JPH0344634B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is particularly applicable to small diameter pipes (φ250m/m~
This relates to a construction method for advancing a buried pipe array with a diameter of 600 m/m), and in detail, at the beginning of the buried pipe array, the excavated soil is removed by a cutter, and the pipes are pushed in sequentially from the starting shaft. This invention relates to a gravel removal device in a propulsion method using a tubular propulsion device that propels a buried pipe array by force.

[Conventional technology]

This type of underground pipe propulsion method, which does not require excavation at the installation site for roads, etc., has many achievements due to its excellent advantages, but these results have been achieved with large diameter pipes, and small diameter pipes have been used. Since the diameter of the pipe is small, the following problems remain to be solved, and no one suitable for practical use has yet been proposed.

[Problem that the invention seeks to solve]

(1) In the case of large-diameter pipes, the soil excavated at the beginning of the buried pipe row can be passed through the pipe and removed to the starting shaft side by a mechanical conveyor without any problems, but in the case of small-diameter pipes However, since no method has been proposed for accurately and smoothly removing the soil excavated with a cutter from the tip of the buried pipe array through the inside of the pipe, if a consolidation propulsion method is adopted without considering soil removal, it will simply be Not only does this increase the load during construction, but there is also the risk of the ground heaving up in areas with shallow earth cover, and there are also disadvantages where construction may not be possible depending on the construction situation.

(2) Especially in the ground where there is a lot of relatively large gravel that cannot be taken in by the cutter, if such gravel appears in front of the propulsion machine, it may cause the entire buried pipe row to be pushed. becomes resistance,
In the worst case, it may completely obstruct progress, so this type of construction method requires a means that can effectively remove relatively large gravel that comes in front of the cutter.

[Means for solving problems]

Therefore, in order to solve the above-mentioned technical problem since the present invention is a small-diameter buried pipe, in particular, the excavated soil is transported into the pipe by a mud water pipe communicating with the receiving space of the cutter attached to the front end of the propulsion machine. The cutter is configured to discharge soil to the starting shaft side through the cutter, and is further provided with an excavation blade on the front surface of the cutter that generates a force to push the gravel away from the center of rotation when the excavation rotation direction is reversed, and an excavation blade on the front surface of the cutter This system is characterized by a nozzle that sprays a high-pressure jet water stream toward an area adjacent to the corresponding area.

[Effect]

To explain the operation of the present invention, the propulsion device 1
The soil excavated by the cutter 3 at the front is moved into the starting shaft 10 by the flow of pressurized mud water sent and discharged by the mud water pipes 14 and 14' communicating with the receiving space 6.
By sequentially removing earth to the side and pushing the pipes 2 sequentially from the starting shaft 10, the entire buried pipe row A is guided by the propulsion device 1 located at the head of the buried pipe row A. This will be promoted in line with the following.

At this time, relatively large gravel E, which cannot be taken in by the cutter 3 because it is restricted by the diameter of the mud water pipes 14 and 14', comes to the front of the cutter 3 of the propulsion device 1 .
When the pushing resistance of the entire buried pipe row A is significantly increased, a high-pressure jet water stream is ejected artificially or automatically toward the areas G and G adjacent to the excavation equivalent area F in front of the cutter 3, and at the same time, the cutter Reverse the direction of rotation of cutter 3 and
When the excavation blade 21 provided on the front side of the excavation blade 21 is reversed, the extrusion force of the gravel E toward the side away from the center of rotation causes the gravel E to be moved in the rotational direction and at the same time pushed toward the outside of the excavation equivalent area F. Then, when the gravel E reaches the adjacent areas G, G which have been partially collapsed by the high-pressure jet water flow, the gravel E is completely pushed out of the excavation equivalent area F for the first time here, Cutter 3 is removed from the front.

Then, the pushing resistance due to the gravel E decreases,
When the original situation returns, the jetting of the high-pressure jet water stream is stopped either manually or automatically, and the direction of rotation of the cutter 3 is returned to the original direction of rotation of excavation, thereby restarting the forward work.

〔Effect of the invention〕

Furthermore, the effects that can be achieved by the present invention are as follows: (a) Pressurized mud water that can easily and accurately transport soil excavated in front of the leading propulsion unit 1 through small-diameter pipes; Since the soil is sequentially discharged to the starting shaft 10 side using the
(1) There is no danger of heaving up the ground.

(b) In addition, by using mud water pressurization together, even in soft ground with a high permeability coefficient, mud water pressure that counters the earth pressure applied to the tip can be applied, causing the ground to collapse due to the earth pressure from around the excavation area. It can enable high-precision propulsion while preventing

(c) In particular, even in the ground where there is a lot of relatively large gravel E that cannot be taken in by the cutter 3, which is restricted by the diameter of the mud water pipes 14 and 14', even if such Even if the gravel E appears in front of the cutter 3, the extrusion rotation effect due to the extrusion force of the excavation blade 21 on the gravel E when the cutter 3 is reversed, and the area G adjacent to the excavation equivalent area F due to the high-pressure jet water flow. By securing an escape area by partially collapsing the soil at G, the gravel E can be accurately, easily, and quickly removed from the front of the cutter 3, and the propulsion work is thereby facilitated. It will not be interrupted or become incapacitated.

〔Example〕

Next, embodiments of the present invention will be described based on illustrative drawings.

The propulsion device 1 is located at the head of the buried pipe row A and guides it along the target line.The propulsion device 1 is made of a steel pipe whose outer diameter is the same as that of the buried pipe A on a large lathe and is used as an outer frame. , has a cutter 3 of the same diameter at its front end.

The cutter 3 has a rotary scraping part 5 which has a conical shape as a whole and is made up of a radial surface grid 4 with the center as a starting point, and a receiving space 6 on the back side of which receives the excavated soil pushed through the surface grid 4. have,
A cutter holding part 7 that supports the rotary scraping part 5
The entire cutter 3 is rotatably attached to the tip of the propulsion device 1 via spherical surfaces 8 and 8' that define the center of rotation a for correcting the cutter axis B on the center line C of the propulsion device 1 . ing.

Note that the cutter 3 is driven by a hydraulic motor provided in the propulsion device 1 at a low speed depending on the hardness of the soil.

The direction correction of the cutter axis B passing through the rotation center a is carried out by three correction jacks 9 that support the free end of the cutter holding part 7 from the radial direction dividing the circumferential direction into three equal parts in the propulsion unit 1 . ...and is controlled by a laser sight 11 provided at the free end of the cutter holding part 7 in order to extend the cutter axis B toward the starting shaft 10 side with the laser line D,
This control is performed by remotely controlling the correction jacks 9 to determine the deviation of the cutter axis B from the target line based on the measurement results of the laser beam D.

Furthermore, to explain the remote control in detail, a survey target 12 using a phototransistor is installed on the bearing wall of the starting shaft 10, and the deviation (deviation amount) of the cutter axis B from the target line is constantly reflected backwards. While measuring with a laser beam D, the correction jacks 9 are electrically controlled via electromagnetic valves by feedback control.

Although the illustrated control means has been explained using a surveying target 12 that uses a phototransistor to electrically and automatically measure the laser beam D, it is possible to manually measure the laser beam D by using a surveying target that visually measures the laser beam D. Of course, it is also possible to artificially control the electromagnetic valve and correct its direction based on the results.

Further, to explain the case where the buried pipe array A is propelled along a target line having a constant slope as an example, the irradiation point of the laser beam D is from the tip of the propulsion device 1 which is always moving forward to the survey target 12. The buried pipe row A is moved along the target line while correcting the cutter axis B using feedback control so that it comes to the deviation point from the target center point determined by the propulsion distance of the cutter and the gradient of the setting conditions. or by adjusting the slope of the cutter axis B, which is determined by the relationship between the slope of the propulsion device 1 itself and the slope of the propulsion device 1 itself using the electronic level device 13 installed in the propulsion device 1, to match the slope of the target line. Under such conditions, the buried pipe array A may be propelled along the target line while correcting the cutter axis B by feedback control so that the irradiation point of the laser beam D always comes to the center point of the target 12. Incidentally, when the propulsion device 1 reaches a shaft (not shown) provided at a certain distance from the starting shaft 10, it is removed from the shaft.

Next, the removal of the excavated soil received by the cutter 3 will be explained.
The excavated soil pushed into the receiving space 6 between...
The earth is sequentially discharged to the starting shaft 10 side along with the flow of pressurized mud water sent and discharged by 4', and the mud water discharged into the shaft 10 is provided in an area below the starting platform 15 of the shaft 10. After being sent to the sedimentation tank 16 and subjected to sedimentation treatment therein, the receiving space 6 of the cutter 3 is
This is what is refluxed to. In addition, the mud water pipe 1
Reference numerals 4 and 14' are flexible pipes that are successively added when the pipe 2 is added.

As the sedimentation tank 16, the starting shaft 11 in which steel sheet piles are driven around the excavated hole is dug down slightly deeper than a predetermined position, and the lower area of the starting platform 15 is used as the settling tank 16 as it is. However, the base needs to be concreted at the same time as the bearing wall to sufficiently stop water.

If the excavated soil accumulates in the sedimentation tank 16 in excess of a certain amount, it is taken out from the shaft 10 using a vacuum hose or a graph bucket, and transported to a disposal site for final treatment.

In the figure, 17 is a vertical push hydraulic jack 18 installed on the starting platform 16 placed in the shaft 11 with a horizontal reference.
is a steel collar interposed at the connection point of the buried pipe 2,
19 is a water pump, 20 is a sludge pump,
The pressurized mud water sent and discharged into the receiving space 6 of the cutter 3 by these pumps 19 and 20 is subjected to pressure that opposes the earth pressure applied to the area corresponding to the excavation, and the mud water pressure causes the earth pressure from around the excavation area to be applied. This prevents it from collapsing.

Further, on the front surface of the cutter 3, an excavation blade 21 has a component force for scraping the excavated soil toward the rotation center side in the excavation rotation direction, and generates a component force for extruding the gravel E toward the side away from the rotation center when reversing the rotation direction. At the same time, a nozzle 22 for spouting a high-pressure jet water stream toward areas G and G adjacent to the excavation equivalent area F on the front surface of the cutter 3 is provided, and the diameter of the mud water pipes 14 and 14' is Relatively large gravel E, which cannot be taken in by the cutter 3, comes.
When the pushing resistance of the entire buried pipe row A increases significantly and exceeds the set pressure, this abnormal pressure increase is sensed and the area G adjacent to both sides of the excavation equivalent area F in front of the cutter 3 is automatically removed. At the same time, the cutter 3
By reversing the rotational direction of the cutter, the gravel E is moved in the rotational direction by the component force that pushes the gravel E away from the center of rotation when the excavation blade 21 provided on the front surface of the cutter is reversed. Push it out towards the outside of area F. When the gravel E reaches the adjacent areas G and G, which have been partially collapsed by the high-pressure jet water flow, the gravel E is completely pushed out from the excavated area F and is removed from the entire surface of the cutter 3. be done.

Then, the pushing resistance due to the gravel E decreases,
When the pressure drops to the set pushing pressure, this is sensed and the high-pressure jet water flow is automatically stopped.
Moreover, the rotational direction of the cutter 3 is returned to the original excavation rotational direction, and the forward work is resumed.

It should be noted that switching the gravel removal device to the operating state can be done manually, and in this case, it is sufficient to notify the operator of the abnormal increase in the pushing pressure using an alarm or the like.

In addition, the location where the escape space for the gravel E is secured due to the collapse of the soil bed caused by the high-pressure jet water flow is not in the upper and lower areas of the excavation equivalent area F, where the soil subsidence or the buried pipe 2 sinks, but on both sides. is the most ideal.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the device for correcting the propulsion direction of a buried pipe array according to the present invention, FIG. 1 is a vertical side view showing an outline of the entire working state, and FIGS. 2 and 3 are the device for correcting the propulsion direction. Figure 4 is a perspective view showing the entire propulsion, Figures 5 and 6 are
The figures are a schematic plan view and a schematic front view showing the working state of the gravel removal device. 1 ... Propulsion machine, 2... Tube, 3... Cutter, 6
...Acceptance space, 14,14'...Mud water pipe,
21...Drilling blade, 22...Nozzle, E...Gravel, F
...Excavation equivalent area, G, G... Area adjacent to the excavation equivalent area.

Claims (1)

[Claims] 1 A tubular outer shape that is located at the head of the buried pipe row A and is guided and propelled by the removal of excavated soil by the cutter 3 and the pushing force of the pipes 2 that are successively pushed in from the starting shaft 10. The propulsion device 1 is configured so that excavated soil is discharged to the starting shaft 10 side through the mud feed and discharge pipes 14 and 14' communicating with the receiving space 6 of the cutter 3 attached to the front end of the propulsion device 1 . Further, an excavation blade 21 is provided on the front surface of the cutter 3 to generate a component force to push the gravel E away from the rotation center when the excavation rotation direction is reversed.
A gravel removal device for a propulsion machine for a buried pipe array, characterized in that it is provided with... and a nozzle 22 that spouts a high-pressure jet water stream toward areas G and G adjacent to the excavated area F in front of the cutter 3. .