Foundation method for caissons

• US 3,906,735 A
• Filed: 02/27/1974
• Issued: 09/23/1975
• Est. Priority Date: 05/02/1972
• Status: Expired due to Term

• Current Assignee: Olav Mo
• Original Assignee: Olav Mo
• Inventors: Mo, Olav
• Primary Examiner(s): Shapiro, Jacob
• Application Number:
  US05/446,335
• Time in Patent Office: 573 Days
• Field of Search: 61/46,46.5,50,52,64 114/65A
• US Class Current: 405/207
• CPC Class Codes: E02B 17/0017 Means for protecting offshore constructions
• CPC Class Codes: E02B 17/025 Reinforced concrete structures E02B17/021 takes precedence
• CPC Class Codes: E02B 2017/0052 Removal or dismantling of offshore structures from their offshore location
• CPC Class Codes: E02B 2017/0069 Gravity structures
• CPC Class Codes: E02D 23/02 Caissons able to be floated on water and to be lowered into water in situ floating caisson foundations E02D27/06

Abstract

A method is provided for the production of a support structure for supporting a platform above the surface of the sea. The support itself comprises a base which rests on the sea bed and which includes a plurality of depending cells which are open at the bottom and which can be pressed down into the deeper layers of the sea bed. The process includes the steps of (1) constructing at least a portion of the cells of the base of the support structure in dry dock; (2) enclosing the bottoms of the cells with temporary bottom closures to form a series of buoyancy chambers; (3) floating the partially constructed base in deep water; and (4) completing the construction of the support structure in deep water, the temporary bottom closures being removed after the support structure has sufficient self-floating capability.

Claims

1. A method for the production of a support structure for supporting a platform above the surface of the sea, said support structure comprising a base which rests on the sea bed and which comprises at least one downwardly extending hollow wall member which is open at the bottom so as to define a downwardly opening compartment and which can be pressed down into the deeper layers of the sea bed, said process comprising the steps of:

constructing a portion of said base including said downwardly extending hollow wall member in a dry dock;

enclosing the open bottom of said downwardly extending hollow wall member with a temporary bottom closure member so as to close off the compartment defined by the downwardly extending wall member and thereby provide a buoyancy chamber;

floating the partially constructed base portion in deep water; and

completing construction of the support structure in deep water, sAid temporary bottom closure member being removed after the support structure has sufficient self-floating capability.

2. A method according to claim 1 wherein said wall member comprises a plurality of independent downwardly extending cylindrical wall members and wherein said temporary bottom closure member comprises a unitary member closing each of said plurality of wall members, said method further comprising removing the temporary closure members by flooding water into the spaces defined by the temporary closure members and the wall members.

3. A method according to claim 1 wherein said temporary bottom closure member comprises a floating tank.

4. A method according to claim 1 wherein said hollow wall member comprises a plurality of independent downwardly extending cylindrical wall members, a plurality of separate temporary bottom closure members being provided for each of said cylindrical wall members to close off said plurality of cylindrical wall members, the temporary closure members being removed by flooding water into the chambers defined by the temporary bottom closure members and the cylindrical wall members.