JPS60238529A - Manhole construction work - Google Patents

Abstract

PURPOSE:To construct a manhole without interruption with road traffic by a method in which excavation is made by means of water jet while pushing up an excavation cylinder and a manhole wall by a pusher from an opening for manhole provided in the segment constructed by a shield construction work. CONSTITUTION:A manhole opening 3 is provided in the segment constructed by shield construction work and a cover 4 is detachably provided to the opening 3. An excavation cylinder 22 is provided to the downside of the cover 4 and inserted into the aperture between the cover 4 and the segment 2 by a pusher 27. The manhole wall 29 is connected to the lower end of the cylinder 22, and while pushing up them by the pusher 27, the ground in the cylinder 22 is degraded by water jet and discharged from the outlet 14 of the cover 4. The manhole wall 29 is reached to the ground's surface by the same procedure to construct the cover of the manhole. The manhole can be constructed without interruption with road traffic.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application This 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.

(2) Conventional technology The conventional technology for constructing a manhole for a shield shaft is to excavate a shaft from the road surface toward the underground shield shaft.

(3) Problems to be solved by the invention In the conventional technology as described above, various machines for excavation must be placed on the road and the excavated soil must be carried out to the ground, which causes a significant obstruction to road traffic. Since there are various restrictions on construction, there are problems such as longer construction periods and higher costs per construction.

(4) Means for Solving the Problems In order to solve the above problems, the present invention embeds a segment having a manhole opening closed by a removable lid at a predetermined location, and then this lid An excavation cylinder is placed at the bottom of the segment, and the excavation cylinder is pushed between the manhole opening and the lid, and is pushed up into the ground above the segment by an appropriate pushing means. Connect to the bottom end of and push up.
After that, the lower end of the upper large hole surrounding wall is connected to the upper end of the next manhole surrounding wall, and the process of pushing up is repeated, and the ground inside and above the excavation cylinder is collapsed by means such as water injection, and this collapsed sand is excavated. After the discharge is discharged from the discharge port of the lid which rises together with the cylinder and the manhole surrounding wall reaches near the ground level, the manhole cover part on the ground is constructed.

(5) Operation: An underground shaft is constructed using the well-known shield construction method, but special segments such as steel, which are different from ordinary concrete segments, are buried in the locations where manholes are planned. This segment has a manhole opening closed by a removable lid. First, a drilling tube is placed at the bottom of this lid, and the drilling tube is pushed between the manhole opening and the lid, and then It is pushed up into the ground above the segment by means of pushing up.

Next, a manhole circumferential wall having a cylindrical shape or the like having the same diameter as the excavation tube is connected to the lower end of the excavation tube and pushed up, and then the upper end of the manhole circumference wall corresponding to the lower end of the upper manhole circumference wall is connected and pushed up.

By repeating the above process, the connected peripheral wall is pushed up with the excavation tube at the top, but at this time, the ground inside and above the excavation tube is collapsed by means such as water injection - this collapsed earth and sand is It is discharged from the discharge port of the lid which rises together with the excavation tube.

In this way, the excavation tube is pushed up to the ground level, and after the excavation tube is removed, an artificial lid opening on one side of the ground is constructed.

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

Reference numeral 2 denotes a special segment used for the manhole forming part, which is made of one steel, and an opening 3 for the manhole is provided in the upper part, and this opening 3 is closed with a lid 4.

Annular gaskets 5 and 6 are attached to the grooves formed on the inner periphery of the opening 3 and the outer periphery of the lid 4, respectively, and these gaskets 5 and 6 are crimped together to prevent muddy water, etc. from forming. Preventing influx.

Reference numeral 8 denotes a ring for fixing the lid 4 to the segment 2, which is divided into two parts, and the lid 4 is fixed to a downward protrusion 10 on the periphery of the opening 3 of the segment 2 with a plurality of bolts 9.

In addition, an injection nozzle 11 for water, etc., a discharge port 12 for muddy water, a discharge port 13 for stones, etc. are provided at appropriate locations on the lid 4, a valve 14 is provided for the discharge port 12, and a removable lid 15 is provided for the discharge port 13. .

In addition, an appropriate reinforcing chemical solution is injected into the ground 18 at the bottom of the horizontal shaft where the segment 2 is to be installed to increase the bearing capacity of the ground 18. In addition, a plurality of grout injection holes 19 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 21 is placed on the bottom of the segment directly below the opening 3, as shown in FIG. Next, we will use strong materials such as steel pipes.
+ After placing the 11-section eccentric 9-section base 91 on the base 91, a telescopic support 23 is erected in the center as a support means. Cylinder type lever - Extend this to support the lid 4 as shown in Figure 2.

First, as shown in FIG. 3, a plurality of lifting jigs 25 such as small chain blocks are fixed to the upper part of the segment 2. The push-up cylinder 27 is attached to the base 2
Place it on top of 1. This push-up cylinder 27 is used to move a push-up member 28 up and down using hydraulic pressure or the like, and the excavation tube 22 is placed on it.

Thereafter, each cylinder 27 is expanded and contracted to raise the excavation tube 22, and its upper end is attached to the inner and outer gaskets 5 and 6 as shown in FIG.
Push it in between and push it up into the ground while pushing out the space between the two padskin 5.6. At this time, the seals 5 and 6 prevent groundwater from flowing into the segment 2.

After pushing up the excavation cylinder 22 sufficiently in this way, each push-up cylinder 27 is retracted and the next cylindrical peripheral wall 2 is pushed up as shown in FIG.
9 is placed on the push-up cylinder 27, the lower end of one excavation tube 22 is engaged with the upper end of the next peripheral wall 29, and each push-up cylinder 16 is extended again and pushed up as shown in FIG.

By repeating the above operations, a plurality of connected peripheral walls 29
is being pushed up against the ground above segment 2, but -
A ramp 30 is already provided on the inner periphery of each peripheral wall 29.

In the above work, as shown in Fig. 5, the push-up cylinder 27
When retracted, there is a risk that the excavation tube 22 will fall together with the lid 4 due to the earth pressure applied to the lid 4 inside the excavation tube 22.

To prevent this, a downward protrusion 10 as shown in FIG.
A braking band 16 is installed in a groove on the inner circumference of the protrusion 10 by a plurality of setscrews 17 screwed into a plurality of screw holes provided in one protrusion 10. By pressing this braking band 16 and tightening the excavation cylinder 22, the excavation tube 22 is stopped. After preventing this, the cylinder 27 is retracted. The braking band 16 is also used as appropriate during the process of pushing down the peripheral wall 29 one after another.

As shown in FIG. 11, the upper end of the excavation cylinder 22 has a knife hole, which has a plurality of injection holes 31 for high-pressure water and high-pressure air.
A high pressure hose 34 is connected to the lower end of this communication hole 32.

As shown in FIG.
5 is provided on the outer periphery of the upper end of the peripheral wall 29 at the lower end thereof, and a recess 36 is provided in which the projecting edge 35 engages, and the engagement between the two connects the excavation tube 22 and the peripheral wall 27. The joints have a similar structure, and appropriate gaskets are attached to these joints.

There is a receiving edge 38 on the inner periphery of the lower end of the excavation tube 22.
As the lid 4 rises, the receiving edge 38 engages with the peripheral edge of the lid 4 and pushes it up, causing it to rise together.

Therefore, as described above, while pushing up the excavation tube 22, high pressure water is ejected from each jet hole 31 to collapse the soil above the excavation tube 22 and reduce the resistance of the soil to the excavation tube 22 rising.

The muddy water generated by the collapse of the soil is discharged into the segment 2 by opening the valve 14, and the discharged sewage is appropriately treated by a mud pump (not shown).

During this mud removal, if the muddy water outlet 12 is clogged with stones or the like mixed in the muddy water, the lid 15 is removed and the muddy water is appropriately removed from the discharge port 13.

Further, as shown in FIG. 7, a plurality of support pieces 39 fixed to the receiving edge 38 of the excavation tube 22 and a plurality of support pieces 40 fixed to the inner side of the surrounding wall 29 are connected by a plurality of direction correction jacks 41. It is connected.

Therefore, as mentioned above, during the work of pushing up the excavation tube 22 and the surrounding wall 29 following it, measurements are always taken using an inclinometer to understand the errors in the -X and Y directions, and the direction correction jack is adjusted accordingly. 41 to correct the direction of the excavation tube 22.

On the other hand, on the ground, the position of the upper end of the excavation tube 22 is calculated by surveying, and a temporary lining board 43 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.

In this way, the excavation tube 22 is pushed up close to the lining plate 43, and while regulating traffic during the lowest traffic hours of the night, the lining plate 43 is removed, and the entire excavation tube 22 is pushed up to the ground. 22. Remove the jack 41 for one-way correction of the lid 4 and reinstall the lining plate 43 so as not to interfere with daytime traffic. When the nighttime traffic volume decreases again, the traffic is regulated - the lining plate 43 is removed again, the upper end of the peripheral wall 29 is opened, and the upper part of the manhole is constructed with concrete etc. as shown in Figure 9. A hole circumferential frame 44 is formed and this circumferential frame 44 is closed by a removable manhole cover 45.

On the other hand, at the lower end, the lower end of the peripheral wall 29 and the segment 2
are integrally connected by welding a ring plate 46 or the like, and furthermore, a removable storage ramp 47 is provided.

In the ground where the above construction method is applied, as shown in the graph in Figure 12, if we take the depth (■4) on the vertical axis and the tonosho (P) on the horizontal axis, the downward pressure due to the gravity of the ground, that is, the active earth pressure, is a line. (I), and when upward pressure is applied in opposition to this active earth pressure, the pressure when the ground starts to move upward due to this pressure, that is, the passive pressure becomes line (II), and this line (
The range of I) and (II) is the static earth pressure range.

Therefore, when the excavation cylinder 22 is pushed up, if the pushing force applied to the ground above it is greater than the line (TI), the ground will be pushed down and the ground will be raised. Further, if the supporting capacity of the ground directly above the excavation tube 22 becomes lower than the range of line (1) due to collapse of the ground due to water injection from the injection nozzle 11 or the injection hole 31, a cave-in occurs and the ground caves in.

Therefore, the geology of the ground where the manhole is planned to be constructed should be investigated in advance by drilling, etc., and a pressure gauge 50 should be installed at a suitable location within the excavation pipe 22 to constantly measure the earth pressure - this earth pressure is measured by the line () shown in Fig. 12. T) Excavation pipe 22 before going on JJ
Stop pushing up the excavation tube 22 and increase the water injection to lower the earth pressure. Also, before the earth pressure falls below line (1), stop the water injection and push up the excavation tube 22. Therefore, care must be taken to ensure that the construction work can be carried out without adversely affecting the ground.

In the embodiment, one end of the excavation cylinder is shaped like a knife and is provided with an injection hole for high-pressure water, but a rotating excavation blade may also be provided in this part.

(7) Effects As mentioned above, in this invention method, the hole for the manhole is formed from the bottom of the shield in the ground, and the only work above ground is the construction of the entrance and exit for the manhole on the road surface, which is the final stage of construction. Therefore, there will be no impact on road traffic during most of the construction period. In addition, since the earth and sand produced by excavation are carried out together with the earth and sand produced by the shield method, it can be carried out efficiently.
Since there are no traffic restrictions, the construction period is significantly shorter than above-ground construction, and construction costs are also reduced. Furthermore, the lower end of the excavation tube at the top is closed with a lid, and the muddy water generated inside the excavation tube is discharged from the outlet provided in this lid, so that the earth and sand inside the excavation tube will fall all at once during construction work. There is no risk of posing a danger to the Leeshield, which has caused the ground to cave in. By controlling the discharge of muddy water from the excavated earth and the pushing up of the excavation tube, construction can proceed without adversely affecting the ground. .

[Brief explanation of the drawing]

Figures 1 to 9 are longitudinal sectional side views of each process showing an embodiment of the first method of the present invention, Figure 10 is an enlarged vertical sectional view with a partial cutout of the brake hand tightening section, and Figure 11 is a cross-sectional view of the excavation tube. FIG. 12, an enlarged vertical cross-sectional view of a portion, shows the range of static pressure. 2 Sekume: / 1-13・Opening for human hole, 4 Lid-1
1 injection nozzle, 12 sewage discharge port, 14 valve, 21 base, 22 excavation tube, 27. Push as two means -
Cylinder, 29 peripheral wall - 31 injection hole - 45 manhole cover. Patent applicant Fudo Construction Co., Ltd. Agent Kama 1) Sentence 2 (H) ↓ Figure 12 (P)

Claims (1)

[Claims] In a method of constructing an underground mine using the shield method, a segment having a manhole opening closed with a removable lid is buried at a predetermined location, and then an excavation tube is placed under the lid. It is pushed between the opening for the manhole and the lid and pushed up into the ground above the segment using a suitable pushing means, and then the surrounding wall of the manhole is connected to the lower end of the excavation cylinder and pushed up, and then the manhole in the upper part is pushed up. The lower end of the surrounding wall is connected to the upper end of the next manhole surrounding wall, and the process of pushing it up is repeated, and the ground inside and above the excavation tube is collapsed by means such as water injection, and this collapsed earth and sand rises together with the excavation tube. A manhole construction method characterized in that the manhole is discharged from the discharge port of the lid, the manhole surrounding wall is made to reach near the ground, and then a manhole cover part on one ground is constructed.