JPH08199979A - Device at starting tunnel opening in pipe jacking method - Google Patents

Abstract

PURPOSE: To prevent underground water from flowing into a shaft, by attaching a metal tool fitting a cutting-off plate provided with a cutting-off plate or a reverse preventive metal tool, to the tunnel opening of a buried pipe of an earth-retaining wall and sealing the external periphery of the buried pipe. CONSTITUTION: A metal tool 1 fitting a cutting-off plate provided with a flange at the front end of a cylindrical part is attached to the periphery of the starting tunnel opening 11 of the buried pipes of an earth-retaining wall 10 and the surrounding part is fixed by concrete 8. A cutting-off material 2 made of an elastic ring-form rubber or the like, a retaining ring 3, a reverse preventive metal tool 4, a setting metal tool 5 for the retaining ring are fastened by bolts and nuts 6, 7 at the flange of the metal tool 1 fitting a cutting-off plate. A hard rubber besides a metallic material can be used for the preventive metal tool 4 against tumbling and it is kept on the setting metal tool 5 for the retaining ring. When a burying pipe 9 is jacked, the cutting-off plate 2 is set not to be turned up due to the underground water pressure or the like and the periphery of the buried pipe 9 is completely sealed. In this way, the underground water can be prevented from flowing from the starting tunnel opening into the shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting pit device for starting a front conductor and a buried pipe from the inside of a starting shaft in a propulsion method. Relates to a start pit device for preventing leakage of groundwater, earth and sand, etc.

[0002]

2. Description of the Related Art In the propulsion method, the front conductor and the buried pipe are sequentially pushed and buried by pushing the front conductor and the buried pipe from the well hole that penetrates the earth retaining wall in the front of the starting shaft. In the case of construction with a lot of soil or soft soil conditions, groundwater, earth and sand, etc. will flow into the shaft from the gap between the outer diameter of the conductor and the buried pipe and the hole of the shaft, and the ground will be submerged in the shaft, or the ground around the shaft will be submerged. It was the current situation that safe promotion construction could not be performed due to the collapse of the.

For this reason, a cylindrical water stop plate mounting metal fitting is fixed to the mine mouth portion penetrating the earth retaining wall in the front of the starting shaft, and a flange portion provided at the tip of the water stopping plate mounting metal fitting is
A device has been developed in which a ring-shaped water stop plate having a diameter smaller than the outer diameter of the buried pipe is pressed by a water stop plate press fitting and fastened with bolts and nuts. According to this device, when the front conductor or the buried pipe passes through the water stop plate, the water stop plate made of rubber is slidably contacted with the outer circumference of the front conductor or the buried pipe to seal the gap and to prevent the underground water, earth and sand, etc. In order to prevent the inflow to the vertical shaft, the number of accidents such as submersion of the vertical shaft and depression around the vertical shaft was reduced.

[0004]

With the above-mentioned conventional starting pit device, groundwater and earth and sand are blocked by the usual propulsion method, and safe propulsion construction is possible. However, in the case of soil conditions with confined water. In bad ground, the water stop plate is reversed to the vertical shaft due to the earth pressure around the buried pipe and the pressure of the pressurized water during propulsion, and the water stop plate easily separates from the outer periphery of the buried pipe due to groundwater and sediment, and ground water and earth and sand are pitted. Accidents that flow into the interior often occur.

Further, in recent years, the number of small-diameter pipe propulsion constructions has increased, and the work of pulling and correcting the lead conductor and the buried pipe has been increased in order to correct the accuracy defect of the lead conductor during propulsion. Occasionally, the water stop plate is reversed by the recoil of the leading conductor and the buried pipe and bent to the vertical shaft side. When the propulsion is restarted in this state, as mentioned above, the water stop plate loses the force of pressing the front conductor and the buried pipe, and it is easily turned up by the groundwater pressure and earth pressure during propulsion to eject into the shaft. Invite.

In order to prevent this, even if a method of minimizing the gap between the water stop plate pressing member and the outer diameter of the embedded pipe is used, the inverted water stop plate has no force to press the embedded pipe. , As it is pushed, it is easily pushed up by the earth and sand stored between the outer circumference of the buried pipe and the water stop plate, causing the water stop plate to be deformed or damaged, and creating voids around the outer circumference of the buried pipe does not prevent the inflow of groundwater or earth and sand. . In order to solve the above problems,
(EN) Provided is a starting wellhead device which does not invert even when the water stop plate of the starting wellhead device is pulled out and enables safe and reliable propulsion construction.

[0007]

Means for Solving the Problems That is, the present invention is to provide a water stop plate mounting tool in which a flange is formed at the tip of a cylindrical portion, and insertion holes for bolt insertion which are provided at equal intervals around the entire circumference of the flange. A ring-shaped water stop plate that is inserted through a bolt that penetrates through the insertion hole and abuts the flange, and a retaining ring that is inserted through the bolt and abuts the water stop plate. And a retaining ring pushing metal fitting inserted through the bolt so as to come into contact with the holding ring, and a taper or circular cross-section inversion prevention fastening metal fixed to the water stop plate side at the tip of the holding ring pushing metal fitting. It is a starting hole entrance device in the propulsion method characterized by being performed.

Steel is generally used as the metal fitting for the water stop plate, and is manufactured to have a size such that the water stop plate can be installed on the flange portion. In the insertion hole portion of the flange, a bolt is fixed to the flange portion by penetrating the insertion hole. The length of the bolt is such that the water stop plate, the retaining ring, and the retaining ring pressing fitting can be attached.

The water stop plate is made of an elastic ring-shaped rubber material or the like. The inner diameter of the water stop plate is smaller than the outer diameter of the buried pipe so that it can be bent and slidably contacted with the outer circumference of the buried pipe. Satoshi A hole is provided in the outer peripheral direction of the water blocking plate so as to match the position of the bolt fixed to the flange.

Since the retaining ring attached to the water stop plate needs to have a space for accommodating the inversion prevention metal, the thickness and the inner diameter are determined by the size of the inversion prevention metal.

As the inversion prevention metal member, steel material, hard rubber or the like is used so as to resist the inversion of the water blocking plate, and fixed to the tip of the retaining ring pressing metal member so as not to move to the front of the water blocking plate. Keep it.

[0012]

According to the above-mentioned invention, the inversion prevention metal fitting installed inside the retaining ring, that is, on the water stop plate side at the tip of the retaining ring pressing member, always holds the side where the water stop plate is about to be reversed. Since it is in a state, even if the soil under poor soil conditions causes pressured water or earth pressure to act on the water stop plate and try to invert the water stop plate to the vertical shaft, the reversal prevention metal fittings prevent it. Similarly, even when pulling out the front conductor or the buried pipe, even if the water stop plate tries to reverse due to the recoil of the front conductor or the buried pipe, it is blocked by the inversion prevention metal fitting and the water stop plate does not reverse. .

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view for explaining a starting shaft entrance device that is an embodiment of the present invention. A water stop plate fitting 1 having a flange formed at the tip of a cylindrical portion is fixed to a pit opening 11 of the earth retaining wall 10 on the front surface of the starting shaft 13. Insertion holes 1 through which the bolts 6 are inserted at equal intervals all around the flange portion.
2 are provided. The bolt 6 is inserted into the insertion hole 12 and fixed to the flange. A ring-shaped water stop plate 2 is inserted into and attached to the bolt 6 so as to abut the flange. Next, the retaining ring 3 is attached to the bolt 6 so as to abut the water blocking plate 2. Further, the bolt 6
At this point, a retaining ring pressing member 5 is attached so as to abut the retaining ring 3. Then, by tightening the tightening nut 7 on the bolt 6, the water stop plate 2, the retaining ring 3, and the retaining ring pressing member 5 are integrated. An inversion prevention metal fitting 4 having a tapered cross section is fixed to the water stop plate 2 side of the tip of the retaining ring pressing metal fitting 5. Concrete 8 is placed on the outer periphery of the water stop plate mounting bracket 1 to integrate the starting shaft device and the retaining wall 10.

Generally, a steel material is used as the material of the water stop plate fitting 1, and the water stop plate 2 is manufactured to have a size such that the water stop plate 2 can be installed on the flange portion. The length of the bolt 6 fixed to the flange portion is such that the water stop plate 2, the retaining ring 3 and the retaining ring pressing member 5 can be attached.

The shape of the retaining ring pressing member 5 may be a ring shape integrated over the entire circumference, but a long one that is individually installed at each bolt 6 position is superior in workability of mounting. .

The water stop plate 2 is made of an elastic ring-shaped rubber material or the like, and has an inner diameter smaller than the outer diameter of the buried pipe so that it can be bent and slidably contacted with the outer circumference of the buried pipe. Has been done. A hole is provided in the outer peripheral direction of the water stop plate 2 so as to match the position of the bolt 6 fixed to the flange.

The retaining ring 3 mounted in contact with the water stop plate 2 has a thickness and an inner diameter determined by the size of the inversion prevention metal fitting 4 in order to secure a space for accommodating the inversion prevention metal fitting 4 installed on the inner circumference. To be

FIG. 2 is a vertical cross-sectional view for explaining a state in which the buried pipe 9 passes through the inside of the starting shaft device during propulsion. As the embedded pipe 9 moves forward, the water blocking plate 2 bends forward together with the embedded pipe, slidingly contacting the outer periphery of the embedded pipe 9 to seal the gap.

As the material of the inversion prevention fitting 4, the water stop plate 2 is used.
In order to obtain a resistance force capable of resisting the reversal force, the steel material or hard rubber is used.

FIG. 3 is a vertical sectional view for explaining an embodiment in which the inversion prevention fitting 4 has another shape. As the shape of the inversion prevention ring 4 fixed to the tip of the retaining ring pressing member 5, it is also possible to use a shape having a circular cross section.

Hereinafter, a situation at the time of propulsion using the starting hole device according to the invention will be described. With the advance of the buried pipe 9,
The water stop plate 2 is bent forward by the embedded pipe 9 and seals the gap while slidingly contacting the outer periphery of the embedded pipe 9. Assuming that the soil condition is soft and there is a lot of groundwater, groundwater and earth and sand flow into the waterstop plate mounting bracket 1 from the gap between the wellhead 11 of the earth retaining wall 10 and the outer diameter of the buried pipe 9, and the waterstop plate Try to push the end face of 2 toward the vertical shaft and invert it. However, the inversion prevention metal fitting 4 is in contact with the shaft side of the water stop plate 2 to prevent the water stop plate 2 from being pushed toward the shaft side.

Further, even when the lead conductor and the buried pipe 9 are pulled out, the ground water and the earth and sand flowing into the water stop plate mounting bracket 1 together with the pulling force push the end face of the water stop plate 2 toward the vertical shaft, Due to the frictional force generated by the retreat of the buried pipe 9, the water stop plate 2 is attempted to be inverted to the vertical shaft side, but as described above, since the inversion prevention metal fitting 4 is in contact with the vertical shaft side of the water stop plate 2, Inversion of the water blocking plate 2 is reliably prevented.

[0023]

With the starting shaft device of the present invention, the water stop plate is constantly supported from the rear by the inversion preventing metal against the pressured water or the earth pressure in the ground where the soil condition is bad, and is inverted backward. It was not possible to do this, and it was constantly in pressure contact with the outer circumference of the lead conductor and buried pipe, and groundwater and sediment did not flow into the shaft. In addition, even when pulling out the lead conductor and the buried pipe, against groundwater pressure, earth pressure and frictional force with the buried pipe,
The action described above prevents the water stop plate from being reversed.

As described above, the inflow and ejection of ground water and earth and sand from the starting pit device are eliminated, and there is no accident such as submersion of the vertical shaft or depression around the vertical shaft, and safe and reliable propulsion construction can be performed.

[0025]

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view illustrating a starting hole entrance device of the present invention.

[Fig. 2] Fig. 2 is a vertical cross-sectional view for explaining the situation of the starting hole entrance device during propulsion.

FIG. 3 is a vertical cross-sectional view for explaining an inversion prevention fitting having another shape.

[Explanation of symbols]

 1 Water stop plate mounting bracket 2 Water stop plate 3 Retaining ring 4 Inversion prevention metal fitting 5 Retaining ring pressing metal fitting 6 Bolt 7 Tightening nut 8 Concrete 9 Buried pipe 10 Soil retaining wall 11 Wellhead 12 Insert hole 13 Starting shaft

Claims (1)

[Claims] 1. A launching hole entrance device installed on the front surface of a shaft for launching a front conductor and a buried pipe, and a water stop plate mounting bracket having a flange at a tip of a cylindrical portion, and the entire circumference of the flange. Insertion holes for inserting bolts provided at equal intervals, a ring-shaped water stop plate attached so as to pass through the insertion holes and fixed to the bolts and come into contact with the flange, and the insertion holes for the bolts. A retaining ring mounted so as to abut the water stop plate, a retaining ring pressing fitting that is inserted through the bolt so as to abut the retaining ring, and a water retaining plate side at the tip of the retaining ring pressing metal. A starting hole device in a propulsion method, characterized in that it is constituted by a fixed taper or an inversion prevention metal member having a circular cross section.