Performance of suction caissons in sand and clay

Abstract

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.

Horizontal Bearing Capacity of A New Bucket Foundation with Partial Inclined Wall

“…x  is the horizontal resistance stress of soil acted on outer wall of bucket foundation (kPa), z  is the vertical resistance stress of soil acted on bottom of bucket foundation (kPa), 1 T is the friction force between soil and outer wall at front side of bucket foundation (kN), 2 T is the friction force between soil and outer wall at posterior side of bucket foundation (kN), b T is the friction force between soil and bottom of bucket foundation (kN). The bucket foundation would be failure or rotated around point A by horizontal bearing capacity u P .…”

“…Bucket foundation, a new foundation top closed and bottom opened, which like a cup upside down is buried in seabed, is adapt to the character of seabed and could be used as foundation, of offshore wind power project (as showed in Fig. 1),offshore oil and gas resources project, and mooring project for floating structures at sea [1][2][3][4][5][6].…”

Numerical modelling of transient cyclic vertical loading of suction caissons in sand

“…Among different types of foundations, suction caissons, also termed bucket foundations or suction anchors, should be highlighted (Iskander et al, 2002;Houlsby et al, 2005a). They consist of a hollow cylinder open towards the bottom.…”

3D zero-thickness coupled interface finite element: Formulation and application

“…Suction caissons or bucket foundations are a particular case of anchors. They 20 may be used as permanent foundations for offshore structures [7,8,9]. They consist of steel cylinders open towards the bottom.…”

“…Solving the mechanical contact problem consists in finding the field of displacement u for all points x ∈ Ω i verifying these equations and subjected to the contact constraints Eqs. (5) and (7). Considering a field of admissible virtual velocities δẋ on Ω i , the weak form of the principle of virtual power reads…”