JPH0560039B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tubular lock bolt used for stabilizing various ground conditions.

[Prior Art] In addition to lock bolts that are fixed to the ground using a mechanical fixing mechanism, there are also known lock bolts that use an injection type. Typical injection type lock bolts are listed below.

Attach a cloth packer, cement milk injection tube, and exhaust tube to the anchor, insert it into the hole being drilled, pump milk from the injection tube, inflate the cloth packer to fix the anchor in the hole, and then inject milk. It is a lock bolt that is filled into the hole by drilling, and the filling is completed after confirming that milk comes out from the exhaust hole.

As shown in Japanese Patent Publication No. 57-920, this is a lock bolt in which a tubular lock bolt material with a male thread cut at the rear end is inserted into a drilled hole and fixed by injecting adhesive from the pipe opening.

As shown in Japanese Unexamined Patent Publication No. 62-41899, a drilling rod is inserted into a tubular rock bolt having a number of holes on the peripheral wall, and while drilling with a tip bit, the tubular rock bolt is inserted into the ground, and the drilling rod is inserted into the ground. This is a lock bolt that is fixed to the ground by injecting a fixing agent into the lock bolt and injecting it through a hole in the peripheral wall after the rod is pulled out.

As shown in Japanese Unexamined Patent Publication No. 62-50600, a lock bolt that is deformed vertically and whose tip is closed is inserted into a hole, and pressure is applied from the end to enlarge the lock bolt so that it comes into close contact with the hole wall. The patent discloses a lock bolt, and also discloses a lock bolt that expands and fixes a C-shaped pipe.

[Problems to be Solved by the Invention] Since the above-mentioned method uses an adhesive and a fixing agent compared to the lock bolt using a mechanical fixing method, it can be applied to a wide range of geological formations, but it has the following problems.

(Lock bolt) A. It is necessary to insert an anchor, cloth packer, and two injection/exhaust tubes during drilling, and the dimensions of the injection tube are limited and the diameter is small. Therefore, only cement milk can be injected, and mortar It is not possible to use cheap materials such as

(b) Cloth packs etc. are easily damaged and must be handled with care, and manual labor is often required for filling the cloth packs and installing each exhaust tube.

C. In order to speed up the hardening of the injected cement milk, a hardening accelerator is required, and the system is a two-component system consisting of the cement milk's main ingredient and a hardening agent, which has disadvantages such as the complexity of the equipment and the hassle. In practical terms, it is only used when there is no other method other than injection, such as in areas where there is a lot of spring water.

(Lock bolt) When a lock bolt is inserted and adhesive is injected, the lock bolt comes out due to the injection pressure, making it impossible to inject.

(Lock Bolt) E. It is a self-drilling lock bolt, and dirt and debris from the drilling enters the surrounding wall hole, and dirt from the drilling also gets clogged between the tubular rock bolt and the ground, so the fixing agent may not be injected or may not be injected. However, the quality of the fixing agent was extremely poor, such as being weak and sticky even when used.

(f) Although this is a tubular lock bolt having a large number of holes in a steel pipe, the surface of the tube is smooth and the lock bolt is fixed with resistance only on the surface that is in contact with the holes, so it has a drawback that the fixation is weak. Further, even if the lock bolt has a large number of holes, it takes time and effort to drill the holes, resulting in a very expensive lock bolt.

(g) Furthermore, like the above-mentioned (b), there is a drawback that the lock bolt is pushed out by the injection pressure when the fixing agent is injected.

(Lock bolt) H. The method of enlarging and fixing the lock bolt on the hole wall had the disadvantage that a gap was created between the hole wall and the lock bolt, allowing spring water to enter and causing corrosion of the lock bolt.

High-pressure water and high-pressure oil had to be used when enlarging the relock bolts, making the work sometimes dangerous.

H. Even though the hole wall surface was damaged by drilling, there were problems in terms of durability with only friction-based fixation.

In view of the above points, an object of the present invention is to provide a tubular lock bolt that can be securely fixed to the ground without coming out of the drilled hole due to the injection pressure when injecting a fixing agent or the like.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a lock bolt that is driven into a borehole formed in the ground, and is inserted into the lock bolt and between the rock bolt and the borehole wall through a metal fitting that is hooked at the rear end. A tubular lock bolt into which a fixing agent is injected between the lock bolts has a curvature that irregularly bends once or more with a radius of curvature larger than the drilling diameter over the entire length of the lock bolt in the axial direction, and the outer circumferential wall has the above-mentioned curves along the generatrix direction. It is characterized by the formation of wavy irregularities with a radius of curvature smaller than that of the warp. Further, in order to facilitate the injection of a fixing agent between the lock bolt and the wall of the drill hole after driving it into the drill hole, an injection pipe is provided from the rear end of the lock bolt toward the middle in the longitudinal direction.

[Function] The tubular lock bolt has a curvature that irregularly bends once or more with a radius of curvature larger than the diameter of the drilled hole over the entire length in the axial direction, and a wavy unevenness with a radius of curvature smaller than the curvature along the generatrix direction of the outer peripheral wall. Because of this, when inserted into the borehole, the lock bolt comes into contact with the borehole wall due to warping and frictional force, supports the injection reaction force of the fixing agent, and securely fixes the lock bolt.

[Example] Figures 1 and 2 show the procedure of the fixing method using the tubular lock bolt of the present invention, in which 1 shows a hole drilled in the ground, 2 shows a tubular lock bolt, and 3 shows a hole around the outside of the tubular lock bolt. 4 is a warp in the tube axis direction, 5 is a flange formed at the rear end of the tubular lock bolt, 6 is a spherical washer or end metal, 7 is a fixing agent injection pipe, and 8 is a packer.

After lightly inserting the tip of the tubular lock bolt 2 into the hole 1 drilled in the ground, drive it into the hole 1 with the driving machine 9 as shown in Fig. 1, and insert the injection pipe into the opening of the lock bolt 2. is inserted, the fixing agent 10 is injected (FIG. 2), the injection pipe 7 is pulled out, and the ground is stabilized by hardening the fixing agent.

The tubular lock bolt 2 has a curvature that irregularly bends once or more with a radius of curvature larger than the diameter of the drilled hole over its entire length in the axial direction, and forms wavy irregularities with a radius of curvature smaller than the curvature along the generatrix direction of the outer peripheral wall. ing. That is, as shown in Figs. 6 and 7, the tubular body is pressed at regular intervals to create unevenness 3, and at the same time, the deformation is controlled to create warpage (axial curvature) larger than the diameter of the drilled hole 1. ) 4 is formed. The lock bolt may be made of any material such as steel pipes, resin pipes, aluminum pipes, etc., as long as it is particularly elastic and provides a certain degree of fixation due to friction due to warping.

The opening of the tubular lock bolt 2 is provided with an outward flange 5 to which a spherical washer or end piece 6 is fitted. As will be described later, a threaded portion may be formed in the opening of the lock bolt and a flange may be attached afterwards. When lock bolt 2 is driven into drilled hole 1, unevenness 3
The outer peripheral surface with the sled 4 is in frictional contact with the borehole wall and supports the reaction force of injection of the fixing agent. The initial fixing force is supported by the end metal 6 of the opening.

FIG. 3 shows the case where the tubular lock bolt 2 is driven into the drilled hole 1 and, at the same time, the fixing agent 10 is injected by the driving/injection combination machine 11 having the injection port 12 in the center.

4 and 5 show the case where the fixing agent is injected into the drilled hole before driving. As shown in FIG.
After filling with 0, the tubular lock bolt 2 is driven in and fixed by the driving machine 9 as shown in FIG.

The concave and convex portions 3 of the tubular lock bolt 2 are not necessarily wave-shaped as shown in FIG. That is, Fig. 8 A to D
1 shows the surface shape of a tubular lock bolt before being warped. FIG. 8A is designed so that the tubular surface corresponds to a concave portion and the tubular surface corresponds to a convex portion, and care has been taken so that the unevenness does not become larger than the outer diameter of the tubular shape. That is, random unevenness 3a is provided inside the outer diameter of the tubular shape.

The tubular surface shown in Figure B has a sawtooth-like unevenness 3b with a narrow tip and a large rear end, making it easy to insert and difficult to pull out.

Figure C shows one in which spherical parts 3c are formed at intervals, and Figure D shows one in which tapered parts 3d are formed at intervals, so as not to damage the ground due to the geology which requires a smooth surface. This takes into account the shape that can be inserted.

The above is an example of a shape that achieves the desired purpose without damaging the hole, taking into consideration the purpose of use and geology. Various changes are possible depending on the required amount. It is important that the diameter D of the drilled hole 1 is larger than the pipe diameter d. The shape of the warp may be a screw type (ribbon screw type) or the like. The number of warps increases or decreases depending on the size of the warp width L, the nature of the ground, the size of the hole diameter D, the initial fixing force of the lock bolt, and the pullout resistance due to the lock bolt injection pressure.
At least one is required, and in some cases it is desirable to provide a large number.

The fixing agent 10 may be an organic or inorganic adhesive (particularly a cement mixture) or a mixture thereof with appropriate additives, as long as it can be cured and fixed after being filled. The injection method is not limited to injecting the fixing agent after driving the lock bolt, but it is also possible to fill the hole with the fixing agent and then driving the lock bolt.

Although the flange 5 is formed at the opening of the tubular lock bolt 2, the end piece 6 may be secured using a screw. For example, as shown in FIG. 9, a male thread 2a is formed in the opening of the lock bolt 2, the end metal 6 is inserted into this part, and a nut 14 is screwed into the male thread 2a, or the opening of the lock bolt 2 is formed as shown in FIG. A female thread 2b is formed at the end, and after the end metal 6 is inserted, the bolt 15 is screwed. Further, as a modification of the flange, as shown in FIG. 11, the tube end may be expanded in diameter to form a spherical head 2C, and the end piece 6 may be held by the head 2C. Further, as shown in FIG. 12, a through hole 2d may be provided in the diametrical direction near the rear end of the tubular lock bolt 2, and a pin 16 may be inserted through the hole 2d to lock the end piece 6 therein.

Next, we will show an example in which a drainage function is provided when there is underground water in the ground.

As shown in FIG. 13, after the tubular lock bolt 2 is driven by the driving and water injection device 11, a fixing agent is injected between the hole wall and the tubular lock bolt. Next, as shown in FIG. 14, the tip and the inside of the lock bolt are washed with water using the pipe 17, the fixing agent is removed by air blowing, and groundwater 20 from the ground is discharged from the tip through the tubular lock bolt 2. Figure 15). If there is a large amount of groundwater 20, the injection pipe 18 is connected to the upper wall of the tubular lock bolt 2 as shown in FIG. The lock bolt is constructed while draining underground water from the tip.

[Effects of the Invention] As described above, in the present invention, since a tubular lock bolt with unevenness and warp is driven into a hole in the ground, the injection reaction force of the fixing agent can be supported and the fixing agent can be reliably filled. Other advantages are listed below.

Since tubular lock bolts are obtained by pressing steel pipes, they are not only extremely low cost, but can also be processed at the point of use using a simple press machine.

Because the rock bolt is initially fixed by friction in the warped portion of the tubular rock bolt, the rock bolt stabilizes the ground and prevents dangers due to cave-ins and collapses.

Since the lock bolt is fixed in the hole by friction in the warped portion, the lock bolt does not slip out of the hole due to the injection pressure of the fixing agent, etc., and the fixing agent can be completely press-fitted, resulting in high-quality lock bolt fixing.

The lock bolt is established quickly and has the ability to take even the slightest load from the ground.

The rock bolt has certain irregularities on its peripheral wall, and has the ability to resist movement of the ground through the fixing device.

Even if there is spring water, the fixing agent etc. can be completely filled and the fixing effect can be improved, and it can also have a drainage function.

The rock bolt is not fixed to the ground by itself, but the area around the rock bolt is hardened with a fixing agent, which prevents deterioration of the rock bolt due to corrosion etc.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the tubular lock bolt of the present invention driven into a drilled hole, Fig. 2 is a sectional view of the lock bolt of Fig. 1 in which a fixing agent is injected, and Fig. 3 is a sectional view of the tubular lock bolt of the present invention inserted into a drilled hole. Figures 4 and 5 are cross-sectional views of the case in which the fixing agent is injected into the drilled hole and the fixing agent is injected simultaneously with the driving and injection machine. 7 is a perspective view of a tubular lock bolt, FIG. 7 is a sectional view showing a sled model showing the state of sled, and FIGS. 8 A, B, C, D
A perspective view showing an example of the uneven shape of the lock bolt surface before being shaved; FIGS. 9 to 12 are partial cross-sectional views showing modified examples of the end of the tubular lock bolt; FIG.
Figures 1 to 16 are cross-sectional views showing examples of construction of the tubular lock bolt of the present invention when there is a lot of groundwater. 1... Hole drilling, 2... Tubular lock bolt, 3...
Unevenness, 4... Warp, 5... Flange, End metal (washer), 7... Injection pipe, 8... Packer, 9...
... Drive-in machine, 10... Fixing agent, 11... Drive-injection combination machine.

Claims (1)

[Scope of Claims] 1. In a rock bolt that is driven into a hole made in the ground and injects a fixing agent into the rock bolt and between the rock bolt and the wall of the hole through a end metal hooked at the rear end, the axis of the rock bolt is It is characterized by having a curvature that irregularly bends once or more over the entire length in the direction with a radius of curvature larger than the drilling diameter, and on the outer peripheral wall, wavy irregularities with a radius of curvature smaller than the curvature are formed along the generatrix direction. Tubular lock bolt. 2. Claim No. 2, characterized in that the lock bolt is provided with an injection pipe that extends from the rear end toward the middle in the longitudinal direction to directly inject the fixing agent between the outer circumferential wall and the drilling wall from the middle in the longitudinal direction. The tubular lock bolt according to item 1.