JPH058284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for installing an offshore work platform, that is, a platform, in a shallow sea area.

[Problem that the invention seeks to solve]

In the case of a tower-type concrete platform, stability is always ensured when being towed or submerged because the overall center of gravity is located lower than the center of buoyancy even when mounted equipment is mounted in deep waters; In shallow waters, it may not be possible to lower the center of gravity below the center of buoyancy due to water depth, making it difficult to ensure stability. For this reason, loading equipment onto the upper deck will be carried out after the caisson has been sunk.
Prolonging the construction period is unavoidable.

Furthermore, in the case of tower-type structures, conventional construction methods require mounting equipment in calm waters that are deeper than the installation water depth, which is disadvantageous in shallow waters.

This invention was made with the aim of solving the problems of concrete platforms in shallow waters, and attempts to solve this problem by supporting the upper deck with a barge and towing it separately from the caisson. be.

[Means for solving problems]

In the present invention, the upper deck is supported by a barge, and the load of the upper deck and onboard equipment is borne by the barge.
By towing it separately from the caisson, it is possible to load onboard equipment all at once. As a result, when installing onboard equipment, it is not necessary in calm waters that are deeper than the installation water depth.

A concrete caisson has a tower section, and the tower section is separated into a tip section and a main section, and the caisson is constructed in parallel with the upper deck containing the overhead equipment. Then, the tip of the constructed tower section is installed at the connection position between the upper deck and the main body of the tower section before being towed. The upper deck is mounted on a barge, and the caisson itself is docked and towed to its respective designated site.

After the caisson main body is sunk at the installation site, the main body and tip of the tower are joined together, and the upper deck containing the mounted equipment is raised with jacks and fixed to the tip of the tower.

〔Example〕

The present invention will be explained below based on the drawings showing one embodiment.

The present invention is a method for installing a platform A in a shallow sea area by mounting onboard equipment 2 on an upper deck 1 and towing it together with a concrete caisson 3 having a tower section.

The caisson 3 has a tower section with a tip section 3a and a main body section 3.
The tip part 3a is attached to the upper deck 1 and towed separately from the caisson 3. After the caisson 3 is submerged, the tip portion 3a and the main body portion 3b are joined.

The construction procedure of the embodiment shown in FIG. 1 will be explained.

This embodiment is a method in which the tower parts are joined at sea.

First, the caisson main body 3 is constructed and docked out (I), and the tip 3a of the caisson tower section is installed on the upper deck 1 including the overlaying equipment 2, which was manufactured in parallel. is mounted on a barge 4 with a cradle (), and this is towed together with the caisson body 3 to the sinking site of the caisson body 3 ().

After being towed to a predetermined installation site, the caisson 3 is sunk into the seabed, its tower main body 3b and tip 3a are joined, and jacks 5 for lifting the upper deck 1 are set around the tower (). .

Subsequently, the upper deck 1 is pulled up by the jack 5 () and fixed to the tower tip 3a at a predetermined position, and the jack 5 is removed to complete the installation work of the platform A ().

Next, the embodiment shown in FIG. 2 will be explained.

This embodiment is a method in which the tower parts are joined underwater.

First, as in the first embodiment, the upper deck 1, on which the upper deck equipment 2 and the tower tip 3a are installed, is towed together with the caisson 3 to the sinking site by a barge 4 with a large notch (,,).

After caisson 3 is sunk, the tower section is joined (). At this time, the joints are lined with mortar.

Subsequently, the upper deck 1 is raised by the jack 5 () and fixed to the tip 3a to form the platform A ().

〔Effect of the invention〕

This invention is as described above, and since the upper deck and caisson are towed separately, onboard equipment can be loaded all at once, and problems with stability during towing can be avoided.

Furthermore, by using a barge with a large notch, there is no restriction on the use of the barge due to the rewer interval, and there is no need to use a pedestal.

Furthermore, since the caisson, upper deck, and onboard equipment can be constructed in parallel, the construction period can be shortened.

[Brief explanation of drawings]

Both FIG. 1 and FIG. 2 are construction procedure diagrams showing an embodiment of the present invention. A...Platform, 1...Upper deck,
2... Onboard equipment, 3... Caisson, 3a... Tower tip, 3b... Tower main body, 4... Barge, 5... Jacket.

Claims (1)

[Claims] 1. A concrete caisson having a tower section is constructed by separating the tower section into a tip section and a main body section, and the tip section of the tower section is attached to an upper deck containing overlay equipment manufactured in parallel with the caisson. The caisson body and the docked-out caisson body were then towed to the respective predetermined installation sites, the caisson body was sunk, and the tower body and the tower tip were joined, and then the upper deck containing the onboard equipment was removed. A method for installing an offshore work platform that consists of raising it and fixing it to the tip of the tower.