JP3121736B2 - Sidewall advanced method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel construction method and, more particularly, to a side-wall tunnel construction method for advancing a shaft before construction of a main shaft.

[0002]

2. Description of the Related Art Techniques for constructing a side wall tunnel include a mountain construction method using a sheet pile method, a NATM (New Austrian tunneling method), and a TBM having a circular cross section of a tunnel.
(Tunnel boring machine) and two other methods.

[0003] In the case of a side wall tunnel using the TBM, as shown in FIG. 7, a circular advanced shaft 51 is first excavated at the lower part of both side walls of a tunnel section to become a main shaft 50. In other words, in this method, the advanced shaft is dug below the side wall of the main shaft so that the excess digging (hatched portion) is about half of the digging section, and the opposing concrete wall 52
The arched H-steel and concrete blasting on these concrete walls are used to support the concrete wall, and in addition to this, while excavating the ground improvement rock bolts 54, the main tunnel 50 having the designed cross section is excavated. .

[0004]

However, in the case of the advanced side wall tunnel by the mountain method, although the setting of the tunnel sectional shape is arbitrary, the excavating efficiency is lower than that of the TBM.
A concrete wall that serves as a foundation for an arch-shaped support spanning the walls on both sides of the advanced shaft must be cast, and the installation and curing of this formwork lengthens the construction period, and also requires extra drilling for excavation The amount of concrete and the amount of concrete used has increased, and it is now an inefficient method of construction.

[0005] Therefore, in the case of advanced side wall tunneling by the TBM method, since the cutter surface of the TBM is circular, a considerable portion is dug into the cross section of the main pit, or if the inside of the main pit is temporarily buried. Since the advanced shaft is inscribed at a point with the main shaft even when drilling in contact with the main shaft, the advanced shaft cannot be used as a support for the main shaft, and its effectiveness as an advanced shaft cannot be expected.

In the present invention, the above-mentioned drawbacks of the conventional method have been solved. The object of the present invention is to increase the excavation efficiency and to secure safety by using a TBM method, a shield method, or a combination of these methods. The aim is to provide an advanced sidewall tunneling method that employs the shielded TBM method and has a reduced amount of excavation compared to these conventional methods.

Another object of the present invention is to reduce the amount of excavation by excavating an advanced shaft that is inscribed in a line rather than a point with respect to the cross section of the shaft, and to reduce the amount of excavation. The aim is to provide a side wall tunnel advanced construction method that can be used as a part of the main shaft support or lining part.

[0008]

SUMMARY OF THE INVENTION The present invention has been made based on the above object, and the gist of the present invention is to excavate an advanced shaft near the side wall of a tunnel section of the main pit before excavating the main pit. In the side wall shaft advanced construction method, the TBM and the shield machine are so constructed that the side wall of the advanced shaft is linearly overlapped with the side wall of the main shaft so that the respective cross sections of the side walls are substantially inscribed.
Or Cutter Cutter in Full Shield TBM
The advanced tunnel method is characterized in that the advanced tunnel is excavated into a vertically long elliptical cross section by inclining the shaft to the left or right in the excavation direction .

[0009] In the drilling method of the above-mentioned Honko, if those that mechanical drilling, TBM, but not any type of construction methods, such as mountain method and shield method typified by such as NATM, advanced pilot tunnel
About TBM, Shield Machine , Full Shield T
The tunnel section is excavated as a vertically long elliptical shape by inclining either the left or right of the circular cutter surface in the BM (the TBM also serves as a shield machine) in the excavation direction .

[0010] When the overlapping portions on both sides of each of the advanced shaft and the main shaft become linear, point contact occurs when a great circle inscribes a small circle, but an ellipse is formed into a substantially large circle. When the small circle of the shape is inscribed, it shows that the overlapping part becomes linear, and the main pit is excavated with the linearly overlapping part.

Another feature of the present invention is that the support of the side overlapping portion of the advanced shaft by excavation of the advanced shaft is also used as a part of the side wall support of the main shaft to be excavated later. is there.

[0012] Still another feature of the present invention is that the lining of a side overlapping portion of the pit due to the excavation of the advanced shaft is also used as a part of the side wall lining of a main pit to be excavated later. .

[0013]

According to the present invention, a circular shape such as a TBM is first inscribed in a linearly overlapping state at the lower part of the designed tunnel shaft side wall.
Incline the cutter drum to the left or right in the direction of excavation
Excavation of an advanced shaft with a vertically long elliptical cross-section, connecting between the overlapping upper ends of the advanced shaft, and supporting or lining it to minimize the overburden of the main shaft, Part supports or linings will also serve as part of these pits.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The outline of a TBM as an example used in the present invention will be described below with reference to FIGS.

A large number of cutting cutters 2 are arranged on a cutter surface 1 of a TBM (arrow A), and this surface is rotated by an electric motor 6 while being inclined to the left by an angle θ as shown in a plan view. It allows drilling of an advanced shaft with a vertical elliptical cross section.

The cutter head support 7 at the rear of the cutter drum 3 is configured such that its left and right sides can be expanded and contracted by hydraulic cylinders 12 and 13, and the supports 14 and 15 are pressed against the pit wall by the extension thereof. 1
By automatically adjusting the press-contact forces of 4 and 15, the cutter head is tilted and excavated to prevent the cutter head from shifting in the left-right direction, thereby keeping the tunnel alignment constant.

A gripper 8 is connected to the main beam 11 with thrust jacks 4 and 5 interposed therebetween, and the gripper 8 can be extended and contracted by a gripper jack 9.

On the other hand, a belt conveyor (not shown) for transporting excavation debris into the box-shaped main beam 11 is provided in a groove shape.

A roof support 17 is provided above the cutter head support 7 via a hydraulic cylinder 16 to prevent the TBM excavation from bending up and down.

The advanced side wall tunneling method of the present invention using the TBM having the above-described structure will be described below.

First, before constructing along a relatively large-diameter main shaft tunnel planned line as a two-lane or more lane or a line of a line, at a location which is to be a lower portion on both side walls of the tunnel cross section of the main shaft 20, Excavation of vertically long elliptical advanced shafts 21 and 22 inscribed so as to linearly overlap with a part of the lower part of the side wall.

In excavation, the gripper jack 9 is extended to press the gripper 8 against the pit wall 19 to take a reaction force.
The cutter surface 1 is pressed against the face by the extension force of the thrust jacks 4 and 5, and the cutter drum 3 is rotated by the electric motor 6 to excavate the tunnel. Thrust jack 4,
When 5 is extended by one stroke, excavation is interrupted, the rear support 10 is extended and grounded, and then the gripper 8 is contracted, and then the extending thrust jacks 4 and 5 are contracted to advance the gripper 8. Then, the gripper 8 is again extended and pressed against the pit wall 19, and then the cutter drum 3 is rotated to excavate.

The excavated debris is scooped up by the cutter drum 3 and has a first end located inside the drum.
It falls on the step conveyor 11 and is discharged to the rear of the tunnel.

In the excavated tunnel (FIG. 1), the H steel is supported in a ring shape along the circumference of the pit wall 19 by a support erector (not shown), and thereafter the pit wall including the H steel is formed. Spray concrete. Depending on the properties of the tunnel ground, instead of the above-mentioned concrete spraying, the segments are wound in the circumferential direction of the tunnel by an erector (not shown) (see FIG. 1).

Thereafter, when excavating the main shaft, the upper half is excavated (FIG. 1), and the segments or supports of the advanced shafts 21 and 22 are removed according to the excavation, or these are cut together with the slip. Meanwhile, between the upper ends of both side walls of the portion overlapping with the side wall of the main shaft 20, the H steel 23 is supported or the segment 24 is wound (FIG. 1, FIG. 6 or FIG. 5).

Subsequently, the lower half of the main shaft is excavated. In this case, the invert construction of the main shaft is performed by using the H steel of the advanced shaft,
This is performed by placing concrete between the lower ends of both side walls of the segment 24 or laying a PC concrete slab (FIG. 1).

In this manner, the side wall of the main shaft 20 is also used as a portion overlapping with the advanced shaft 21, and the rest only needs to be constructed with the upper and lower inverts of the main shaft.

The secondary lining with concrete can be performed on the support with the H steel and the shotcrete or the support with the segments.

[0029]

As described above, according to the method of the present invention having the above-described structure, the advanced shaft shaft side wall is shifted with respect to the main shaft side wall .
Each wall section is substantially inscribed so that superimposed linear
And a circular cutter drum such as TBM on either side
The following effects can be expected due to the excavation at an angle.

A part of the advanced shaft and the excavation line on the side wall of the main shaft can be linearly aligned, and no excavation loss (excessive excavation for securing the bottom width) does not occur.

It is economical because a part of the shaft support (spray + steel support or segment) can also be partially used as the main shaft side wall support.

With the conventional TBM, an advanced shaft shown in FIG. 7 is excavated, and a concrete wall 52 is constructed in the excavated portion.
As in the case of assembling the support on the upper portion, a stable structure is obtained without stress concentration in the final structure such as the contact portion between the concrete wall 52 and the support. Note that TB
The rapid workability of M can be exhibited, and the safety against skin fall etc. is improved due to mechanical excavation.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a tunnel section showing construction means of the method of the present invention.

FIG. 2 is a schematic side view of a TBM used in the method of the present invention.

FIG. 3 is a plan view of FIG. 2;

FIG. 4 is a front view of the cutter drum shown in FIGS. 2 and 3;

FIG. 5 is an explanatory view showing a state in which a part (segment) of an advanced shaft is used also as a part of a main shaft support in the method of the present invention.

FIG. 6 is a partial explanatory view showing an example in which a main shaft support is constructed above an advanced shaft segment.

FIG. 7 is an explanatory view of a cross section of a tunnel in a conventional side wall shaft advanced construction method.

[Explanation of symbols]

 A TBM 1 cutter surface 4, 5 thrust jack 6 electric motor 7 cutter head support 8 gripper 10 rear support 19 advanced tunnel shaft 20 main shaft 21, 22 advanced shaft-procedure of the method of the present invention

──────────────────────────────────────────────────続 き Continuing on the front page (73) Patent holder 000201478 Maeda Construction Industry Co., Ltd. 2-10-26 Fujimi, Chiyoda-ku, Tokyo (72) Inventor Takashi Sakai 2-10-2 Otowa, Bunkyo-ku, Tokyo Otowa NS Building 7F Inside the Advanced Construction Technology Center (72) Inventor Mitsuhiro Higo 2-5-8 Kitaaoyama, Minato-ku, Tokyo Inside Mazumi Co., Ltd. (72) Inventor Yoshiaki Ishida 4-12-20 Nihonbashi Honcho, Chuo-ku, Tokyo Inside Sato Kogyo Co., Ltd. (56) References JP-A-6-294279 (JP, A) JP-A-4-353192 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E 21D 9/00 E21D 13/00-13/04 E21D 11/40

Claims (3)

(57) [Claims] 1. A method for excavating an advanced shaft near a side wall of a tunnel cross section of a main shaft before excavating the main shaft, wherein a side wall portion of the advanced shaft is respectively connected to a side wall portion of the main shaft. TB so that the side wall cross-section of
M, shield machine or full shield TBM
The circular cutter drum to the left or right in the direction of excavation
And thereby excavating the advanced shaft into a vertically long elliptical cross section. 2. The method according to claim 1, wherein the support of the side overlap portion of the pit by excavation of the advanced shaft also serves as a part of a side wall support of the main pit to be excavated later. Sidewall tunnel advanced construction method described. 3. The lining of a side overlap portion of the pit due to excavation of the advanced shaft is also used as a part of a side wall lining of a main pit to be excavated later. Sidewall advanced construction method described in 1.