JPH0642296A - Concrete placing device for tunnel lining - Google Patents

Abstract

PURPOSE:To make it possible to hold uncured concrete directly after it is placed and promptly assemble reinforcement in a succeeding process and prevent the concrete placed outside a cylinder-shaped inner side form from leaking out to a weir structure side. CONSTITUTION:Cylinder-shaped inner side forms are formed one after another near a working face of a tunnel to be excavated with an excavator 1 and lining concrete is consecutively placed outside an inner side form 4 in the longitudinal direction of the tunnel by means of a sliding concrete placing pipe 28. There is laid out a weir structural body which provides an outer peripheral grip ring 13 and a middle grip ring 12 and an inner peripheral grip ring 11 inside a skin plate 2 of the excavation in such a fashion that this placed concrete may be pushed backward. There is laid out a ring-shaped rubber seal material, which holds this weir structural body with a gripper holding device 7 against the push force produced by the placed concrete and provides a slit which allows reinforcing bars to pass through, but does not allow the concrete to pass through.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel lining for holding the cast concrete and preventing it from leaking out from the concrete placing space when assembling the reinforcing bars and placing the concrete. Related to concrete pouring equipment.

[0002]

2. Description of the Related Art In recent years, a so-called direct-cast concrete lining method has been widely used in shield tunnels. This direct-cast concrete lining method is
It is known as a construction method for speeding up construction and labor saving, and without constructing an expensive and complicated assembly segment, assemble the inner formwork at the tail part of the excavator at the same time as excavating the shield excavator, You can directly place lining concrete,
For this reason, there is an advantage that the lining concrete can be quickly installed and that water stoppage and structural weakness can be eliminated since no joints are generated. In addition, a pressure plate that plays the role of a gable form is pushed out to the tail void side by a pressure jack, etc., and the concrete that has not solidified in the form is pressed, and this concrete is promoted while filling it with the ground. There is also an advantage that back filling injection is not required. By the way, when the cast concrete is unreinforced, unlike the segments, the concrete ring cannot bear the tensile force, so that the primary lining concrete is often made of a reinforced concrete structure. in this case,
In order to speed up the construction, a plurality of arc-shaped rebar cages assembled in advance in a cage shape are placed on the outer periphery of the inner formwork and held in place with a metal object etc., after which concrete placing is performed. .

When the concrete is placed,
The propelling jack moves the excavator forward, and the pressure jack presses the unconsolidated concrete to fill the tail void generated behind the excavator, and the pressure plate of this pressure jack shrinks for the next process. I am trying. Further, if there is pressurized groundwater on the ground side, this groundwater may flow into the formwork, causing unconsolidated concrete to flow back to the excavator side. In order to prevent backflow of this concrete, generally, a pressure plate is left as a formwork for a predetermined time until the concrete hardens to a certain degree, or an early strengthening agent is added to the concrete, or it is dehydrated to achieve early self-sustaining property. There is.

[0004]

However, in the concrete placing device described above, it is necessary to press and support the concrete surface with the pressure plate until it hardens even if the early strengthening agent is added or even if the dehydration is intended. During this time, there was a problem that the process was delayed because it could not move on to the next work such as the building of the reinforcing steel cage.

An object of the present invention is to solve the problems of the above-mentioned conventional techniques, to hold concrete that has not solidified yet immediately after pouring, and to promptly perform the rebar assembling work in the next step. It is an object of the present invention to provide a concrete lining device for tunnel lining in which concrete cast on the outside of the tubular inner formwork does not leak to the weir structure side.

[0006]

A concrete placing device for tunnel lining according to the present invention sequentially forms a tubular inner form near a face of a tunnel excavated by an excavator, and is slidable in the axial direction of the tunnel. The lining concrete is sequentially placed on the outside of the inner formwork by the concrete placing pipe, and this placing concrete is pushed backward, and inside the skin plate of the excavator, the outer circumference grip ring and the intermediate grip unit and the inside A weir structure equipped with a perimeter grip ring is arranged, and this weir structure is held by a gripper holding device against the pressing force of the cast concrete, and the rebar is passed through the cast concrete side of this weir structure. It is configured by arranging an annular rubber seal provided with a slit that does not let concrete pass through.

[0007]

In the concrete lining device for tunnel lining of the present invention, the weir structure arranged inside the skin plate of the excavator is held by the gripper holding device at the end of the cylindrical inner formwork. , It is possible to hold the unconsolidated concrete immediately after pouring and to quickly perform the work of assembling the rebar in the next step, and the slit that opens only when the rebar passes through the annular rubber seal provided on the pouring concrete side of the weir structure. By forming the, the concrete cast into the cylindrical inner formwork does not leak into the chamber on the weir structure side.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a concrete lining device for tunnel lining according to the present invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 1 indicates a shield excavator 1, a skin plate 2 forming an outer shell of the shield excavator 1 has a cylindrical shape, and a front portion of the skin plate 2 rotates to excavate the ground. A disk-shaped cutter 3 is attached. A blade (not shown) is arranged on the front surface of the cutter 3. In addition, the tip of the cylindrical inner formwork 4 is inserted into the tail portion inside the skin plate 2.
The inner mold 4 is formed by assembling a plurality of arc-shaped molds with an unillustrated erector device or the like. The pressure plate 5 is in contact with the end surface of the inner mold 4 on the skin plate 2 side. This pressure plate 5 is a shield propulsion jack 6
Is held by the rod 6a. The shield propelling jack 6 propels the shield excavator 1 forward as the face of the cutter 3 is excavated. The propulsion stroke amount of the propulsion jack 6 is such that the inner formwork 4 can be built.

On the other hand, on the gripper holding device 7 fixed to the excavator 1, the inner pressure jack 8, the intermediate pressure jack 9 and the outer pressure jack 10 having a long stroke are arranged at equal intervals in the circumferential direction. Has been done. Further, on the outside of the inner form frame 4 that has entered the tail portion of the skin plate 2, an inner circumference grip ring 11 and an intermediate grip ring 12 are provided.
A weir structure 14 including the outer peripheral grip ring 13 is arranged. The inner grip ring 11 of the weir structure 14 is fixed to the outer surface of the inner mold 4 via a gripper 15, and the outer grip ring 13 is gripper 16.
The intermediate grip ring 12 is fixed to the inner surface of the skin plate 2 via the grippers 17 and 18 and the inner grip ring 11 and the outer grip ring 13 via the grippers 17 and 18. The intermediate grip ring 12 has a ring shape as a whole by combining a plurality of arc-shaped ring pieces. Then, the inner grip ring 11 and the intermediate grip ring 1
The outer peripheral grip ring 2 and the outer peripheral grip ring 13 are supported by the inner pressure jack 8, the intermediate pressure jack 9 and the outer pressure jack 10 which are arranged correspondingly. Each of the above grippers is operated by a hydraulic jack or a pneumatic jack (not shown).

On the other hand, the existing concrete 1 of the weir structure 14
A reinforcing bar cage 20 is arranged on the 9th side. As shown in FIG. 3, the reinforcing bar cage 20 is formed of vertical reinforcing bars 21, horizontal reinforcing bars 22, and reinforcing bar fixing fittings 23. A slit rubber plate 24 made of hard rubber is arranged on the surface of the weir structure 14 on the side of the existing concrete 19. The slit rubber plate 24 has a ring-shaped overall shape, and the tail end 25 is formed by bending the inner end. The tail seal portion 25 contacts the outer surface of the inner mold 4 and
It prevents the concrete from leaking between the tail seal portion 25 and the inner formwork 4. In addition, the slit rubber plate 24,
Slits 27 through which the vertical reinforcing bars 21 and the horizontal reinforcing bars 22 of the reinforcing bar cage 20 are inserted are formed at a predetermined pitch.

Further, at a predetermined position of the outer circumference grip ring 13, a tip of a concrete placing pipe 28 is extended through a through hole (not shown). This concrete placing pipe 28 is a substantially U-shaped steel pipe for supplying fresh concrete into the formwork, and is slidably attached to the tip of a concrete carrying pipe 29 connected to a concrete supply source such as a concrete pump (not shown) behind the tunnel. Connected in a state of being movably inserted, concrete is sequentially supplied to the form 4 through the concrete placing pipe 28. The concrete placing pipe 28 can be moved in the axial direction of the tunnel, and the state where the discharge port is slightly projected from the outer peripheral grip ring 13 is maintained during concrete placing.
The discharge port of the concrete placing pipe 28 can be housed in the outer peripheral grip ring 13 and closed when the concrete is pressurized. In this state, the already poured concrete which has not solidified yet can be pressed backward to fill the tail void generated between the ground and the ground.

Reference numeral 30 in FIG. 3 denotes a connecting fitting which is attached to the end portion of the vertical reinforcing bar 21 of the reinforcing bar car 20.

The operation will be described below.

FIG. 4 shows a concrete pouring completion state,
The inner circumference grip ring 11, the middle grip ring 12 and the outer circumference grip ring 13 of the weir structure 14 are pressed by the inner pressure jack 8, the middle pressure jack 9 and the outer pressure jack 10 of the gripper holding device 7 against the pressure of the lining concrete. Held against. The end of the vertical reinforcing bar 21 of the reinforcing bar cage 20 provided on the side of the poured concrete 19 extends to the gripper holder 7 side through the slit of the hard rubber slit rubber plate 24 provided on the dam structure 14.

Next, as shown in FIG. 5, the gripper 15 provided on the inner peripheral grip ring 11 is fixedly contacted with the outer surface of the inner form frame 4, and the gripper 16 provided on the outer peripheral grip ring 13 is attached to the skin plate 2. The gripper 17 provided on the intermediate grip ring 12 is connected to the inner peripheral grip ring 11, and the gripper 18 provided on the intermediate grip ring 12 is connected to the outer peripheral grip ring 13.
Thereby, the dam structure 14 is fixed at a predetermined position with respect to the skin plate 2 and the inner mold 4. Weir structure 14
When is fixed, the gripper holding device 7 is separated from the weir structure 14, and the gripper holding device 7 and the pressure plate 5 are moved to a position where a space for building a reinforcing bar cage is formed. Then, the rebar cage 20 assembled in this space in an evenly divided state is built into the rebar cage 2
The vertical reinforcing bar 21 of 0 is joined to the vertical reinforcing bar 21 of the existing reinforcing bar cage 20 through the connecting fitting 30. In this rebar building, the outer rebar frame and the inner rebar frame are built in sequence,
It is also possible to make it integrated by a width stop reinforcing bar or the like.

When the rebar cage 20 is assembled and connected, as shown in FIG. 6, the inner pressure jack 8, the intermediate pressure jack 9 and the outer pressure jack 10 of the gripper holding device 7 are placed in the weir structure 14. Circumference grip ring 11,
Intermediate grip ring 12 and outer grip ring 13
And assemble the inner formwork 4 into the existing inner formwork 4,
The inner mold 4 is pressed and supported by the pressure plate 5. Then, the concrete outlet of the concrete placing pipe 28 is projected into the formwork, and the placing space is filled with concrete from this outlet.

Next, as shown in FIG. 7, in order to gradually expand the concrete placing space, the concrete placing pipe 23 and the pressure jacks 8, 9 and 10 are retracted in synchronization with each other in accordance with the filling state. , Placing one set of inner formwork. After the concrete is placed, the inner pressure jack 8, the intermediate pressure jack 9, and the outer pressure jack 10 are pressure-extended, and the propulsion jack is extended to propel the excavator 1. At this time, in order to replenish the concrete filled in the tail void at the time of passage, the concrete pouring pipe 2
It is also possible to extend 8 again and fill it with concrete.

In the above embodiment, the inner pressure jack 8, the intermediate pressure jack 9 and the outer pressure jack 10 provided on the gripper holding device 7 are used to form the inner peripheral grip ring 11 and the intermediate grip ring 12 of the dam structure 14. And the outer peripheral grip ring 13 is supported, but the inner pressure jack 8 and the outer pressure jack 10 are annular bodies,
Of course, the intermediate pressure jack 9 may be a comb-shaped body.

[0019]

As is clear from the above description, according to the present invention, it is possible to quickly carry out the work of assembling the rebar in the next step while holding the concrete which has not solidified yet immediately after pouring. Concrete poured into the tubular inner formwork will not leak to the weir structure side. Moreover, even if the lining thickness is non-uniform, no additional formwork is required, which allows a tunnel with a homogeneous concrete structure to be quickly constructed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a concrete placing device according to the present invention.

FIG. 2 is a cross-sectional diagram of the concrete pouring device shown in FIG.

3 is a partially enlarged cross-sectional view of the concrete placing device shown in FIG.

FIG. 4 is a diagram showing a first stage of construction by the concrete placing device according to the present invention.

FIG. 5 is a diagram showing a second stage of construction by the concrete placing device according to the present invention.

FIG. 6 is a diagram showing a third stage of construction by the concrete placing device according to the present invention.

FIG. 7 is a diagram showing a fourth stage of construction by the concrete placing device according to the present invention.

[Explanation of symbols]

 1 Shield Excavator 2 Skin Plate 4 Inner Form 5 Pressure Plate 7 Gripper Holding Device 8 Inner Pressure Jack 9 Intermediate Pressure Jack 10 Outer Pressure Jack 11 Inner Grip Ring 12 Intermediate Grip Ring 13 Outer Grip Ring 14 Weir Structure 20 Reinforcing cage 28 Concrete placing pipe

Claims (1)

[Claims] 1. A cylindrical inner formwork is sequentially formed in the vicinity of a face of a tunnel to be excavated by an excavator, and a lining concrete is sequentially placed on the outer side of the inner formwork by a concrete placing pipe slidable in the tunnel axial direction. In the concrete lining device for tunnel lining, which is installed and presses the poured concrete backward, a weir equipped with an outer grip ring, an intermediate grip unit and an inner grip ring inside the skin plate of the excavator. A structure is arranged, and this weir structure is held by a gripper holding device against the pressing force of the cast concrete, and a slit is provided on the cast concrete side of this weir structure, through which the reinforcing bars pass but the concrete does not pass. A concrete pouring device for tunnel linings, which is equipped with an annular rubber seal.