JPH0676686B2 - Ground consolidation method and combination pipe used for it - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a natural consolidation method for strengthening the natural ground by injecting a chemical solution during tunnel excavation and the like, and a combined pipe used therefor.

[Conventional technology]

Conventionally, in tunnel excavation work, etc., the ground has been strengthened in the first stage of excavation. To strengthen this ground, use a pipe roof construction method for soft ground, etc., press a pipe of approximately the same diameter as the hole drilled by boring etc., and insert the injection pipe into the pipe. Then, by intermittently retracting the injection pipe while discharging the chemical liquid such as water glass from the tip of the injection pipe, the chemical liquid is gradually filled and cured from the tip side of the pipe to reinforce the ground. ing. However, the chemical injection method is used in a place where the ground is relatively in good condition. That is,
Do not insert the pipe into the hole drilled by boring etc. to reinforce the hole, insert the injection pipe directly into the drilled hole, and while retracting the injection pipe intermittently, remove the water glass etc. from the injection pipe. Reinforcement is performed by discharging a chemical solution and hardening it in a drilled hole. However, in such a construction method, it is necessary to intermittently retreat the injection pipe to discharge and cure the chemical liquid, and to fill the deep hole with the chemical liquid curing body step by step, which makes the work complicated and time-consuming. Also, there is a drawback that a large-sized device is required. Recently, a method has been developed in which a urethane resin-based chemical liquid that cures quickly and has a large foaming pressure is used in place of the water glass-based chemical liquid. However, in this method, since the urethane resin-based chemical liquid is rapidly cured, it is not possible to gradually fill and strengthen the inside of the drilled hole with the cured body as in the case of using the water glass-based chemical liquid. That is, even if an attempt is made to retract the pipe after the urethane-based chemical liquid is discharged, the chemical liquid will momentarily cure, and the pipe cannot be retracted. The pipe is necessarily left in the drilled hole. Therefore, this method has a drawback that it cannot be applied when the length of the drilled hole is long.

[Problems to be Solved by the Invention]

The present invention has been made in view of such circumstances, and it is possible to cope with long drilling without the need for large-scale equipment and to strengthen the ground in a short time, and a combination pipe used therefor. The purpose is to provide.

[Means for Solving the Problems]

In order to achieve the above object, the ground consolidation method of the present invention,
Insert a pipe with a plurality of small holes on the outer circumference into a long hole drilled in the ground, and inject the effervescent chemical into the bag that is installed around the outer circumference of a predetermined part of the pipe. The bag body is inflated by using the expanded bag body as a partition to divide the elongated hole into a plurality of spaces in the lengthwise direction, and the congealing chemical liquid is discharged from the outer peripheral hole of the pipe into each of the separated spaces. After filling each space, it is permeated and hardened into the ground from the peripheral wall of the long hole to form a consolidation region in the ground portion in the long hole and the outer circumference of the long hole. An inflatable bag body wound around the outer periphery of the middle portion of the press-fitting pipe; a plurality of small holes formed in the outer peripheral wall of the press-fitting pipe portion on the tip side of the formation position of the bag body; Tube extending from the flexible bag toward the inlet of the pipe and the tip of itself is located behind the inflatable bag. A short press-fit pipes juxtaposed with the press-fit pipes to be located, the combination pipe comprising a plurality of small holes formed in the outer peripheral wall of the distal end side of the short press fitting pipe and the second aspect.

[Action]

That is, the ground consolidation method of the present invention is to insert a pipe directly into a long hole drilled in the ground, expand the inflatable bag body on the outer periphery of the pipe by injecting a foaming chemical solution, and The interior is divided into multiple spaces, and in order to discharge the congealing liquid such as urethane from the pipe into each of the divided spaces, the entire inside of the long hole is uniformly filled with the consolidating liquid. Can penetrate into. Therefore, the construction time can be shortened, and at the same time, the step of sequentially pulling out the pipes is not required, so that a large device or the like is not required. Further, since the inside of the long hole is divided into each space by partition walls, the pressure in each space increases due to the injection of the consolidating chemical liquid, whereby the consolidating chemical liquid fills the space. After that, it penetrates into the ground around the long holes and hardens there.
Therefore, solidification areas are formed not only in the long holes but also in the ground around the long holes, so that the solid ground is sufficiently strengthened both inside and inside the long holes. Become.

Next, examples will be described.

〔Example〕

FIG. 1 shows a combined pipe 1 used in one embodiment of the present invention.
Is shown. This combination pipe 1 is a combination of three types of pipes, and the first pipe is shown in FIG.
As shown in, the inflatable bag body 2 made of cloth or the like (cloth or the like that allows compressed air to pass but does not allow chemical liquid to pass through) is wrapped around the outer periphery of about 1/3 from the end of the long press-fitting pipe, A large number of small holes 3 are formed on the outer peripheral wall of the portion on the tip side of the formation position of the bag body 2. The tip 4 of the press-fitting pipe 1 is formed as a closed point. A tube 6 for press-fitting the expansive drug solution from the bag body 2 extends in the rear end direction of the pipe 1. Reference numeral 5 is a coupler provided at the tip of the tube 6. The second pipe is approximately two-thirds of the above press-fitting pipe and is installed in parallel with the press-fitting pipe. As shown in FIG. An inflatable bag body 2 made of cloth or the like is wound around the outer periphery, and a large number of small holes 3 are formed in the outer peripheral wall of the tip end side of the inflatable bag body 2. Such attachment of the inflatable bag body 2 is performed by attaching the left and right ends of the inflatable bag body 2 to the outer circumference of the pipe with a string or the like and extending the tube 6 from the bag body 2 as shown in FIG. The third pipe has a total length of about 1/3 of that of the press-fitted pipe and is installed side by side with both of the above-mentioned pipes. Is configured. Each of these pipes has an inner diameter of 15 mm and a length of 500 mm.
The pipes are connected by screws.

The solidification of the natural ground 9 using the above-mentioned combination pipe is performed as follows. First, as shown in FIG.
The combined pipe 1 is inserted into the slotted hole 10 as shown in the figure, and in this state, the inlet portion of the slotted hole 10 is closed with a packing material 7 made of cloth or the like. Then, in that state, the quick-setting and high-foaming urethane resin is injected into the first and second inflatable bag bodies 2 of both pipes by using a pump (not shown), and the bag body 2 is shown in FIG. Inflate rapidly as shown. As a result, the expanded bag body 2 serves as a partition wall, and the inside of the elongated hole 10 is divided into three spaces 11 in the length direction. 3 spaces in this case
11 are set to have substantially equal intervals. Next, from that state, a chemical liquid made of urethane foam resin is injected into the above three pipes and discharged from a small hole on the outer periphery thereof. In this case, since the inside of the long hole 10 is divided into each space, the discharged urethane resin chemical liquid is evenly filled in each of the spaces, whereby the long hole 10 is evenly filled with the urethane resin. become. Then, due to the foaming pressure of the urethane resin, the urethane resin filled in each of the compartments permeates from the hole wall 12 of the elongated hole 10 to the outer peripheral portion, and as shown in FIG. The solidified region 8 is also formed in the ground portion around the hole. In this way, the ground is strengthened well.

Although the three combined pipes 1 are used in the above embodiment, instead of each of them, a small hole 3 is formed in the entire press-fitting pipe shown in FIG. ) Bag 2
What formed the 2nd bag body 2 in the position corresponding to the formation position of may be used. Further, the congealing chemical liquid discharged from the pipe is not limited to the urethane resin, and for example, a water glass type chemical liquid may be used.

〔The invention's effect〕

Since the present invention consolidates the ground as described above, the working time can be significantly shortened, at the same time, long drilling can be performed, and large equipment is not required. Then, since the inside of the long hole is divided into small parts and the consolidating chemical liquid is discharged into each space, the discharged chemical liquid permeates into the ground around the outer periphery of the long hole by its own pressure and hardens. Therefore, not only the inside of the long hole but also the ground around the long hole is solidified, and it becomes possible to realize the strong reinforcement of the ground.

[Brief description of drawings]

FIG. 1 is an overall view of a combined pipe used in an embodiment of the present invention, FIGS. 2 (a), (b), and (c) are explanatory views of each pipe used therein, and FIG. 3 is an inflatable bag body. FIG. 4, FIG. 5, FIG. 6 and FIG. 6 are partial enlarged views showing a state in which is attached, and are explanatory views of a working state of an embodiment of the present invention. 1 ... pipe, 2 ... expandable bag, 3 ... small hole, 5 ...
Coupler, 6 ... Cube, 7 ... Packing material, 8 ...
Consolidation area, 9 ... Ground, 10 ... Long hole

Claims (2)

[Claims] 1. A pipe having a plurality of small holes formed in its outer periphery is inserted into a long hole drilled in the ground, and foam is formed on a bag body provided around the outer periphery of a predetermined portion of the pipe. A pesticide solution is injected to inflate the bag, and the expanded bag is used as a partition to divide the elongated hole into a plurality of spaces in the lengthwise direction, and each of the separated spaces is fixed from the outer peripheral hole of the pipe. After the binding chemical is discharged to fill each space, it is permeated and hardened from the peripheral wall of the long hole into the ground, and a consolidation region is formed in the ground portion in the long hole and the outer circumference of the long hole. Ground consolidation method. 2. A press-fitting pipe, an inflatable bag body wound around the outer periphery of an intermediate portion of the press-fitting pipe, and a plurality of members formed on an outer peripheral wall of a part of the press-fitting pipe which is located on the tip side of the formation position of the bag body. A small hole, a tube extending from the inflatable bag body in the inlet direction of the pipe, and a short press-fitting pipe juxtaposed with the press-fitting pipe so that the tip of itself is located on the rear side of the inflatable bag body, A combination pipe having a plurality of small holes formed in the outer peripheral wall on the tip side of the short press-fitting pipe.