JPS5945072B2 - Concrete placement method for vertical underground penstock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a concrete IJ-casting method for a vertical underground penstock.

For example, as shown in FIG. 1, a penstock 3 is installed in an underground power station 2 installed in a ground 1, and rolled concrete 4 is placed between the penstock 3 and the ground 1. Therefore, it is a vertical underground penstock.

In this case, the rolled concrete 4 has conventionally been constructed using a packet or shoot method.

By the way, as shown in FIG. 2A, the penstocks 3 are suspended by the crane device 5 and stacked as shown in FIG.
Then, in a cycle consisting of iron pipe installation and concrete pouring, rolled concrete 4 is placed between the piled up penstock 3 and the ground 1 via a packet 6 as shown in Fig. 2C. For construction methods that are repeated, the above-mentioned pouring method can be used.

However, as shown in Fig. 3, all of the penstocks 3 are first installed via the iron pipe support frame 7, etc., and if the construction method involves pouring concrete 1 later, the following problems arise. There is.

A In the case of the packet method, the clearance between the penstock 3 and the ground 1 is narrow (generally 600u+ or less), so the packet capacity becomes small and the laying capacity decreases.

B In the case of the chute method, it is necessary to raise the discharge port to the concrete 1 as the concrete placement surface rises, so it is necessary to move the entire chute equipment or remove the chute near the discharge port.

In the present invention, a penstock is installed in advance in a shaft formed in the ground, a seal plate is provided at the lower end, a chute pipe is arranged between the penstock and the ground, and the chute pipe is Concrete discharge ports are provided at predetermined intervals in the vertical direction, and each concrete discharge port is closed by a lid body.
In this state, a predetermined amount of concrete is poured into the chute pipe, and the lid of the lowest concrete discharge port of the exposed concrete discharge port group is opened to discharge the concrete in the chute pipe. The present invention provides a method for placing concrete for a vertical shaft-type underground penstock, which is characterized by repeating the following steps: By changing the discharge position of the concrete discharge port according to the concrete discharge position, it is possible to eliminate the need for moving equipment or the work of workers at the concrete pouring position each time the concrete pouring surface rises.
Furthermore, even if the concrete falls over a long distance, the concrete falls within the sealed chute pipe, resulting in less separation.

Hereinafter, one embodiment of the present invention will be described based on FIGS. 4 to 9.

In FIG. 4, reference numeral 10 denotes a vertical shaft formed in the ground 11, into which a penstock 13 and the like are installed in advance via an iron pipe support 12 and the like.

A seal plate 14 is arranged on the iron pipe support frame 12,
Therefore, the lower end of the shaft 10 is closed.

In the shaft 10, a chute pipe 15 is disposed between the penstock 13 and the ground 11 over the entire length in the vertical direction, and the upper end of the chute pipe 15 communicates with a hopper 17 via a shutter 16. There is.

As shown in FIGS. 4 to 6, the chute pipe 15 has concrete discharge ports 18 at predetermined intervals in the vertical direction, and each of these concrete discharge ports 18 is closed by a lid 19.

That is, the lower end of the lid body 19 is supported on the chute tube 15 side via the hinge 20, and the upper end is supported on the chute tube 15 side.
It is held down by a presser foot 21 from the side.

A backing 22 is provided between the lid body 19 and the chute pipe 15 so as to surround the concrete discharge port 18,
Further, gunpowder 23 is provided between the lid body 19 and the presser foot 21.

24 indicates an ignition line.

As shown in FIG. 4, first, a chute pipe 15 is installed in parallel with the installation of the penstock 13.

At this time, all the lids 19 close the concrete discharge ports 18 as shown in FIGS. 5 and 6.

Concrete 25 is first put into the hopper 17 in a closed state, and then passes through a lock chamber formed by a set of shutters 16 and is transferred one block at a time to the chute tube 15 in a sealed state.
Fall inside.

As shown in FIG. 7, an amount of concrete ■2 corresponding to the rolled concrete amount ■1 is charged into the chute pipe 15.

In this way, a predetermined amount of concrete 2 is placed inside the chute pipe 15.
5, the presser foot 21 holding down the lowest lid 19 of the exposed lids (i.e., concrete discharge ports) group is destroyed using gunpowder 23.

The gunpowder 23 is ignited from an ignition line 24 that is routed up to the vicinity of the upper charging section.

If the presser foot 21 is destroyed, the lid body 19 will be removed from the chute tube 1.
5 is opened by the pressure of the concrete 25 inside, and the concrete 25 is discharged.

As a result, as shown in FIG. 8, the concrete 25 flows out onto the outer surface of the penstock 13 and is poured.

Next, a predetermined amount of concrete 25 in the chute pipe 15 has flowed out, and it is determined whether or not the opened concrete discharge port 18 is buried in the concrete 25 using a placement height measuring device 26 using ultrasonic waves.

Then, as shown in FIG. 9, similarly to the previous cycle, concrete ■2 corresponding to the rolled concrete amount ■1 is poured into the chute pipe 15.

At this time, since the concrete discharge port 18 opened in the previous cycle is in the concrete 25, the chute pipe 15
is in a sealed state.

After that, the concrete discharge port 18 in the second stage from the bottom is opened, and concrete 25 is poured.

According to the above-mentioned method of the present invention, since it is a chute method, the placing ability can be improved.

Furthermore, since the discharge position of the concrete discharge port can be changed depending on the pouring condition, it is not necessary to move the equipment each time the concrete pouring surface is raised or to perform work by a worker at the pouring position.

Furthermore, even if the concrete falls over a long distance, the concrete falls within the sealed chute pipe, resulting in less separation.

[Brief explanation of the drawing]

Figure 1 is a longitudinal front view showing the state after concrete pouring, Figures 2 a-c are longitudinal front views showing the general method of installing iron pipes, and Figure 3
The figure is a vertical front view showing a construction method in which iron pipes are installed first, Figures 4 to 9 show an embodiment of the present invention, Figure 4 is a vertical front view before concrete placement, and Figure 5 is a main view. FIG. 6 is a longitudinal sectional side view of the unit, and FIGS. 7 to 9 are longitudinal sectional front views showing working conditions. 10... vertical shaft, 11... ground, 13.
... Penstock, 14 ... Seal plate, 15
... Chute tube, 11 ... Hopper,
18... Concrete discharge port, 19...
- Lid body, 25... concrete.

Claims (1)

[Claims] 1. A penstock is installed in advance in a shaft formed in the ground, a seal plate is provided at the lower end, and a chute pipe is arranged between the penstock and the ground, and this chute pipe is vertically Concrete is discharged at predetermined intervals, and each concrete discharge port is closed with a lid, and in this state, a predetermined amount of concrete is poured into the chute pipe, and the exposed concrete discharge port group is A method for placing concrete in a vertical underground penstock, which is characterized by repeatedly opening the lid of the lowest concrete outlet and discharging concrete from the chute pipe.