Physical experiments have been conducted to study the scouring around a pipe over an erodible bed under wave motion. The results show that the depth of the wave-induced scour is reduced when the pipe is installed in a primary depth. It is also indicated that when the primary installation depth of the pipe, $|e|$, exceeds a specified depth, no scouring occurs underneath the pipe. This specific depth is called the equivalent depth of wave-induced scour, $Se$. The equivalent depth of wave-induced scour is estimated as a function of pipe diameter and the Keulegan–Carpenter number. With respect to the primary installation depth of the pipe, a new equation is suggested to predict the scour depth before installation of the pipe. And the scour width is predicted in two other new equations. The proposed equations are then simplified in the form of diagrams. The experiments cover small KC numbers $(KC<6)$ that represent deep water conditions.

1.
Sumer
,
B. M.
, and
Fredsoe
,
J.
, 1990, “
Scour Below Pipelines in Waves
,”
J. Waterway, Port, Coastal, Ocean Eng.
0733-950X,
116
(
3
), pp.
307
323
.
2.
Sumer
,
B. M.
, and
Fredsoe
,
J.
, 2002, “
The Mechanics of Scour in the Marine Environment
,”
Advanced Series on Ocean Engineering
, Vol.
17
,
World Scientific
,
Singapore
, pp.
38
76
.
3.
Mousavi
,
M. E.
, 2005, “
Physical Modeling of Scouring Around Offshore Pipelines
,” M.Sc. thesis, Iran University of Science & Technology, Tehran.
4.
Yeganeh-Bakhtiary
,
A.
,
Mousavi
,
M. E.
, and
Tohidi-Vahdat
,
A.
, 2006, “
Time Scale of Scouring Around Submarine Pipelines
,”
Proceedings of the 25th International Conference on Offshore Mechanics and Arctic Engineering
,
ASME
,
Hamburg
, Paper No. 92381.
5.
Mousavi
,
M. E.
,
Yeganeh-Bakhtiary
,
A.
, and
Enshaei
,
N.
, 2006, “
Equilibrium Profile of Current-Induced Scour Around Submarine Pipelines
,”
Proceedings of the 25th International Conference on Offshore Mechanics and Arctic Engineering
,
ASME
,
Hamburg
, Paper No. 92383.
6.
Fredsoe
,
J.
,
Sumer
,
B. M.
, and
Arnskov
,
M. M.
, 1992, “
Time Scale of Wave/Current Scour Below Pipelines
,”
Int. J. Offshore Polar Eng.
1053-5381,
2
(
1
), pp.
13
17
.
7.
Li
,
F.
, and
Cheng
,
L.
, 1999, “
Numerical Model for Local Scour Under Offshore Pipelines
,”
J. Hydraul. Eng.
0733-9429,
125
(
4
), pp.
400
406
.
8.
Nielsen
,
P.
, 1992, “
Coastal Bottom Boundary Layers and Sediment Transport
,”
Advanced Series on Ocean Engineering
, Vol.
4
,
World Scientific
,
Singapore
.
9.
Mao
,
Y.
, 1986, “
The Interaction Between a Pipeline and Erodible Bed
,” Ph.D. thesis, Technical University of Denmark, Lyngby, Denmark.
10.
Kjeldsen
,
S. P.
,
Gjørsvik
,
O.
,
Bringaker
,
K. G.
, and
Jacobsen
,
J.
, 1973, “
Local Scour Near Offshore Pipelines
,”
Proceeding of the Second International Conference on Ports and Ocean Engineering Under Arctic Conditions
,” University of Iceland, pp.
308
331
.
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