JPH0449276Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a nozzle for press-fitting an anchor material used in constructing a steel pipe type lock bolt used to reinforce the ground around the outer periphery of a tunnel in tunnel excavation.

[Conventional technology] This type of lock bolt can be roughly divided into two types: tip-fixed type and fully adhesive type.The latter type of fully adhesive type lock bolt is installed in the case of high-quality ground.
The work is carried out in the order of (1) drilling, (2) injection of fixing material, and (3) driving of lock bolts, but in the case of bad ground, the hole wall collapses immediately after drilling, and the fixing material is injected. This makes it difficult to drive lock bolts, making it impossible to install lock bolts.

Conventionally, as a lock bolt used in the case of such bad ground, a steel pipe 21, as shown in FIG. There was a steel tube type lock bolt that utilizes.

In the case of this conventional steel tube type lock bolt, as shown in FIG. 6, a drilling device 24 equipped with a rod 26 having a bit 25 at the tip is attached to the end of the steel tube 21 without the female thread 22 first. The steel pipe 21 is driven into the ground A using the following method. Next, after attaching the screw member 27 having the injection hole to the female thread 22 by screwing the male screw (large) 28, as shown in FIG. The flange 31 is connected and fixed by screwing the cap nut 32 and the external thread (small) 29 of the screw member 27. Thereafter, the fixing material B such as mortar is pumped and injected through the injection hole of the screw member 27, and permeates into the surrounding ground A from the inside of the steel pipe 21 through the small hole 23 on the outer periphery as shown in FIG. . Then, as shown in the figure, after removing the pressure feed pipe 30, a washer 34 and a nut 35 are attached to stabilize the ground A, and the construction is completed. In addition, in order to prevent the steel pipe 21 from slipping out during pressure feeding of the fixing material or before solidification,
A wedge 33 is used.

[Problems to be solved by the invention] In such a conventional method of press-fitting an anchoring material into a steel tube type lock bolt, the flange 31 of the pressure feed pipe 30 is disposed opposite to the screw member 27, and the anchoring material B is inserted into the screw member 2.
Since it is injected from the mouth of the steel pipe 7, it is difficult for the air inside the hole to escape, the fixing material does not penetrate well, and the fixing effect tends to be uneven. Since it is necessary to fill the space with fixing material, there is a problem in that a large amount of fixing material such as mortar is required.

[Means for solving the problem] The nozzle for press-fitting fixing material with a built-in air pipe of the present invention was developed to solve the above-mentioned problem. In the nozzle of the fixing material pressure feeding pipe, which is inserted into a steel pipe for lock bolts with many small holes drilled in the steel pipe and presses the fixing material into the steel pipe, the nozzle has an air jet part equipped with a check valve at the tip inside the nozzle. A trachea is provided, and the tip of the air tube is placed close to the tip of the nozzle.

[Operation] The nozzle for pressing in the anchoring material of the present invention is constructed as described above, so after driving the steel pipe for the lock bolt into the ground as in the conventional method, the nozzle is inserted deep into the steel pipe and kept immobile by means of a cap nut or the like.
Next, the fixing material is pumped into the steel pipe through the nozzle from the pressure pipe, and the fixing material is injected from the inner surface of the steel pipe through numerous small holes into the outer periphery of the steel pipe and into cracks in the surrounding ground.When the nozzle is removed after injection is completed, compressed air is sent from the air supply pipe to supply air from the air outlet at the tip, and the entire nozzle can be easily pulled out from the steel pipe.

[Embodiment] An embodiment of the present invention will be described based on the drawings, focusing mainly on the construction of lock bolts.

Figure 1 shows steel pipe 1 for lock bolts according to the present invention.
In the cross-sectional view, the steel pipe 1 has a diameter of about 50 mm and is open at both ends, the peripheral wall of one end is turned outward to make the wall thicker, and a screw 2 is provided on the outer periphery of that end. A large number of small holes 3 are bored throughout the entire body, and a large number of irregularities 4 are provided on the outer peripheral surface.

Next, the construction order will be explained. First, as in the conventional example described above, the end opposite to the screw 2 is placed first, and a drilling device 24 equipped with a rod 26 having a bit 25 at the tip is used. and drive the steel pipe 1 into the ground A (see Figure 6).

Next, the punching device 24 is removed, and the fixing material press-fitting nozzle 7 of the present invention is inserted into the steel pipe 1 instead, as shown in FIG.

The nozzle 7 of the present invention is provided at the tip of the fixing material pressure feeding tube 6, and includes an air tube 9 having an air jet section 10 equipped with a check valve 11 at the tip thereof.The tip of the air tube 9 is shown in the figure. It is placed close to the nozzle tip like this. In the illustrated example, the check valve 11 is a ball check valve, and as shown in FIG. The seat member 13 is screwed onto the air pipe 9 via a threaded portion 14 . Further, the air supply pipe 9 is integrally supported by the pressure supply pipe 6 at its base, and the pressure supply pipe 6 is connected to a fixing material pressure supply source, and the air supply pipe 9 is connected to a pressurized air supply source.

The nozzle 7 of the present invention having such a configuration is
It is inserted into the steel pipe 1 up to the seal part 8 at the base. It is preferable to provide a packing around the seal portion 8 to ensure sealing against the inner surface of the steel pipe 1.

In addition, in order to prevent the nozzle 7 from slipping out of the steel pipe 1 when press-fitting the fixing material, a cap nut 5 that engages with the shoulder of the pressure-feeding pipe 6 is screwed onto the external thread 2 as shown in the figure, or and the stepped part of the steel pipe 1 (the left end of the male thread 2 in FIG. 2), or by engaging the hook member between the pipe 6 and the stepped part of the steel pipe 1, or by supporting the pressure pipe 6 with other equipment, The pressure feed pipe 6 may be held against the steel pipe 1.

Furthermore, as in the conventional example, a wedge 17 is used to prevent the steel pipe 1 from slipping out while the fixing material B is being press-fitted or before the fixing material is solidified.

After inserting and holding the nozzle 7 into the steel pipe 1, the fixing material B, such as mortar, is force-fed from the pressure-feeding pipe 6, and the nozzle 7
The fixing material is injected from the inner surface of the steel pipe through a large number of small holes 3 into the outer periphery of the steel pipe and cracks in the surrounding ground A.

To pull out the nozzle 7 from the steel pipe 1 after injection is complete, first release the holding means of the pressure feed tube 6, such as by removing the cap nut 5, and then send pressurized air to the air feed tube 9 to check the tip. While blowing air out through the valve 11, the nozzle 7 is gradually pulled out. In this way, air is supplied from the air jet section located close to the tip of the nozzle to the gap created by the withdrawal of the nozzle 7, so that the nozzle can be withdrawn from the steel pipe very smoothly.

After the nozzle 7 is pulled out, a cylindrical cavity C is created in which no fixing material exists, as shown in FIG.
A stress measuring steel rod 20 can be fixed to the bottom of the hollow hole C, if necessary. Therefore, if the steel rod 20 is set as shown,
As time passes, tensile stress is applied to the steel pipe 1 due to movements such as the protrusion of the ground, but this does not apply to the steel bar 20, so the elongation of the steel pipe 1 with respect to the standard length of the steel bar 20 is calculated. It can be used as an effective means for safety as it can be measured at any time to determine the stress applied to the steel pipes, and in turn detect the movement of the ground.

Note that, after removing the nozzle 7, the washer 18 and nut 19 are attached to stabilize the ground A and complete the construction, which is the same as in the conventional case.

Furthermore, the nozzle of the present invention can also be applied to the steel pipe 21 of the type shown in FIG. If the fixing material is not attached to the female thread 22 by supporting it, it can be used in the same manner as described above.

Since the fixing material B can be injected from the back of the steel pipe 1, the air inside the steel pipe can easily escape, the fixing material can penetrate well, and the fixing effect will not be uneven. You can easily pull out the nozzle by feeding the
It has good workability and can perform high-quality construction.

After press-fitting the fixing material B, by pulling out the nozzle,
As shown in FIG. 4, since a cavity C corresponding to the volume of the nozzle 7 is created, the fixing material can be saved by the amount of the cavity C. Furthermore, since a large number of lock bolts are driven, even if the savings for each bolt is small, the overall savings effect is extremely large.

When you want to measure the stress applied to the steel pipe due to the movement of the ground after lock bolt driving, use the hollow hole C.
A steel rod 20 is planted at the bottom of the steel rod 20 and a steel pipe 1.
The stress applied to the steel pipe can be measured at any time from the relative displacement with the end face of the steel pipe, which can be used as an effective means for safety measures.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the steel pipe for lock bolts according to the present invention, Fig. 2 is an explanatory sectional view of the nozzle of the present invention in use, Fig. 3 is an explanatory sectional view of the air jetting part of the nozzle, and Fig. 4 is the same. An explanatory cross-sectional view after construction with a nozzle, Fig. 5 is a cross-sectional view of a steel pipe for lock bolts according to a conventional example, Fig. 6 is an explanatory cross-sectional view of the conventional example during construction (), and Fig. 7 is an explanatory illustration of the same construction (). The cross-sectional view and FIG. 8 are explanatory cross-sectional views after the same construction. 1...Steel pipe for lock bolt, 3...Small hole, 6...
... Fixing material pressure feeding pipe, 7... Nozzle, 9... Air feeding pipe,
DESCRIPTION OF SYMBOLS 10... Air blowing part, 11... Check valve, A... Earth, B... Fixing material.

Claims (1)

[Scope of utility model registration request] In the nozzle of the fixing material pressure feed pipe, which is inserted into the lock bolt steel pipe that is driven into the ground and has many small holes drilled in the entire outer peripheral wall, and presses the fixing material into the steel pipe, there is a non-return check at the tip inside the nozzle. 1. A nozzle for press-fitting a fixing material having a built-in air supply pipe, characterized in that an air supply pipe has an air jetting part equipped with a valve, and the tip of the air supply pipe is positioned close to the nozzle tip.