## Backfilling of trenches exposed to waves

Publication: Research - peer-review › Conference article – Annual report year: 1997

### Standard

**Backfilling of trenches exposed to waves.** / Hjelmager Jensen, Jacob; Fredsøe, Jørgen.

Publication: Research - peer-review › Conference article – Annual report year: 1997

### Harvard

*Proceedings of the Coastal Engineering Conference*, vol 3, pp. 3231-3243.

### APA

*Proceedings of the Coastal Engineering Conference*,

*3*, 3231-3243.

### CBE

### MLA

*Proceedings of the Coastal Engineering Conference*. 1997, 3. 3231-3243.

### Vancouver

### Author

### Bibtex

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### RIS

TY - CONF

T1 - Backfilling of trenches exposed to waves

A1 - Hjelmager Jensen,Jacob

A1 - Fredsøe,Jørgen

AU - Hjelmager Jensen,Jacob

AU - Fredsøe,Jørgen

PB - American Society of Civil Engineers

PY - 1997

Y1 - 1997

N2 - This paper treats the numerical prediction of initial and long-term morphology of small pipeline trenches. For this purpose a refined flow and sediment transport description is applied such that the entire mathematical problem is formulated and solved on a curvilinear grid using a k - ε turbulence-closure. The backfilling process of trenches exposed to either waves or a steady current is of importance in relation to the implementation of pipelines in the marine environment. With respect to the sedimentation of trenches, the non-dimensional Trench-Keulegan-Carpenter number, KC = a/L, where a is the excursion length of a particle in waves and L the trench length, is investigated in detail, and an optimal KC-number for the backfilling rate is found. Coherent structures in the non-uniform unsteady trench-flow are shown to dominate the deposition rate when present. The importance of a detailed description of the flow is further justified by comparing predictions of a very simple flow-model neglecting convective terms with the sophisticated flow-model.

AB - This paper treats the numerical prediction of initial and long-term morphology of small pipeline trenches. For this purpose a refined flow and sediment transport description is applied such that the entire mathematical problem is formulated and solved on a curvilinear grid using a k - ε turbulence-closure. The backfilling process of trenches exposed to either waves or a steady current is of importance in relation to the implementation of pipelines in the marine environment. With respect to the sedimentation of trenches, the non-dimensional Trench-Keulegan-Carpenter number, KC = a/L, where a is the excursion length of a particle in waves and L the trench length, is investigated in detail, and an optimal KC-number for the backfilling rate is found. Coherent structures in the non-uniform unsteady trench-flow are shown to dominate the deposition rate when present. The importance of a detailed description of the flow is further justified by comparing predictions of a very simple flow-model neglecting convective terms with the sophisticated flow-model.

JO - Proceedings of the Coastal Engineering Conference

JF - Proceedings of the Coastal Engineering Conference

SN - 0893-8717

VL - 3

SP - 3231

EP - 3243

ER -