JPS5851573B2 - How to install structures for ice seas on the seabed - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing a marine structure on the seabed;
More specifically, the present invention relates to a method for safely, quickly, and economically sinking a marine structure, which has a structure that becomes unstable because its water line area decreases during installation, onto the seabed.

Conventionally, when installing offshore structures such as the jacket type, the structure is towed to the desired location using a purge or offshore crane and then submerged.
In the case of structures with a structural shape where the water line area rapidly decreases during the process of being submerged, such as structures for water and sea, the structure becomes extremely unstable during submergence, so it is safe to do so if the water depth exceeds 20 to 30 m. Currently, there is no way to install it economically.

The present invention has been made in view of the above-mentioned current situation, and it is an extremely effective and suitable method for installing underwater and marine structures on the seabed, which allows the underwater and marine structures to be sunk and fixed to the seabed extremely safely, quickly, and extremely economically. The appendix is intended to provide a method.

That is, the present invention provides an upper structure section having an anti-icing section formed in a substantially trapezoidal shape so as to be able to break the surging water basin by bending it upwards on the upper part of the lower structure section that incorporates the ballast tank, and the lower structure section has an anti-icing section. A marine structure consisting of piles erected at intervals around the circumference and equipped with sliding stopping means is installed by towing it into the sea area, and then first placing the piles in a floating state on the seabed. and then using the erected pile as a guide to adjust the ballast in the ballast tank and sink the structure for water and sea in cooperation with the stopping means provided on the pile. The gist of the method is to install structures for water and sea on the seabed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for installing a marine structure according to the present invention on a seabed will be explained by way of an embodiment with reference to the drawings.

First, to briefly explain the structure of the structure A for water and sea, it includes a ballast tank 1, as shown in FIG. 1 as a front view and as shown in FIG. 2 as a plan view. An upper structure part 4 having a platform 3 formed above is integrally joined to the upper surface of the central part of the lower structure part 2, and this upper structure part 4 is different from the lower structure part 2. The anti-icing section 5 is formed in a substantially trapezoidal shape so that the ice-blocking section 5 can be bent upward to break the basin of water pushed upwards. It has become.

In the present invention, through holes 6 passing through the upper and lower surfaces are provided at required intervals on the outer peripheral edge of the lower structure section 2 including the ballast tank 1 of the structure A for water and sea, and each of the through holes 6 In each case, a stake 7 of a required length is slidably inserted.

Next, the method for installing the structure according to the present invention on the seabed will be explained in detail.

3 to 9, a first embodiment of the method for installing the above-mentioned underwater structure A on the seabed is illustrated in front view explanatory views for each step.

First, when installing structure A for water and sea and towing it to the site,
Air is injected into each ballast tank 1 of the lower structure part 2 to make the marine structure A float, and the pile 7 is raised to stop the piles T provided at regular intervals along the axial direction. By fitting the stopper 9 provided in the lower structure part 2 into the lowest stopper hole 8 of the stopper holes 8, the pile 7 is fixed to the structure A for water and sea at the raised position.

(Refer to Figure 3) Next, when the structure A for water and sea is towed and installed at the site, the stopper 9 is removed from the stopper hole 8 after being positioned using an anchor etc. γ is dropped and sunk into the seabed ground to some extent, and in this state each pile 7 is again fixed to the structure A for water and sea by the stopper 9.

(See Figure 4) Subsequently, ballast is injected into the ballast tank 1 in the lower structure 2, a load is applied to the pile 7, and the pile 1 is press-fitted into the seabed ground.

In this case, depending on the condition of the seabed ground and the number of piles 7, the piles 7 may be divided into loads and the above operations may be repeated to press-fit the piles.

(See Figure 5) At this point, the stoppers 9 are removed from the stopper holes 8 of each pile 7, but in the state shown in Figure 5, a large load is applied to each stopper 9 and it cannot be removed, so the ballast tank The stopper 9 can be easily removed by adjusting the amount of ballast inside the stopper 1.

(See FIG. 6) Next, the stopper 9 is removed from the pile 7, and the structure A for water and sea is sunk using the pile 7 as a guide.

At this time, if a large horizontal force is applied to the structure due to waves or tidal currents, several anchor cables may be used to stop the structure from moving horizontally while lowering it.

Furthermore, when the distance between the bottom surface of the structure A for water and sea use and the seabed is relatively short, it may be allowed to fall freely using the piles 7 as a guide, but the ballast should be adjusted so that the descending speed of structure A for water and sea use does not increase. There is a need to.

(See Figure 7) After the structure A for water and sea reaches the bottom, the upper part of each pile 7, that is, the part protruding from the upper surface of the lower structure part 2,
To prevent collisions such as ice spots, it is preferable to remove them by cutting with dynamite or removing the joints.

(See Figure 8) When the above operations are completed, underwater concrete 10 is finally injected into the gap between the pile 7 and the through hole 6 into which it is loosely inserted and fixed.

However, if the structure needs to be moved at a later date, such as an oil drilling rig, it is not fixed.

(See FIG. 9) Next, a second embodiment and a third embodiment of the present invention will be described.

The second and third embodiments are also similar to those described in the first embodiment, in which the stopper 9 is removed from the pile 7,
Since the steps other than the step of "sinking the structure A for water and sea using as a guide" (see FIG. 7) are the same, only this step will be explained here, and other explanations will be omitted.

What is shown in a front view explanatory diagram in FIG. 10 is a second embodiment of the above process, that is, the process of "extracting the stopper 9 from the pile 7 and sinking the structure A for water and sea using the pile 7 as a guide". In this example, the water/sea structure A
In order to adjust the descending speed during the sinking of the pile 7 and the horizontality of the underwater structure during the descent, a stop means, that is, a rack 11 is installed on the side of the pile 7 in the axial direction, as shown in FIGS. 11 and 12. Due to the spring effect of the spring 12 attached to the stopper 9, the stopper 9 dynamically inserts into the next stopper recess during the descent, temporarily stopping the descent of the structure. It is configured such that when the stopper 9 is pulled out by the provided hydraulic cylinder 13, the structure A is lowered by the distance of the rack.
By repeating this operation, structure A can be safely submerged while maintaining its levelness.

FIG. 13 shows a third embodiment of the above process, and in this embodiment,
As shown, a wire 14 is attached to the top of the pile 7,
This wire is operated by a pulley 15 and a winch 16 installed inside the structure A for water and sea, so that the descending speed and horizontality of the structure A for water and sea can be adjusted. It is designed to be able to be safely submerged while maintaining the levelness of A.

Next, to describe the effects of the present invention, the present invention provides an upper structure that includes an ice-breaking section formed in a substantially trapezoidal shape so that the surging water basin can be bent upward and broken at the upper part of the lower structure section that includes a built-in ballast tank. A structure for water and sea is constructed by providing a section and erecting piles equipped with sliding stop means at intervals around the lower structure. After that, first, the pile is erected on the seabed in a floating state, and then the ballast in the ballast tank is adjusted using the erected pile as a guide, and in cooperation with the stopping means provided on the pile, the pile is erected on the seabed. Since the structure is sunk, the on-site installation of structures for water and sea, which are unstable when sunk as mentioned above, can be carried out safely, quickly, accurately, and extremely economically. Furthermore, polysulfuric acid installed on the seabed can be effectively used as foundation piles for structures used in water and sea to withstand large horizontal forces applied to the structures by water or wave forces.

In addition, as mentioned above, since the piles are equipped with a stopping means, even if the seabed is a slope, it is possible to fix the underwater structure horizontally to the seabed, and it is possible to fix it horizontally on the seabed even if the seabed is a slope. Its effects are significant, as it does not require a support vessel such as a crane ship, making the submergence work safer and more economical.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is an explanatory diagram of the structure as seen from the front, FIG. 2 is an explanatory diagram of the same as seen from the top, and FIGS. 3 to 9 each illustrate the structure of the present invention. FIG. 10 is an explanatory front view showing the first embodiment of the method for installing the structure on the seabed, and FIG.
Fig. 11 is an enlarged longitudinal cross-sectional view of the pile, Fig. 12 is an enlarged cross-sectional view of the pile, and Fig. 13 is a front view showing the third embodiment of the structure in a submerged state. be. A: Structure for water and sea, 1: Ballast tank, 2: Lower structure, 4: Upper structure, 5: ...Ice breaking section, 7...Pile,
8, 11...Stopping means.

Claims (1)

[Claims] 1 At the top of the lower structure containing a built-in ballast tank, an upper structure is provided with an anti-icing section formed into a substantially trapezoidal shape so that the surging water basin can be bent upward and broken, and a space is provided around the lower structure. A structure for use in water and sea is constructed by erecting piles equipped with sliding means for stopping the structure, which are installed by being towed into the sea area, and then first erecting the piles on the seabed in a floating state. Next, the erected pile is used as a guide to adjust the ballast in the ballast tank, and the structure for water and sea is submerged in cooperation with the stopping means provided on the pile. Installation of objects on the ocean floor is a method.