the upstream side of the mudmat, whilst in the second mode scour initiates at the downstream side of the mudmat and propagates to the upstream side. For both modes, the rate of scour development reduces as the mudmat becomes relatively larger (i.e. as D2/D1 increases). However this reduction does not coincide with a reduction in maximum scour depth. Instead, it is shown that the relative scour depth of the superstructure (S0/D1) actually increases as the mudmat becomes larger (i.e. as D2/D1 increases). This trend of increasing scour depth and reducing scour rate with the introduction of a larger mudmat is observed for all structure aspects ratios; however, for small h1/D1 the scour depth is the smallest and the scour rate is the slowest. Collectively, the results of the present study provide some insight into the scour protection provided by a skirted mudmat foundation.

Original languageEnglish
Title of host publicationScour and Erosion IX - Proceedings of the 9th International Conference on Scour and Erosion, ICSE 2018
EditorsYeh Keh-Chia
Place of PublicationChina
PublisherCRC Press/Balkema
Pages359-366
Number of pages8
ISBN (Electronic)9780429667794
ISBN (Print)9780367074678
Publication statusPublished - 10 Oct 2018
Event9th International Conference on Scour and Erosion, ICSE 2018 - Taipei, Taiwan, Province of China
Duration: 5 Nov 20188 Nov 2018

Publication series

NameScour and Erosion IX - Proceedings of the 9th International Conference on Scour and Erosion, ICSE 2018

Conference

Conference9th International Conference on Scour and Erosion, ICSE 2018
CountryTaiwan, Province of China
CityTaipei
Period5/11/188/11/18

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  • Cite this

    Yao, W., An, H., Draper, S., & Cheng, L. (2018). Experimental study of local scour around submerged cylinders supported by a skirted mudmat in steady current. In Y. Keh-Chia (Ed.), Scour and Erosion IX - Proceedings of the 9th International Conference on Scour and Erosion, ICSE 2018 (pp. 359-366). (Scour and Erosion IX - Proceedings of the 9th International Conference on Scour and Erosion, ICSE 2018). CRC Press/Balkema.