JPS59185295A - Tunnel drilling method - 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 The present invention relates to a method for creating a large diameter tunnel by excavating the ground surrounded by a vibratory roof.

Conventionally, tunnels have been constructed by driving a vibratory roof into the ground and then excavating the ground surrounded by the vibratory roof using a Metzel excavator, a shovel excavator, or by hand digging.

In this type of tunnel excavation method, the vibe roof is provided to prevent the ground around the tunnel from collapsing when the ground inside the tunnel is excavated, and as the excavation progresses, it is surrounded by the vibe roof. Shoring consisting of girders, columns, and beams is sequentially assembled along the inside of the bi-roof in the tunnel, and the bi-roof is supported by the shoring.

This shoring is assembled after the bottom of the tunnel has been completely excavated at the face, but since the face is sloped with its angle of repose, the excavated top of the face is The shoring at the front end is located at a distance corresponding to the slope of the face, and the distance increases in proportion to the excavation height of the tunnel.

Therefore, the bi-proof is supported between the frontmost shoring and the ground in front of the face, but if the distance between the supporting points becomes long, the bi-proof will bend and the ground above will sink. As a result, the tracks built on top of it will sink, which will have a negative impact on train operations.

For this reason, with conventional tunnel excavation methods, the excavation height cannot be increased, and therefore, large diameter tunnels cannot be constructed.

In order to solve these problems, the present invention aims to excavate the upper part of the ground surrounded by the vibration roof before excavating the lower part when excavating the inside of the vibration roof that has been poured to form a large diameter tunnel. After excavation, the shoring is assembled one by one, and the shoring exposed at the bottom by the ground excavation is supported by a support girder fixed to the beam at the lower end of the shoring supported on the bottom of the tunnel at the top. However, the present invention provides a tunnel excavation method characterized by assembling lower columns and girders on a support structure with exposed lower end beams.

An embodiment of the present invention will be explained with reference to the drawings. First, a retaining wall (1) is constructed by driving a large number of piles in parallel at both ends of a tunnel to be excavated, and then a vertical shaft (2) is constructed at a height of excavate to a depth equivalent to 2. In this case, a vertical shaft is not required when excavating a tunnel into a mountain that rises from the ground surface.

Next, a large number of steel pipes are installed continuously along the entire length of the planned tunnel on both sides and the top of the planned tunnel cross section from -10,000 to the other side of the shaft (2), thereby creating a vibrator. The end portion of the vibe roof (3), which constitutes the roof (3) and faces the planned tunnel entrance of both shafts (2), is supported by reinforcing girders (4) fixed in the shaft, and the ends of the vibe roof are reinforced in advance.

After constructing the vibe roof (3) in this way, the upper half of the earth retaining wall (1) in the starting shaft (2) portion of the planned tunnel cross section surrounded by the vibe roof (3) is removed, and the vertical shaft (2) is removed.
The upper pillar (61
(61) and connect and fix the upper girder (7) and the upper beam (8) between the upper ends and lower ends of the upper pillar 161 + 6, respectively, and assemble the shoring (9). (9) and the steel pipe constituting the vibrating roof (3), a disstasis piece αα is installed in the gap between the vibrating roof (3) and the tosho to be supported by the shoring (9) via the vibrating roof (3).

In addition, the upper beam (8
) is the upper girder (7) in contact with the excavated bottom of the tunnel upper part (5).
This is to support the earth pressure exerted by the tunnel through the upper pillar (6) +61, but it is preferable to lay mortar or iron plates on the bottom of the tunnel and then construct the tunnel on top of that.

In this way, excavation of the upper part of the tunnel (5) and shoring (9)
The excavation of the upper part of the tunnel (5) of a certain length, in which a plurality of supports (9) +91...(9) are provided at predetermined intervals in the length direction of the tunnel, is carried out in advance by repeating the assembly of (5) in sequence. After that, from the shaft (2) side, insert a support girder α2 made of ehim having a length spanning several widths of the shoring (9), and move the support girder ti2 forward from the rearmost shoring (9). It is erected across the upper beams (8) of several lengths of shoring (9) and fixed to the upper beams (8) using U-ports or the like. Two of these support girders are placed on each side of the upper beam (8).

Next, on the shaft (2) side, the earth retaining wall (1) in the lower half of the planned Toshinel' cross section is removed, and then the lower end upper beam (8) of the support (9) and the vibration roof (3) are removed. Use a shovel or the like to excavate the ground α3 surrounded by the lower parts of both sides of the tunnel to the bottom of the planned tunnel by the length of the support construction pitch.

Through this excavation, the upper shoring (9) is removed from the by roof (3).
), but the vibe roof (3) does not bend downward because it is supported by the support girder α4a fixed over several sections of support.

The upper column f61 (61) of the upper support (9) exposed in the lower part of the toshinel that has been excavated in this way is joined with the lower column G9α9 and fixed, and the lower column α5 (19) Fix the beam 0e and assemble the lower support 0η.In this case as well, it is preferable to apply a layer of mortar or lay a steel plate αυ on the bottom of the excavation before constructing the lower beam. Distasi heath 08) is interposed and fixed in the gap between the steel pipe of 09 and bi-proof (3), and the earth pressure is received by the lower column 151 t15).

In parallel with the formation of the lower support 0η for this spasi, the upper shoring (9) is assembled along with the excavation for the subashi at the upper part of the Toshinel (5), and this work is sequentially repeated until the lower part of the Toshinel 04) is formed. The upper and lower supports (9) 0η are formed while the excavation is delayed by a certain length with respect to the upper part of the toshinel (5).

At this time, each time the lower shoring (171) is formed, both sides of the opening 2 of the support girder (2) fixed on both sides of the upper beam (8) at the lower end of the upper shoring (9) 1 wood brother upper beam (8
) and move it forward alternately by one spacing of the shoring, then fix it again, and the front end of the support girder 040 is received on the bottom of the excavation of the upper part of the toshinel (5) via the upper beam (8). The rear end portion is received by the assembled lower support Uη, and the upper support (9) suspended in between is supported by the support girder U2.

In this way, the excavation of the upper part of Toshinel (5) and the upper shoring (9)
), excavation of the lower part of the Toshinel and assembly with the lower support 0 are carried out to the reaching shaft, and the excavation of the large-diameter Toshinel is completed.

Note that it is desirable that the first part of the support (9) α-force be assembled in the shaft (2) prior to excavation.

Thereafter, formwork is assembled within the shoring, and the shifrit is cast, and the upper beam (8) installed between the lower ends of the upper shoring (9) is removed to complete the tocinel.

In addition, in Example 8 above, the planned Toshinel cross section was excavated by dividing the height into two parts, the upper half and the lower half, but in the case of a Toshinel with a larger height, it was divided into multiple parts. Of course, the excavation and shoring assembly may be carried out sequentially from above to below. Further, even if the Tocinel cross section has a horseshoe shape, it can be excavated by the method of the present invention.

As described above, the present invention forms a bi-proof by driving a large number of steel pipes from the top surface of the toshinel to be excavated to both sides, and the upper part of the ground surrounded by the bi-proof is placed before the lower part. The upper part of the Toshinel is excavated, and as the excavation of the upper part of the Toshinel progresses, supports consisting of the upper columns, upper girders, and upper beams installed between the lower ends of the upper pillars are assembled at appropriate intervals in the length direction of the Toshinel. After arranging a support girder in the length direction and fixing the support girder to the upper beam of the shoring, the support girder is used to support the support girder through the bottom surface of the upper part of the toconel, and then the support girder is placed below the upper beam of the shoring. The lower part of the Toshinel is excavated along the support girder, and as the excavation progresses, the lower column and lower beam are assembled on the upper pillar of the support. Since this relates to the Tosinel excavation method, which is characterized by repeated excavation and shoring assembly, the planned Tosinel cross section is divided in the height direction, and the excavation of the upper Tossinel is carried out at an appropriate length. Since the lower tosinel is excavated using the same method, the excavation height of the upper and lower tossinels becomes lower, and the length of the sloped part due to the angle of repose of the face ground becomes shorter and the excavation height approaches the top of the face. As a result, the unsupported distance of the bi-proof at the face is shortened, preventing the steel pipes that make up the bi-proof from bending, and preventing ground subsidence. By eliminating this, there will be no negative impact on the orbit of the Earth's surface.

Furthermore, since the shoring is first erected on top of the toshinel that is excavated in advance, the column length of the shoring is shortened and the erection work can be carried out smoothly. Since the supporting girders are fixed to the upper beams fixed to the upper beams over several widths, the supporting girders can reliably support the supporting girders, which will be suspended due to the excavation of the lower part of the toshinel. By attaching and fixing the lower column and lower beam to the shoring in this state, it is possible to easily and safely excavate a large-diameter tocinel with a large height.

Further, according to the method of the present invention, there is no need to improve the Metsusel excavator according to the cross-sectional shape of the tossel unlike the conventional Messel excavator, and it can be applied to tossel excavation of any cross-sectional shape.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a simplified longitudinal side view showing the excavation state of the upper part of the toshinel, and FIG. 2 is a simplified longitudinal side view showing the state in which the lower part of the toshinel is excavated following the upper part. , Fig. 3 is an enlarged longitudinal sectional front view taken along line A-A in Fig. 1, Fig. 4 is an enlarged longitudinal sectional front view taken along line B-B in Fig. 2, and Fig. 5 shows the lower end of the middle girder or lower girder. It is a sectional view showing the support structure of the section. (2) -... Vertical shaft, +31... Pipe roof, (5
)...Toshinel upper part, (61...upper column, (7)...
・Upper girder, (8)... Upper beam, (9)... Shoring, 02.
・・Support girder, circle・−Toshinel lower part, αω・lower column, (1θ
...lower beam, (!η...lower support. Patent applicant: Ken Okuyama - Okumura Co., Ltd. Nobunichi Mizukami, 11 years old)

Claims (1)

[Claims] ■ A large number of steel pipes are cast from the top of the tunnel to be excavated to both sides to form a vibratory roof, and the upper part of the tunnel is excavated before the lower part of the ground surrounded by the vibratory roof. As the excavation progresses at the top of the tunnel, the upper pillar,
Shoring consisting of the upper girder and the upper beam installed between the lower ends of the upper columns is assembled at appropriate intervals along the length of the toshinel, and then
After arranging a support girder in the length direction of the tunnel and fixing the support girder to the upper beam of the support, the support girder is not used to support the support through the bottom surface of the upper part of the tunnel. The lower part of the tunnel is excavated below the beam along the support girder, and as the excavation progresses, the lower column and lower beam are assembled on the upper column of the support. A tunnel excavation method characterized by repeated excavation of the upper part and subsequent erection of shoring.