JPH0768848B2 - Tunnel construction method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tunnel construction method capable of improving the work efficiency of tunnel excavation work.

b. Conventional technology In the tunnel construction, the ground will be improved prior to this construction. In this case, prior to the excavation work, as shown in FIGS. 5 and 6, the operation rod of the drilling machine is operated along the tunnel outer circumference planned line L, and the column-shaped pile is formed on the tunnel outer circumference planned line L. 100 are continuously molded. This pile 100 is obtained by injecting a ground hardening material from the tip of an operation rod and impregnating the ground hardening material in the depth direction of the target ground to harden the ground. Next, after strengthening the excavated surface,
The boring machine is moved forward, and the operating rod is operated again along the planned line L for the outer circumference of the tunnel.

Thus, as shown in FIG. 7, the pile 100 by the columnar stirring unit is
Are sequentially formed in the depth direction of the tunnel. Then, the portion 101 (indicated by diagonal lines) protruding to the inside of the tunnel outer circumference schedule L is scraped off, and cement is sprayed on the inner surface of the tunnel to form the foundation work of the tunnel construction. As related prior arts, JP-A 1-137094 and JP-A 2-252891
There is a gazette.

c. Problem to be Solved by the Invention However, in the conventional construction method as described above, it is necessary to scrape off the pile protruding inside the tunnel outer peripheral planned line L, resulting in a decrease in work efficiency. Further, in the past, since small-diameter piles were continuously formed, it took a long time to form the piles.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, improve the work efficiency, and provide a tunnel construction method capable of efficiently discharging muddy water and the like during pile forming.

d. Means for Solving the Problems In order to solve the above problems, the present invention operates an operation rod of a boring machine in a depth direction of the ground at predetermined intervals along a tunnel outer circumference planned line of the ground to be excavated by the tunnel. Then, the ground hardening material is jetted from the jetting portion provided at the tip of the operating rod to form a continuous wall of the columnar stirring section along the tunnel outer peripheral planned line, and the inside of these columnar stirring sections is excavated to form the tunnel hole. A method for constructing a tunnel to be formed, in which a ground hardening material is supplied to the operation rod using a high-pressure pump, and the operation rod of the hole drilling machine is sequentially operated at predetermined intervals along the tunnel outer peripheral planned line. Is rotated within a range of a predetermined angle outside the planned tunnel outer circumference line to form a large-diameter, substantially semi-circular columnar stirring section, and the ends of these columnar stirrers correspond to the tunnel outer circumference planned line. Only to form a substantially semicircular columnar stirring portion on the outside of the tunnel periphery planned line not to enter on the side, is to build a tunnel drilled inside the ground of the tunnel periphery scheduled line.

Further, in order to solve the above problems, the present invention provides the operation rod of the boring machine with a passage for discharging air and muddy water in addition to the passage of the ground hardening material, and through this passage, the muddy water at the time of forming the columnar stirring portion is provided. It is to discharge.

e. Operation Tunnel Prior to this construction, the operation rod of the hole drilling machine is turned to a predetermined angle outside the planned tunnel outer circumference line of the ground to be excavated. The hole drilling machine rotates the operation rod to advance in the depth direction of the target ground. Next, the operation rod is rotated within a predetermined angle range to eject the ground hardening material from the ejection portion, and the operation rod is slowly pulled out. In this way, the pile of the columnar stirring portion having a substantially semicircular shape is sequentially formed only on the outer side of the tunnel outer peripheral planned line. Muddy water or air during operation of the operating rod is drained from a hole provided separately from the ground hardening material injection hole provided in the operating rod of the boring machine to form a pile having a desired shape.

f. Embodiment One embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a drilling machine and related equipment used in the tunnel construction method of the present invention.

In FIG. 1, a boring machine 1 is composed of a self-propelled base 2, a lift 3 provided on the base 2, and a boring machine body 4 mounted on the lift 3. . A ground hardening material composed of cement and an admixture is fed under pressure from an ultrahigh pressure pump 5 to the boring machine body 4. The ground hardening material is supplied to the ultra-high pressure pump 5 from a mixing plant 6 which mixes cement and an admixture.

Reference numeral 7 is a water supply tank for supplying water to the mixing plant 6. A sand pump 9 for pumping muddy water 8 discharged from an operation rod described later is provided behind the drilling machine 1, and the muddy water 8 pumped by the sand pump 9 is provided.
Is stored in the muddy water tank 10. Reference numeral 11 is a dehydrator for removing water from the muddy water 8 stored in the muddy water tank 10. The water dehydrated by the dehydrator 11 is an underwater pump.
It is collected in the neutralization treatment tank 13 by 12 and neutralized.

2 and 3 show the operating rod 14 of the boring machine body 4.

The operation rod 14 is provided with two holes 15 and 16 inside a square rod, and one hole 15 is one through which the ground hardening material is pumped and jets the ground hardening material from the nozzle 17 at the tip. The hole 16 is opened slightly downward from the position of the nozzle 17 and is used as a passage for muddy water or air. A metal crown 19 provided with a tip 18 for excavation is attached to the tip of the operation rod 14.

Next, a method of constructing a tunnel using the above device will be described with reference to FIG. Reference numeral 20 is a tunnel outer peripheral planned line, and the operating rod 14 of the hole drilling machine 1 is advanced along this tunnel outer peripheral planned line 20 to excavate. This drilling is performed by rotating a metal crown 19 provided with a tip 18 while jetting water from a nozzle 17 of an operating rod 14 with a jet. Next, the operation hardening rod 14 is moved backward and rotated within a certain angle range to inject the ground hardening material. In the ground, piles 21a, 21b, 21c, ... Of substantially semicircular columnar stirring portions are formed only on the outer side of the tunnel outer peripheral planned line 20. At this time, muddy water or the like generated in the ground is discharged to the outside from the hole 16 through the hose 22. Since the metal crown 19 is provided at the tip of the operation rod 14, the ground hardening material before solidification is prevented from flowing out from the drilled hole. Next, when the injection of the ground hardening material is completed, the hole 16 is closed, and the ground hardening material is further pressure-fed from the nozzle 17 to absorb the air pool inside the drilled hole into the ground. And operating rod 14
And the lid (not shown) instead of the metal crown 19 is pulled out and the solidification of the ground hardening material is waited. On the other hand, the boring machine 1 sequentially forms the columnar stirring section. When the semi-circular piles 21a, 21b, 21c, ... Are formed outside the planned tunnel outer circumference line 20 to a certain depth, the tunnel is dug up to the portion where the piles 21a, 21b ,. . When the wall of the part where the tunnel is dug is hardened, the semicircular piles 21a, 21 of a certain depth are again formed on the entire circumference of the planned tunnel outer circumference line 20.
Mold b, ... Then, when the piles 21a, 21b, ... Are formed, the piles are dug up to the formed portion. Since the ground hardening material is not sprayed inside the planned outer circumference line 20, it is possible to easily carry out excavation.

g. Effect of the Invention As described above, according to the tunnel construction method of the present invention, the operation rods of the boring machine are sequentially moved along the tunnel outer circumference planned line at predetermined intervals. Rotate within the range of a predetermined angle outside,
A large-diameter, substantially semi-circular columnar stirring section is formed at predetermined intervals along the tunnel outer circumference planned line, and the operation rods of the hole drilling machine are sequentially moved within a predetermined angle range outside the tunnel outer circumference planned line. By rotating the columnar stirrer with a large diameter to form a semi-circular shape, the columnar stirrer should be approximately half outside the tunnel outer circumference line so that the end of each columnar stirrer does not go inside the tunnel outer circumference line. Since the circular columnar stirring portion is formed, the excavated portion is not impregnated with the ground hardening material, so that excavation work can be easily performed.

Further, since the ground hardening material is supplied to the operation rod using a high-pressure pump, a large-diameter, substantially semicircular columnar stirring section can be formed. it can. In addition, muddy water generated in the holes during drilling work and forming the columnar stirring portion can be discharged through a passage different from the passage for the ground hardening material, so that work efficiency at the time of forming the columnar stirring portion can be improved. Furthermore, since the air pool generated inside by the injection of the ground hardening material is absorbed into the ground, the required pile shape can be obtained, and thus the desired strength can be maintained.

[Brief description of drawings]

1 to 4 show an embodiment of a tunnel construction method according to the present invention. FIG. 1 is a conceptual diagram showing a drilling machine and related equipment, and FIG. 2 is a vertical section showing an operating rod of the drilling machine. Fig. 3 is a perspective view showing the operation rod, Fig. 4 is a conceptual view showing the tunnel construction method. 5 to 7 show a conventional tunnel construction method, and FIG. 5 is a longitudinal sectional view,
FIG. 6 is a horizontal sectional view, and FIG. 7 is a vertical sectional view. 1 ... Drilling machine, 4 ... Drilling machine body, 5 ... Ultra-high pressure pump, 8 ... Muddy water, 14 ... Operation rod, 15,16 ... Hole, 17
…… Nozzle, 20 …… Planned line around the tunnel, 21a, 21b,
21c …… Pile.

Claims (2)

[Claims] 1. An operation rod of a hole drilling machine is operated in a depth direction of the ground at predetermined intervals along a planned tunnel outer circumference of the ground to be excavated by the tunnel, and the ground is ejected from a jet portion provided at the tip of the operation rod. A method of constructing a tunnel in which a hardening material is injected to form a continuous wall of columnar stirring parts along a planned line around the tunnel, and the inside of these columnar stirring parts is excavated to form a tunnel hole. While supplying the ground hardening material to the operation rod, the operation rods of the boring machine are sequentially arranged within a predetermined angle outside the tunnel outer circumference planned line at predetermined intervals along the tunnel outer circumference planned line. Rotate to form a large-diameter, roughly semi-circular columnar stirring section, and keep the ends of these columnar stirring sections outside the tunnel outer circumference planned line so that they do not enter inside the tunnel outer circumference planned line. Semicircular form a columnar stirring section, building construction method of a tunnel, characterized in that to build a tunnel drilled inside the ground of the tunnel periphery scheduled line only. 2. The operation rod of the boring machine is provided with a passage for discharging air and muddy water in addition to the passage for the ground hardening material, and muddy water at the time of forming the columnar stirring portion is discharged from this passage. The tunnel construction method according to claim (1).