JPH03213787A - Device and method for laying concrete-covered pipe line on bottom - Google Patents

Abstract

PURPOSE:To easily carry out the laying work of a pipe line on the water bottom by installing a main buoyancy tank in which water can be filled on a pipe line covered with concrete and installing a pressureproof buoyancy tank on the main buoyancy tank. CONSTITUTION:A main buoyancy tank 4 in which water can be filled is installed on a pipe line 2 covered with concrete 1. A pressureproof buoyancy tank 5 which possesses the strength resisting the water pressure at the water depth for laying work and has a buoyancy in the degree in which the pipe line 2 slightly sinks is installed on the main buoyancy tank 4. Accordingly, when the pipe line consisting of steel pipe covered with the concrete having a large weight is laid on the water bottom, the dead weight of the pipe line can be reduced drastically. Accordingly, the work for laying the pipe line on the water bottom can be carried out easily.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for preventing pipelines laid on the bottom of the water from floating up due to compressed air in order to supply compressed air to compressed air storage tanks sunk on the seabed. The present invention relates to a concrete-covered pipeline sinking device and a method for sinking the same to facilitate the sinking work when a concrete cover is provided around the pipeline.

[Conventional technology]

In recent years, compressed air generated by a compressor using surplus electricity at night is stored in a compressed air storage tank sunk to the bottom of a large body of water, for example, 300 meters deep, and the stored compressed air is used during peak power hours during the day. It has been proposed that electricity be generated and supplied using electricity.

In that case, a pipeline is required to send compressed air between a facility such as an underwater compressed air storage tank that stores compressed air and a power plant on land.

Since this pipeline sends compressed air, it works on all sides, so if you want to lay this pipeline on the bottom of the water instead of burying it underground, you need to make sure that it is around the outside of the pipeline so that it does not float up. However, concrete-covered pipelines are extremely heavy and difficult to transport by water, and conventionally they must be lowered to the bottom using a crane ship. The problem is that it is impossible.

[Problems to be Solved by the Invention] The present invention has been made in order to solve the above-mentioned problems when transporting a concrete-coated pipeline on water and sinking it to the bottom of the water. The object of the present invention is to provide a submersion device and a method for submerging the same into the water that can be easily submerged into the water.

[Means to solve the problem]

As a means for solving the above problems, the sinking device of the present invention has a main buoyancy tank that can be filled with water installed on the top of a concrete-covered pipeline, and the main buoyancy tank can withstand water pressure at the depth of the water to be submerged. It is constructed by installing a pressure-resistant buoyancy tank that is strong and has enough buoyancy to cause the pipeline to sink slightly.The method for sinking a pipeline using the above-mentioned sinking device is to install it on a concrete-covered pipeline. Compressed air was injected into the pressure-resistant buoyancy tank provided in the main buoyancy tank to the extent that the pipeline sank slightly, and the main buoyancy tank was also injected with air to float and was towed to the sinking position. It is characterized by being sunk by injecting water into the main buoyancy tank and lowering it to the bottom of the water while suspending the pipeline, and it can be safely and easily sunk using a floating crane ship, etc. It will be.

[Example] The present invention will be described in detail below with reference to the drawings. Fig. 1 is a front sectional view of a concrete-coated pipeline sinking device in an embodiment of the present invention, and Fig. 2 is a FIG. 2 is an overall side view illustrating a method for sinking a pipeline using the sinking device shown in the figure.

First, this sinking device is attached to the upper part of the pipeline 2, which has a concrete coating 1 on its outer periphery, using a mounting bracket 3, as shown in Fig. 1. It consists of an attached main buoyancy tank 4 and a pressure-resistant buoyancy tank 5 provided inside.

The main buoyancy tank 4 can be filled with water, but the pressure-resistant buoyancy tank 5 is strong enough to withstand the water pressure at the water depth H in which it is submerged.

Note that the pressure-resistant buoyancy tank 5 may be provided outside the main buoyancy tank 4, but if it is provided inside the main buoyancy tank 4, this device can be formed compactly, and the pressure-resistant buoyancy tank 5 is connected to the main buoyancy tank 4. will be protected.

Moreover, although this submersion device is attached to the upper part of the pipeline 2 with the mounting bracket 3, it may be placed on the side of the pipeline 2 after being submerged.

The procedure for sinking the above-mentioned pipeline 2 into the seabed B using the sinking device having the above configuration will be explained below. First, the water depth H2 to be sunk is
= 300m, in a pressure-resistant buoyancy tank 5 that is made strong enough to withstand water pressure at the water bottom B, that is, approximately 31 atmospheres in this case, there is a buoyancy that causes the pipeline 2 coated with concrete 1 to sink slightly. Inject compressed air so that it occurs.

Therefore, the size of this pressure-resistant buoyancy tank 5 needs to be set to a size sufficient to realize the above condition.

Next, air is also injected into the main buoyancy tank 4, the pipeline 2 is floated on the water surface W, and the pipeline 2 is towed to the submerged position shown in FIG. 2 by a work boat or the like.

Next, at the submerged position, open the valve of the main buoyancy tank 4 to inject water, and while keeping the valve open, suspend the tank from a crane ship 7 or the like on the water surface W via the wire 8.
This pipeline 2 is slowly sunk into the seabed B.

After the pipeline 2 is sunk into the seabed B, the sinking device is separated from the pipeline 2 or the pressure buoyancy tank 5 is evacuated to complete the sinking operation.

〔Effect of the invention〕

As explained above, according to the sinking device and method of the present invention, when a pipeline such as a steel pipe coated with heavy concrete is sunk to the bottom of water, the weight of the pipeline becomes very small. The effect is that the work can be done easily and safely.

Furthermore, if the present invention is adopted, concrete-covered pipelines can be towed to the burial position in a floating state, so
Another advantage is that it can be easily transported by water.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a concrete-covered pipeline sinking device in one embodiment of the present invention, and FIG.
FIG. 2 is an overall side view illustrating a procedure for sinking a pipeline according to a method for sinking a pipeline using the sinking device shown in the figure. 1... Concrete covering, 2... Pipeline, 4
...Main buoyancy tank, 5...Pressure buoyancy tank, B...
・Seafloor, H...water depth.

Claims (1)

[Claims] 1. A main buoyancy tank that can be injected with water is attached to the concrete-coated pipeline, and the main buoyancy tank has strength to withstand water pressure at the depth of the water to be submerged, and the pipeline is slightly A concrete-coated pipeline sinking device equipped with a pressure-resistant buoyancy tank that has enough buoyancy to sink. 2. Inject compressed air into the pressure-resistant buoyancy tank installed in the main buoyancy tank attached to the concrete-covered pipeline to the extent that the pipeline sinks slightly, and also inject air into the main buoyancy tank to sink it. A method of sinking concrete-covered pipelines in which, after being towed to the location, water is poured into the main buoyancy tank, and the pipeline is suspended and sunk to the bottom of the water.