JP2784561B2 - Ground mountain consolidation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for solidifying a soft ground with a chemical liquid for solidifying in a tunnel excavation work or the like.

[0002]

2. Description of the Related Art Conventionally, in a tunnel excavation work performed in a stratum such as a soft or crushed ground, in the first stage of the excavation, the ground is strengthened by using, for example, the following construction method. That is being done. In this method, as shown in FIGS. 6 and 7, the digging surface of the ground 3 indicated by the dashed lines A and B (in FIG. 6, the dashed line C indicates the hole of the tunnel, and the dashed line A Around the outer periphery of the area surrounded by C, the holes 1 and 2 having different lengths of about 6 m and 3 m are alternately drilled toward the depth of the ground 3 along the outer circumference of the ground. By filling the hole with a consolidating chemical and hardening it to form a roof conforming to the tunnel shape, it is possible to prevent loosening of the ground 3 and deformation of the ground surface due to excavation, and to enable safe excavation work It is to be. That is, in this method, first, a drill blade is attached to the tip of a drill drive shaft, and a hole is drilled in the ground 3 with the drill blade (see FIG. 3). Next, after drilling holes 1 and 2 of a predetermined length, a drill blade and a drill drive shaft are taken out, and a discharge pipe (not shown) is coaxially inserted into each hole 1 and 2. Then, the consolidating chemical is discharged from the distal end of the discharge pipe, and the inside of each of the holes 1 and 2 is filled with the consolidating chemical and permeates the periphery to consolidate the portion D. In this way, the ground 3 is strengthened. At this time, the interval between the holes 1 and 2 having different lengths is usually set to about 30 cm.

[0003]

However, in the above-mentioned method, the interval between the burials of the discharge pipes is as short as about 30 cm, and there is a problem that the ground becomes brittle when the hole is made in the ground 3 with the drill drive shaft. In addition, 6
m, the ground can only be consolidated, for example, if the distance of the soft ground in the tunnel excavation work is long, first the ground is consolidated to 6m by the above construction method, and a tunnel is drilled.
Subsequently, it was necessary to cope with soft ground with other assistance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for solidifying a ground which is easy to perform and can deeply solidify the ground in a single process. I do.

[0005]

In order to achieve the above-mentioned object, the present invention provides a method for solidifying a ground pile, comprising a step of forming a hole in a long hole drilled in the ground at or near each end thereof. it fits interpolation a different discharge pipe of is, substantially simultaneously from the opening of the plurality of discharge tubes, impregnated cured in place Yamauchi by ejecting consolidating chemical solution made of foamed urethane resins, consolidated regions natural ground Is formed.

[0006]

That is, the inventor of the present invention has a simple working process,
In addition, a series of studies were conducted to obtain a method of solidifying the ground deeply by a single operation. During the course of that research,
Drilling a deeper hole in the ground deeper than before, inserting a discharge pipe of approximately the same length into the hole, and discharging the consolidation chemical liquid from the opening formed in the peripheral wall of the discharge pipe, one operation I tried to recall that it would be possible to consolidate the ground more deeply.
However, in the above-mentioned method, if a recently used quick-hardening chemical is used as the consolidation chemical, the chemical hardens rapidly, so that it is in the middle of the discharge pipe (about 5 to 6 m from the surface to be excavated).
This causes a problem that the chemical solution is discharged from the opening and hardened quickly, and the rapid-curing chemical solution does not reach the tip of the discharge pipe. And, even if the injection speed of the drug solution is increased, the injection holes for a long time gradually increase the number of closed holes,
Only three holes are ejected. Further, even when a plurality of tubes are bundled, if a single pump is used to inject the chemical solution, the injection time will be shifted, and the holes of the adjacent tubes will be closed.
Furthermore, even when the partition wall is provided, the partition wall enters the adjacent section through the gap between the rocks, and injection into the section becomes impossible. Therefore, in order to solve this problem, further studies, the perforated elongated hole in the natural ground, fitting inserted a plurality of discharge tubes of different lengths with an opening at a distal end near Then, when the consolidation liquid comprising the foamable urethane resin is discharged substantially simultaneously from the openings of the plurality of discharge pipes, the liquid is foamed from different positions and the fluidity is reduced.
Because the chemical solution that flows out at the same time, near the middle of each opening
The foaming chemical flowing in the forward direction and the foaming chemical flowing in the reverse direction
As if a wall was created to collide and block further flow
The long hole is divided into several blocks,
The present inventors have found that it is possible to uniformly fill the inside of the rack with a chemical solution and to harden the solution, thereby consolidating the ground.

Next, the present invention will be described in detail based on embodiments.

[0008]

FIG. 1 shows four discharge pipes 4, 5, 6, and 7 having different lengths used in the solidification method of the present invention. Each of the discharge pipes 4, 5, 6, and 7 has a different length of 5 m, that is, is set to 20 m, 15 m, 10 m, and 5 m. It is set to 17 mm. And the discharge pipe 4,
In the vicinity of the distal ends of 5, 6, and 7, six discharge holes 8 for discharging the consolidating chemical liquid are formed at regular intervals.

The solidification of the ground using the four discharge pipes 4, 5, 6, 7 is performed as follows. That is, first, as shown in FIG. 2, the drill drive shaft 10 is attached to a drive device (not shown), and the drill blade 11 is attached to the tip of the drill drive shaft 10. Next, by operating the driving device, the drill blade 11 is rotated to drill a long hole 12 in the ground 3. Next, after drilling to a predetermined length (about 20 m), the drill blade 11 and the drill drive shaft 10 are taken out from the elongated hole 12. Then, as shown in FIG. 3 and FIG.
In a state where the cords 6 and 7 are bundled with the string 15, they are inserted into the long holes 12. Then, the vicinity of the opening of the elongated hole 12 is closed with the closing component 16. Then, hoses (not shown) of a consolidation chemical liquid press-in pump are connected to the rear ends of the discharge pipes 4, 5, 6, and 7, and one press-in pump is installed for each hose.
The consolidation chemical is pressed into the discharge pipes 4, 5, 6, 7 at substantially the same time from the press-fitting pump, and is injected into the discharge pipes 4, 5, 6, 7.
The ink is discharged from the discharge hole 8 at the tip of the nozzle 7. As a result, the consolidation liquid fills the long holes 12, and then penetrates into the ground 3 and hardens due to the filling pressure and the press-fitting pressure.
As shown in FIG.
3 and a portion around the long hole 12 is formed in the consolidated region 14. In this way, the solidified region 14 is continuously formed in the ground 3 in an arch shape, so that the ground 3 is reinforced while the discharge pipes 4, 5, 6, and 7 remain in the ground 3. You.

According to this ground consolidation method, four discharge pipes 4, 5, 6, and 7 having different lengths are inserted into the perforated long holes 12, and the consolidation liquid is discharged. A consolidation region 14 is formed in and around the elongated hole 12. Therefore, the work process of consolidating the ground 3 is easy, and the consolidation region 14 can be formed deep into the ground 3 by one operation.

In the above embodiment, the four discharge pipes 4, 5, 6, and 7 are previously bundled with the string 15 and inserted into the elongated hole 12, but are limited to the string 15. Instead, a belt-shaped member may be used as long as the discharge tubes can be bundled, or these four members may be bonded with an adhesive or the like. Alternatively, the bundles may be inserted one by one into the long holes 12 without bundling them in advance.

Further, the diameter of the long hole 12 is such that the discharge pipe group in a state where the four discharge pipes 4, 5, 6, 7 are bundled is
It is preferable to set so as to be in a state of substantially contacting the inner peripheral surface.

In the above embodiment, the consolidating chemical is discharged from the discharge holes 8 of the discharge pipes 4, 5, 6, 7 substantially simultaneously, so that the chemical discharged from the discharge holes 8 is discharged. The inside of the elongated hole 12 is divided into several blocks (four blocks in the embodiment) with the force of the above, and the reversion of the chemical discharged from the discharge hole 8 on the tip side of the discharge hole 8 is prevented (blocking effect). As a result, each block is uniformly filled with the medicinal solution, and as a result, the long holes 12 are uniformly filled with the medicinal solution. As described above, in order to exhibit the blocking effect, it is preferable to arrange the discharge pipes 4, 5, 6, 7 as shown in the drawing.

The number of discharge holes 8 provided in each of the discharge pipes 4, 5, 6, and 7 is not limited to six.
It is appropriately set depending on the size of the long hole 12, the type of the consolidating chemical, and the like. And it may be provided not only at the side peripheral wall of the discharge pipe but also at the top of the tip.

As the consolidating chemical used in the above embodiments, a quick-setting liquid usually made of a foamable urethane resin is used . However , in consideration of the arrival time of the consolidation liquid discharged from each position, it is also possible to press-fit consolidation liquids having different curing times. And the above-mentioned chemical liquid for consolidation includes the following (A) to (C) as a polyol component.
A liquid chemical for consolidation comprising a foamable urethane resin containing a mixture and having an OH value of 550 or more,
The ratio of the above components (A) to (C) is A / B / C in weight ratio.
= 100/0/0 to 50/40/10 is particularly preferably used. The liquid state time (rise time) until the above components are mixed and foamed in the consolidating chemical solution composed of the foamable urethane resin.
Is preferably set to, for example, about 60 to 180 sec from the viewpoint of workability.

(A) A diol containing at least one of ethylene glycol, diethylene glycol and triethylene glycol in an amount of 60% by weight or more and having an OH value of 700 or more. (B) A polyol having an average functional group of 3 to 8 functional groups and an OH group in the range of 100 to 600. (C) A diol containing 20% by weight or more of ethylene oxide.

By using such a chemical solution, the chemical solution sufficiently penetrates into the ground, and the permeated chemical solution is quickly gelled in the ground, so that the ground can be more favorably strengthened.

[0018]

As is evident from the foregoing description, the natural ground consolidation method of the invention, in the long hole, the respective tips plurality of discharge tubes having different opening at length in the vicinity to fit interpolation, said plurality At the same time, a consolidating chemical liquid made of a foamable urethane resin is discharged from the opening of the discharge pipe, and the chemical liquid is hardened to consolidate the ground. This makes it extremely easy to reinforce the ground, and it is possible to reinforce the ground deep in one operation. In addition, a quick-setting liquid chemical for consolidation can be used, and the working time can be reduced. Furthermore, the chemical liquid discharged from the opening of the discharge pipe divides the inside of the long hole into several blocks by the force of the discharge, so as to prevent the chemical liquid discharged from the opening on the distal end side from the discharge opening from returning. Thus, the liquid medicine is uniformly filled, and as a result, it is possible to uniformly fill the long holes with the liquid medicine.

[Brief description of the drawings]

FIG. 1 is a partial perspective view of four discharge pipes used in an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a construction state of solidification of ground.

FIG. 3 is a longitudinal sectional view showing a construction state of solidification of ground.

FIG. 4 is a view taken in the direction of arrow A in FIG. 3;

FIG. 5 is a vertical cross-sectional view showing a construction state of solidification of the ground.

FIG. 6 is an explanatory diagram showing a conventional example.

FIG. 7 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 3 Ground 4, 5, 6, 7 Discharge pipe 8 Discharge hole 12 Slot 13 Hardened part 14 Solidified area

Claims (1)

(57) [Claims] To 1. A long hole drilled into the natural ground, each of the tip or to fit interpolation a different discharge pipe lengths with an opening at a vicinity thereof, substantially simultaneously from the opening of the plurality of the discharge pipe
And a solidifying region formed in the ground by discharging a consolidating chemical solution made of a foamable urethane resin and allowing the liquid to penetrate and harden into the ground.