JPH03187493A - Constructing method of tunnel - Google Patents

Abstract

PURPOSE:To prevent the fall of sediment in the ground into a tunnel by advancing a messel sheet pile and a shoe after hardening the concrete between timbers, charging a back-filling material into a tail void part, and repeating this process. CONSTITUTION:The inner part of a timbering frame with a tunnel sectional form formed of a front frame 1 and a rear frame 3 is excavated while a plurality of messel sheet piles 5 and a shoe 6 are successively press-fitted to the outer circumference of the timbering frame by use of a propulsive jack 7. Timbers 18 are longitudinally assembled at proper intervals in a tail part 8 surrounded by the messel sheet piles of a messel excavator 1 rear part, then concrete 20 is placed between the timbers 18, 18, and after hardening thereof, the messel sheet piles 5 and the shoe 6 are advanced. A back-filling material is charged into the tail void part between the concrete and the ground formed at the time of press-fitting of the messel sheet piles 5, and this process is repeated to construct a tunnel. Hence, the fall of the sediment in the ground into the tunnel can be prevented, and the tunnel can be efficiently excavated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 3] The present invention relates to a method for constructing a tunnel using the Metzel construction method.

[Conventional technology]

Traditionally, shield construction methods and mesocell construction methods have been widely adopted as tunnel construction methods.

In the shield construction method, a strong steel shell called a shield is used to excavate segments while absorbing reaction force, and the structure is constructed by removing excavated soil and assembling new segments. Since it is forced into the ground, there is a risk of disturbing the ground and causing ground subsidence.

On the other hand, the Metsucel method has the advantage of preventing the occurrence of ground subsidence, since a plurality of Metsucel sheet piles arranged in parallel on the outer peripheral surface of the shoring frame are pressed into the ground one after another.

[Problem to be solved by the invention]

However, in the Metsucel construction method, after the Mesocel sheet piles are pressed into the ground one after another, the inside of the pile is excavated, and the tunnel is excavated while assembling the supporting members consisting of the shoring and wooden sheet piles in the tail part. When the 7-cell sheet pile excavator moves forward, earth and sand may fall into the tunnel from between the shorings, and tail voids are created at the rear end of the mensel sheet piles, causing the ground to loosen. During construction, the wooden sheet piles had to be pressed against the ground using cambers, making the work complicated and reducing efficiency.

The present invention aims to solve these problems by providing a method for constructing a tunnel using the Metzel construction method.

[Means to solve the problem]

In order to achieve the above object distantly, the tunnel construction method of the present invention uses a Metsu cell excavation machine in which a plurality of Metsu cell sheet piles are arranged around the outer periphery of a support frame so as to be able to slide back and forth, and the Metsu cell sheet piles are sequentially pressed into the ground. In this method, tunnel-shaped supports are assembled at appropriate intervals in the length direction within the tail section surrounded by Metsucel sheet piles at the rear of the Metsucel excavator, and then concrete is poured between these supports. The method is characterized in that the Metsucel sheet pile is advanced after the concrete has hardened, and the tail void between the concrete and the ground that occurs when the Metsucel sheet pile is press-fitted is filled with a backfilling injection material. .

[For production]

The tunnel is lined by pouring concrete between the supports assembled within the tail of the Metsucel sheet pile at the rear of the Metsucel excavator, and by advancing the Metsucel sheet pile after this concrete has hardened, the inner surface of the excavated ground is covered. Since the concrete wall is covered, earth and sand from the ground will not fall into the tunnel. Furthermore, if a sheet is stretched between the inner surface of the Metsu Cell sheet pile and the shoring during concrete placement, the edges between the Metsu Cell sheet pile and the concrete can be reliably cut.

Furthermore, it becomes possible to arrange a form inside the concrete wall and perform secondary lining at the same time.

On the other hand, by filling the tail void between the concrete and the ground, which occurs when Metsucel sheet piles are press-fitted, with the backfilling injection material, the tail void can be treated easily and reliably, and the collapse of other piles can be prevented.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. A Metzel excavator (1) has a supporting frame formed by a front frame (2) and a rear frame (3) formed in a cross-sectional shape of a tunnel.
The front and rear frames (2) and (3) are connected to each other by a plurality of traction jacks (4) (4) so that they can move toward and away from each other in the front and rear directions, and these front and rear frames (2) A plurality of Metsucell sheet piles (5) (5) (5)...(5) and a shoe (6) which are long in the front and back direction are attached to the outer circumferential surface and outer bottom surface of (3), respectively, so that their opposing side edges can slide freely relative to each other. Further, the front end inner surface of each metsu cell sheet pile (5) and each shoe (6) and the front frame (2) are connected by a propulsion jack (7).

In addition, each Metsusel arrow 1Ii (5) has a thin tail portion (8) formed by cutting off the inner surface of the rear portion extending rearward from the rear frame (3) to an appropriate thickness.
) is further provided with a thin eave part (9) protruding from the outer periphery thereof. The cross-sectional shape of this eave part (9) is as shown in FIG.
Side wall portions (9) continuous to both side edges of the tail portion (8) are provided on both side edges.
a> (9a) may be provided, or as shown in FIGS. 6 and 7, the wall portion may be formed gradually thinner toward the tip without providing such a side wall portion. good.

0ω is the distance from the rear part of each Metsu cell sheet pile (5) to the tail part (8
), and as shown in Fig. 4, the front and rear ends thereof have openings 00G2) on the inner surface of the Metsucell sheet pile (5) and the end face of the open tail portion (8), respectively. The opening 01) on the inner surface of the Metsu cell sheet pile (5) is connected to two backfilling injection pipes arranged inside the machine.

04) A pin for fixing the Hamessel sheet pile (5) and shoe (6) to the rear frame (3).
The front and rear support holes (+5) (16) provided in the front and rear support holes (+5) (16) are releasably engaged with the locking holes 07) provided at the rear of the Metsel sheet pile (5) and the shoe (6).

When excavating a tunnel with the Metsusel excavator (1) configured in this way, as is well known, the propulsion jack (7
) are activated sequentially to release Metsucel sheet pile (5) and shoe (6).
) into the ground for a specified length. At this time, the Metsel sheet pile (5) and shoe (6) are fixed to the rear frame (3) by locking the pin 04) from the rear support hole 0ω to the locking hole 07) before press-fitting, Metsucel sheet pile (5
) is press-fitted one by one or several sheets at a time, the pin 04) of the mesocell sheet pile (5) to be press-fitted is removed, and after press-fitting, the pin Q4) is inserted into the hole aω and the hole θD.

In this way, all the Metsu cell sheet piles (5) and shoes (6) are press-fitted, and the front support hole o5 of the rear frame (3) is completed.
Pass through and attach the Metsu cell sheet pile (5) and shoe (6) to the pin side.
After locking it in the locking hole 0'7), extend the rond of the traction jack (4) while contracting the ronds of all the propulsion jacks (7) and attach it to the rear frame (3). Advance the front frame (2), then remove all pins 04), and then contract the rond of the traction jack (4) to advance the rear frame (3) and lock its rear support hole 0ω. Match hole 07).

As the rear frame (3) moves forward, the space surrounded by the tail part (8) of the Metsucel sheet pile (5) becomes wider, and by repeating the above operations, a space is created in which the shoring structure 08) can be assembled. , Assemble a tunnel-shaped shoring 08) inside the tail part (8) along the inner circumferential surface of the tail part (8), and install a splicing material 09) between the shoring side and the already assembled shoring 08). After fixing with wire mesh and stretching wire mesh, the inner surface of the tail part (8) and these shoring QFD
08) The space between is sprayed with concrete depending on the construction method.
21 is poured.

This concrete C! For spraying of Φ, Metsucel sheet pile (5
) may be sprayed directly onto exposed areas of the ground created by press-fitting. In this case, the tail void described below does not occur,
Does not require backfill injection.

At this time, a form frame may be assembled inside the concrete QI as a primary lining, and concrete may be poured between the concrete (a) and the form frame to form a secondary lining at the same time.

For the first lining, ready-mixed concrete may be poured by incorporating a form without using the spraying method.

In this way, the inner circumferential surface of the tail portion (8) is lined with a concrete layer of a predetermined thickness, and after the concrete layer has hardened, each Metsu cell sheet pile (5) and shoe (6) are installed again as described above. advance.

At this time, when each Metsu cell sheet pile (5) moves forward, mortar (21) etc. is injected from the backfilling injection vibe 0■ through the injection hole 00), and the excavated ground that is created behind the tail part by the advance of the Metsu cell sheet pile (5) The gap (tail void) between the concrete layer (c) and the concrete layer (c) is filled with the mortar (21), etc.

In addition, if concrete is placed directly on the inner surface of the tail section (8), the concrete may adhere to the tail section (8) and obstruct the smooth advancement of the Metsucel sheet pile (5), so shoring is not necessary. Before assembling the tail part (8), as shown in Figure 3, apply a resin sheet to the inner peripheral surface of the tail part (8).
It is desirable to cut the edge of the concrete (a) by setting the concrete (2) or applying grease or the like.

In this way, the assembly of the shoring 08) within the tail part (8) and the concrete between the shoring sides 08) C! pouring of I,
Metsucel excavator after hardening of the concrete QΦ (
The tunnel is constructed by repeating the forward movement of step 1) and filling the tail void portion with mortar (21) during the forward movement.

FIG. 8 shows another embodiment of the mortar filling means into the tail void, in which backfilling injection holes 0 (
When concrete (C>I) is placed in the tail part (8) without providing I), a cylindrical injection port (23) is arranged in the side of the adjacent shoring (08), After that, concrete 12G was poured using a spraying method, etc., and the concrete C! After curing of Φ, move the Metsucell drilling machine (1) forward to seal the resin from inside the injection hole (23) (22)
The mortar is backfilled into the tail void created between the concrete wall and the ground through the injection port (23).

Other work steps are the same as in the above embodiment.

In addition, a resin seam 1- (22
), the resin sheet) is used during backfill injection.
(22) may be partially torn to allow the injection port (23) to communicate with the tail void.

[Effects of the Invention] As described above, according to the tunnel construction method of the present invention, in the method of excavating a tunnel with a Metzel excavator,
After assembling tunnel-shaped shoring in the tail section surrounded by Metsucel sheet piles at the rear of the Metsucel excavator, concrete is poured between the said shoring and the previously assembled shoring, and after the concrete hardens, the Metsucel sheet piles are advanced. Therefore, the lining of the tunnel can be easily and reliably formed by pouring concrete between the supports assembled in the tail part of the Metsucel sheet pile at the rear of the Metsucel excavator. If the Metsel sheet pile is advanced after this concrete has hardened, the inner surface of the excavated ground will be covered with a concrete wall, which will prevent earth and sand from falling into the tunnel, creating a good working environment. This enables efficient tunnel excavation.

In addition, if a sheet is stretched between the inner surface of the Metsu Cell sheet pile and the shoring when concrete is poured, the edges between the Metsu Cell sheet pile and the concrete can be reliably cut, and the Metsu Cell excavator can be propelled smoothly. Furthermore, by filling the tail voids between the concrete and the ground that occur when Metsucel sheet piles are press-fitted with a backfilling injection material, the tail voids can be treated easily and reliably, and the collapse of the ground can be prevented. It is.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a simplified longitudinal side view of the Metsusel excavating machine in the state of tunnel excavation, FIG. 2 is a simplified front view showing the arrangement of Metsusel sheet piles, and FIG. A rear view, FIG. 4 is an enlarged longitudinal sectional side view of the tail portion, FIG. 5 is a rear view of the eaves portion of the Metsusel sheet pile, FIG. 6 is a rear view of another form of the eaves portion, and FIG. 7 is a side view thereof. FIG. 8 is a simplified longitudinal sectional side view showing another means of the backfill injection method. (1)...Metsucel excavator, (2)(3)...Front and rear frames, (4)...Traction jack, (5)...Metsucel sheet pile, (7)...Propulsion jack, ( 8)...
Tail part, 00)...back injection hole, side...shoring,
(21) Concrete. N 6 a ice 6

Claims (6)

[Claims] (1) In a method of excavating a tunnel by sequentially pressing the Messel sheet piles into the ground using a Messel excavator in which a plurality of Messel sheet piles are arranged around the outer periphery of a supporting frame so as to be able to slide forward and backward, the rear part of the Messel excavator After assembling tunnel-shaped shoring within the tail section surrounded by Messel sheet piles, concrete is poured between the shoring and the previously assembled shoring, and after the concrete hardens, the Messel sheet piles are advanced. How to build a tunnel. (2) The method for constructing a tunnel according to claim (1), characterized in that a sheet is stretched between the inner surface of the Messel sheet pile and the shoring, and then concrete is poured. (3) The tunnel construction method according to claim (1) or (2), characterized in that the concrete is poured by a spraying method. (4) In the rear part of the Messel sheet pile, provide an injection hole that opens on its inner surface and rear end surface, and fill the tail void between the concrete and the ground that occurs when the Messel sheet pile is press-fitted with backfilling injection material through the injection hole. A claim characterized in (
1) Method of constructing the tunnel described. (5) The tunnel construction method according to claim (4), characterized in that an eaves portion is provided rearwardly protruding from the outer periphery of the rear end of the Messel sheet pile, and the injection hole is opened inward of the eaves portion. . (6) After installing a pouring pipe with a length corresponding to the concrete pouring thickness between the shorings, pour concrete;
2. The tunnel construction method according to claim 1, wherein the tail void is filled with filler material through an injection pipe after the Messel sheet pile is press-fitted.