JPH02210195A - Method and device of constructing subaqueous tunnel - Google Patents

Abstract

PURPOSE:To enable execution of excavation without contaminating ambient environment by a method wherein a pipe through which earth recovered in an earth chamber is recovered on a working ship on the sea is installed, and a tunnel body is built at the rear part of the excavating device as a groove is excavated in a sea bottom. CONSTITUTION:A partition wall 11 is built on the inner side of a shield excavator 1 to form an earth chamber 12. The one end of an earth transport pipe 2 is mounted to the earth chamber 12, and the other end is connected to a plant 31 on a working ship 3 on the sea. A mud water recovery pipe is installed in the earth chamber 12, and after mud water separated at the plant 31 is transported to the earth chamber 12 again. This method enables excavating advance of the shield excavator, construction of a tunnel, and execution of covering with earth without contaminating an ambient water area even when there is no covering thickness of earth on a sea bottom.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides an underwater tunnel that does not pollute surrounding water bodies when dredging a trench, especially when constructing a tunnel in a place with shallow soil cover. The present invention relates to a construction method and device.

<Conventional Technology> There are two methods for constructing tunnels under water: shield tunnels and submerged tunnels.

The shield construction method is a method in which the shield machine moves forward while excavating earth and sand in front by taking a reaction force from the segments assembled at the rear or the concrete wall that has been placed.

With this construction method, there will be no effect of water contamination if the covering soil is thick enough, but if there is no covering thickness of soil at all and the excavation is carried out while digging a trench on the seabed, the excavated soil will spread into the surrounding area. and contaminate it.

Furthermore, since the excavated earth and sand is discharged backward through a transport pipe, it is necessary to extend the pipe sequentially each time the shield excavator moves forward.

On the other hand, the immersion method involves digging a trench on the seabed and submerging the box manufactured on land inside the trench.

As a result, large work vessels have to travel back and forth on the sea or stay at anchor, which can easily become a hindrance to maritime traffic.

In addition, when excavating and backfilling trenches, there is a lot of work that involves dispersing earth and sand into the surrounding area (and contaminating seawater).

<Objective of the present invention> The present invention has been made for the construction of tunnels under the above conditions, and is capable of excavating tunnels without polluting the surrounding environment even when there is no thickness of earth and sand covering. The purpose is to provide a method and device that can.

Furthermore, it is an object of the present invention to provide a method and apparatus that do not require complicated extension and connection work of earth removal pipes even as excavation progresses.

Furthermore, it is an object of the present invention to provide a method and a device that reduces the amount of work required at sea and does not obstruct marine traffic compared to the immersion method.

<Configuration of the present invention> Next, one embodiment of the present invention will be described.

<A> Shield excavator The shield excavator 1 used in the construction method of the present invention is of a type that particularly takes earth and sand into a face.

In other words, part or all of the entire surface of the shield excavator 1 is opened, and a partition wall 11 is provided on the inside of the shield excavator 1 to open the earth and sand chamber 1.
form 2.

The earth and sand taken into the earth and sand chamber 12 are prevented from flowing into the interior of the machine body by the partition wall 11.

<Exposure> The structure above the earth and sand transport pipe is almost the same as that of a known shield excavator, but in particular, in the shield excavator of the present invention, one end of the earth and sand transport pipe 2 is attached to a part of the earth and sand chamber 12.

This earth and sand transport pipe 2 does not penetrate inside the shield excavator 1.

For this purpose, the other end of pipe 2 is raised towards the water,
The upper end thereof is exposed above the water, and the structure is such that it can be transported to a plant 31 of a work boat 3, which will be described later.

Furthermore, in the sediment chamber 12, in parallel with the sediment transport pipe 2,
Install muddy water recovery pipe 21.

In this muddy water recovery pipe 21, the plant 31 of the work boat 3
This is a pipe that transports the muddy water that has been separated in the sand chamber 12 again.

Kuha> Work boat 3 is floating on the water surface above the shield excavator 1 (.

This work boat 3 has a plant 31 that separates muddy water and earth and sand.
This is provided.

The above-described earth and sand transport pipe 2 and muddy water recovery pipe 21 are connected to this plant 31.

Furthermore, a charging tube 32 for charging the separated earth and sand into the sea again is attached to the work boat 3 in a substantially vertically downward direction.

<Construction Method> Next, a construction method that combines the above devices will be explained.

<A> Excavation Similar to the known shield tunneling machine, forward force is obtained by taking reaction force in the tunnel body 13 formed at the rear of the shield tunneling machine 1.

The tunnel body 13 employs known methods such as segment assembly and concrete pouring.

Then, the earth and sand are taken into the earth and sand chamber 12 using a rotary cutter at the front or the like.

<Exit> Transport of earth and sand to the surface of the water The earth and sand taken into the earth and sand chamber 12 is pushed up to the surface of the water through the earth and sand transport pipe 2 together with muddy water.

Therefore, unlike the conventional method, there is no need to transport the earth and sand backward through the inside of the tunnel body 13.

Since the end of the earth and sand transport pipe 2 is open toward the plant 31 of the work boat 3, the transported earth and sand is separated into mud and muddy water.

<C> Recovery of muddy water The muddy water does not have to be disposed of outside the work boat 3, and therefore the muddy water with a high specific gravity can be replenished without waste.

2) Covering with earth and sand The upper part of the tunnel body 13 constructed on the seabed is covered with earth and sand for protection.

To this end, earth and sand are dropped from the earth and sand injection tube 32 of the work boat 3 toward the upper part and surrounding area of the tunnel body 13 constructed on the seabed.

<E> In order to protect the tunnel body 13, the method of mounting a protective block on the top or around the tunnel body or injecting mortar around the tunnel body 13 is the same as the conventional method.

<Effects of the Present Invention> Since the present invention is a construction method and apparatus for construction as described above, the following effects can be obtained.

<B> Even under conditions where the thickness of the earth and sand covering the water bottom is small, it is possible to excavate with a shield excavator, construct a tunnel, and cover with earth and sand without polluting the surrounding environment.

<Exposure> Since tunnels can be constructed while excavating trenches at depths where there is no earth and sand covering, the length of the tunnel can be shortened compared to when installing at a deep location, making it extremely economical. It is.

<C> The excavated earth and sand is not passed through the inside of the machine like in conventional shield excavators, but is transported directly from the face to the sea for disposal.

Therefore, there is no need for the complicated work of extending the earth and sand discharge pipe as the aircraft moves forward.

Furthermore, there is no need to install transport pipes for earth and sand discharge or other installations inside the shield excavator, and sufficient internal space can be secured.

<2> Excavating with the upper part of the shield excavator exposed on the seabed.

Therefore, even if a problem occurs with machinery, repairs or other measures can be taken from the sea.

[Brief explanation of the drawing]

Figure 1: Explanatory diagram of the construction state of the present invention Figure 2: Front view

Claims (2)

[Claims] (1) Using an excavation device that has a sand chamber with its front open and is equipped with a pipe that pushes the earth and sand in this chamber above the water, and moves forward by taking a reaction force to the rear, A method of constructing an underwater tunnel, in which a trench is excavated on the water bottom with virtually no earth covering, a tunnel body is constructed behind it, and the earth and sand stored in the earth and sand chamber is collected by a floating work boat. (2) Part or all of the front surface is open, and a partition is installed inside to form a sediment chamber, and one end of the pipe that discharges the sediment inside towards the water is opened in the sediment chamber. The other end is open to the outside of the device, and the device moves forward by taking the reaction force to the rear. It is a device for constructing underwater tunnels.