JP4170867B2 - Tunnel excavation method - Google Patents

Description

  The present invention relates to a tunnel excavation method using a free section excavator.

  A general NATM (New Austrian Tunneling Method) method has one excavation cycle of “excavation process → slipping process → support construction process → concrete spraying process → rock bolt process” for one face. In the excavation process, excavation is performed in the direction of the face using a construction machine such as a free section excavator and a hydraulic breaker. In the slipping process, excavated soil is carried out by construction machines such as wheel loaders, hydraulic excavators and dump trucks. In the support construction process, the support work is built with a construction machine such as an elector. In the concrete spraying process, concrete is sprayed onto the tunnel ground after excavation by construction machines such as a sprayer and a mixer truck. In the rock bolt process, the rock bolts are buried by boring the tunnel ground with a construction machine such as a wheel jumbo.

  In the above-mentioned NATM method, tunnel excavation with a free-section excavator is superior to the shield method and TBM (Tunnel Bowling Machine) method, but is slow in excavation.

  Therefore, in the past, the tunnel excavation section was divided into an upper half section and a lower half section, and a bench-cut method or a full-section method was used for excavating the tunnel, and it was a hinge-type cutter boom that could be bent in the middle of the cutter boom. There is a tunnel excavation method that employs a cross-section excavator to improve excavation efficiency (see, for example, Patent Document 1).

  In another conventional method, the length of the bench that allows the tunnel excavation section to be divided into an upper half and a lower half, and that the lower half can be installed together with the upper half on one side of the tunnel center. The mini-bench part and the other side is a short bench part with a bench length that can be used to install a construction machine. There is a tunnel excavation method that attempts to improve excavation efficiency by performing a slippage at the same time and performing spraying with a sprayer installed in the upper half of the short bench portion (see, for example, Patent Document 2).

JP-A-10-115187 JP 2002-21467 A

  However, in the tunnel excavation method referred to in Patent Document 1, the efficiency of the excavation work itself is superior due to the adoption of a free-section excavator that is a hinge-type cutter boom, but the efficiency in the process from excavation work to slipping work is improved. I can't plan. In particular, in the long bench cut method or short bench cut method in which the excavation part is clearly divided into two parts, the excavation construction machine and the free cross-section excavator are complicated when the upper half section is displaced on the bottom plate. Therefore, safety and work efficiency will be reduced. In the mini-bench cut method or the micro bench cut method, since the excavation is performed after excavation of the entire section, the excavation cycle is not different from the general tunnel excavation method, and the excavation after excavation on the bottom plate of the lower half section is performed. Since the unloading machine and the free-section excavator are complicated, the safety and work efficiency are lowered.

  Further, even in the tunnel excavation method referred to Patent Document 2, it is not possible to improve the efficiency in the process from excavation work to slippage work. In particular, the lower half of the work is being done with a slip, but it is necessary to drop the upper half of the work into the lower half of the board. Since it takes time and effort to remove the dropped gap again with the construction machine, the efficiency is worse than that of a general gap removal process. On the other hand, spraying on the upper half of the short bench section cannot be performed until the upper half board is dropped into the lower half board, and as a result, it is the same as waiting for completion of the upper half board. Furthermore, the spraying of the parts (one side wall part and one side arch part) where the mini bench part large back face is cut off waits for the completion of the slippage in the lower half board. That is, although spraying and slipping are performed in parallel, as a result, the spraying work is performed after waiting for the slipping work, so the work on the upper half side and the lower half side is common. The efficiency is worse than the spraying process.

  In view of the above circumstances, an object of the present invention is to provide a tunnel excavation method capable of improving the excavation efficiency by improving the efficiency of transition between processes.

To achieve the above object, a tunnel excavation method according to claim 1 of the present invention is to be subject to tunnel divided into two divided sections in the width direction, each divided section is always lower half portion upper half a drilling step of drilling by the drilling machine in a state positioned at the front side of the parts, the drilling soil caused by the excavation process a tunnel excavation method repeated for the muck step of issuing shear by shear volume machine In the excavation step , the excavator is alternately loaded into the two divided sections , the excavator loaded in each divided section is placed on the ground of the lower half, and the upper half is excavated after excavating the lower half. The slipping step is carried out by carrying out the excavator and carrying it into an empty divided section , and the slipping machine is excavated in at least one of the divided sections. When the machine is in operation, the other division Wherein the running to include the timing of issuing simultaneously shear in.

The tunnel excavation method according to a second aspect of the present invention is the tunnel excavation method according to the first aspect, wherein the slipping- out step includes a bucket for scraping the excavated sediment in front and a conveyor for transporting the excavated sediment in the rear to the rear. It is characterized by performing with the slot machine provided with.

  In the tunnel excavation method according to the present invention, the back of the tunnel is divided into a plurality of divided sections in the width direction, and the divided sections are further divided into an upper half part and a lower half part, and excavation and slipping are performed for each divided section. Thus, the excavation process and the slipping process are separated in each divided section, and the respective process operations are substantially performed concurrently. As a result, the efficiency of the transition between each process is improved, and the excavation efficiency can be improved. Further, when shifting from the excavation process to the excavation process, the free-section excavator and the excavator are not complicated, so that safety and work efficiency can be improved.

  In the slipping process, a slip loader equipped with a bucket that scrapes the excavated soil in the front and a conveyor that transports the excavated sediment that has been swept by the bucket to the rear is used. Then you can remove it.

  Exemplary embodiments of a tunnel excavation method according to the present invention will be described below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.

  1 is a cross-sectional front view of a tunnel excavation method according to the present invention, FIG. 2 is a tunnel cross-sectional plan view of the tunnel excavation method according to the present invention, and FIG. Is a tunnel sectional plan view showing the tunnel excavation procedure, FIG. 5 is a tunnel sectional side view showing the tunnel excavation procedure, FIG. 6 is a tunnel sectional plan view showing the tunnel excavation procedure, and FIG. 8 is a cross-sectional plan view of the tunnel showing the tunnel excavation procedure, FIG. 9 is a plan view of the tunnel cross-section showing the tunnel excavation procedure, FIG. 10 is a plan view of the tunnel cross-section showing the tunnel excavation procedure, and FIG. FIG.

  In this embodiment, high-speed excavation is performed under the following conditions. (1) The geological situation of the construction site can be understood to some extent. (2) The face K is stable. (3) The average compressive strength of the face K is about 10 MPa. (4) Moisture does not adhere to the face K.

  As shown in FIG. 1 to FIG. 3, the tunnel excavation method in the present embodiment is divided into a plurality of face sections K in the width direction of the tunnel. In the present embodiment, the back is divided into two divided sections of a left half A and a right half B with respect to the center line S of the tunnel.

  Furthermore, in the present embodiment, the face K is divided into two parts, a lower half a and an upper half b, in the vertical direction of the tunnel in the divided section. That is, this excavation method adopts a bench cut method, and in particular, adopts a mini bench cut method in which excavation is performed by a construction machine having a bench length L of about 4 m and installed on the ground G in the lower half a. .

In the tunnel excavation procedure, first, as shown in FIGS. 4 and 5, the face K of the lower left half Aa is mechanically excavated. The construction machine used for this machine excavation is a free-section excavator 1 (excavation capacity 150 m ³ / h), and includes a bent middle boom that can swing vertically and horizontally as an excavation part 1a. Moreover, the cutting drum part 1b is provided so that expansion-contraction is possible in the longitudinal direction of a boom. Thereby, the free section excavator 1 can excavate a wide area in a short time. The excavation length L1 in one excavation cycle for excavating the lower left half Aa is preferably approximately 1.2 m.

  Next, as shown in FIGS. 5 and 6, the face K of the upper left half Ab is mechanically excavated by the free section excavator 1. The excavation length L2 in one excavation cycle for excavating the upper left half Ab is preferably approximately 1.2 m.

  Next, as shown in FIG. 8, the excavated earth and sand generated by the excavation of the left half A of the divided section is removed. The construction machine used for the slippage is a slipping machine 2, which has a bucket 2b for scrambling excavated earth and sand with respect to a boom 2a that can swing in the vertical and horizontal directions. It has a conveyor 2c that carries out excavated earth and sand in the front in the length direction of the tunnel that is in the rear. Further, as shown in FIG. 8, in the right half B which is an adjacent divided section, mechanical excavation of the face K in the lower right half Ba is performed in parallel with the slippage in the left half A. That is, the free-section excavator 1 that has completed the machine excavation in the left half A is moved to the right half B, the slip loader 2 is loaded into the vacant left half A, and the left half A is slipped out. And machine excavation in the lower right half Ba. The excavation length L3 in one excavation cycle for excavating the lower right half Ba is preferably approximately 1.2 m.

  Next, as shown in FIG. 9, the face K in the upper right half Bb is mechanically excavated by the free section excavator 1. At this time, if the left half A is not completely removed, the left half A is continuously removed in parallel with the mechanical excavation of the upper right half Bb. The excavation length L4 in one excavation cycle for excavating the upper right half Bb is preferably approximately 1.2 m.

  Next, as shown in FIG. 10, excavated earth and sand generated by excavation of the right half B is excavated by the excavator 2. That is, the free section excavator 1 that has completed the mechanical excavation in the right half B is withdrawn, the slip loader 2 is carried into the vacant right half B, and the right half B is slipped out.

Subsequently, as shown in FIG. 9 or FIG. 10, after excavation and slipping of the left half A are completed, the ground M corresponding to the face K of the left half A is sprayed. Although the construction machine used for this spraying is not shown in the figure, it is a compressor-mounted sprayer (spraying capacity 20 m ³ / h), and as shown in FIG. (10 minutes 3N) lining concrete 3 is constructed. That is, spraying is performed in the left half A in parallel with excavation or slipping out of the right half B.

  Subsequently, after the spraying of the left half A is completed, the lock bolt 4 is embedded in the ground M corresponding to the face K of the left half A. The construction machine used for embedding the lock bolt 4 is a wheel jumbo (150 kg class), although it is not clearly shown in the figure, and the lock bolt 4 is embedded in the natural ground M as shown in FIG.

  In addition, when the spraying of the left half A is completed, excavation and slipping out of the right half B are completed. Therefore, after excavation and slipping of the right half B is completed, the ground M corresponding to the face K of the right half B is sprayed by the spraying machine. That is, spraying is performed at the right half B in parallel with the embedding of the lock bolt 4 at the left half A.

  Then, after the spraying of the right half B is completed, the lock bolt 4 is embedded in the ground M corresponding to the face K of the right half B by the wheel jumbo. Thereby, as shown in FIG. 11, the construction of spraying the lining concrete 3 and the embedding of the lock bolt 4 is completed on the ground M corresponding to the face K of the entire cross section, and one excavation cycle is completed.

  In addition, one drilling cycle continues. In this case, after the construction of burying the lock bolt 4 in the left half A is completed, the face K of the left half A (lower left half Aa) is mechanically excavated. That is, machine excavation is performed in the left half A in parallel with the embedding of the lock bolt 4 in the right half B.

  Therefore, in the above-described tunnel excavation method, the tunnel back is divided into a plurality of divided faces K in the width direction, and the excavation process is performed at each face K by performing excavation and slipping for each divided face K. The process work is performed substantially in parallel with each other while separating the process and the slipping process. As a result, the efficiency of the transition between each process is improved, and the excavation efficiency can be improved. Further, when shifting from the excavation process to the excavation process, the free-section excavator and the excavator are not complicated, so that safety and work efficiency can be improved.

  In addition, the method further includes the step of spraying the lining concrete 3 onto the ground M corresponding to the face K for which excavation and slipping has been completed, and burying the lock bolt 4 in the ground M where the spraying has been completed. Therefore, the next process work is substantially performed concurrently while separating the excavation process, the slipping process, the spraying process, and the burying process. As a result, the efficiency of the transition between each process is improved, and the excavation efficiency can be improved. In addition, since the construction machine is not complicated when moving to each step, safety and work efficiency can be improved.

  In the excavation process, a mini bench cutting method is employed in which the face K is divided into a lower half a and an upper half b, and excavation is performed by a construction machine installed on the ground G of the lower half a. Since the excavation cycle time is shortened with the above effects, excavation efficiency can be further improved.

  Further, in the slipping process, since the slipping machine 2 including the bucket 2b for scraping the excavated sediment in the front and the conveyor 2c for transporting the excavated sediment in the rear to the rear is adopted, it is free. The cross-section excavator 1 can be juxtaposed to be displaced.

  In addition, in the spraying process, the concrete structure with the initial strength (10N / 3N) is applied to the natural ground M as the inner wall material with an average of 10cm, so that the tunnel structure can be supported by the sprayed concrete. Work can be omitted. Moreover, the support | cover with the intensity | strength which does not require steel support work with the sprayed lining concrete 3 and the lock bolt 4 can be obtained.

  In the above-described embodiment, the excavation procedure in the case where the face K of the tunnel is divided into two in the width direction has been described. However, the face K of the tunnel is divided into a plurality of widths in the width direction. In this case, for example, the working face K is sequentially excavated from the left side to the right side, the excavated soil is removed in the order of the finished face K, and the lining concrete is applied in the order of the ground M corresponding to the finished face K after the excavation and removal. 3 can be sprayed, and the lock bolt 4 can be buried in the order of the natural ground M where the spraying is completed, and the above-described effects can be obtained.

  In the above-described embodiment, the excavation is performed after the excavation is completed. However, the excavator 1 and the excavator 2 are juxtaposed with each other at the time of mechanical excavation. It is possible to remove the gap at the same time.

  As described above, the tunnel excavation method according to the present invention is useful for the tunnel excavation method using a free-section excavator, and in particular, improves the excavation efficiency by the parallel operation by improving the efficiency of transition between the processes. be able to.

It is a tunnel cross-section front view of the tunnel excavation method according to the present invention. It is a tunnel section top view of the tunnel excavation method concerning the present invention. It is a tunnel cross section side view of the tunnel excavation method concerning the present invention. It is a tunnel cross-sectional top view which shows a tunnel excavation procedure. It is a tunnel cross section side view which shows a tunnel excavation procedure. It is a tunnel cross-sectional top view which shows a tunnel excavation procedure. It is a tunnel cross section side view which shows a tunnel excavation procedure. It is a tunnel cross-sectional top view which shows a tunnel excavation procedure. It is a tunnel cross-sectional top view which shows a tunnel excavation procedure. It is a tunnel cross-sectional top view which shows a tunnel excavation procedure. It is a tunnel cross section front view which shows a tunnel excavation procedure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Free-section excavator 1a Excavation part 1b Cutting drum part 2 Sludge machine 2a Boom 2b Bucket 2c Conveyor 3 Covering concrete 4 Rock bolt A Left half part Aa Lower left half part Ab Upper left half part B Right half part Ba Right lower half part Bb Upper right half G Ground K Face face L Bench length L1, L2, L3, L4 Excavation length M Ground mountain S Center line

Claims (2)

Applicable to tunnels divided into two divisions in the width direction ,
A drilling step of drilling by the drilling machine in a state where the lower half portion always the divided sections is positioned on the near side with respect to the upper half portion, muck step of issuing shear by shearing the product machine excavated earth and sand produced by the excavation process A tunnel excavation method that repeatedly carries out
The excavation process includes
The excavator is carried alternately into the two divided sections , the excavator loaded in each divided section is placed on the ground of the lower half, and the upper half is excavated after excavating the lower half,
The slipping step is
Carrying out the excavator and carrying it into a vacant divided section , and carrying out the slotting machine when the excavator is operating in at least one of the divided sections A tunnel excavation method characterized in that it operates so as to include a timing at which it is simultaneously shifted in a section . The slipping step is performed by a slipping machine including a bucket for scraping excavated sediment in front and a conveyor for transporting excavated sediment trapped in the bucket to the rear. Tunnel excavation method.

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