JPS63151795A - Method of construction of tunnel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for constructing a tunnel under relatively shallow water.

[Conventional technology]

Conventionally, there have been two main methods for constructing tunnels under water: the shield method and the submerged method.

The shield method is a construction method developed to excavate tunnels in geological formations that are not self-supporting and prone to collapse.
J. After embedding a steel cylinder in the ground and excavating the soil that flows into this area, and after the shield has advanced,
This is a construction method that safely constructs tunnels by assembling divided steel or concrete linings called segments into a cylindrical shape concentrically with the shield, while preventing the lining from collapsing.

In addition, in the submerged method, lining structures (submerged cans) that have been manufactured on land in advance are lined up and connected to the bottom of the water.
−& is a prefabricated construction method.

[Points to be solved by the invention]

In the shield method, even if a mini-pit is excavated as shown in Figure 7, there is a membership fee for excavating the tunnel 2 up to the vertical shaft 1 using the cut-and-cover method, which is not economical1. It was difficult to take measures against high water pressure because the excavation was deeper than the floor surface, and it was necessary to apply boundary pressure to shaft 1 and change between the shield method and the open-cut method, which lengthened the construction period.

In addition, in the case of the immersion method, as shown in Figure 8, it is necessary to extend and excavate a tunnel 2 using the cut-and-cover method, which is not economical, as is the case with the shield method. In addition, water transportation was subject to restrictions during this period due to the work involved in sinking the immersed pipe 4 and digging trenches under the water.

In addition, as shown in Figure 8, there are sections using the open-cut method and sections using the immersed method, which required a change in construction method and lengthened the construction period, and a 40-way submerged pipe extension dog was required near the construction site. Therefore, if the dog was not nearby, it was impossible to adopt the submerged method, and if the submerged pipe 4 was buried deep, it became difficult to connect the submerged pipe because it had to be submerged from outside the pipe. .

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to make it possible to construct a tunnel using the same shield excavation machine throughout the entire section, thereby making it possible to eliminate the need for the cut-and-cover method, thereby making it economical. This tunnel eliminates the limitations of marine transportation and the problems associated with connecting immersed pipes, eliminates the need for special high water pressure measures, shortens the construction period, and eliminates the need for a manufacturing dock for immersed pipes. Our goal is to provide construction methods for

[Means and operations for resolving problem 1] In order to achieve the above object, the present invention excavates from a starting shaft built on the surface of the earth to the bottom of the water using a shield excavator, and as the shield excavator advances. The segments are rolled up, and after reaching the water bottom, a shield excavator is used to excavate a specified depth * on the water bottom, and the segments are rolled up to form an immersed pipe, which is then installed in an excavated trench on the water bottom to create an immersed pipe. Backfill earth and sand was laid in the underwater part of the site.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

The shield excavator 10 used in the tunnel construction method according to the present invention is equipped with a cutter head 11 and a propulsion jack 12. This is used to remove the waste from the machine and to set up the segment 130. Further, at the rear end of the shield main body 14 of the shield excavator 10, a plurality of tail seals 15 are provided as shown in FIG.
is provided, and the tail seal 15 during excavation is segment +
3 or the outer surface of the segment 17, which becomes the submerged pipe 16, to hold the water honey.

A starting shaft 19 is constructed on the ground surface 18 as shown in Figure 1,
A tunnel 21t'' is excavated obliquely from the starting shaft 19 to the water bottom 20 by the shield excavator 10.

In this case, the treatment plant 23 is driven by the slurry pump 22.
The mud water is sent into the cutter head 11 through the mud water pipe 24, the excavated earth and sand (sludge) is turned into slurry, and the mud water pump 2
The slurry made into slurry by the drive of No. 5 is removed from the slurry water pipe 26t-
and is discharged to the treatment plant 23 via.

A segment winding device (not shown) included in the shield excavator 10 as the shield excavator 10 is propelled.
Winding of segment) 13 is performed.

In this way, the tunnel 2I is excavated 111ttt-t-, and when the tunnel 2I is excavated and reaches the branching point B between the underground and the water bottom 20, the shield excavator 10 is controlled horizontally and a trench A of depth B is excavated in the water bottom 20.

The underground portion uses ordinary thin-walled segments 13, and the underwater portion segments 17 are rolled up to form the immersed pipe 16, and the immersed pipe 29 is provided with partition walls 27 as shown in FIG. It has a water storage part 28 in the upper part. Further, the partition wall 27 is provided with an opening 3I through which a worker 30 can enter and exit, and this opening 31 is provided with a lid 32.

Then, in order to stabilize the immersed pipe 16, it is injected into the water storage section 28.

After the segments 17 are rolled up, the backfilling soil 34 is transported by a transport construction ship 33 and laid in the underwater exposed portion of the submerged pipe 29.

A vertical shaft (not shown) is constructed to reach the ground surface on the opposite shore, and after the shield excavator 10 reaches the vertical shaft, it is disassembled and carried out, and the necessary parts are water-tightened from inside the shaft and secondary sill construction (concrete construction) is carried out.
I do.

〔Effect of the invention〕

As detailed above, the tunnel construction method according to the present invention involves msuing from a starting shaft constructed on the surface of the earth to the bottom of the water using a shield tunneling machine, and winding up the segments as the shield tunneling machine advances, and after reaching the bottom of the water. A trench with a predetermined depth is excavated on the water bottom using a shield excavator, and an immersed pipe is formed using a segment.The immersed pipe is installed in the excavated trench on the water bottom, and the exposed part of the immersed pipe is backfilled with earth and sand. This is characterized by the fact that it can be installed.

Therefore, just as a shield excavator is used to excavate underground and underwater, it is possible to construct a tunnel using the same shield excavator throughout the entire section, making it possible to eliminate the need for open-cut construction methods and making it more economical. become.

In addition, although the result under the water is the same as that of a submerged pipe, there are no restrictions on marine transportation and problems associated with connecting submerged pipes.

In addition, since the buried pipe is buried at almost the same level as the waterbed floor, special measures against high water pressure are not required, and the construction period can be shortened because the construction can be carried out continuously using the same construction method (shield construction method). This also makes the manufacturing dock of immersed pipes unavoidable.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the construction of an underground tunnel by the construction method of the present invention, Figure 2 is an explanatory diagram of the construction of an underwater tunnel by the construction method of the present invention, Figure 3 is a sectional view along the line ■-- in Figure 1, Figure 4 is a cross-sectional view taken along line IV-fV in Figure 2, figure 5 is a vertical cross-sectional view of an immersed pipe consisting of segments, figure 6 is an explanation of the structure of the tail seal part of the shield excavator (2), and figure 7 , FIG. 8 is an explanatory diagram of a conventional tunnel construction method. 10 is a shield excavator, 13.17 is a segment, 16
19 is the starting shaft, 20 is the water bottom, and A is the ditch.

Claims (1)

[Claims] A shield excavator excavates from the starting shaft built on the surface of the earth to the bottom of the water, and as the shield excavator advances, segments are rolled up.After reaching the bottom, the shield excavator excavates a trench of a predetermined depth on the water bottom. A method for constructing a tunnel, characterized in that an immersed pipe is formed by winding segments, the immersed pipe is installed in an excavated trench at the bottom of the water, and backfilling earth and sand is laid in the exposed underwater part of the immersed pipe.