JP4007366B2 - Filling method for underground cavity and filling pipe for filling underground cavity - Google Patents

Description

  The present invention relates to a filling method for underground cavities and a filling pipe used for the filling method.

Various underground cavities such as abandoned mines such as lignite mines, coal mines, quarries, etc., air defense tunnels, waterway tunnels, etc. May cause disasters such as sinking the ground surface or sinking surface structures.
Therefore, in order to prevent the collapse of the underground cavity, various underground cavity filling methods for filling the underground cavity with a filler have been performed.

For example, according to the construction method disclosed in Japanese Unexamined Patent Publication No. 2002-81054 (Patent Document 1), according to the previous construction method, the filling material extends from the filling target area where filling in the underground cavity is required to the outside. Outflow, wasted the waste of the filler, was uneconomical, etc. First, low fluidity through the injection pipe at the end (outer periphery) of the filling target area The filling target region is made a closed space by forming an end wall body that closes the cross section of the underground cavity, and then the highly packed medium filling filler is filled in the closed filling target region. The filling material is limitedly filled only in the region to be filled by filling the inside of the material.
Such a limited filling method can be used to fill long and narrow underground cavities such as underground waterways, greatly reducing the amount of wasted material that flows out of the filling target area and shortening the construction period. This is an economical method.

However, in the construction method disclosed in the publication, a normal hollow straight pipe is used as the injection pipe, and it is recognized that the filler is discharged from the lower end opening of the injection pipe, as shown in FIG. In such normal injection by the pipe 1, the filler 2 discharged downward spreads evenly in the horizontal direction in the underground cavity, and even if it is injected by the Tremy method that suppresses the filler falling speed, It is difficult to suppress the spread of the filler 2 in the horizontal direction.
Actually, when the end wall body 3 is formed, the filler 2 is filled into the underground cavity while exhibiting a conical shape with a gentle gradient of about 15 to 25%, and the cross section of the underground cavity is It is necessary to inject a large amount of the filler 2 until the end wall 3 that is completely closed is formed.
For example, when a long and narrow underground cavity having a cross section with a width of 2 m and a height of 1.5 m is filled with the filler 2 filled with a gradient of about 20%, the end wall 3 that completely closes the cross section is as follows. Since the underground cavity has a shape extending in the axial direction, about 30 m3 of injection is required to form the underground cavity.
As described above, this construction method using a normal pipe as an injection pipe requires a large amount of end filler, which is uneconomical for raising the material cost, and requires a construction period for carrying out a large quantity of injection. There was a problem that it was long and inefficient.

  On the other hand, instead of a normal hollow straight tube, a slit is formed outside the injection tube as described in JP-A-7-286319 (Patent Document 2) and JP-A-10-266185 (Patent Document 3). The end filler is discharged in the width direction of the underground cavity, i.e., the underground cavity by using an injection device provided with a rubber pipe or a coating film having If the end wall body is formed in a direction orthogonal to the axial direction, the amount of filler required can be reduced.

However, the injection devices described in these documents have a special structure for forming vertical grouting veins in the rock, and it is more costly to simply convert this to the underground cavity filling method. It is not appropriate because it becomes too high.
JP 2002-81054 A Japanese Patent Laid-Open No. 7-286319 Japanese Patent Laid-Open No. 10-266185

  Therefore, the present invention provides a filling tube that can be reduced in cost with a simple configuration, and can reduce the amount of filler used by using this filling tube, which is more efficient and economical than the conventional one. It is an object to provide a simple underground cavity filling method.

In the first aspect of the present invention, a plurality of discharge holes 32... Are arranged along the axial direction on the side surface of the pipe whose lower end is closed, and the lower one is opened larger and the upper one opened smaller. A filling tube for filling an underground cavity, comprising an inner tube 34 and an outer tube 35 slidably fitted to the outside of the inner tube 34 in the axial direction.

The filling pipe for filling an underground cavity according to claim 1, wherein a marking indicating the opening direction is provided at an upper extension position of the discharge hole 32.

According to the third aspect of the present invention, (1) the boring hole 36 reaching the filling target region of the underground cavity 33 from the ground is drilled, and (2) the underground cavity filling according to the first or second aspect is performed in the borehole 36. And inserting the filling pipe to the position where the lower end thereof reaches the vicinity of the bottom surface of the underground cavity 33, and appropriately rotating the inner pipe 34 of the filling pipe so that the discharge holes 32. (3) While the outer pipe 35 of the filling pipe is slid upward, the end filling material 37 is pumped from the upper end side of the filling pipe while opening the discharge holes 32. By doing so, the end filler 37 is discharged from the discharge holes 32 in an open state to form an end wall 38 that closes the transverse section of the underground cavity 33. It is an underground cavity filling method.

In the underground cavity filling method of the present invention according to claim 4, the slide of the outer pipe 35 is buried in the end filling material in which the discharge holes 32. The underground cavity filling method according to claim 3, wherein the filling is performed in accordance with an increase in the bulk of the end filler.

The underground cavity filling method of the present invention according to claim 5 is characterized in that the sliding of the outer pipe 35 is performed by operating a wire or the like attached to the outer pipe 35. It is a construction method.

The filling tube for filling the underground cavity of the present invention can discharge the end filler from the discharge hole of the opened inner tube by sliding the outer tube upward. Further, the discharge direction of the end filler can be controlled by rotating the inner pipe, which is convenient for closing the end of the underground cavity and can be manufactured at a low cost because it has a simple structure.

The underground cavity filling method of the present invention can reduce the material cost by reducing the amount of the end filler used, and can be constructed economically and efficiently in a short construction period.

An inner tube 34 in which a plurality of discharge holes 32... Are arranged in the axial direction on the side surface of the tube whose lower end is closed, and the lower one is opened large and the upper one is opened small. A filling pipe for filling an underground cavity, comprising an outer pipe 35 slidably fitted in the axial direction on the outside of 34.

(1) Drilling a boring hole 36 reaching the filling target area of the underground cavity 33 from the ground. (2) Filling the bore hole 36 with the above-mentioned filling pipe for filling the underground cavity, and its lower end near the bottom surface of the underground cavity 33. And the inner pipe 34 of the filling pipe is appropriately rotated to direct the discharge hole 32... In the transverse direction of the underground cavity 33, and (3) the outer pipe 35 of the filling pipe is slid upward. As a result, the discharge holes 32... Of the inner pipe 34 are opened in order from the lower one, while the end filling material 37 is pumped from the upper end side of the filling pipe to open the discharge holes 32. An end portion filling material 37 is discharged from the end portion to form an end portion wall body 38 that closes the transverse cross section of the underground cavity 33.

First, an embodiment of the underground cavity filling method will be described in detail with reference to FIGS.
In this underground cavity filling method, the above filling is performed in order to fill the filler only in a desired filling target region of the underground cavity 11, that is, to fill the filler so as not to flow out of the region. End filling material 12 is injected and filled in the end portion of the target region in advance, and the filling target region is closed by the end wall body 13 formed thereby, and then the filling material is filled in the closed filling target region. This is a so-called limited filling method that is used for filling and filling, and is particularly suitable for filling and filling a required filling target area in a long and narrow underground cavity such as a groundwater channel. .
In the present embodiment, description will be made assuming a case where ground water is filled in the long and narrow underground cavity 11.

  14 is a filling pipe for filling an underground cavity, which closes the lower end of a pipe having a required length and has a pair of vertically-slit discharge holes 15 and 15 at opposite positions on the side surfaces in the vicinity of the lower end. (FIG. 3). Marking (not shown) for indicating the opening direction of the discharge holes 15, 15 is provided at the upper extended positions of the discharge holes 15, 15.

The filling tube 14 is intended to be used to form the end wall 13 by injecting filling the end filler 12 in the end portion of the filling region of interest in an underground cavity in the underground cavity filling method, the The end filler 12 that is pumped and fed from the upper end can be discharged sideways from the discharge holes 15 and 15.
The opening areas of the discharge holes 15 and 15 are appropriately determined from the relationship between the pumping pressure of a pumping pump (not shown) and the pipe diameter.

  The underground cavity filling method of the present embodiment is performed as follows using the filling pipe 14.

  (1) First, the boring hole 16 for inserting the filling pipe 14 is drilled from the ground to the position of the end of the filling target region of the underground cavity 11.

  (2) Subsequently, the filling tube 14 is inserted into the boring hole 16 and installed so that the lower end thereof reaches the vicinity of the bottom surface of the underground cavity 11. At this time, the marking indicating the opening direction of the discharge holes 15 and 15 of the filling pipe 14 is confirmed and the filling pipe 14 is appropriately rotated so that the discharge holes 15 and 15 are moved in the transverse direction (longitudinal direction) of the underground cavity 11. (To the direction perpendicular to each other), facing the both wall surfaces.

  (3) Then, the end filler 12 is pumped from the upper end side of the filling pipe 14 by a pumping pump (not shown) and discharged from the discharge holes 15, 15 toward the opposing wall surfaces. Inject into the underground cavity. In the process of this injection, the pumping pressure and the filling amount on the pumping pump side are monitored.

In order to prevent the water quality of the groundwater filled in the underground cavity from being deteriorated as much as possible and to prevent separation of the end filling material in water as much as possible, the injection holes 15 and 15 of the filling pipe 14 have already been injected. The filling tube 14 is inserted in accordance with the increase in the bulk of the end filler 12 so that the end filler 12 discharged from the end 12 is buried in the outlet filler 12 and does not directly touch the groundwater. It is performed while sliding upward in stages (FIGS. 1 and 2).
The slide timing and slide amount are determined from the pumping pressure and the filling amount on the pumping pump side being monitored.

  Since the end filler 12 is discharged from the discharge holes 15 and 15 of the filling pipe 14 in the transverse direction of the underground cavity 11, that is, in the direction of both wall surfaces, the gradient in the longitudinal direction of the underground cavity 11 is made steep. It fills and fills up in the form of a mountain with a gentle gradient (FIGS. 1 and 2).

(4) When the discharge holes 15 and 15 reach the vicinity of the top end of the underground cavity 11 by the sliding of the filling pipe 14, the final filling is started.
Then, it is confirmed that the end wall body 13 that completely closes the transverse section of the underground cavity 11 is formed by the increase in the pumping pressure monitored on the pumping pump side, and the filling is finished.

In the present construction method, the end filler 12 is discharged in the direction of the wall surface of the underground cavity 11 using the filling pipe 14 in this way, so that the end portion that closes the underground cavity cross section with a smaller filling amount than in the conventional method. The wall body 13 can be formed.
Specifically, the end wall 13 can be formed with a steep slope of about 100% in the longitudinal direction of the underground cavity and a slope of about 10% in the transverse direction. In the case of the underground cavity 11 having a cross section with a height of 1.5 m, an end filler 12 of about 6 m3 is sufficient.

  (5) A boring hole (shown in the figure) is formed by forming an end wall body 26 at the other end of the filling target region in the same procedure as described above and closing the filling target region. The filling of the underground cavity is completed by injecting and filling the filling material.

  As described above, according to the present construction method, the end wall 13 can be formed with a steep slope. Therefore, the cost can be reduced by reducing the amount of the end filler 12 used, and the construction period can be shortened. Can do. Further, the filling tube 14 can be manufactured with a simple structure at low cost, and is not fixed in the underground cavity at the time of construction, and can be recovered after use, and thus can be reused or diverted.

4 (a) to 4 (e) are examples of a filling tube in which the number, arrangement, and shape of the discharge holes are changed. In other words, the filling tube 14 has a pair of vertically-slit discharge holes 15 and 15 formed at opposite positions on the side surfaces near the lower end, but the discharge holes may be round holes ( (A)), and if it is sufficient to discharge the end filler 12 in one direction, only one opening may be provided on one side (FIGS. (B) and (c)). Further, the discharge hole may be a horizontally long discharge hole, or a combination of a slit discharge hole and a round discharge hole may be used.
In addition, when it is preferable to discharge the end filler 12 in three or more directions due to the shape of the underground cavity or the like, three or more discharge holes may be provided ((d), (e ) Shows one provided with discharge holes in four directions.)

The above-mentioned round hole-shaped discharge holes and slit-shaped discharge holes tend to have a higher discharge speed in the former, but the shape and the like of the discharge holes are determined by the plasticity and fluidity of the end filler 12. This can be done in consideration of the fresh properties of
For example, when the end filler 12 having low fluidity and high self-supporting property is used, the end filler is rapidly discharged using a filling pipe having a round hole-like discharge hole, thereby forming a steep mountain shape. The made end wall 13 can be formed in a short time.
On the other hand, when filling the end filler 12 having a relatively low material separation resistance, a filling tube having slit-like discharge holes with a low discharge speed is used in order to reduce material separation in water as much as possible. Is good.

  In addition, although the present Example demonstrated and demonstrated the case where underground water was filled in the underground cavity, of course, this construction method can also be constructed also in an underground cavity without underground water.

Next, another embodiment of the underground cavity filling method will be described in detail with reference to FIGS.
Although the construction method of this embodiment is a long and narrow underground cavity like the underground water channel as in the case of Example 1, there is no underground water in the interior, and it is necessary to consider separation of the end filler in water. It assumes no case.
However, when using an end filling material with high resistance to separation in water, it can be constructed even in underground cavities filled with groundwater.

21 is provided with a plurality of longitudinally slit-like discharge holes 22... On the side surfaces facing each other of a pipe having a required length with the lower end closed, from the vicinity of the lower end to a position corresponding to at least the height of the underground cavity 23. It is a filling tube for filling an underground cavity opened in a state aligned in a direction (FIG. 7). The total opening area of the discharge holes 22... Is larger than the cross-sectional area of the filling tube 21 so that the pressure of the end filling material pumped through the filling tube 21 does not become excessively high. It is preferable to leave.
Further, markings (not shown) for indicating the opening direction of the discharge holes are provided at the upper extended positions of the discharge holes 22.

  The underground cavity filling method of the present embodiment is performed as follows using the filling pipe 21. (1) First, the boring hole 24 for inserting the filling pipe 21 is drilled from the ground to the position of the end of the filling target area of the underground cavity 23.

  (2) Subsequently, the filling tube 21 is inserted into the boring hole 24 until its lower end reaches the vicinity of the bottom surface of the underground cavity 23, and the filling tube 21 is marked to indicate the opening direction of the discharge holes 22 ... The discharge holes 22... Are fixed in a state facing the both wall surfaces in the transverse direction of the underground cavity 23.

(3) Then, the required end filling material 25 is pumped from the upper end side of the filling pipe 21 by a pumping pump, discharged from the discharge holes 22, and injected into the underground cavity 23.
On the pumping pump side, the pumping pressure, the filling amount, etc. are monitored through this injection process.

  The end filler 25 that is pumped through the filling pipe 21 is discharged from all the discharge holes 22... From the upper side to the lower side in the direction of both wall surfaces of the underground cavity 23, that is, the transverse direction. The slope in the longitudinal direction is steep and the slope in the transverse direction is gradual (FIGS. 5 and 6). Further, a part of the end filling material 25 discharged from the upper discharge holes 22... Flows downward along the outer surface of the filling tube 21, so that the end filling material 25 is filled in a state where it swells downward as a whole. The circumference of the tube 21 is filled.

As the end filling material 25 is discharged, the lower discharge holes 22 are covered and closed by the end filling material 25 that flows downward from the upper direction through the filling tube 21 and discharge resistance. Therefore, the discharge amount and the discharge speed from the lower discharge hole 22... Decrease, and the discharge amount and the discharge speed from the upper discharge hole 22. .
Eventually, the discharge is made only from the uppermost discharge hole 22..., And the discharge amount and discharge speed from the discharge hole 22. Therefore, the discharge from the uppermost discharge hole 22... Is performed in the direction of the wall surface of the underground cavity with higher directional accuracy.

  (4) This injection filling is completed after confirming that the end wall 26 that completely closes the transverse section of the underground cavity 23 is formed by the increase of the pumping pressure monitored on the pumping pump side.

  (5) After the end wall 26 is formed at the other end of the filling target region in the same procedure as described above to close the filling target region, a boring hole (not shown) is drilled in the filling target region. The filling of the underground cavity is completed by injecting and filling the filling material.

  Also in the construction method of the present embodiment, the end filler 25 is discharged in the direction of the wall surface of the underground cavity 23 in the same manner as in the construction method of the first embodiment, so that the cross-section of the underground cavity can be reduced with a smaller filling amount than conventional. A closed end wall 26 can be formed.

Further, in this construction method, unlike the construction method of the first embodiment, the filling pipe 21 is not slid and pulled up, so that the end filler 25 (end wall body 26) is caused by vibration and vibration of the filling pipe 21 in the filling process. Collapse can be suppressed. Therefore, the end wall body 26 can be formed with the minimum end filler 25.
The filling tube 21 is embedded in the end wall body 26 formed as described above, and has a function of fixing the end wall body 26.

FIG. 7 shows a filling tube provided with the discharge holes 22... Having the same shape and the same opening area. However, the amount of filler discharged from the upper discharge holes 22. In the case where the amount discharged from the discharge holes 22... Is too large, it is preferable to make the opening area of the discharge holes 22.
That is, the end filling material 25 tends to discharge more from the upper discharge holes 22... With a small pressure loss and less from the lower discharge holes 22. The balance of the discharge amount from the upper and lower discharge holes 22... Can be adjusted by increasing the upper discharge holes 22.
If the total opening area of all the discharge holes 22 is increased by opening the lower discharge holes 22 in this way, the pumping pressure of the pump can be lowered. Further, since the discharge speed from the uppermost discharge hole 22... For finally discharging the end filler 25 becomes higher, it contributes to further improving the discharge direction accuracy.

8 (a) to 8 (e) are examples of the filling tube in which the number, arrangement, and shape of the discharge holes are changed. That is, the filling pipe 21 has the vertically slit-like discharge holes 22... Formed at the positions of the side surfaces facing each other, but the discharge holes may be round holes ((a) in the figure). In addition, if it is sufficient to discharge the end filler 12 in one direction, the end filler 12 may be opened only on one side surface ((b) and (c) in the figure). Further, the discharge hole may be a horizontally long discharge hole, or a combination of a slit discharge hole and a round discharge hole may be used.
In addition, when it is preferable to discharge the end filler 12 in three or more directions due to the shape of the underground cavity or the like, discharge holes may be provided in three or more directions (see FIGS. )).

Finally, still another embodiment of the underground cavity filling method will be described in detail with reference to FIGS.
When the cross-sectional width of the underground cavity to be filled is wide, if the construction method of Example 2 using the filling pipe 21 is adopted, the distance from the filling pipe 21 to the wall surface is large. Before the filler sufficiently expands in the width direction and reaches the wall surface, the lower discharge hole 22... Is closed by the end filler flowing down from above, and the end filler becomes the upper discharge hole 22. It will come to discharge only from.
If filling is continued for a required time in such a state, an increase in the pumping pressure on the pumping pump side due to the blockage of the lower discharge holes 22... Continues more than necessary, and in particular, the underground cavity filled with groundwater. If it is going to be filled, there will be a concern about the material separation of the end filler in water by the amount of the falling height of the end filler discharged from the upper discharge holes 22.

  The underground cavity filling method of the present embodiment described below is suitable for construction in an underground cavity having a wide transverse cross section as described above, and further in an underground cavity filled with groundwater.

31 is the same as the filling tube 21 described in the second embodiment, that is, a plurality of longitudinally slit-like discharge holes 32... To a position corresponding to at least the height of the underground cavity 33 and arranged in the axial direction thereof, and a hollow cylindrical shape fitted to the outside of the inner pipe 34 so as to be slidable in the axial direction. This is a filling tube for filling an underground cavity , consisting of the outer tube 35 (FIG. 9).

  The outer tube 35 can be slid up and down with respect to the inner tube 34 by a wire operation or the like, whereby the discharge holes 32... Can be closed or opened. Since the outer tube 35 is relatively lightweight, the slide can be easily operated. In order to make the slide smoother and prevent the inner tube 34 from rising, It is preferable that a lubricant such as grease is filled between the outer pipe 35 and the outer pipe 35.

  Further, markings (not shown) indicating the opening direction of the upper discharge holes 32... Are provided on the upper extension positions of the discharge holes 32.

  The underground cavity filling method of the present embodiment is performed using the filling pipe 31 as follows.

  (1) First, the boring hole 36 for inserting the filling pipe 31 is drilled from the ground to the position of the end of the filling target region of the underground cavity 33.

(2) Subsequently, the filling tube 31 is inserted into the boring hole 36 and installed so that the lower end thereof reaches the vicinity of the bottom surface of the underground cavity 33, and the inner tube 34 is fixed. At this time, after confirming the marking indicating the opening direction of the discharge holes 32..., The inner pipe 34 is appropriately rotated so that the discharge holes 32. deep.
The outer pipe 35 is lowered to the vicinity of the bottom surface of the underground cavity 33 together with the inner pipe 34 so as to block the discharge holes 32... Do not) to be able to slide upward.

  (3) Then, the wire etc. is operated to raise the outer tube 35 by one slide, and the lowermost discharge hole 32... Of the inner tube 34 is opened. Here, the amount of one slide can be determined so that, for example, the area of the discharge hole 32.. it can.

  (4) Subsequently, the end filler is pumped through the lowermost discharge hole 32... Which is opened by pumping the required end filler 37 from the upper end side of the filling pipe 31 by the pump. 37 is discharged and injected into the underground cavity 33. This injection is performed while monitoring the pumping pressure and filling amount of the pump.

  The injection is performed in order to prevent the lower discharge holes 32... From being blocked early by the end filling material 37 discharged from the upper discharge holes 32. In order to prevent the water quality of the groundwater from being deteriorated as much as possible and to prevent the end filler 37 from being separated in water as much as possible, the open discharge holes 32. Then, the outer tube 35 is slid upward in a stepwise manner as the bulk of the end filler 37 increases so as to be buried in the discharged end filler 37 (FIG. 11). . The amount of one slide and the time interval of each slide are determined from the pumping pressure of the pump and the filling amount.

  Since the end filler 37 is discharged from the discharge hole 32 of the filling pipe 31 in the transverse direction of the underground cavity 33, that is, in the direction of both wall surfaces, the gradient in the longitudinal direction of the underground cavity 33 is steep, It is filled in a mountain shape with a gentle slope (Figs. 10 and 11).

(5) When the outer tube 35 slides repeatedly in parallel with the injection and reaches the position where the lower end of the outer tube 35 is higher than the top end of the underground cavity 11, final filling is started.
In the final filling, it is confirmed that the end wall 38 that completely closes the cross section of the underground cavity 33 is formed by the increase of the pumping pressure, and the filling is finished.

  Also in this embodiment, the end filler 37 is discharged in the direction of the wall surface of the underground cavity 33 in the same manner as in the first and second embodiments, so that the cross section of the underground cavity 33 can be reduced with a smaller filling amount than before. A closing end wall 38 can be formed.

  (6) A boring hole (not shown) drilled in the filling target area after forming the end wall 38 at the other end of the filling target area and closing the filling target area in the same procedure as above. The filling of the underground cavity is completed by pouring and filling the filling material through.

  Thus, in the construction method of the present embodiment, the end filler 37 is filled while sliding the outer tube 35 upward, so that the early closing of the lower discharge holes 32... Can be prevented. It can efficiently fill underground cavities.

Further, even when filling an underground cavity filled with groundwater, the end filler 37 is discharged into the already discharged end filler 37, so that material separation is prevented and the groundwater is discharged. Can be prevented.
For example, in the case of filling in an underground cavity that is not filled with groundwater, that is, filling in the air, there is no risk of material separation, so the sliding method (sliding time and sliding amount) of the outer tube 35 is It can be changed as appropriate.

  It is to be noted that the number, arrangement, and shape of the discharge holes of the inner pipe 34 can be changed as in the first and second embodiments.

It is the (a) side view and (b) top view which showed a mode that the underground cavity was filled with the filler by Example 1 of an underground cavity filling method . It is an expanded horizontal sectional view same as the above. It is the perspective view which showed the filling pipe | tube used in a present Example. (a)-(e) is the perspective view which showed the example of the other filling pipe | tube which can be used in a present Example. It is the (a) side view and the (b) top view which showed a mode that the underground cavity was filled with the filler by Example 2 of an underground cavity filling method . It is an expanded horizontal sectional view same as the above. It is the perspective view which showed the filling pipe | tube used in a present Example. (a)-(e) is the perspective view which showed the example of the other filling pipe | tube which can be used in a present Example. It is the perspective view which showed a mode that the outer tube | pipe of the filling tube used in Example 3 of an underground cavity filling method was slid. It is (a) side view and (b) top view which showed a mode that the underground cavity was filled with a filler using the said filling pipe. It is an expanded horizontal sectional view same as the above. It is (a) side view and the (b) cross-sectional view which showed a mode that the filler was filled by the conventional underground cavity filling method.

Explanation of symbols

11, 23, 33 Underground cavities 12, 25, 37 End fillers 13, 26, 38 End wall bodies 14, 21, 31 Discharge pipes 15, 22, 32 Discharge holes 16, 24, 36 Drill holes 34 Inner pipe 35 Outer pipe

Claims (5)

A plurality of discharge holes are arranged along the axial direction on the side surface of the pipe whose lower end is closed, and an inner pipe in which the lower one is opened larger and the upper one is opened smaller, and the outer pipe is arranged outside the inner pipe. A filling tube for filling an underground cavity characterized by comprising an outer tube that is slidable in a direction and fitted. 2. The filling pipe for filling an underground cavity according to claim 1, wherein a marking indicating the opening direction is provided at an upper extension position of the discharge hole. (1) Drill a boring hole that reaches the filling target area of the underground cavity from the ground,
(2) Insert the filling pipe for filling the underground cavity into the borehole to the position where the lower end reaches the vicinity of the bottom of the underground cavity, and rotate the inner pipe of the filling pipe appropriately. Direct the discharge hole in the transverse direction of the underground cavity,
(3) While opening the discharge hole of the inner pipe in order from the lower one by sliding the outer pipe of the filling pipe upward, the end filling material is pumped from the upper end side of the filling pipe to open the state. An underground cavity filling method characterized by forming an edge wall body that closes a transverse section of the underground cavity by discharging an edge filler from the ejection hole. Slide the outer tube in accordance with the increase in the bulk of the end filler while keeping the open discharge hole of the inner tube buried in the end filler already discharged. The underground cavity filling method according to claim 3. 5. The underground cavity filling method according to claim 3, wherein the sliding of the outer pipe is performed by operating a wire or the like attached to the outer pipe.

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