JPS6151089B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an invert slide formwork apparatus.

In tunnel construction, in order to prevent the ground from collapsing, it is necessary to construct a structural support that can mechanically resist earth pressure as soon as possible after excavation.

If the lining is left in an unstable state for a long period of time, because the bottom is the last to be lined, side wall earth pressure may act before the bottom has developed its strength, causing a ``plate bulge'' phenomenon. It is necessary to complete the lining as soon as possible.

By the way, conventional forms (end plates) for invert concrete (floor concrete) have the following problems.

<B> In conventional tunnels, approximately 50 cm of inverted concrete is first poured, and all temporary vehicles run on top of it.

The final finished concrete is poured on top of the inverted concrete that was poured several months earlier.

<B> Inverted concrete has been neglected in the past because it can be used as a simple partition plate.

However, in reality, there were problems such as maintaining accurate height and dealing with reinforcing bars that penetrated the cross section of the end plate.

What's more, every time concrete was poured, new gable boards were being processed.

Therefore, the work of assembling the formwork is complicated, and the efficiency of the framework is low.

<C> Furthermore, when forming drainage grooves in the center or sides of the invert, the finished height and the ease of erecting the formwork are required.

The present invention has been made to improve the above-mentioned problems, and an object of the present invention is to provide an invert slide formwork device that has excellent formwork operability and workability and can provide high pouring accuracy.

Next, an embodiment of the present invention will be described. First, each part of the apparatus according to the present invention will be described.

[B] Overall description As shown in FIG. 1, the invert slide formwork device 1 of the present invention includes a pedestal 2, a end plate 3 provided on the excavated side (hereinafter referred to as "front") of the pedestal 2,
It consists of a running section that runs on rails 11 and a braking section that is placed on the existing invert.

[B] Frame The pedestal 2 is composed of two longitudinal girders 21 arranged in parallel in the longitudinal direction of the tunnel, and a transverse girder 22 that connects the longitudinal girders 21 in the cross-sectional direction of the tunnel.

The total length of the longitudinal girder 21 is made to be at least slightly longer than the casting distance for one span of inverted concrete, since the pedestal 2 slides in the excavation direction.

[C] Running part A telescopic running jack 5 is attached to the front end of the longitudinal girder 21 so as to face the floor, and a support roller 51 that runs on the rail 11 laid on the floor ground is provided at the tip of the running jack 5. .

A rotating arm 6 is rotatably supported at the rear end of the longitudinal girder 21, and a guide roller 61 is provided at the tip of the rotating arm 6.
will be established.

That is, the invert slide formwork device 1 is configured to be able to travel with the rotating arm 6 and the traveling jack 5 supporting the invert slide formwork device 1.

[D] Braking section A stopper 4 is provided on the rotary arm 6 side (hereinafter referred to as "rear") of the longitudinal girder 21 so as to protrude toward the floor surface.

The entire length of the stopper 4 is formed to be shorter than that of the rotating arm 6, so that the stopper 4 can support the invert slide formwork device 1 in place of the rotating arm 6 when pouring invert concrete as described later. When the invert slide formwork device 1 is supported by the stopper 4, the lower surface of the stopper 4 is engaged with the existing invert surface, and movement of the invert slide formwork device 1 can be prevented.

Note that it is also possible to configure the stopper 4 to be extendable and retractable.

In this case, the level of the pedestal 2 can be easily determined.

[E] End plate A end plate 3 is arranged in front of the invert slide formwork device 1 in the tunnel crossing direction.

The end plate 3 is a vertical plate attached to the transverse girder 22 that communicates with the longitudinal girder 21 in the transverse direction.

Therefore, when the pedestal 2 is slid, the pedestal 2
It will move together with the.

When placing inverted concrete, it is necessary to expose the reinforcing bars 82 from the end plate 3 in the excavation direction.

Therefore, for example, as shown in FIG.
The end plate 3 is formed to a size that allows the reinforcing bars 82 to protrude from the lower surface, and furthermore, a cross member 3 is provided on the front outer surface of the end plate 3.
1 are attached at some intervals, and the space between the end plate 3 and the cross member 31 is divided into small sections in the vertical direction.

The open space below the end plate 3 can be blocked by inserting the narrow plate body 32 into these small sections at a position where it does not collide with the reinforcing bars 82 and fixing it with a camber 33.

[F] Groove formwork The groove formwork 7 is used when forming, for example, a water collection groove or a drainage groove on the invert surface.

The groove formwork 7 is a continuous formwork with a U-shaped cross section as shown in FIG.

Next, the construction method will be explained [a] Preparation for extraction (Figure 2) A tunnel is excavated using a known excavation method, and the excavated soil is transported outside the tunnel.

After completing one span of excavation, a new invert A
A rail 11 is laid on the floor surface in the casting range, and the invert slide formwork device 1 is pulled out.

That is, the rotating arm 6 of the invert slide formwork device 1 is opened and supported on the existing invert B, and at the same time, the traveling jack 5 is extended to levitate the invert slide formwork device 1 and move it by a distance of one span in the excavation direction. do.

The rail 11 is not buried, but when the invert slide formwork device 1 is moved, the rail 11 is moved in the excavation direction and reused.

Anchor bolts and sprayed concrete are then applied to the entire area of the ground to form an arch-shaped primary lining.

[B] Installation of the formwork (Fig. 3) To cast the invert, the rotating arm 6 of the invert slide formwork device 1 is folded, and the stopper 4 is landed on the existing invert B.

Further, on both sides of the end plate 3, as shown in FIG. 1, auxiliary formwork 9 made of narrow reinforcing plates is arranged in parallel with the longitudinal girder 21.

The purpose of this auxiliary formwork 9 is to form the corner of the invert to be cast into an inclined surface to prevent the joint part from slipping with the side wall.

[C] Invert pouring After completing the installation of the invert slide formwork device 1, pour concrete.

At this time, by aligning the finished surface of the poured concrete with the upper edge of the end plate 3 and the upper edge of the groove formwork 7, an accurate finished surface can be easily obtained.

As a result, a track slab 8 having a groove 81 in the center is formed on the floor surface.

[D] Demoulding and movement After the curing period has elapsed, the rotating arms 6 are expanded, and at the same time the traveling jacks 5 are extended to peel off all the formwork from the track slab 8.

The peeling work can be completed with a simple operation of floating the invert slide formwork device 1, so it does not require much effort.

The floating invert slide formwork device 1 is moved in the excavation direction to successively place invert concrete.

Since the present invention is as explained above, the following effects can be expected.

<B> Unlike conventional methods, temporary invert concrete is not poured, and the finished surface is constructed in one step, allowing transport vehicles to run on top of it, resulting in better troughability.

<B> Since the formwork is formed integrally with the pedestal and the pedestal is configured to be movable, the formwork can be moved and installed quickly, and work efficiency can be improved.

<C> Since the level is determined from multiple locations (end plate, upper edge of groove formwork, etc.), the finished surface of invert concrete (top surface of track slab) can be formed accurately.

<d> There is no longer a need to manufacture gable boards, place reinforcements, and align them with the ground excavation surface each time concrete is poured.

<E> Since the invert corner can be formed on a precise slope surface, it becomes easy to set the formwork for lining the side wall.

<F> When using trench formwork, water collection trenches and drainage trenches can be constructed at the same time.

[Brief explanation of the drawing]

Figure 1: Explanatory diagram of one embodiment of the present invention, 2nd and 3rd
Figure: Explanatory drawing of the construction method, Figure 4: Enlarged view of the end of the end plate, Figure 5: Construction drawing of the invert concrete placement state. 1: Invert slide formwork device, 2: Frame,
3: Wife board, 4: Stopper, 5: Running jack,
6: Rotating arm.

Claims (1)

[Claims] 1. A plurality of longitudinal girders are integrally attached with one end plate in the transverse direction and a groove formwork in the longitudinal direction, and both ends of the longitudinal girders are configured to be movable. Invert slide formwork equipment.