JPS5833360B2 - Press-in construction method and equipment for water and sewage pipes in ground with a lot of groundwater - Google Patents

Description

[Detailed Description of the Invention] When water, sewage, etc. are installed by being forced into the ground, if there is a lot of groundwater, the ground at the tip of the pipe will flow out with the water, eventually collapsing greatly and sinking into the ground. This is dangerous.

In addition, the direction of propulsion is often inaccurate because the earth pressure applied around the pipe is uneven.

Therefore, when carrying out press-in propulsion work in such ground, it is necessary to use the well point construction method in advance to lower the groundwater level so that there is no water in the pipes, or use sodium silicate,
It is customary to inject a mixture of bentonite, cement, etc. into the soil to remove water from the pipes, stop the water, and increase the strength of the soil before construction.

However, since the well point method is a type of well point method, it cannot be said that it is a construction method that can be used in all cases, as it may cause ground subsidence or create separate wells for use by nearby residents. do not have.

In addition, even with the chemical injection method, strongly alkaline sodium silicate is injected into the ground at high pressure, which may cause abnormal upheavals in soft ground or change the groundwater to alkaline, causing abnormalities in the human body or agricultural products. There are cases where this is very difficult, and in any case (a trowel is not a construction method that can be used).

In addition to these, there are construction methods such as the pressure air method and the muddy water pumping method in which an airtight chamber is provided at the tip of the pipe and air or muddy water is pumped into the chamber to withstand underground water pressure. It cannot be used in ground with good soil quality, and if the depth is very deep, it requires high pressure that humans cannot withstand (it is only possible to use it in extremely limited situations because it becomes impossible to work). It can be said that this construction method is suitable only for

As described above, groundwater is the most troublesome entity in pipe press-in promotion construction.

The present applicant has proposed a pipe which improves the drawbacks of the various construction methods mentioned above and enables safe and reliable pipe press-fitting installation work using Japanese Patent Application No. 52-51356 and No. 52-87530. This paper presents the development and presentation of the press-in propulsion method and its equipment.

The pipe press-in propulsion method and its equipment developed and proposed by the applicant in Japanese Patent Application No. 52-51356 are as follows.

An excavator with a cutting blade opening at the front end and an internal excavating blade and a screw conveyor is installed at the front, followed by a press-in pipe and pushed from behind to propel it into the ground, and the excavating blade is rotated to dig into the ground. In a pipe press-in propulsion device that excavates soil and removes the soil using a screw conveyor, a storage chamber for the excavated soil is formed between the excavation blade and its drive device in a closed chamber with a partition wall, and a rear stop is attached to the soil removal device installed below the chamber. Equipped with a water valve, the mechanism allows the soil discharge port to be opened and closed by moving forward and backward with a jack.During normal operation when groundwater does not flow in, the soil is discharged by moving the soil removal device and rear water stop valve backward with a jack. Open the mouth and drive and rotate the soil removal device to discharge the excavated soil into the pipe. If a large amount of groundwater flows in with quicksand, adjust the soil removal device and rear water stop valve as appropriate. The soil removal device is moved forward until the gap is reached, and the open area of the soil discharge port and rear water stop valve is reduced to reduce the speed and volume of flowing water, and the soil removal device is filled with sediment to prevent the flow of soil. If the water does not stop even after the above operations, use a jack to move the soil removal device and rear water stop valve forward to close the soil discharge port and stop the driving rotation of the soil removal device. After the excavation blade continues to excavate the ground and propel the pipe until the storage chamber is filled with soil and compacted, the rear water stop valve is opened and the soil removal device is driven to rotate to discharge the soil.

This is a press-in propulsion method for water and sewer pipes, etc., which is characterized by repeatedly repeating the above operations, and its equipment.

However, it was a complex construction method that was adapted to various situations.

The present invention improves the construction method and equipment, and provides a screw conveyor for discharging excavated soil with not only a rear water stop valve that opens and closes the soil discharge port side, but also a front water stop valve that opens and closes the soil extraction port side. Water supply in the ground where there is a lot of underground water,
This is a suitable construction method and apparatus for press-fitting sewage pipes, etc., and the details thereof will be described below with reference to figures.

1 is a disc-shaped cutter that rotates and excavates the earth and sand in front, and 2 is a prime mover that drives the cutter 1.

3 is a screw conveyor for discharging excavated soil, 4 is a prime mover that drives it, and 5 is a jack that moves it forward and backward.

The casing of the prime mover 4 is non-rotatably coupled to a jack 5, and the rear end of the jack 5 is non-rotatably coupled to a mounting base fixed to the tube shell 8.

6 is a water stop valve that opens and closes the front of the screw conveyor (earth extraction port), and 7 is the back of the screw conveyor (earth discharge port).
This is a rear water stop valve that opens and closes the .

The mounting distance between the front water stop valve 6 and the rear water stop valve 7 on the screw conveyor shaft is set to be slightly longer than the length of the screw conveyor casing 12.

8 is a tube shell, 9 is a cutting edge, 10 is a closed chamber for storing excavated soil, and 11 is a partition wall forming the closed chamber 10.

12 is a cylindrical screw conveyor casing.

A closed chamber 10 is formed by a partition wall 11 between the disc-shaped cutter 1 and the prime mover 2 that drives the cutter, a screw conveyor casing 12 is connected to the lower part of the closed chamber 10, and a front water stop valve is installed in the screw conveyor casing 12. A screw conveyor 3 for discharging soil is equipped with a screw conveyor 3 equipped with a water stop valve 6 and a rear water stop valve 7, and is moved forward and backward by a jack 5, and the front water stop valve 6 is used for the soil extraction port side, and the rear water stop valve 7 is used for the soil discharge port side. This is a pipe press-in propulsion device which is characterized in that it can be opened and closed freely and is driven and rotated by a prime mover 4 to discharge soil.Next, a pipe press-in propulsion construction method using this mechanism will be described.

The blade mouth hood of the main excavator is a closed room 10, which is blocked off by a partition wall 11.

A disc-shaped cutter 1 is driven and rotated therein to excavate and store earth and sand in the room.

Therefore, unless the exit from the partition wall 11 is opened, neither soil nor water will be discharged to the rear.

In order to discharge this earth and sand, a small-diameter earth discharge screw conveyor 3 is installed below the partition wall, and a front water stop valve 6 and a rear water stop valve 7 are installed at the rear of the screw casing 12.
Since the screw conveyor casing 1 is equipped with
2, the screw conveyor 3 is advanced by the jack 5, and a first step is first taken in which the rear water stop valve 7 on the soil discharge port side is closed and the front water stop valve 6 on the soil extraction port side is opened.

Next, a second step is taken in which the following press-fit tube is pressed from behind to drive the tube shell 8 forward, and the disc-shaped cutter 1 is rotated by the prime mover 2 (trowel drive) to perform press-fit excavation.

Next, the excavated soil is introduced and filled into the closed chamber 10, and when the press fit becomes impossible, the screw conveyor 3 is driven and rotated by the prime mover 4, and a third step is taken in which the excavated soil is introduced and filled into the screw conveyor casing 12.

Next, screw conveyor 3 is jacked 5 (
When the trowel is moved back, the front water stop valve 6 is closed, the rear water stop valve 7 is opened, and the fourth step is performed in which the prime mover 4 drives and rotates, water does not enter the screw conveyor casing 12.
The sediment accumulated inside is discharged.

By sequentially repeating the above operations, the construction can be carried out safely and reliably without causing a large amount of water leakage and collapse even in places where a considerable amount of groundwater is flowing, and the structure and operating principle are simple and clear, so the operator is highly skilled. It is also economical because the machine is light and compact, so the size of the starting shaft is small, and the machine is easy to maintain and maintain.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view showing the state where the rear water stop valve is closed and the front water stop valve is opened, press-fit excavation is performed, and the water is completely shut off. Figure 2 is a vertical cross-sectional view showing the state where the water stop valve is completely shut off after the press-fit is stopped. 1 is a longitudinal cross-sectional view showing a state in which soil is being discharged while completely shutting off water by opening a rear water stop valve, and shows 1... a disk-shaped cutter, 2... a prime mover that drives the cutter, 3...・Screw conveyor, 4
...Motor to drive, 5. Jacket to move forward and backward, 6. Front water stop valve, 7. Rear water stop valve, 8..
- Tube shell, 9... Tip blade opening, 10... Closed chamber for storing excavated soil, 11... Partition wall, 12... Screw conveyor casing.

Claims (1)

[Scope of Claims] 1. A front end portion (having a cutting edge 9, an inner chamber of this front end portion is a closed chamber 10 for storing excavated soil divided by a partition wall 11, and a front end portion of this closed chamber 10 (having a cutter) Rotating disk 1
An excavator tube shell 8 device is provided with an earth-removing screw conveyor casing 12 which is rotatably attached and opens into the closed chamber 10, and is driven forward from the rear, the earth-removing screw conveyor 3 A water stop valve 6 is installed at the front end of the shaft of the screw conveyor 3, and a rear water stop valve 7 is installed at a position slightly longer than the length of the conveyor casing 12 on the shaft of the screw conveyor 3 at a distance from the front end water stop valve 6. , a prime mover 4 is attached to the shaft of this screw conveyor 3.
At the same time, the casing of the prime mover 4 is connected to a mounting base fixed to the tube shell 8 (to which a press-fit propulsion device is used, such as water and sewer pipes, which is connected so as to be able to move forward and backward via a jack 5). Then, the screw conveyor 3 is moved forward by the jack 5 (trowel) in the screw conveyor casing 12, the rear water stop valve 7 on the soil discharge port side is closed, and the front water stop valve 6 on the soil extraction port side is opened. While pressing the tube shell 8 from the rear,
A second machine that performs press-fit excavation by rotationally driving the disc-shaped cutter 1.
When the excavated soil is introduced into the closed chamber 10 and becomes full and cannot be press-fitted, the screw conveyor 3 is driven and rotated by the prime mover 4 to move the excavated soil into the screw conveyor casing 12.
The third step is to introduce and fill the inside of the tank, and to move the screw conveyor 3 backward with the jack 5 and close the front water stop valve 6.
A method for press-fitting water, sewage pipes, etc. in ground with a lot of groundwater, which is characterized by repeatedly repeating a fourth step of opening a rear water stop valve 7 and discharging earth and sand by driving and rotating it with a prime mover 4. 2. The front end has a cutting edge 9, and the inner chamber of this front end is defined by a partition wall 11 (a closed chamber 10 for storing excavated soil), and the rotary disc 1 with a cutter is rotatable at the front end of this closed chamber 10. In the excavator tube shell 8 device, which is equipped with an earth removal screw conveyor casing 12 that is attached and opens into this closed room 10 and is driven forward from the rear, a At the same time as installing the water stop valve 6, install the rear water stop valve 7 at a position slightly longer than the length of the conveyor casing 12 on the shaft of the screw conveyor 3 at a distance from the front end water stop valve 6. A groundwater system characterized in that the rotating shaft of a prime mover 4 is coupled to the shaft of a screw conveyor 3, and the casing of this prime mover 4 is coupled via a jack 5 to a mounting base fixed to a tube shell 8 in a rotation-preventing manner. Press-in propulsion equipment for water and sewer pipes, etc. in ground with a lot of water.