JP2009293196A - Rock bolt structure and its tensile yield strength test method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tensile yield strength test method for a rock bolt structure for easily testing tensile yield strength of the rock bolt structure made of fiber-reinforced resin without breaking it. <P>SOLUTION: This rock bolt structural body 1 is provided with a rock bolt 2 having a spiral crest part 22 on its outer peripheral face, a nut 3 engaging with the rock bolt, and a plate 4 inserted into the rock bolt. The nut is provided with a screw hole 31 into which the rock bolt is screwed and an insertion part 32 provided with a tapered face 321 being concentric with the screwing hole having one end face side becoming thinner and inserted into the plate. The plate is provided with an insertion hole 42 through which the rock bolt is inserted, in which the insertion part of the nut is inserted, and which has a tapered shape being in contact with the tapered shape. This rock bolt structural body does not protrude from a construction face remarkably even after construction and it is free of such a problem as to be caught during work. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rock bolt structure used for reinforcing a construction surface such as a wall surface or a slope, and a tensile strength test method thereof. More specifically, the present invention is made of fiber reinforced resin, can be constructed by the same handling as steel rock bolts, has sufficient tensile strength after construction, and may protrude significantly from the construction surface. The present invention relates to a rock bolt structure having excellent workability. The present invention also relates to a tensile strength test method for a rock bolt structure that can be easily tested without damaging the tensile strength of the rock bolt structure made of fiber reinforced resin.

Construction of the new Austrian tunnel method (also called NATM), which is reinforced with rock bolts, which are supporting members, for excavation work and repair work on wall surfaces and slopes such as mountain tunnels, dams and revetments. The method is known. In such a construction method, as illustrated in FIG. 7, a rod-like lock bolt 92 whose outer peripheral surface is threaded is embedded in the construction surface 8, and then a through hole is provided in the head of the lock bolt 92 exposed from the rock or the like. The plate 94 is passed through, and then the nut 94 is fastened to the head to fix the plate 94.
Such a lock bolt structure 91 including the lock bolt 92, the nut 93, and the plate 94 is usually made of steel, and the members 92, 93, and 94 are damaged even when a tensile force of about 180 kN is applied to the plate 94. There is nothing.

However, the rock bolt structure made of steel lacks a support function due to deterioration due to aging and corrosion caused by acid soils such as volcanoes and hot springs, resulting in decreased tensile strength or damage. There is.
Further, when excavating the construction surface with the rock bolt structure provided, the excavation blade comes into contact with the lock bolt structure and wears greatly. Furthermore, since the rock bolt structure is made of steel, it is heavy and has poor workability during transportation and construction. Also, contributing to accelerate the global warming for CO ₂ emissions is large in the production of steel.

In order to solve the above problems, lock bolts using glass fiber reinforced resin (also referred to as GRP or GFRP) instead of steel materials have been proposed (see, for example, Patent Documents 1 and 2). Such a GRP lock bolt is a screwable shape in which a spiral convex portion is provided on the peripheral surface of a rod-like body, and can be used in the same manner as a steel lock bolt. In addition, it is less susceptible to corrosion than steel rock bolts, can be cut without being worn even when it comes into contact with the above-mentioned drilling blade, and promotes global warming due to low CO ₂ emissions during production It has the feature that it can be controlled. Furthermore, since it is an insulator, induced current and stray current do not flow through the lock bolt, noise is not transmitted, and troubles due to these do not occur.

JP 07-217628 A JP-A-11-280397

  However, the strength of the GRP lock bolt, such as compression, bending and shearing in the cross-sectional direction, is weaker than that of the steel lock bolt, and sufficient strength cannot be obtained unless the axial length of the nut is significantly increased. For this reason, since the nut shaft length is significantly longer than the steel lock bolt, there is a problem that it is difficult to use, for example, projecting significantly from the construction surface after construction and causing troubles such as frequent catching at the time of work. Moreover, when constructing on the surface of shotcrete, it may be covered with a waterproof sheet that is constructed at the time of secondary lining, but it is not preferable because a nut or the like comes into contact with and breaks the waterproof sheet.

  Furthermore, the tensile strength of the steel lock bolt is measured by gripping the steel lock bolt with a chuck that is fixed while gripping both ends of the steel lock bolt, and pulling the chucks away from each other. However, since the GRP lock bolt is fragile to gripping, an appropriate tensile strength cannot be measured. For this reason, the work which is complicated and cannot be reused, such as bonding and fixing the end of the GRP lock bolt and the chuck, has been performed.

  The present invention solves the above-mentioned conventional problems, is made of fiber reinforced resin, can be constructed by the same handling as steel rock bolts, and has sufficient tensile strength after construction, An object of the present invention is to provide a rock bolt structure that does not protrude greatly from the construction surface and has excellent workability. It is another object of the present invention to provide a tensile strength test method for a lock bolt structure that can be easily tested without damaging the tensile strength of the fiber reinforced resin-made rock bolt structure.

The present invention is as follows.
1. A lock bolt structure comprising: a lock bolt having a spiral peak on an outer peripheral surface; a nut screwed into the lock bolt; and a plate inserted through the lock bolt. The nut is made of a fiber reinforced resin impregnated with a curable resin and cured, and the nut is made of a fiber reinforced resin impregnated with a thermosetting resin and cured, and the screw hole into which the lock bolt is screwed and the screw engagement A fiber reinforced with a taper surface which is the same axis as the hole and has one end surface side of the screw hole narrowed, and an insertion portion which is inserted into the plate, the plate being impregnated with a thermosetting resin and cured A lock bolt structure made of resin, having a tapered insertion hole through which the lock bolt is inserted, the insertion portion of the nut being inserted, and being in contact with the tapered surface.
2. The plate includes a plate-shaped plate main body and a grip portion formed at a central portion of the plate main body, raised on the nut side, and having the insertion hole at the center. The described rock bolt structure.
3. The nut insertion portion includes a slit that is cut from the distal end side along the axial direction of the lock bolt. The described rock bolt structure.
4). The lock bolt impregnates the thermosetting resin and integrally winds the thread-like fiber material on the surface of the rod-like long fiber material that is continuous in the length direction at intervals in the outer peripheral axis direction. The threaded fiber part that has been tightened forms a spiral concave groove part, and the convex part is formed between the adjacent concave groove parts, and then the thermosetting resin is cured. The above 3. The described rock bolt structure.
5. The above-mentioned item 4, wherein the long fibrous fiber is a glass fiber. The described rock bolt structure.
6). 2. The plate and the nut are made of glass fiber reinforced resin. Thru 5. The rock bolt structure according to any one of the above.
7). 2. The tensile strength is 180 kN or more. A rock bolt structure according to any one of claims 1 to 6.
8). The lock bolt is a solid body or a hollow body. The rock bolt structure according to any one of 7 to 7.
9. A lock bolt structure tensile strength test method for a lock bolt structure comprising: a lock bolt made of fiber reinforced resin; a nut screwed into the lock bolt; and a plate inserted through the lock bolt. A mounting plate having an insertion hole for inserting a bolt and having a mounting plate larger than the plate, a plate support jig provided with a tension member provided on the mounting plate, and a screwing hole for screwing with the lock bolt of the lock bolt structure. A lock bolt support jig provided, the lock bolt of the lock bolt structure to be tested is inserted into the plate support jig and screwed with the lock bolt support jig, and then the plate support jig and The lock bolt support jig is gripped and pulled, and the tensile strength when the lock bolt structure is damaged by the pull is defined as the tensile strength. Lock bolt structure Tensile strength test method comprising.
10. The rock bolt structure is the same as in the above 1. 8. The rock bolt structure according to any one of 8 to 8. The lock bolt structure tensile strength test method described.

According to the lock bolt structure of the present invention, since the lock bolt, nut and plate assembled in the structure are fiber reinforced resin, they are less likely to corrode compared to steel lock bolts, Cutting is possible without causing the excavation blade to wear, and since CO ₂ emission during production is small, it is possible to prevent global warming. Furthermore, since it is an insulator, induced current and stray current do not flow through the lock bolt, noise is not transmitted, and troubles due to these do not occur.
Moreover, the construction method using a plate and a nut can be used similarly to steel rock bolts. Furthermore, since the nut insertion part can be inserted into the plate insertion hole, the entire nut length is slightly longer than that of the steel lock bolt structure even if the nut holds the lock bolt longer. Since it can be made to a certain length, it does not protrude significantly from the construction surface even after construction, and workability problems such as being caught during work do not occur.

Moreover, when a plate is provided with a plate main body and a holding part, since it can provide required intensity | strength without increasing the whole thickness of a plate, it can make it easy to handle at the time of conveyance, storage, and construction.
Furthermore, when the nut insertion part is provided with a slit, the tip end side of the insertion part is likely to be bent, so when the nut insertion part is inserted into the plate, the tip end side is pressed against the lock bolt side, Therefore, even when gripping with a shorter axial length, the lock bolt can be firmly gripped without being concentrated due to the force concentrated on a part of the nut and the lock bolt.
Further, when the lock bolt is produced by winding a thread-like fiber material around a rod-like long fiber to form a peak portion, the tensile strength necessary for the support member can be obtained.
Furthermore, when the rod-like long fiber is a glass fiber, a stronger tensile strength can be obtained.
Moreover, when the plate and nut are made of glass fiber reinforced resin, a strong tensile strength can be obtained.
Furthermore, when the tensile strength is 180 kN or more, it has the same strength as that of a normal steel rock bolt structure and can be easily applied to the same use as that of a steel rock bolt structure.
If the lock bolt is solid or hollow, the lock bolt structure can be constructed in the same manner as a normal steel rock bolt that is solid, and a construction method for injecting chemicals can be used. A lock bolt structure using a hollow lock bolt can be used.

  According to this lock bolt structure tensile strength test method, even a lock bolt made of fiber reinforced resin whose grip strength is weaker than that of steel can be tested in a state closer to the state after construction. The tensile strength can be tested. In addition, unlike the conventional tensile strength test method using only lock bolts, since the test is performed as a lock bolt structure, the necessary tensile strength can be tested under conditions closer to the actual state after construction.

  Furthermore, when the rock bolt structure to be tested is the rock bolt structure of the present invention, the tensile strength can be tested without being damaged by the test.

Hereinafter, the rock bolt structure of the present invention and the tensile strength test method thereof will be described in detail with reference to FIGS.
1. Lock bolt structure The lock bolt structure of the present invention is characterized by assembling a lock bolt, a nut screwed into the lock bolt, and a plate inserted through the lock bolt. The lock bolt, nut, and plate are made of fiber reinforced resin impregnated with a thermosetting resin and cured.
The “thermosetting resin” can be arbitrarily selected as long as it is used for fiber reinforced resins. For example, unsaturated polyester resins, vinyl ester resins, epoxy resins, polyamide resins, phenol resins, etc. Can be mentioned. Moreover, the fiber used for said "fiber reinforced resin" can also be selected arbitrarily, for example, glass fiber, carbon fiber, Kepler fiber, etc. can be mentioned.

As shown in FIG. 2, the shape of the “lock bolt” is a rod-shaped body that is provided with a helical peak portion 22 that can be used as a male screw on the peripheral surface and can be screwed into a nut. It doesn't matter. In particular, when the peak portion has the same pitch as that of the steel lock bolt, the same workability as that of the steel lock bolt can be obtained when the nut is turned. The tip shape of the lock bolt can be arbitrarily selected depending on the application, and examples thereof include a sharp end shape (see, for example, the tip 21 illustrated in FIG. 2) and a flat shape. In addition, a hole or the like for injecting a drug or the like or discharging groundwater can be provided. Furthermore, the lock bolt may be either a solid body or a hollow body. Particularly in the case of a hollow body, the hollow portion can be filled with a chemical solution and released into the ground from a hole provided at the tip. Moreover, you may comprise the protrusion of arbitrary shapes, such as rod shape and a bowl shape, and the hole of arbitrary shapes.
The diameter of the lock bolt can be arbitrarily selected. Examples of this include 22 mm and 25 mm, which are the same as the diameter of the steel rock bolt.

The method for producing the lock bolt is not particularly limited, and a generally known structure can be selected. As an example of this, a thread-like fibrous material is integrally wound spirally around the surface of a rod-like long fibrous fiber impregnated with a thermosetting resin and continuous in the lengthwise direction, and tightened. The thread-like fiber part raised and tightened forms a spiral concave groove part, and a convex peak part is formed between the adjacent concave groove parts, and then the thermosetting resin is cured. Can be mentioned.
The “rod-like long fiber product” is a fiber product of long fibers cured in a rod shape with a thermosetting resin. As the long fibers, the fibers mentioned as the fiber reinforced resin can be arbitrarily selected. Of these, glass fiber is particularly preferable.
The above-mentioned “thread-like fiber” is a fiber used to form a concave groove and a convex peak by winding and tightening around a long fiber, for example, vinylon, tetron, kepler, nylon Glass yarn, glass roving and the like can be exemplified.

The shape of the “nut” includes a screw hole to be screwed with the lock bolt, a taper surface having the same axial shape as the screw hole, and one end surface side of the screw hole being narrowed. It may be provided with a substantially cylindrical insertion portion that can be inserted, and may have a surface for turning with a tool such as a wrench, a protrusion of an arbitrary shape such as a rod shape and a hook shape, and a hole of an arbitrary shape. . In addition, the length of the insertion portion may be a length that is inserted into the plate when the rock bolt structure is configured, or may be a length that is partially exposed from the plate.
When the insertion portion of such a tapered surface is inserted into and inserted into the insertion hole of the plate, it is pressed toward the axial center by the taper of the insertion hole, and the lock bolt is more firmly gripped.
The taper angle of the insertion portion, that is, the inclination θ with respect to the axial direction of the screwing hole 31 illustrated in FIG. 3A can be arbitrarily selected, for example, 10 to 20 ° (particularly preferably 11 to 19 °). And more preferably 12 to 18 °. By setting the inclination θ in such a range, the lock bolt structure can be firmly held without being damaged.

Further, as illustrated in FIG. 3, the nut insertion portion may include a slit 322 cut from the distal end side along the axial direction of the lock bolt. The number of slits may be only one, or two or more. When the number of slits is 2 or more, the slits can be provided at equal intervals along the peripheral surface.
The length of the screwing hole of the nut can be set to a length that allows gripping with a force that does not damage the lock bolt and the nut at the time of construction and after the construction. Examples of such a length include 30 to 100 mm (particularly preferably 40 to 90 mm, and more preferably 40 to 85 mm). If it exceeds 100 mm, the length of protrusion from the construction surface after construction becomes particularly long, which hinders workability such as frequent catching at the time of work, making it difficult to use. Moreover, when constructing on the surface of shotcrete, it may be covered with a waterproof sheet constructed at the time of secondary lining, but it is not preferable because the nut comes into contact with the waterproof sheet and breaks.

The “plate” includes a tapered insertion hole through which a lock bolt is inserted and in contact with the tapered surface of the insertion portion of the nut. Such a tapered insertion hole can press the insertion portion of the inserted nut in the axial direction of the lock bolt.
Further, the plate can include a plate-shaped plate body and a grip portion formed at the center of the plate body, raised to the nut side, and having an insertion hole at the center. The shape of the plate body is not particularly limited, and may be a disk shape or a square plate shape. In particular, in the case of a disk, since there are no corners, it is easy to handle without touching the corners and causing injury. Further, the shape of the grip portion is not particularly limited, and may be a cylindrical shape, a prismatic shape, or the like. Furthermore, it is possible to make the entire plate into a thick disk shape without clearly including a gripping portion. Further, the ribs can be provided around to ensure strength.
The length of the insertion hole of the plate can be set to a length that allows gripping with a force that does not damage the lock bolt and the nut during and after the construction. Examples of such a length include 30 to 80 mm (particularly preferably 40 to 60 mm, and more preferably 40 to 50 mm). If the thickness exceeds 80 mm, the projecting length from the construction surface after construction becomes particularly long, which impedes workability such as frequent catching during work, making it difficult to use.

The plate and nut can be prepared by any manufacturing method, for example, any of thermosetting resin selected from at least one of short fiber, long fiber, and woven fabric and molded using an existing molding method. And impregnating and curing. When produced in this way, the tensile strength required for the support member can be obtained.
Moreover, the fiber mentioned as said fiber reinforced resin can be arbitrarily selected for this short fiber, long fiber, and woven fabric. Of these, glass fiber is particularly preferable. Thus, when a fiber is glass fiber, stronger tensile strength can be obtained.

The tensile strength of the present lock bolt structure is preferably 180 kN or more. This is because the tensile strength of a normal steel rock bolt is 120 kN or more or 176 kN, which is a strength necessary for normal construction.
The construction method for reinforcing the construction surface using the present rock bolt structure can be performed in the same manner as a normal construction method using a steel rock bolt. For example, it can be performed by a construction method such as the new Austrian tunnel method.

2. Method for testing tensile strength of rock bolt structure The method for testing tensile strength of rock bolt structure according to the present invention is a method of testing the tensile strength of rock bolt structure of the above-described lock bolt structure, and includes a mounting hole through which the lock bolt is inserted. And a plate support jig provided with a mounting plate larger than the plate and a tension member provided on the mounting plate, and a lock bolt support jig provided with a screwing hole for screwing with the lock bolt of the lock bolt structure. The lock bolt of the lock bolt structure to be tested is inserted into the plate support jig and screwed into the lock bolt support jig, and then the plate support jig and the lock bolt support jig are gripped and pulled. Thus, the tensile strength when the lock bolt structure is damaged is defined as the tensile strength.
The present tensile strength test method can be particularly suitably applied to the lock bolt structure of the present invention, but is not limited thereto, and is used for tensile strength tests of other fiber reinforced resin lock bolts and the structure. be able to.

  The “plate support jig” is a jig for pulling a lock bolt with a tensile tester through a plate and a nut in a state where the lock bolt structure is assembled. There are no particular restrictions on the shape and material of the mounting plate and the tension member constituting the plate support jig. As an example of this, a mounting hole larger than the diameter of the lock bolt is provided at the center and a mounting plate made of a metal plate larger than the plate, and provided along the outer periphery of the mounting plate and coaxial with the mounting hole of the mounting plate. There may be mentioned a plate support jig comprising a tensile member that is positioned and connected to a tensile shaft of a tensile tester.

The “lock bolt support jig” is a jig for supporting the tip end side of the lock bolt that is normally embedded in the construction surface and pulling it with a tensile tester. The shape and material of the lock bolt support jig are not particularly limited. As an example of this, a jig body provided with a screw hole having a female screw that can be screwed at the same pitch as the peak portion of the lock bolt, and a tensile shaft of a tensile testing machine that is positioned coaxially with the lock bolt. And a lock bolt support jig provided with a connecting portion to be connected to the head.
The plate support jig and the lock bolt support jig preferably have a tensile strength of at least 180 kN and are not damaged. Further, the lock bolt support jig needs to secure a contact area with the lock bolt so as not to damage the peripheral surface of the lock bolt in the tensile strength. As an example of this, the length of the female screw portion can be 180 mm or more.

Hereinafter, the lock bolt structure of this embodiment and its tensile strength test method will be described in detail with reference to the drawings.
1. Configuration of Rock Bolt Structure As shown in FIG. 1, the lock bolt structure 1 of the first embodiment includes a lock bolt 2, a nut 3 screwed into the lock bolt 2, a plate 4 inserted through the lock bolt 2, Consists of.
As shown in FIG. 2, the rock bolt 2 is a solid long rod-like body having a diameter of 25 mm, which is the same as a kind of steel rock bolt, and is embedded in a construction surface such as a wall surface or a slope of a mountain tunnel. An end-shaped tip 21 and a spiral peak 22 provided on a peripheral surface functioning as a male screw are provided.
Such a rock bolt 2 is a rod-like shape impregnated with a thermosetting resin and is continuous in the length direction, and is made of a long fiber and a fiber fiber such as vinylon on the surface of the long fiber fiber. A spiral groove portion and a peak portion 22 were formed by being integrally wound in a spiral manner and spaced apart in the axial direction, and then the thermosetting resin was cured. The lock bolt 2 produced in this way has a tensile strength of about 1 kN / mm ² .
In addition, this lock bolt 2 is not restricted to the said manufacturing method, It can produce by another manufacturing method.

  The nut 3 is made of a glass fiber reinforced resin formed by using an existing molding method using long fibers, and has a substantially cylindrical shape with a length of about 80 mm as shown in FIG. And a conical tapered surface 321 having an inclination angle θ of about 15 ° with respect to the axial direction of the screw hole 31. The insertion portion 32 has a length of about 45 mm, two slits 322 cut from the end face of the insertion portion 32 along the axial direction of the screwing hole 31, and a regular hexagonal shape that can be tightened with a tool such as a wrench. A head 33 having a chamfered peripheral surface.

  The plate 4 is made of a glass fiber reinforced resin obtained by forming a short fiber, a long fiber, and a glass woven fabric using an existing forming method, and has a diameter of about the same size as a normal steel plate as shown in FIG. A disc-shaped plate main body 41 of 170 mm and a central portion of the plate main body 41 are provided so that the surface opposite to the contact surface 411 with the construction surface of the plate main body 41 is raised, and an insertion hole 42 is provided at the center. A cylindrical gripping portion 43 is provided, and a plurality of ribs 44 provided radially between the peripheral surface of the gripping portion 43 and the plate body 41. Further, the insertion hole 42 is provided with a conical tapered surface 431 having an inclination angle θ from the shaft center that is the same as the inclination angle θ of the taper surface 321 of the nut 3 so as to contact the entire taper surface 321 of the nut 3. It has been.

Such a lock bolt structure 1 is constructed in the following procedure. First, as shown in FIG. 5, a 3 to 4 m lock bolt 2 is embedded under the construction surface 8 which is a wall surface by an arbitrary means. Next, the lock bolt 2 is inserted into the insertion hole 42 of the plate 4, and the plate 4 is disposed so that the contact surface 411 contacts the construction surface 8. Thereafter, the nut 3 is screwed into the lock bolt 2 so that the insertion portion of the nut 3 is inserted into the insertion hole 42 of the plate 4, and the head 3 is turned with a tool until the torque becomes an appropriate torque to fix the nut 3.
At this time, the insertion portion 32 of the nut 3 is inserted into the insertion hole 42, and the taper surface 321 is pressed against the lock bolt 2 by the taper surface 431 of the insertion hole 42 like a wedge, thereby firmly grasping the lock bolt 2. To do. Further, the insertion portion 32 can be made more flexible by the slit 322, and the contact area between the tapered surface 321 and the insertion hole 42 and the contact area between the screw hole 31 and the peak portion 22 of the lock bolt 2 are increased. Therefore, the wall surface or the like can be firmly held without being easily damaged.
Moreover, when it constructs using this lock bolt structure 1, the protrusion length H from the construction surface 8 of the nut 3 and the plate 4 shown in FIG.5 (b) is about 85 mm, and steel plates and nuts are used. Although it protrudes from about 45 mm, which is the protruding length when used, it does not protrude significantly, so there will be no trouble during subsequent operations.
Furthermore, since the present rock bolt structure 1 has a mass that is about 1/4 that of a normal steel rock bolt structure, it is lightweight and easy to handle, and since CO ₂ emissions during production are small, global warming. Can be suppressed.

2. Rock bolt structure tensile strength test method The tensile strength of the lock bolt structure 1 of this example was tested by the following test method.
As shown in FIG. 6, this test method includes a plate support jig 5 that supports the plate 4 of the lock bolt structure 1 and a lock bolt support jig 6 that supports the lock bolt 2 of the lock bolt structure 1. It is measured by pulling the plate support jig 5 and the lock bolt support jig 6 with the tension shafts 71 and 72 of the tensile tester.

The plate support jig 5 is made of metal, and as shown in FIG. 6, a mounting plate 51 having a mounting hole 511 at the center, a tension plate 522 provided at the center of a connection portion 523 connected to the tension shaft 71, and the mounting plate 51. And a tension member 52 composed of four connecting rods 521 for connecting the tension plate 522.
The lock bolt support jig 6 is made of metal, has a cylindrical shape and includes a jig body 61 having a threaded hole 62 in which a female screw capable of being screwed to the lock bolt 2 is cut at the shaft center, And a connecting portion 63 for connecting the shaft 72.

Such jigs 5 and 6 are inserted into the lock bolt 2, and then the connection part 523 of the plate support jig 5 and the connection part 63 of the lock bolt support jig 6 are respectively attached to the tension shafts 71 and 72 of the tensile tester. After that, the tensile strength test was performed by operating the tensile tester so that the tensile shafts 71 and 72 were separated from each other.
As a result, the lock bolt structure 1 was not damaged even when the tensile load was 180 kN. Further, after the tensile strength test, the lock bolt 2 was removed from the lock bolt support jig 6 and the peak portion 22 was visually confirmed, but no damage such as scraping was found.

In addition, in this invention, it can be set as the aspect variously changed within the range of this invention according to the objective and a use, without being restricted to what is shown to the said Example. For example, in the nut 3 of this embodiment shown in FIG. 3, the head 33 also has the same inclined taper as the insertion portion 32, but the present invention is not limited to this, and the taper may not be provided.
Further, the plate 4 has a disk shape from which the gripping portion 43 protrudes. However, the plate 4 is not limited thereto, and may be a square plate or a plate having a thickness as a whole.

It is the side view which cut | disconnected the plate in order to demonstrate the rock bolt structure of this invention. It is a side view for demonstrating the lock bolt which comprises the lock bolt structure of this invention. It is (a) side view and (b) front view for demonstrating the nut which comprises the lock bolt structure of this invention. It is (a) front view, (b) back view, and (c) longitudinal cross-sectional view for demonstrating the plate which comprises the rock bolt structure of this invention. It is a schematic diagram for demonstrating the example using the lock bolt structure of this invention, Comprising: (a) Sectional drawing of the state which provided the lock bolt structure in the tunnel, and (b) One in (a) It is the fragmentary sectional view which expanded the rock bolt structure. It is a schematic cross section side view for demonstrating testing the rock bolt structure of this invention by the rock bolt structure tensile strength test method of this invention. It is a schematic cross section for demonstrating the example which provided the conventional lock bolt structure in the wall surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Rock bolt structure, 2; Rock bolt, 21; Tip, 22; Mountain part, 3; Nut, 31; Screw hole, 32; Insert part, 321; Tapered surface, 322; Slit, 33; 4; plate, 41; plate body, 411; contact surface, 42; insertion hole, 43; gripping part, 44; rib, 5; plate support jig, 51; mounting plate, 511; Connecting rod, 522; tension plate, 523; connection portion, 6; lock bolt support jig, 61; jig body, 62; screw hole, 63; connection portion, 71, 72; .

Claims (10)

A lock bolt structure comprising: a lock bolt having a spiral ridge on an outer peripheral surface; a nut screwed into the lock bolt; and a plate inserted through the lock bolt;
The rock bolt is made of a fiber reinforced resin that is cured after impregnation with a thermosetting resin,
The nut is made of a fiber reinforced resin impregnated with a thermosetting resin and cured, the screw hole into which the lock bolt is screwed, the same axis as the screw hole, and one end surface side of the screw hole is thin. Comprising a tapered surface, and an insertion portion to be inserted into the plate,
The plate is made of fiber reinforced resin impregnated with a thermosetting resin and cured, and includes a tapered insertion hole through which the lock bolt is inserted and the insertion portion of the nut is inserted and in contact with the tapered surface. A rock bolt structure characterized by that.   The lock bolt structure according to claim 1, wherein the plate includes a plate-shaped plate main body, and a grip portion that is formed at a central portion of the plate main body, rises toward the nut side, and includes the insertion hole at the center. .   The lock bolt structure according to claim 2, wherein the insertion portion of the nut includes a slit cut along the axial direction of the lock bolt from the tip side.   The lock bolt impregnates the thermosetting resin and integrally winds the thread-like fiber material on the surface of the rod-like long fiber material that is continuous in the length direction at intervals in the outer peripheral axis direction. The threaded fiber part that has been tightened forms a spiral concave groove part, and the convex part is formed between the adjacent concave groove parts, and then the thermosetting resin is cured. The rock bolt structure according to claim 3, which is manufactured by performing the steps.   The rock bolt structure according to claim 4, wherein the long fibrous fiber is a glass fiber.   The rock bolt structure according to any one of claims 3 to 5, wherein the plate and the nut are made of glass fiber reinforced resin.   The lock bolt structure according to any one of claims 3 to 6, wherein the tensile strength is 180 kN or more.   The lock bolt structure according to any one of claims 3 to 7, wherein the lock bolt is a solid body or a hollow body. A lock bolt structure tensile strength test method for a lock bolt structure comprising a lock bolt made of fiber reinforced resin, a nut screwed to the lock bolt, and a plate inserted through the lock bolt,
A plate supporting jig having a through hole for inserting the lock bolt and having a mounting plate larger than the plate, and a tension member provided on the mounting plate, and a threaded engagement with the lock bolt of the lock bolt structure A lock bolt support jig with a hole,
Insert the lock bolt of the lock bolt structure to be tested into the plate support jig, and screw with the lock bolt support jig.
Next, the plate support jig and the lock bolt support jig are gripped and pulled, and the tensile force when the lock bolt structure is damaged by the tension is defined as the tensile strength of the lock bolt structure. Yield test method.   The lock bolt structure tensile strength test method according to claim 8, wherein the lock bolt structure is the lock bolt structure according to any one of claims 1 to 8.

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