JP3072573B2 - Direct hit shield lining 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 method for constructing direct-cast concrete lining by a shield method.

[0002]

2. Description of the Related Art In a conventional direct-cast shield lining method, there is a method in which lining concrete poured into a formwork space of the method is densely filled by pressing with a press ring which can be freely advanced and retracted on its wife side. The press ring is provided with a sealing material such as an O-ring on the inner and outer circumferences of the press ring to prevent the cement paste from flowing out and to maintain the fluidity of the concrete.

There is also known a method in which a drain portion is provided in a press ring or a formwork to spontaneously dehydrate excess water of cast concrete.

[0004]

In the conventional lining method described above, dewatering efficiency is poor in natural dewatering, and a press ring is sealed to maintain the fluidity of concrete.
There were problems such as difficulty in independence of the lining concrete wife.

[0005]

According to the present invention, in order to solve the above-mentioned conventional problems, a porous drain material 10 is adhered to the surface of a pressurizing face plate 3a having air permeability, and a hollow chamber 11 is formed on the back surface. A plurality of water-permeable dewatering holes 15 are provided inside the lining space 6 between the press ring 3 provided with the lining and the preceding lining concrete 5, and a formwork 8 provided with a hollow chamber 16 on the inner surface is provided. After the concrete 5 ′ is cast into the lining space 6, compressed air is pumped into the hollow chamber 11 of the press ring 3, and the cast concrete 5 ′ is pressurized by the compressed air and the pressing force of the press ring 3. Thereafter, the press ring 3 and the hollow chambers 11 and 16 of the mold 8 are evacuated,
The present invention proposes a direct-cast shield lining method in which surplus water of the cast concrete 5 'is sucked and dehydrated through the drain material 10 and the dewatering hole 15 of the formwork.

[0006]

When the concrete 5 ′ is pressed by the press ring 3, compressed air is introduced into the hollow chamber 11 of the press ring 3 to maintain the fluidity, and the concrete 5 ′ is poured into the concrete 5 ′ via the drain material 10. By applying pressure,
The fluidity of the concrete 5 'becomes better, and a solid filling is ensured.

Then, before the pressurization by the press ring 3, the air in the press ring 3 and the hollow chambers 11 and 16 of the mold frame 8 is suctioned by vacuum using a vacuum pump, and the excess water of the concrete 5 'is efficiently dehydrated at once. As a result, the concrete 5 'is compacted in a short period of time and with sufficient independence of the wife.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An annular press frame 4 having an L-shaped cross section is mounted on an inner periphery of a tail portion of a shield main body 1 on which an annular press ring 3 which moves forward and backward by a jack 2 is attached. After arranging the reinforcing bars 7 in the lining space 6 between the concrete 5 and the concrete 5, the inner form 8 is assembled in a ring shape.

The press ring 3 has a pressing face plate 3 at its tip.
a, a through hole 9 communicating between the front and rear surfaces is formed in the pressing face plate 3.
A porous drain material 10 that allows water and air to pass therethrough and blocks solids is attached to the surface of a, and a hollow chamber 11 is formed on the back side of the pressing face plate 3a.
An air hose 12 connected to a vacuum pump and an air supply pump is connected to the hollow chamber 11.

Further, elastic seals 13 and 14 such as O-rings are mounted on the inner and outer peripheral surfaces of the press ring 3 so as to seal the inner surface of the shield body 1 and the sliding contact surface with the press frame 4 in a watertight manner. Have been.

The inner mold 8 is provided with a number of slits 15 on its peripheral surface and baking porous ceramics into the inside thereof. And a hollow chamber 16 is formed on the inner surface side. A vacuum hose 17 connected to a vacuum pump is connected to the hollow chamber 16.

After the inner mold 8 is installed as described above, the cast-in-place concrete 5 ′ is injected into the lining space 6 from an injection hole provided in the inner mold 8 or the like, and the jack 2 is filled as shown in FIG.
The press ring 3 is moved forward, and compressed air is introduced into the hollow chamber 11 from the air supply pump through the air hose 12 to apply the air pressure transmitted through the through-hole 9 and the drain material 10 to remove the concrete 5 ′. Apply even pressure to give fluidity.

After pressurizing by the press ring 3 for a required time, as shown in FIG. 2, the air in the hollow chambers 11 and 16 of the press ring 3 and the inner mold 8 is moved by a vacuum pump through an air hose 12 and a vacuum hose 17. Is sucked in vacuum, and the excess water in the concrete 5 ′ is forcibly dewatered through the drain material 10 and the slit 13.

After the concrete 5 'has been cured for a required time, the press frame 4 is removed, and the press frame 4 is moved forward to sequentially repeat the same steps as described above.

[0015]

As described above, according to the present invention, dewatering is forcibly performed by vacuum suction from the press ring and the inner mold, so that dewatering can be reliably and efficiently performed in a short time to improve the quality of concrete and lining. In addition to ensuring the independence of the concrete wedge, the seal material seals between the press ring, the shield body and the press frame, and compressed air is introduced into the hollow part of the press ring to pneumatically apply the lining concrete. Since the concrete can be pressurized, the fluidity of the concrete can be increased, the concrete can be more densely filled, and the pressurizing time of the press ring can be shortened.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional side view showing one embodiment of a construction step of the present invention.

FIG. 2 is a partial vertical sectional side view showing another embodiment of the construction process of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield main body 2 Jack 3 Press ring 3a Pressing face plate 4 Press frame 5 Preceding lining concrete 5 'Lining concrete 6 Lining space 7 Reinforcing bar 8 Inner frame 9 Through hole 10 Drain material 11 Hollow chamber 12 Air hose 13 Sealing material 14 Sealing material 15 Slit 16 Hollow chamber 17 Vacuum hose

Claims (1)

(57) [Claims] 1. A porous drain material is adhered to the surface of a pressurizing face plate having air permeability, and the inside of a lining space between a press ring having a hollow chamber on the back surface and a preceding lining concrete. Providing a plurality of dewatering holes having water permeability, and installing a formwork provided with a hollow chamber on the inner surface, placing concrete in the lining space, and then pressing compressed air into the hollow chamber of the press ring. The pressurized concrete is pressurized by the compressed air and the pressing force of the press ring. Thereafter, the hollow space of the press ring and the mold is evacuated, and the casting is performed through the drain material of the press ring and the dewatering hole of the mold. A direct-shield shield lining method characterized by absorbing and dewatering excess water from concrete.