JPH0359235B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a manhole in a shield pit, in which a horizontal hole is excavated underground and its peripheral wall is reinforced with segments.

The conventional technique for constructing a manhole for a shield shaft is to excavate a shaft from the road surface toward the underground shield shaft. However, with such conventional technology, various machines for excavation must be placed on the road and the excavated soil must be transported to the ground, which creates a significant obstacle to road traffic and imposes various restrictions on construction work. As a result, there are problems such as longer construction periods and higher construction costs.

In view of the above-mentioned problems, it is an object of the present invention to provide a method for constructing a manhole that can minimize the amount of construction from the ground.

That is, the present invention embeds a segment having a manhole opening closed by a removable lid at a predetermined location, and then supports the lid by a support means installed within the segment and surrounds the support means. The divided wall plates for forming the circumferential wall of the manhole arranged in the manhole are combined to form a cylinder, and the cylindrical manhole peripheral wall is pushed between the manhole opening and the lid, and is pushed upwards of the segment by an appropriate pushing means. After pushing up into the ground, the cylindrical manhole surrounding wall, which is joined with the dividing wall plate for forming the next surrounding wall, is connected to the lower end of the previously pushed up manhole surrounding wall, and the process of pushing it up is repeated. After bringing the manhole surrounding wall close to the ground, removing the soil within the manhole surrounding wall, and bringing the manhole surrounding wall close to the ground,
This method is characterized by constructing a hole cover part on the ground.

The details of this inventive construction method will be explained below based on an embodiment shown in the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an ordinary segment fixed by means such as press-fitting into a horizontal hole formed underground using the shield construction method, and in the illustrated example, it has a cylindrical shape made of concrete.

2 is a special segment used for the human hole formation part,
It is made of steel, and has an opening 3 for a manhole in the upper part, and this opening 3 is closed with a lid 4.

Annular gaskets 5 and 6 are fixed to the inner periphery of the opening 3 and the outer periphery of the lid 4, respectively.
6 is crimped so as not to create a gap to prevent muddy water from flowing in.

8 is a ring that fixes the lid 4 to the segment 2;
This lid 4 is divided into two parts and is fixed to the segment 2 with a plurality of bolts 9.

In addition, an appropriate reinforcing chemical solution is injected into the ground 11 at the bottom of the horizontal shaft where the segment 2 is to be installed to increase the bearing capacity of the ground 11. In addition, a plurality of grout injection holes 10 are provided in the segment 2 near the outer periphery of the opening 3 at the top, so that the ground near the outer periphery of the opening 3 can be reinforced if necessary. Once the segment 2 is in place, the base 1 is placed on the bottom of the segment directly below the opening 3 as shown in FIG.
2 is placed on the base, and a center cylinder 13 as a supporting means is fixed on this base.

This center cylinder 13 is used to raise and lower a support base 14 using, for example, hydraulic pressure.The support base 14 supports the lid 4, and after the support base 14 and the lid 4 are connected together with bolts or the like, the support base 14 is moved up and down using hydraulic pressure. Remove 8.

If the lid 4 is left in this state for a long time until the start of the next operation, the lid 4 is supported by an appropriate stopper member 15 to maintain safety.

Next, as shown in FIG. 3, a plurality of push-up cylinders 16 as push-up means are arranged on the base 12. This push-up cylinder 16 pushes up the push-up member 1 by hydraulic pressure or the like.
7 is raised and lowered, and the circumferential wall 18 of the manhole is placed on top of it. This peripheral wall 18 has a cylindrical shape, but it surrounds the center cylinder 13 as shown in FIG. 10 by having a plurality of semicircular dividing wall plates 19 made of steel plates or the like, and the adjacent edges of each dividing wall plate are It is welded 20 to form a cylindrical shape.

After forming the peripheral wall 18 in this way and placing it on each member 17, each cylinder 16 is expanded to form the peripheral wall 18.
is raised, and its upper end is pushed between the inner and outer packings 5 and 6 as shown in Fig. 4, and the space between the two packings 5 and 6 is widened and pushed up into the ground. At this time, the gaskets 5 and 6 prevent underground water from flowing into the segment 5, and the lid 4 is fixed to the support base 14 to prevent the lid 4 from rising.

After pushing up the first circumferential wall 18 sufficiently in this way, each push-up cylinder 16 is retracted, and the next circumferential wall 18 is formed on the push-up cylinder 16 as shown in FIG.
After welding 21 the lower end of the first peripheral wall 18 and the upper end of the next peripheral wall 18, each push-up cylinder 16 is extended and pushed up as shown in FIG.

By repeating the above operations, the connected peripheral wall 1
8 is being pushed up into the ground above the segment 2, but during the pushing up, it is always measured whether the peripheral wall 18 is rising vertically or not, and if it is tilting, the pushing cylinder Correct the slope by changing the position.

When the upper end of the surrounding wall 18 reaches the groundwater level or higher, the supporting stand 14 is lowered as shown in FIG. Break up the earth and sand, let it fall downward, and discharge it appropriately.

In this operation, if stones or the like are clogged inside the peripheral wall 18 and cannot be removed by spraying alone, the spraying is stopped and the stones or the like are removed by other appropriate means. On the other hand, on the ground, the position of the upper end of the peripheral wall 18 is calculated by surveying, and a temporary lining board 23 is constructed at the planned location as shown in FIG. This construction will be carried out in an extremely short period of time, during the night when there is the least amount of traffic.

After pushing the surrounding wall 18 up close to the lining plate in this way, the lining plate 23 is removed and the upper end of the surrounding wall 18 is opened while regulating traffic at night when the traffic is at its lowest, as shown in Figure 9. The upper part of the manhole is constructed to form a manhole surrounding frame 24 made of concrete, and this surrounding frame 24 is closed with a removable manhole cover 25.

On the other hand, at the lower end, the lower end of the peripheral wall 18 and the segment 2 are integrally connected by welding a ring plate 26, etc., and a fixed ramp 2 is provided in the peripheral wall 18.
7 is attached, and a removable storage ramp 28 is installed.
will be established.

In the above construction method, the properties of the ground above and below the segment 2 vary widely, and the resistance to the pushing up of the peripheral wall 18 also varies widely.

Therefore, due to the difference in the balance between ground resistance and pressing force, there is a risk that the ground may swell up in shallow areas.

For this purpose, as shown in FIGS. 11 and 12, a plurality of injection nozzles 30 for injecting high-pressure water or high-pressure air are provided at the tip of the leading peripheral wall 18 in an obliquely inward direction, and communication holes communicating with the nozzles 30 are provided. 31 is provided on each peripheral wall 18, and a gasket 3 is provided at the joint of each peripheral wall 18.
2 and a convex part 34 that fits into the concave part 33, which allows the passage through the communication hole 31, and injects high-pressure water or high-pressure air from the nozzle 30 through the communication hole 31 to reduce ground resistance. What is necessary is to push up the peripheral wall 18 while doing so.

However, if the ground collapses too much due to water injection, etc., there is a risk of ground subsidence, so it is necessary to always consider the balance between uplift force and ground resistance during construction.

As mentioned above, in this invented construction method, the shaft for the manhole is formed from the underground shield shaft side, and the only work above ground is the final stage of construction, which is the construction of the entrance and exit for the manhole on the road surface. For most of the period, there will be no impact on road traffic. In addition, since the earth and sand produced by excavation is carried out along with the earth and sand produced by the shield method, it can be carried out efficiently, and there are no traffic restrictions, so compared to above-ground construction, the construction period is shortened and construction costs are reduced. effective.

[Brief explanation of drawings]

Figures 1 to 9 are longitudinal cross-sectional side views showing one embodiment of the construction method of this invention, and Figure 10 is Figure 3A-
FIG. 11 is a cross-sectional plan view taken along line A, FIG. 11 is a perspective view of the dividing wall, and FIG. 12 is an enlarged longitudinal sectional view. 2...Segment, 3...Manhole opening, 4...
Lid, 13...center cylinder as support means for the lid, 16...push-up cylinder as push-up means,
18... Peripheral wall for manhole, 19... Divided wall plate, 25...
…Human hole cover.

Claims (1)

[Claims] 1. In a method of constructing an underground mine using the shield method, a segment with a manhole opening closed with a removable lid is buried at a predetermined location, and then,
The lid is supported by support means installed within this segment, and dividing wall plates for forming the circumferential wall of the manhole, which are arranged so as to surround this support means, are combined to form a cylindrical shape, and the manhole becomes cylindrical. After pushing the circumferential wall between the manhole opening and the lid and pushing it up into the ground above the segment using an appropriate pushing means, the cylindrical manhole circumferential wall to which the dividing wall plate for forming the next circumferential wall is connected is assembled. , connect to the lower end of the manhole surrounding wall that was pushed up earlier, and repeat the process of pushing it up to make the manhole surrounding wall reach near the ground, remove the soil inside the manhole surrounding wall, and raise the manhole surrounding wall to near the ground. A method of constructing a manhole, which is characterized by constructing a manhole cover in the ground after the construction is completed.