JP2002004791A - Method of work for tunnel invert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid declines in workability and quality. SOLUTION: In the method of execution, a continuous conveyor 10, a mobile pier 12 and an auxiliary conveyor 14 are employed. The continuous conveyor 10 is extended and installed along the axial direction of a tunnel 16 to be constructed, and excavated sediment A at facing is transported to the portal side in basic configuration. The mobile pier 12 is installed in parallel to the continuous conveyor 10 by straddling above a floor slab 20b being poured and formed. The auxiliary conveyor 14 transporting the excavated sediment B of the invert is equipped with a first conveyor 14a arranged in parallel to the continuous conveyor 10, a second conveyor 14b installed between the first conveyor 14a and the continuous conveyor 10, and a self-traveling carriage 14c. The excavated sediment B at the invert is placed on the first conveyor 14a of the auxiliary conveyor 14, shifted to the continuous conveyor 10 through the second conveyor 14b and carried to the outside together with the sediment A excavated at the facing.

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 a tunnel invert, and more particularly to a method for tunnel invert suitable for excavating a face, excavating an invert, and forming a slab for closing an invert in parallel. It relates to the construction method.

[0002]

2. Description of the Related Art In a construction work of a mountain tunnel, a method of carrying out excavated earth and sand is usually carried out by a dump truck.
However, such a method of carrying excavated earth and sand has problems such as a vehicle accident and a deterioration of the working environment due to exhaust gas. In order to solve such a problem, recently, a method of carrying out excavated earth and sand using a continuous conveyor has been gradually adopted.

When constructing a tunnel at a bad mountain site, it is necessary to close the invert at an early stage in order to ensure the stability of the excavated tunnel. And the excavation of the invert and the formation of the invert-closing floor slab are performed in parallel.

In such an invert construction method, conventionally, as shown in FIG. 8, for example, as shown in FIG. 8, a movable pier 2 is erected above a floor slab 1 to be cast and formed, and heavy machinery before and after the pier 2 is installed. The movement of the concrete mixer truck was secured.

In FIG. 8, a portion indicated by reference numeral 3 is a continuous conveyor, and the continuous conveyor 3 has its tip extending along the axial direction of the tunnel 4 to be constructed near the cutting face. Used for unloading face excavated soil.

[0006] The continuous conveyor 3 is installed at one end of the tunnel 4 in the width direction, and is designed to avoid conflict with various tunnel construction operations.

The moving pier 2 is arranged in parallel with the continuous conveyor 3, and excavation of the invert is performed by a backhoe 5 or the like in front of the front end side thereof. However, such a conventional invert construction method has the following problems.

[0008]

That is, if the moving pier 2 is installed in parallel with the continuous conveyor 3, they conflict with each other and the workability is deteriorated. Was.

However, in such a method of carrying out the earth and sand, the dump truck 6 and the concrete mixer truck run on the road surface of the invert, and the deterioration of the trafficability, the muddy road surface, and the decrease in the strength of the invert base are caused. Therefore, there is a concern that the workability may deteriorate or the quality may deteriorate.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a tunnel invert construction method capable of avoiding a decrease in workability and quality. Is to provide.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a continuous conveyor for cutting face excavated earth and sand along the axial direction of a tunnel to be constructed and at the widthwise end of the tunnel. Is installed, and a movable pier movable along the tunnel axis is installed substantially in parallel with the continuous conveyor, and in parallel with excavation of a face, excavation of an invert is provided in front of the movable pier and below the movable pier. In the construction method of a tunnel invert for casting and forming an invert closing floor slab, an auxiliary conveyor for transferring invert excavated earth and sand to the continuous conveyor is installed in front of the moving pier, and the invert excavated earth and sand is carried out by the continuous conveyor. I did it. According to the construction method of the tunnel invert configured as described above, an auxiliary conveyor for transferring the invert excavated earth and sand is installed in front of the moving pier, and the invert excavated earth and sand is carried out by the continuous conveyor through the auxiliary conveyor. The invert excavated earth and sand can be carried out together with the face excavated earth and sand by a continuous conveyer without a dump truck or a mixer truck traveling on the inverted roadbed surface, so that a decrease in workability and a decrease in quality can be avoided. The continuous conveyor can be installed at a position under which the excavation of the invert and the formation of the invert-closing floor slab can be performed. According to this configuration, it is possible to effectively use the sediment discharge effect of the continuous conveyor while avoiding competition with the invar operation. The moving pier has a flip-up ramp in the front-rear direction, and can invert excavate a lower portion thereof by flipping up a front ramp installed on the face side. According to this configuration, the excavation position of the invert can be brought close to the casting position of the floor slab, and the invert can be closed in a short time after the excavation of the invert. Safety can be improved. The auxiliary conveyor is arranged in parallel with the continuous conveyor, and transfers the inverted excavated earth and sand upward from below, and transfers the inverted excavated earth and sand received from the first conveyor to the continuous conveyor. And a second conveyor. According to this configuration, even when the continuous conveyor is installed at a high position in order to avoid competition with the invar operation, the invert excavated earth and sand can be easily transferred to the continuous conveyor. The auxiliary conveyor includes a self-propelled movable cart, and the first and second conveyors can be mounted on the cart so as to be pivotable.
According to this configuration, the invert excavated earth and sand can be efficiently carried out while the auxiliary conveyor moves by itself in accordance with the progress of the tunnel construction, and the position of the auxiliary conveyor and the continuous conveyor can be easily adjusted.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 7 show an embodiment of a tunnel invert construction method according to the present invention.

In the construction method shown in FIG. 1, a continuous conveyor 10, a moving pier 12, and an auxiliary conveyor 14 are used as shown in FIG. The continuous conveyor 10 has one end located in the vicinity of the face and the other end extending to the entrance, along the axial direction of the tunnel 16 to be constructed, and conveys the face excavated earth A toward the entrance. Has a basic configuration.

The continuous conveyor 10 is located on one end side in the width direction of the tunnel 16 and, as shown in FIG. 3 to FIG. Below the continuous conveyor 10, excavation of an invert and formation of an invert-closed floor slab 20, which will be described later, can be performed.

That is, in the case of the present embodiment, the continuous conveyor 10 is installed at a high position via the suspension stand 18 in order to avoid conflict with the inverting work, and the invert excavation with a backhoe or the like described later is performed. Care is taken to make it possible.

The height of the continuous conveyor 10 in this embodiment is slightly higher than the upper surface of the main frame 12a of the moving pier 12.

The construction method of the invert shown in FIG. 1 is, for example, a method adopted in a place where the properties of the ground are poor, and excavation of the face, excavation of the invert, and placement of the invert-closed floor slab 20. The formation is performed in parallel.

In FIG. 1, the hatch-side portion indicated by oblique lines is the already formed floor slab 20a, and the front side thereof is the floor slab 20b being formed by casting using the formwork 22. I have. As shown in detail in FIGS. 3 to 5, the invert-closed floor slab 20 is formed so as to connect the lower ends of the lining portions 24 formed on the excavated wall surface after excavation of the face. Since the cross section of the tunnel 16 is closed by the formation, the shape stability of the tunnel 16 is ensured.

The moving pier 12 is provided with a floor slab 20b during casting.
Is installed in parallel with the continuous conveyor 10 so as to straddle the upper part of the conveyor. Details of the installation state of the movable pier 12 used in this embodiment are shown in FIGS.

The movable pier 12 shown in these figures has a main frame 12a and a flip-up front and rear ramp section 1 which is swingably connected to the front and rear ends of the main frame 12a.
2b and 12c.

The main body frame 12a is formed in a slender rectangular shape, and is provided with elastic legs 12d at four corners on the lower surface thereof. In addition, each of these legs 1
An extendable traveling wheel 12e is arranged on the inner side of 2d so as to be close to each leg 12d.

Further, a cylinder 12f for lifting the front and rear ramps 12b and 12c is provided above the front and rear ends of the main body frame 12a. According to the movable pier 12 configured as described above, each leg 12d is contracted, the lower end is separated from the ground contact surface, and the cylinder 12
When the traveling wheel 12e is landed in a state in which the front and rear inclined road portions 12b and 12c are lifted by f, the traveling wheel 12
The traveling pier 12 can be moved along the axial direction of the tunnel 16 by the traveling drive of e.

After moving to an arbitrary position, each leg 12d is extended, its lower end surface is landed, and the traveling wheel 12e is contracted, so that the moving pier 12 is fixed at that position. Can.

When the front and rear ramps 12b and 12c are suspended in this fixed state, as shown by the imaginary line in FIG.
It becomes possible to ride on the main body frame 12a via the 2c.

In FIG. 2, the leg 12d on the rear side of the main body frame 12a is settled on the existing floor slab 20a, and the leg 12d on the front side is settled on the excavated portion of the invert. The main body frame 12a is fixed to the upper side of the floor slab 20b being cast by using the frame 20.

On the other hand, as shown in FIGS. 6 and 7, the auxiliary conveyor 14 for transferring the inverted excavated sediment B is shown in FIGS.
First conveyor 14 arranged in parallel with continuous conveyor 10
a, a second conveyor 14 b provided between the first conveyor 14 a and the continuous conveyor 10, and a traveling carriage 14 c which can move freely.

The first conveyor 14a has a frame 140a
And the conveyor body 14 attached to the frame 140a
1a and inverted excavated soil B on the conveyor body 141a.
Hopper 142a for feeding the feeder, and a conveyor body 141
and a discharge hopper 143a for receiving the earth and sand B from the second conveyor 14a and discharging the same to the second conveyor 14b.

The frame 140a of the first conveyor 14a
Is on a swivel 14e mounted on the traveling vehicle 14c,
The excavated earth and sand B, which is supported in an inclined state via the support frame 14d and is input from the input hopper 142a on the lower end side, is transported upward.

The second conveyor 14b has a frame 140b
And a conveyor body 141b.
Are supported horizontally by the support frame 14d.

The second conveyor 14b has a discharge hopper 143
The inverted excavated earth and sand B discharged from a is received at one end of the conveyor body 141b, transferred to the other end of the conveyor body 141b, and dropped downward from the edge.

The falling position of the excavated sediment B is on the conveying surface of the continuous conveyer 10, and corresponding to the dropped position, as shown in FIG. Receiving hopper 26 that receives B while preventing scattering of B and discharges it to continuous conveyor 10 is detachably installed.

To enable the smooth transfer of the excavated earth and sand B, the conveyor main body 1 of the second conveyor 14b is required.
In this embodiment, since the second conveyor 14b is supported by the swivel 14e of the traveling vehicle 14c, it is necessary to align the position of the traveling vehicle 14c with the receiving hopper 26. It can be easily performed by combining the turning with the turning table 14e.

Now, the continuous conveyor 1 constructed as described above.
0, the moving pier 12, and the auxiliary conveyor 14 are used to construct the invert in parallel with the excavation of the face.
Before the formation of the slab, the excavation of the invert portion is performed, and thereafter, the step of placing and forming the floor slab 20 on the sequentially excavated portion is repeated toward the face side.

For this excavation, for example, as shown in FIGS. 1 and 2, a ground excavator such as a backhoe 28 is used. It is put into the conveyor 14a and the second
It is transferred to the continuous conveyor 10 via the conveyor 14b,
It is carried out together with the excavated earth A.

When excavating the invert, as shown in FIGS. 1 and 2, the front ramp section 12b of the moving pier 12 is maintained in a state of being flipped upward by driving a cylinder 12f. It is desirable to be able to excavate just before 12a.

When the invert is excavated in such a state, the excavation can be performed at a position close to the floor slab 20b being formed using the formwork 22. Can be shortened during the formation of.

That is, this embodiment shown in FIG. 1 and FIG.
As apparent from comparison with the conventional invert construction shown in FIG. 1, in the case of FIG.
The length of the point b at which the material is cast is significantly shorter than that of the conventional method.

This means that in the case of the present embodiment, it is possible to form the invert closing slab 20 necessary for securing the stability of the tunnel 16 in a short time after excavation. In particular, the method is suitable for construction on a bad ground.

According to the construction method of the tunnel invert constructed as described above, the auxiliary conveyor 14 for transferring the invert excavated sediment B is installed in front of the movable pier 12, and the invert excavated sediment B is used to cut the excavated sediment A. Together with the continuous conveyor 10, it is possible to prevent a dump truck or a mixer truck from traveling on an inverted roadbed, and as a result, it is possible to avoid a decrease in workability and a decrease in quality.

In the case of the present embodiment, the continuous conveyor 10 is installed below it so that the invert can be excavated and the invert closing floor slab 20 can be formed. Conveyor 1 while avoiding
0 can effectively utilize the sediment transport effect.

Further, in the case of the present embodiment, the auxiliary conveyor 14 is arranged in parallel with the continuous conveyor 10, and the first conveyor for moving the inverted excavated earth B from below to above.
A conveyor 14a and a second conveyor for transferring the inverted excavated earth and sand B received from the first conveyor 14a to the continuous conveyor 10.
Since it is configured with the conveyor 14b, the continuous conveyor 1 provided at a high position to avoid conflict with the inverting operation
At 0, the invert excavated earth and sand B can be easily transferred.

In this embodiment, the auxiliary conveyor 14
Is equipped with a truck 14c which can move freely, and this truck 14c
Since the first and second conveyors 14a and 14b are rotatably mounted on the vehicle, the inverted excavated earth and sand B can be efficiently carried out while the auxiliary conveyor 14 moves by itself as the tunnel construction progresses. The positioning with the continuous conveyor 10 can be easily performed.

In the above embodiment, the moving pier 12 is
Although the one that can move in the axial direction of the tunnel 16 is illustrated,
The present invention can be used even if it can be moved in the width direction.

[0044]

As described above in detail, according to the method for constructing a tunnel invert according to the present invention, it is possible to avoid a decrease in workability and a decrease in quality.

[Brief description of the drawings]

1A and 1B are a side view and a top view, respectively, showing a construction state of a tunnel invert according to an embodiment of the present invention.

FIG. 2 is an enlarged detailed view of a main part of FIG. 1 (B).

FIG. 3 is a view as viewed from arrows A and B in FIG. 2;

FIG. 4 is a view as seen from arrows C and D in FIG. 2;

FIG. 5 is a view as viewed from arrows E and F in FIG. 2;

FIG. 6 is an enlarged view of a main part of the auxiliary conveyor of FIG. 1;

FIG. 7 is a side view of FIG. 6;

8A and 8B are a side view and a top view of a construction state showing an example of a conventional tunnel invert construction method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Continuous conveyor 12 Moving pier 14 Auxiliary conveyor 14a 1st conveyor 14b 2nd conveyor 14c Moving trolley 14d Revolving base 16 Tunnel 18 Suspension 20 Floor slab 20a Existing slab 20b Floating slab A Cut face excavated soil B Invert excavated earth

Claims (5)

[Claims] 1. A moving pier which can be moved along the tunnel axis by installing a continuous conveyor for carrying excavated earth and sand along the axial direction of the tunnel to be constructed and at the widthwise end of the tunnel. A method of installing a tunnel invert that is installed substantially parallel to a continuous conveyor and, in parallel with excavation of a face, excavates an invert in front of the moving pier and casts an invert closing slab below the moving pier. The method for constructing a tunnel invert according to any one of claims 1 to 3, wherein an auxiliary conveyor for transferring inverted excavated earth and sand to the continuous conveyor is installed in front of the moving pier, and the invert excavated earth and sand is carried out by the continuous conveyor. 2. The tunnel invert construction method according to claim 1, wherein the continuous conveyor is installed at a position below the continuous conveyor where excavation of the invert and formation of a slab for closing the invert can be performed. . 3. The moving pier has a ramp-up type ramp in the front-rear direction, and performs upside-down excavation of a lower portion thereof by flipping up a front ramp installed on a face side. The method for constructing a tunnel invert according to claim 1. 4. The auxiliary conveyor is disposed in parallel with the continuous conveyor, and transfers the invert excavated earth and sand from below to above, and the invert excavated earth and sand received from the first conveyor. The tunnel invert construction method according to any one of claims 1 to 3, further comprising a second conveyor for transferring to the continuous conveyor. 5. The auxiliary conveyor according to claim 1, wherein the auxiliary conveyor includes a trolley that can move freely, and the first and second conveyors are rotatably mounted on the trolley. Construction method of tunnel invert.