Stepped anti-subsidence leg of ocean platform

Abstract

A stepped anti-subsidence leg of an ocean platform includes a leg, a ribbed plate, a stepped ring, transition sections and circular metal rings, the ribbed plate is welded between the leg and the stepped ring to remit stress concentration; the stepped ring is composed of a plurality of superposed steel tubes having different external diameters, a connection part between each two steel tube is provided with the transition section, and the transition section externally includes an inclined circular metal ring; pipe diameters of corresponding stepped sections are determined according to conditions of a surface foundation under a seabed soil level while mounting the leg, the stepped ring is hit to be sunken at 0.5-2.5m depth of the seabed soil level in a construction period of the leg in the seabed, so that an aim of anti-subsidence is implemented, simultaneously, depth of the leg sunken in the seabed also can be reduced about 1 / 3; fillers are placed at the connection part of the transition sections when it is necessary to hit the leg on the spot, and the fillers are externally covered with the inclined circular metal ring to bear loads.

Description

technical field [0001] The invention relates to an anti-subsidence device for pile legs of an ocean platform, in particular to a stepped anti-subsidence pile leg. Background technique [0002] The jacket platform is the most widely used offshore platform in the development process of shallow offshore oilfields in the Bohai Bay of my country, which includes jackets, pile legs and topside modules. After each part is prefabricated on land, it will be hoisted and transported to sea for installation. Among them, pile driving is carried out after the jacket is in place. During the piling process, large steel pipe pile legs need to be welded section by section, and then driven into the seabed. However, because all the pile legs with the same diameter are driven into the seabed, this kind of pile legs is carried by the friction force between the pile and the soil layer, which is called a friction pile. However, due to the large weight of the upper part, the driving depth of the fri...

AI Technical Summary

Problems solved by technology

However, because all the pile legs with the same diameter are driven into the seabed, this kind of pile legs is carried by the friction between the pile and the soil layer, which is called a friction pile. However, due to the large weight of the upper part, the driving depth of the friction pile is very large. , and over a long period of time, the pile legs will slowly settle, which will bring safety hazards to the production on the offshore platform

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