JPH0240097Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an anchor for slope protection work. The purpose is to increase the anchoring stability of anchors necessary for netting work using wire mesh or lath, or other work by providing friction against the wire mesh or lath.

[Conventional technology]

Generally, one type of protection work that artificially creates a slope is a netting work using wire mesh or lath. This construction method is an effective method for suppressing floating stones and debris such as collapsed concrete or mortar on the slope of bedrock, concrete or mortar layers, and preventing falling rocks and debris from becoming flying stones and scattering onto the road surface. It's summery.

In the above-mentioned netting work, anchors of a known shape as shown in FIG. 6 are driven in at predetermined intervals to secure the net to be stretched. If necessary, an upper anchor is driven into the shoulder of the glue, a wire rope is hung from this, and the lower anchor is fixed to the lower anchor which is also driven into the tip of the glue.

If the slope into which the anchor is driven is extremely hard rock, or if it is made of concrete or a layer of mortar, no matter how acute the lower end 13 is, it will be hard and will dig in if the hook part 12 at the top of the anchor is hammered by hand. Because of this, we couldn't just drive in the anchor right away, so we had to drill a pilot hole in advance and insert the anchor.

[Problem that the invention attempts to solve]

However, if the holes are drilled in advance, the anchors will enter the slope smoothly, but because the frictional resistance in the soil against the pulling direction of the anchors is small, there are problems in that they are easy to pull out and the netting lacks stability.

It is also possible to make the drilling depth shallower and leave a small area where the anchor can be driven, but even in that case, the lower end 13 of the anchor is at an acute angle, so even if it can be driven, after it is driven, it will be difficult to Since the frictional resistance is still small, the above problem cannot be solved. In addition, almost the same results were obtained even when the outer surface of the anchor was made to have a different diameter shape.

[Means for solving problems]

In order to achieve the above objectives and solve the problems of the conventional technology, the present invention has been developed by cutting the lower part of a steel bar at an acute angle with a total length of about 40 to 50 times the diameter for anchors used in slope protection works. The cutter is separated into an upper half and a lower half, a joining portion is provided at a part of the cut portion, and the lower end of the lower half is formed at a non-acute angle.

In addition, a part of the joint between the cut parts of the steel bar mentioned above may be provided by welding or adhesive, or when the lower part of the steel bar is cut and separated at an acute angle, a part of the cut part may be left as a joint. You can also do it.

[Effect]

Next, the usage and operation of the present invention will be explained. First, at a predetermined location on the slope of hard rock, concrete, or mortar, a hole with a diameter that can be inserted by hand is pre-drilled to a depth of about 1/3 to 3/4 of the total length of the steel bar. After pushing the lower cut portion of the bar-shaped steel material downward to the bottom of the drilled hole, the upper end is struck with a hammer.

Even if the above-mentioned hammering and pressing of the bar-shaped steel material is done alone, there is not much intrusion due to the non-acute angle lower end.
As a result, pressure is applied to the acute-angled cut part, and a part of the joint of the cut part comes off, causing the upper and lower parts to shift along the cut surface, causing a discrepancy, and the sharp edge of the cut part to protrude diametrically outward. This causes the steel bar to dig into the surrounding wall surface, creating resistance in the direction in which the bar-shaped steel material is pulled out.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.
1 is a bar-shaped steel material that becomes the main body of the anchor,
Its total length should be set to about 40 to 50 times the diameter. In reality, it is common to use steel bars with a diameter of 9 mm to 16 mm, so the diameter is 9 mm to 16 mm.
The length in mm is 360mm to 450mm, and the diameter is 16mm.
When it is mm, the length will be 640mm to 800mm. The lower end of the bar-shaped steel material is sliced into a non-acute angle. The upper part of the bar-shaped steel material is shown to be straight, but it can be bent 90 degrees to form the hook part 4 as shown by the chain line in Figure 2, or it may be welded to another short steel bar to form the hook part 4 as shown in Figure 1. Part 4 can also be molded.

Reference numeral 2 denotes a cut portion formed at an acute angle θ in the range of 10 to 20 degrees, preferably 15 degrees, on the lower part of the bar-shaped steel material, and the cut portion is separated into an upper half portion 1 ₁ and a lower half portion 1 ₂ . A coupling portion 3 is provided at a part of the cut site. As shown in FIG. 2, the connecting portion is formed by connecting a part of the abutting portion of the cut portion 2 by spot welding or other electric or gas welding. Or as shown in Figure 4, the cutting site 2
A known instant strong adhesive is applied to both cut surfaces 2 ₁ and 2 ₂ of the cut surface to join the cut surfaces, or a portion of the cut portion 2 is left in a bridge shape as shown in Fig. 5 to form a joint. It can also be set to 3.

The position of the lower portion where the cut portion is provided may be a distance 4 to 5 times the diameter from the lower end of the steel bar 1. Specifically, when the diameter is 9 mm, it is 36 mm to 45
mm, and when the diameter is 16 mm, set it to about 64 mm to 80 mm.

In order to provide the hook part 4 on the upper part of the bar-shaped steel material, if the upper part is bent or another member is fixed by welding, it is preferable to do this after the cutting part 2 of the lower part is formed. It is also possible to mold the hook portion 4 after completing the driving.

[Effect of idea]

Since the present invention has the above-mentioned configuration, a pilot hole is drilled in advance to a depth of two-thirds to three-quarters of the total length so that the steel bar can be pushed in by hand, and the cutting part is placed in the lower position. Push the pointed steel bar into the bottom of the hole.
Then, by applying hammering pressure with a hammer, the joint of the cut part comes loose and the joint surface shifts, causing the upper and lower acute edges to pierce the peripheral wall of the pilot hole, causing friction around the cut part. Strong resistance occurs.

Therefore, when various types of nets are stretched on a slope, the anchors of the bar-shaped steel material provide excellent fixing stability of the stretched nets.

In addition, although the cut parts of bar-shaped steel materials are separated, they are temporarily joined at some parts, so the cut parts have sharp edges during the process of being transported from manufacturing to the site. It is also safe as it does not protrude to the outside.

Furthermore, the lower end of the bar-shaped steel material is cut into rings and has a non-acute angle, so even if it is driven into the prepared hole and then struck with a hammer, the degree of penetration is small. As the size increases, the frictional resistance in the pull-out direction doubles, making it extremely practical as it can be used as an anchor in this type of slope protection work and can be used in a wide range of applications.

[Brief explanation of the drawing]

The drawings show an example of the anchor in the slope protection work according to the present invention. Figure 1 is a side view of the construction state, Figure 2 is a side view, Figure 3 is a front view, and Figure 4 is a side view of the construction state.
5 is a side view of another modification of FIGS. 2 to 4, and FIG. 6 is a side view of a conventional anchor. 1... Steel bar, 2... Cutting part, 3... Joining part, 4... Hook part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A part of the cut portion where the lower part of a bar-shaped steel material whose overall length is approximately 40 to 50 times the diameter is cut at an acute angle and separated into an upper half and a lower half. An anchor for slope protection work, characterized in that a joint portion is provided, and the lower end of the lower half portion is formed at a non-acute angle. (2) An anchor for a slope protection work as set forth in claim (1) of the utility model registration claim, in which a partial joint of a cut portion of a bar-shaped steel material is provided by welding or adhesive. (3) The anchor for slope protection work according to claim (1) of the utility model registration, in which the joint part is formed by leaving a part intact when the lower part of the bar-shaped steel material is cut and separated at an acute angle.