JPH05332090A - Shield construction method - Google Patents

Abstract

PURPOSE:To enable a tunnel to be constructed in an optional position near the bottom of the water efficiently and with less effect to the environment. CONSTITUTION:A platform ship 1 equipped with a ring shape tunnel block 2, which becomes the structural body of a tunnel, and a discharged earth disposing portion 3 is prepared together with a shield excavator 4 having a guide 5 capable of accommodating said tunnel block 2 connected to its rear end. Between an excavation starting point and an excavation destination point, the shield excavator 4 is advanced toward a shaft 7 on the excavation destination side at the depth where an excavating hole of the shield excavator 4 is exposed to the top surface of the water, then a succeeding tunnel block is supplied to the interior of the guide 5, which becomes hollow as the shield excavator 4 moves forward, and successively connected to tunnel blocks positioned backside. When the shield excavator 4 reaches the shaft 7 on the destination side, the water is discharged from the interior of the tunnel block 2 which is connected to the water bottom 9 and fixed thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield construction method, and more particularly to a method for constructing a tunnel near a water bottom.

[0002]

2. Description of the Related Art In recent years, a shield method has been widely used when excavating a tunnel under the water such as a subsea tunnel.

This is a construction method in which a tunnel excavator called a "shield" is propelled in the earth and sand ground to prevent collapse of the earth and sand while safely excavating and lining work to build a tunnel. Is. According to this construction method,
(1) Workers can safely work because the ground is supported by a shield. (2) Prefabricated lining method that uses segments manufactured at the factory, so construction can be done easily and quickly. Therefore, there are advantages such as excellent quality control, and (3) easy labor saving and easy process control because the same work is repeated.

[0004]

However, when constructing a tunnel in the ground at the bottom of the water by the above-mentioned conventional method, there is a problem that the distance from the bottom of the water to the excavation hole must be kept above a certain level. ..

That is, if the distance from the bottom of the water to the excavation hole is small (the soil cover is thin), it is impossible to stabilize the tunnel face and the ground surface. A depth (overburden) equal to the diameter is required.

[0006] Therefore, the geology at the excavable depth may not be suitable for excavation, or the positional consistency with other tunnels to be connected to the subsea tunnel may be impaired, and the construction is restricted. was there.

Therefore, it is conceivable to adopt a submersion method in which a trench is formed by excavating from the bottom of the water and a structure to be a tunnel is buried therein. Since it is necessary to remove soil, there is a difficulty in terms of efficiency. In addition, since the soil is discharged on a very large scale, the surrounding water pollution is unavoidable and there is a problem that the environmental impact is not small.

Further, it is difficult for a person to work in a shield excavator or a tunnel block installed underwater during excavation in order to ensure safety. Further, assuming such work, if it is attempted to maintain a certain watertight space inside the shield excavator or tunnel block installed on the bottom of the water during digging, if these specific gravities become lighter than water, these will be buoyant. When submerging at the bottom of the water, fixing it at a fixed position on the bottom of the water, and controlling the excavation direction of the shield excavator, it becomes difficult.

The present invention has been made in view of the above-mentioned matters, and it is a technical object to provide a shield construction method capable of performing unmanned excavation work by remote control on the water bottom and reducing the influence on the environment. ..

[0010]

The present invention has the following methods in order to solve the above technical problems. First, an annular tunnel block that should be a tunnel structure,
A shield excavator that can operate in water with a guide that can accommodate this tunnel block and has a larger specific gravity than water is prepared.

Secondly, a starting-side vertical shaft and a reaching-side vertical shaft are respectively formed at the watersides between the excavation starting point and the excavation reaching point. Thirdly, the shield excavator of remote control type is arranged in the vertical shaft of the departure side, and the shield excavator is remotely operated to operate in water, and the excavation hole reaches at the depth exposed from the upper surface of the water bottom. Advance in the direction of the side shaft.

Fourthly, the discharged soil generated by the forward movement is fed to the discharged soil processing section. Fifth, the tunnel block is fed into the guide from a barge. Sixth, the tunnel block is fixed to the groove formed as the shield excavator advances.

Seventh, the next tunnel block is supplied into the hollow guide along with the forward movement of the shield excavator and is sequentially connected to the tunnel blocks located at the rear. Eighthly, when the shield excavator reaches the reaching shaft, the tunnel block fixed to the bottom of the water is drained.

It goes without saying that the construction sequence of the above steps can be appropriately changed depending on the situation of the construction site.

[0015]

[Function] Since the shield excavator is advanced to the reaching side vertical shaft side at a depth where the excavation hole is exposed from the upper surface of the water bottom, the stability of the tunnel face and the surface of the ground which have been problems in the conventional underground propulsion method There is no need to consider stability, and it can be propelled at any depth.

Therefore, the conventional geology at the general excavation depth is not suitable for excavation, or there is no restriction in construction regarding the positional consistency with other tunnels to be connected to the subsea tunnel.

Further, since it is possible to efficiently excavate only a portion which should be a tunnel, it is extremely efficient, and it is possible to reduce the amount of soil discharged to a minimum, thereby reducing the influence on the environment. it can.

[0018]

Embodiments of the present invention will be described with reference to FIGS. When explaining the construction method, the apparatus will be described first. The device is roughly divided into a shield excavator 4 for propelling in water and in the ground, and a pontoon 1 for controlling and supporting the shield excavator 4 on the water.

The shield excavator 4 has a rotary cutter 4a (center shaft type full-section rotary cutter) at its tip, and a pump 4b for pumping soil discharge behind the rotary cutter 4a. A screw conveyor is provided between the rotary cutter 4a and the pump 4b so that mud-like soil can be pumped. Further behind the pump 4b (tail section)
Is provided with a box-shaped guide 5 having an opening at the rear end. It goes without saying that this may be, for example, a circular cross section and is not limited to a particular shape.

The guide 5 has its entire width set to be equal to the excavation width, and is integrated with the shield excavator 4. Further, the shield excavator 4 is provided with a shield jack 4c which can be projected into the guide 5.

On the other hand, the pontoon 1 is on the water surface 21, and has an annular tunnel block 2 and a soil disposal unit 3 which are to be a tunnel structure. The inside of the tunnel block 2 is circular, and the outside is circular above the horizontal center line and prismatic below the center line so that it can be housed inside the guide 5. Further, the soil discharge processing section 3 is composed of a muddy water treatment device and a sludge solidification treatment device.

The tunnel block 2 is preferably a precast pipe, a fume pipe, an arch-culvert pipe, or the like. The pump 4b is detachably connected to the soil discharge processing unit 3 by the slip fluid transport pipe 10. Further, the shield excavator 4 is provided with a controlled device 30, which can be remotely operated by a command from the barge 1, so that all underwater work can be performed unattended.

As an example, a case of constructing an undersea tunnel in the bay will be described. First, before starting excavation, it is necessary to set an excavation start point and an excavation arrival point. Then, the starting-side vertical shaft 6 and the reaching-side vertical shaft 7 are respectively formed at the excavation starting point and the excavation reaching point which are set at the respective watersides.

As shown in FIG. 2, the departure side vertical shaft 6 has its bottom portion set at a position lower than the water bottom 9. The shield excavator 4 is arranged in the departure-side vertical shaft 6. The reaction device 20 is interposed between the rear end of the first-stage tunnel block 2 and the ground, and when the shield jack 4c is projected into the guide 5 to crimp a new tunnel block 2 onto the existing tunnel block 2. It is provided to support the existing tunnel block 2 so as not to retract.

At the start stage of excavation, the earth removal processing section 3 is located on the ground, and the pontoon 1 is on standby as shown in FIG. As the shield excavator 4 advances (indicated by arrow F), the shield excavator 4 digs through the side surface on the advancing side of the departure-side shaft 6. At this time, the shield excavator 4 advances in the direction of the arrival side vertical shaft 7 at a depth where the excavation hole is exposed from the upper surface of the water bottom 9. In addition, the arrival side vertical shaft 7 direction does not always refer to the shortest distance, and it goes without saying that the meandering direction may meander.

Then, when the next tunnel block 2 is dug to the extent that it can be mounted (for example, about 2.5 m), the inside of the guide 5 becomes hollow, but at this time, the tunnel block 2 is moved from the pontoon 1 to the guide 5 It is hung inside and is positioned and connected to the tip of the tunnel block 2 laid earlier. In this case, water enters the tunnel block 2,
The rise is prevented.

At the same time, the covered earthwork 22 is sequentially installed on the laid tunnel. The covered earthwork 22 holds the tunnel itself stably, prevents floating when draining the inside, and is also a measure against anchoring and running anchor of a ship traveling on the water.

The soil discharge 8 generated along with the forward movement is sent to the soil discharge processing section 3 installed on the berth 1, and the tunnel blocks 2 are sequentially connected (FIG. 4). When the shield excavator 4 penetrates the reaching shaft 7 (FIG. 5), the underwater work is completed, and the process moves to the step of draining the inside of the tunnel block 2 fixed to the bottom 9 (FIG. 6). .. Then, the inside of the hollow tunnel block 2 is cleaned, and the anchor 23 is driven into the ground from the bottom to fix the tunnel. However, tunnel block 2
Anchors are fixed to the bottom of the water, anchor 2
The step of driving 3 may be omitted.

After that, the construction is completed by connecting to another existing tunnel as appropriate. The above operation will be summarized with reference to the flowchart of FIG. 8. First, after starting at step 100, the process proceeds to an exploration step 101 for exploring the state in front of the face. In this exploration step 101, ultrasonic waves are emitted from the top of the ship to the bottom of the water, and the presence or absence of geology and obstacles is inspected by the waveform of the reflected wave and the frequency response characteristics. At the same time, the inspection by the probe from the shield excavator 4 is also executed. All control and data exchange of the shield excavator 4 is performed by a control device (not shown) on the pier 1 connected by wire.

When an obstacle is found here, the obstacle is removed in step 102 and step 101
Return to the circulation routine. When the obstacle is completely removed, excavation is started in step 103. Then, at the stage where the next tunnel block 2 has been dug up to a distance where it can be added, the tunnel block 2 is hung from the pontoon 1 (step 104) and connected in water (step 10)
5). In this connection, the shield jack 4c is projected into the guide 5 and the new tunnel block 2 is crimped to the existing tunnel block 2 and necessary reinforcement treatment and waterproof treatment are performed.

Then, after the tunnel blocks are sequentially connected and the laying of the predetermined section is completed, in step 106, the linear state of the existing tunnel block, the buoyancy calculation of the tunnel block (the prediction of the buoyancy after drainage) and the inspection of the water quality state are performed. To do.

After that, the covered earthwork is constructed and, after the completion, the drainage in the tunnel block 2 is performed in step 107. Then, the anchor of the tunnel block 2 is constructed in step 108, and the process ends in step 109.

Thus, by excavating with the shield excavator, it is possible to achieve great automation and save manpower.

[0034]

According to the present invention, since the shield excavator is advanced to the arrival side vertical shaft side at a depth where the excavation hole is exposed from the upper surface of the water bottom, there is a problem in the conventional underground propulsion type construction method. It is not necessary to consider the stability of the tunnel face and the stability of the ground surface, and it can be propelled at any depth.

Therefore, the geology at the conventional general excavation depth is not suitable for excavation, or there is no restriction in construction regarding the positional consistency with other tunnels to be connected to the subsea tunnel.

Further, since it is possible to efficiently excavate only the portion that should be a tunnel, it is extremely efficient, and it is possible to reduce the impact on the environment by minimizing the required amount of soil removal. it can.

[Brief description of drawings]

FIG. 1 is an overall side view showing an embodiment of the present invention.

FIG. 2 is a side view for explaining a process showing an embodiment of the present invention.

FIG. 3 is a side view for explaining a process showing an embodiment of the present invention.

FIG. 4 is a side view for explaining a process showing an embodiment of the present invention.

FIG. 5 is a side view for explaining a process showing an embodiment of the present invention.

FIG. 6 is a side view for explaining a process showing an embodiment of the present invention.

FIG. 7 is an overall perspective view showing an embodiment of the present invention.

FIG. 8 is a flowchart showing an embodiment of the present invention.

[Explanation of symbols]

 1 ・ ・ Boat, 2 ・ ・ Tunnel block, 3 ・ ・ Ejection disposal section, 4 ・ ・ Shield excavator, 5 ・ ・ Guide, 6 ・ ・ Departure side shaft, 7 ・ ・ Destination side shaft, 8 ・ ・ Discharge Sat, 9 ... water bottom.

Claims (1)

[Claims] 1. A pontoon having an annular tunnel block to be a structure of a tunnel and an earth-moving treatment section, and a guide capable of accommodating the tunnel block connected to the tail end to operate in water and have an overall specific gravity higher than that of water. Preparing a large shield excavator, and forming a starting side vertical shaft and a reaching side vertical shaft at each waterside between the excavation starting point and the excavation reaching point, respectively, the remotely operated shield in the starting side vertical shaft A step of arranging an excavator and operating this shield excavator remotely underwater to move forward while excavating the water bottom in the direction of the reaching side vertical shaft at a depth where the drilling hole is exposed from the upper surface of the water bottom. The step of sending the generated soil to the soil disposal section, the step of supplying the tunnel block from the ship to the inside of the guide, the tunnel in the groove formed as the shield excavator advances. The step of fixing the block, the step of supplying the next tunnel block into the hollowed guide along with the advance of the shield excavator and sequentially connecting to the tunnel block located in the rear, the shield excavator to the reaching side shaft When it arrives, the process of draining the inside of the tunnel block fixed to the bottom of the water is fixed, and the shield construction method.