Ocean Systems Engineering Volume 4, Number 2, June 2014 , pages 99-115 DOI: https://doi.org/10.12989/ose.2014.4.2.099 |
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Safety assessment of caisson transport on a floating dock by frequency- and time-domain calculations |
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H.Y. Kang and M.H. Kim
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Abstract | ||
When caissons are mounted on a floating transportation barge and towed by a tug boat in waves, motion of the floating dock creates inertia and gravity induced slip forces on the caisson. If its magnitude exceeds the corresponding friction force between the two surfaces, a slip may occur, which can lead to an unwanted accident. In oblique waves, both pitch and roll motions occur simultaneously and their coupling effects for slip and friction forces become more complicated. With the presence of strong winds, the slip force can appreciably be increased to make the situation worse. In this regard, the safety of the transportation process of a caisson mounted on a floating dock for various wind-wave conditions is investigated. The analysis is done by both frequency-domain approach and time-domain approach, and their differences as well as pros and cons are discussed. It is seen that the time-domain approach is more direct and accurate and can include nonlinear contributions as well as viscous effects, which are typically neglected in the linear frequency-domain approach. | ||
Key Words | ||
caisson transport; floating barge; safety; slip force; friction force; inertia/gravity effects; nonlinear terms; roll-pitch coupling; frequency-domain and time-domain analysis; irregular waves/winds. initial inclination; deck flooding | ||
Address | ||
H.Y. Kang and M.H. Kim:Ocean Engineering Program, Department of Civil Engineering, Texas A&M University, 3136 TAMU, College Station, TX, USA, 77843-3136 | ||