Suction Pile Research Articles

Field Installation and Pullout Test of Embedded Suction Anchors

The field installation and pullout tests of an embedded suction anchor were conducted inside the Okpo Harbor located along the southeastern coast of South Korea in 2003. The embedded suction anchor was made of steel with an outside diameter of 1.91 m, length of 2.5 m, and thickness of 3 cm. It was installed by a 9.25-m-long suction pile attached at the top of the anchor. During installation of the embedded suction anchor and retrieval of the suction pile, the water pressure inside the suction pile versus the pile embedded length relationship was carefully measured. In addition, during the embedded suction anchor pullout test, the load versus anchor vertical displacement relationship was measured. The measured pullout capacity was then compared with the analytical prediction. The analytical solution was selected from various available solutions of deeply embedded plate anchors available from the literature through detailed comparisons with the results from geotechnical centrifuge model tests on embedded suction anchors. Comparison indicated that the predicted embedded suction anchor resistance matched reasonably well with the field test result.

Field Installation and Pullout Test of Embedded Suction Anchors

The field installation and pullout tests of an embedded suction anchor were conducted inside the Okpo Harbor located along the southeastern coast of South Korea in 2003. The embedded suction anchor was made of steel with an outside diameter of 1.91 m, length of 2.5 m, and thickness of 3 cm. It was installed by a 9.25-m-long suction pile attached at the top of the anchor. During installation of the embedded suction anchor and retrieval of the suction pile, the water pressure inside the suction pile versus the pile embedded length relationship was carefully measured. In addition, during the embedded suction anchor pullout test, the load versus anchor vertical displacement relationship was measured. The measured pullout capacity was then compared with the analytical prediction. The analytical solution was selected from various available solutions of deeply embedded plate anchors available from the literature through detailed comparisons with the results from geotechnical centrifuge model tests on embedded suction anchors. Comparison indicated that the predicted embedded suction anchor resistance matched reasonably well with the field test result.

Transition of soil friction during suction pile installation

A series of laboratory model tests on the suction pile installation in sand have been conducted to obtain the relationship between the applied suction pressure inside the pile and the resulting pile penetration. The relationships have been used to estimate the mobilized soil strength during the pile installation. This reduction in the soil strength due to the applied suction pressure is described as a function of a nondimensional parameter to characterize the variation and transition of the soil strength during the pile installation. The nondimensional parameter includes all pertinent pile and soil properties that are thought to affect the behavior of the suction pile during installation.Key words: suction pile, suction pressure, mobilized effective soil friction angle.

Performance of suction caissons in sand and clay

The use of suction caissons (suction piles) in marine environments has been increasing in the last decade. A suction caisson is a steel pipe with an open bottom and a closed top that is inserted into the ground by pumping water out of it. Pumping creates a differential pressure across the caisson's top that pushes it into place, thus eliminating the need for pile driving. There are a number of uncertainties in the design of suction caissons. First, the state of stress and soil conditions adjacent to a suction caisson differs from those around typical driven piles or drilled shafts. Second, the axial load capacity of suction caissons depends on the rate of loading, hydraulic conductivity, drainage length, as well as the shearing strength properties of the foundation material. Finally, during pullout, volume change characteristics of the surrounding soils may change the theoretical suction pressures. A review of the existing knowledge relating to the design and construction of suction caissons is presented in this paper along with the results of a laboratory study on model caissons in sand and clay. Test results indicate that the use of suction pressure for installation of caissons is a viable alternative to conventional methods. Suction was also shown to resist some axial tensile loads.Key words: suction, pile, bucket, foundation, anchor, capacity.

Analytical Validation of Pullout Loading Capacity of Suction Piles in Clay

An analytical solution for the estimation of the ultimate pullout loading capacity of suction piles has been developed by considering two potential failure modes (i.e., the soil tension failure and the pile pullout failure). The analytical solution has been used to identify the dominant failure mode under various circumstances. Finally, the validation of the analytical solution has been made through comparisons with the laboratory model tests results.

Suction piles for mooring of mobile offshore bases

As part of the feasibility study of constructing mobile offshore bases (MOBs), suction piles are currently being studied to provide the necessary mooring capability for this very large floating structure. MOB position will be controlled by dynamic positioning (DP) during operation. However, during repair, storage, and lay-up periods, or for hybrid mooring in combination with DP, conventional mooring techniques need to be considered. For this reason, suction piles are currently being investigated analytically and experimentally as one option to provide necessary mooring resistance. This paper discusses the laboratory model testing program, development of an analytical solution for successful installation of suction piles in the seafloor, and verification of the analytical solution through field tests.

Design and Installation of Suction Anchor Piles at Soft Clay Site

Innovative suction anchor piles have been used for permanent mooring of a process and accommodation barge at an oil and gas field developed by ELF Congo in the Gulf of Guinea. Twelve mooring lines, equipped with steel suction anchor piles, were successfully preinstalled at the site in July–August 1995, and the process barge was connected in early 1996 for the start of production. With a water depth ranging between 150 and 300 m, the Nkossa field is among the deepest ones offshore Western Africa to date, and the soils at the site consist of soft normally consolidated clays, representative of deep water sites. The anchoring system design is presented together with a description of the suction pile installation operations. The monitored performance of the suction piles during installation is evaluated, including the orientation and tilt at touchdown and the penetration rate during suction penetration. The installation behavior appeared to be easy and smooth, and the measured penetration resistances were in p...

Soil structure interaction model for a suction pile platfiorm : Rasmussen, J L; Christensen, N H; Haahr, F Proc 10th International Conference on Offshore Mechanics and Arctic Engineering, Stavanger, 23–28 June 1991V1-Part B, P601–610. Publ New York: ASME, 1991

Soil structure interaction model for a suction pile platfiorm : Rasmussen, J L; Christensen, N H; Haahr, F Proc 10th International Conference on Offshore Mechanics and Arctic Engineering, Stavanger, 23–28 June 1991V1-Part B, P601–610. Publ New York: ASME, 1991

Breakput resistance of large suction piles : Christensen, N H; Haahr, F; Rasmussen, J L Proc 10th International Conference on Offshore Mechanics and Arctic Engineering, Stavanger, 23–28 June 1991V1-Part B, P617–622. Publ New York: ASME, 1991

Breakput resistance of large suction piles : Christensen, N H; Haahr, F; Rasmussen, J L Proc 10th International Conference on Offshore Mechanics and Arctic Engineering, Stavanger, 23–28 June 1991V1-Part B, P617–622. Publ New York: ASME, 1991