JP2001323799A - Cover for rock bolt and square plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover for a rock bolt and a square plate, which can completely cover a base-side end of the rock bolt driven into a primary linking concrete wall, and each corner portion of the square plate, eliminates damage of a cutoff sheet to almost perfection and therefore exerts its essential protective function to the full. SOLUTION: The cover A for the rock bolt and the square plate, is formed of a synthetic resin material with flexibility, and covers the base-side end of the rock bolt 8 driven into the primary lining concrete wall W of a tunnel. The cover consists of a nut cap 1, an annular collar piece 2, and a plurality of plate cover pieces 3. The nut cap 1 is fitted onto a nut 11 screwed into the base-side end of the rock bolt 8 via the square plate 9, to thereby cover the base-side end. Further, the nut cap has its lower end opened 4, and has a top wall 5 at an upper end thereof. The annular collar piece 2 has a predetermined width and is arranged on the periphery of the nut cap 1 at an upper edge thereof, in a manner gradually extending from the top wall 5. The plate cover pieces 3 are arranged on the periphery of the annular collar piece 2 in a manner radially extending therefrom while having the same width as that of the collar piece. Each plate cover piece 3 has a length and a width which each are sufficient enough to cover the corner portion 9a of the square plate 9 fitted onto he rock bolt 8, and is formed so as to curve toward the opening 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the construction of a tunnel wall mainly composed of rock bolts and shotcrete, and a square plate or nut at the base end of a lock bolt which is driven through a primary lining concrete wall. The present invention relates to a lock bolt and a cover for a square plate for protecting a waterproofing sheet interposed between a primary lining concrete wall and a secondary lining concrete wall from being damaged.

[0002]

2. Description of the Related Art Conventionally, a method of interposing a waterproof sheet between a primary lining concrete wall and a secondary lining concrete wall when constructing a concrete wall of a tunnel inner wall is widely known. According to this construction method, a large number of rock bolts are driven almost perpendicularly to the primary lining concrete wall formed by spraying concrete on the inner wall surface of the tunnel, and the primary lining concrete wall is A rectangular square plate is fitted to the base end of the projecting lock bolt, and a nut for pressing the square plate against the primary lining concrete wall is screwed. And
A nut cap having a rounded outer peripheral surface is fitted to the nut portion to protect the waterproof sheet from being damaged by the base end of the nut or the lock bolt.

However, the protection of the square plate is not considered, and in order to more reliably protect the waterproof sheet, breakage due to a corner of the square plate during the secondary lining work is also a problem. Was. Therefore, in order to prevent such breakage of the water-stop sheet, for example, a lock bolt and a cover for a square plate disclosed in Japanese Patent Application Laid-Open No. 9-273397 have been developed. The lock bolt and the cover for the square plate have a concave hole that can be fitted and held with a nut screwed into a base end portion of the lock bolt that is pierced through the primary lining concrete on the inner wall of the tunnel. A plate-like blade extending radially is formed on the outer periphery of the nut cap that covers the base end of the lock bolt, and a disk is provided at the tip of each blade. . Then, with the nut cap fitted to the nut portion, each blade portion is positioned on a diagonal line of the square plate so that each disk portion is addressed to the corner portion of the square plate, and the lock bolt including the nut is provided. The base end and the corners of the corner plate are both covered, thereby protecting the waterproof sheet.

[0004]

However, in the lock bolt and the cover for the square plate, although each disk portion is directed to the corner of the square plate, the work is performed to increase the work efficiency. When I hurried, the disk sometimes shifted from the corner. Usually, the sprayed surface of the primary lining concrete wall tends to be uneven, and in many cases, it is not possible to drive a rock bolt almost perpendicularly to the concrete sprayed surface. If this happens, not only will any corner of the square plate rise from the spray surface,
Although the lock bolt and the cover for the square plate are attached at right angles to the lock bolt, since the square plate is not arranged at a right angle, the disk portion may float away from any corner of the square plate. there were. In such a situation, there is a possibility that the waterproof sheet may hit the corner and break.

Further, since each of the radially extending blades is provided so as to be perpendicular to the square plate, there is a space between the respective blades on the upper surface of the square plate, so that each of the blades has a space. A large step is created between the upper edge of the portion and the upper surface of the square plate. Therefore, since the water-stop sheet covering the upper surface of the space is supported and stretched at the upper edge of each blade, there is a possibility that the water-stop sheet may be broken there by the pressure of the concrete sprayed to form the secondary lining concrete wall. In each case, the protection function of the waterproof sheet could not be achieved.

As described above, when the protective function of the waterproof sheet cannot be fulfilled, the waterproof sheet is put on the primary lining concrete wall surface, and then the concrete is sprayed to form the secondary lining concrete wall, and then the concrete spray surface is formed. This causes a problem that the lock bolt and the cover for the square plate are not sufficient to achieve the original purpose.

Accordingly, the present invention has been made to solve the above-mentioned problem, and it is desirable to completely cover both the base end of the lock bolt including the nut and each of the corners of the square plate to almost eliminate the breakage of the waterproof sheet. It is an object of the present invention to provide a lock bolt and a cover for a square plate which are capable of sufficiently exerting a protective function and achieving an original object.

[0008]

In order to achieve the above object, a lock bolt and a cover for a square plate according to the present invention are made of a flexible synthetic resin material and are cast on a primary lining concrete wall of a tunnel. A lock bolt and a square plate cover for covering the base end of the lock bolt, wherein the cover is fitted to a nut screwed to the base end of the lock bolt via a square plate to cover the base end, A nut cap having a lower end opened and having a top wall at an upper end; an annular flange piece having a predetermined width provided around an upper end outer peripheral edge of the nut cap so as to smoothly extend from the top wall; It consists of a plurality of plate cover pieces extending in the same thickness and radially around the periphery of the annular flange piece, and each plate cover piece covers a corner of the square plate fitted into the lock bolt. Consisting formed with the structure to be curved To have a width and the opening side of the cap nut is.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a lock bolt and a cover for a square plate according to the present invention will be described with reference to the drawings. 1 is a front perspective view of a lock bolt and a cover for a square plate, FIG. 2 is a rear perspective view of the same, and FIG. 3 is a side sectional view of the same. The lock bolt and the cover A for the square plate are integrally formed of a synthetic resin material or a synthetic rubber material having appropriate flexibility, and are generally formed by a nut cap 1, an annular flange piece 2, and a plurality of plate cover pieces 3. Be composed. The nut cap 1 is relatively thin and cylindrical, and has a lower end face opening 4 and an upper end face closed by a top wall 5. The inner diameter of the nut cap 1 is set slightly smaller than the outer diameter of the nut cap 1 in a range where the nut cap 1 is fitted to the nut 11 described later. Further, a lock bolt 8 described later is provided at the center of the top wall 5.
A through hole 6 facing the base end is provided.

More specifically, a predetermined width is formed on the outer peripheral edge of the upper end of the nut cap 1 so as to continuously and gently extend from the top wall 5, that is, to form a conical shape having a gentle upper surface. An annular flange piece 2 on the circular contour is provided. Then, on the peripheral edge of the annular flange piece 2, the same thickness as it is at equal intervals and radially, that is,
The plate cover pieces 3 are extended. It is preferable that each plate cover piece 3 has a width equal to that of which the whole is divided into eight equal parts, and a length and a width covering a diagonal portion 9a of a rectangular plate 9 fitted to the lock bolt 8. , And is curved so as to form a bowl shape facing the opening 4 side of the nut cap 1 as a whole. This is because the corner portion 9a can be completely covered, and the plate cover piece 3 has a spring action acting on the opening 4 side. In addition, the upper surface of the outer peripheral corner 1a of the top wall 5 of the nut cap 1 is formed in an arc shape so as to minimize the step and prevent the waterproof sheet from being damaged. Further, a plurality of reinforcing ribs 7 having a substantially triangular side surface are provided radially and integrally between the outer periphery of the upper end of the nut cap 1 and the lower surface of the annular flange piece 2.

The lock bolt and the cover A for a square plate according to the present invention have the above-described structure, and the method of using them will be described below. FIG. 4 shows a state in which the primary lining work has been performed. Concrete is sprayed on the inner wall surface of the tunnel to form the primary lining concrete wall W, and the rock bolt is penetrated through the primary lining concrete wall W. 8 is installed so as to be substantially perpendicular to the wall surface. The square plate 9 is fitted and the nut 11 is screwed into the base end of the lock bolt 8 projecting from the primary lining concrete wall W by inserting the lock bolt 8 into the through hole 10. Then, the nut 11 is screwed to press the square plate 9 against the surface of the primary lining concrete wall W. At this time, the base end of the lock bolt 8 slightly protrudes from the nut 11. In this state, the lock bolt and the cover A for the square plate are fitted to the nut 11 so as to cover the base end of the lock bolt 8.

That is, the outer peripheral edge of the annular flange piece 2 between the plate cover pieces 3 is pinched by a finger, and the opening 4 of the nut cap 1 is pressed against the nut 11 to cover the push nut 11 and the base end of the lock bolt 8 as it is. Thus, the lock bolt and the cover A for the square plate are fitted. At this time, FIG.
As shown in (2), each plate cover piece 3 is positioned on a diagonal line of the square plate 9 so as to cover each corner 9a. Thereafter, the same operation is repeated for other parts.

Next, the lock bolt and the cover A for the square plate are fitted to the base end portion of the lock bolt 8 in this manner, and then a waterproof sheet (not shown) is attached to the surface of the primary lining concrete wall W. And a secondary lining concrete wall (not shown) is sprayed thereon.
At this time, the base end of the lock bolt 8 and the nut 11 are covered by the nut cap 1. Each of the corners 9a of the corner plate 9 is covered with a plate cover piece 3 and is provided so that the annular flange piece 2 extends smoothly as shown by a chain line in FIG. Since the plate cover pieces 3 extend in the same thickness and radially as they are, there is nothing protruding from the upper surfaces thereof, and the top wall of the nut cap 1 is formed by the flexibility of each plate cover piece 3. From 5 onwards, the entire body is curved with a gentle curve. In the present invention, the annular collar piece 2
It is necessary that each plate cover piece 3 is smoothly extended from the annular flange piece 2, that is, the outer peripheral edge of the upper end of the nut cap 1. Further, since the plate cover pieces 3 are relatively wide and evenly spread, the outer peripheral portion of the nut cap 1 covers a wide area, so that even when a water-stop sheet is covered, the space between the plate cover pieces 3 is increased. The waterproof sheet is less likely to get into the water and is not damaged.

Further, a relatively wide plate cover piece 3 is provided.
Each corner 9a of the corner plate 9 is covered by the corner plate 9 so that even if each plate cover piece 3 slightly deviates from the diagonal position of the square plate 9, the corner 9a does not protrude from the plate cover piece 3, and Since each plate cover piece 3 is formed so as to be curved toward the opening 4 side, the outer peripheral end does not jump up even when pressed by elastic force, and covers each corner 9a firmly. Therefore, also in this case, the water stop sheet is hardly broken and damaged.

FIG. 6 shows a case where the lock bolt 8 is cast on the primary lining concrete wall W so as not to be substantially perpendicular to the surface thereof.
a floats from the surface of the primary lining concrete wall W. However, each of the plate cover pieces 3 is curved and the tip thereof is lowered, so that the plate cover piece 3 completely covers the corner 9a without floating. Therefore,
Also in this case, the water stop sheet is hardly broken and damaged by the corners 9a.

Therefore, the nut cap 1 is fitted to the base end of the lock bolt 8 and the nut 11, and the plate cover piece 3 is firmly covered to the corner 9a of the square plate 9, so that the result is that. The entire surface can be covered with a flat surface, and there is no step that may cause breakage, thereby making it possible to almost completely eliminate breakage of the water stop sheet.
Further, the lock bolt and the cover A for the square plate according to the present invention are easy to hold and handle if the outer peripheral edge of the annular flange piece 2 is pinched between the respective plate cover pieces 3 by hand. Also,
Since a gap is provided between the plate cover pieces 3, the base end of the lock bolt 8 or the nut 11
Is easy to see, and there is also an effect that the mounting work of the lock bolt and the cover A for the square plate can be easily performed.

In the present invention, the width of each plate cover piece 3 is a size obtained by equally dividing the whole into eight. However, the gap between each plate cover piece 3 may be narrowed and widened. Also, four plate cover pieces 3 are provided at regular intervals,
If the square plate 9 is a polygon other than a quadrangle, the number of the plate cover pieces 3 may be changed correspondingly, and the shape may be variously changed.

[0018]

As described above, the lock bolt and the cover for the square plate according to the present invention have an annular flange piece having a predetermined width so as to smoothly extend from the top wall on the outer peripheral edge of the upper end of the nut cap. A plurality of plate cover pieces having the same thickness and radially extending as they are on the periphery of the annular flange piece, and each of the plate cover pieces is a corner of a square plate fitted to the lock bolt. It has a length and width to cover and is formed so as to be curved toward the opening side of the nut cap, so that each plate cover piece is curved with a gentle curve without steps due to its flexibility and spring action, The waterproof sheet can be smoothly placed along the upper surface, and the corners of the corner plate can be completely covered, and the corners protrude from the plate cover piece. No etc. does. Thereby, there is an effect that the original purpose can be sufficiently achieved by sufficiently exhibiting the protection function without damaging the waterproof sheet. Further, the lock bolt and the cover for the square plate according to the present invention have an effect that the molding is easy and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a front perspective view of a lock bolt and a cover for a square plate according to the present invention.

FIG. 2 is a rear perspective view of the same.

FIG. 3 is a side sectional view of the same.

FIG. 4 is a longitudinal sectional view showing a use state of a lock bolt and a cover for a square plate.

FIG. 5 is a plan view of the same.

FIG. 6 is a longitudinal sectional view showing a use state of a lock bolt and a cover for a square plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nut cap 2 Ring piece 3 Plate cover piece 4 Opening 5 Top wall 8 Lock bolt 9 Square plate 9a Square part 11 Nut A Lock bolt and cover for square plate W Primary lining concrete wall

Claims (1)

[Claims] 1. It is made of a synthetic resin material having flexibility,
A lock bolt and a square plate cover for covering a base end of a lock bolt cast into a primary lining concrete wall of a tunnel, wherein the cover is fitted to a nut screwed to the base end of the lock bolt via a square plate. A nut cap which covers the base end thereof, has a lower end opened, and has a top wall at the upper end, and a predetermined periphery provided on the outer peripheral edge of the upper end of the nut cap so as to smoothly extend from the top wall. An annular flange piece having a width, and a plurality of plate cover pieces radially extending on the periphery of the annular flange piece with the same thickness as they are, and each of the plate cover pieces is inserted into the lock bolt. A lock bolt and a cover for a square plate, having a length and a width covering a corner of the square plate, and being formed so as to be curved toward the opening side.