JPH10220195A - Friction type bolt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display fixing force immediately after the execution of works even in a weak bedrock, where friction by driving is not expected. SOLUTION: The friction type bolt 2 is composed of an external member 4, an internal member 5, inserting members 8, an axial-shaped member 10, etc. Both the external member 4 and the internal member 6 are formed in a cylindrical shape and the inserting members 8 are constituted of shaft sections 802 inserted into the guide holes 20 of the internal member 6 and base sections 804. A tapered surface 1002 is formed at the front section of the axial-shaped member 10. The inserting members 8 are held and disposed by the external member 4 under the state, in which the front ends of the inserting members 8 are placed on the inside in the radial direction of the outer circumferential surface of the external member 4. Accordingly, the inserting members 8 are moved by contacts among the tapered surface 1002 and the base sections 804 when the external member 4 and the internal member 6, to which the inserting members 8 are arranged, are inserted into an excavated pit and the axial-shaped member 10 is put into the internal member 6, and the shaft sections 802 of a plurality of the inserting members 8 are penetrated to a bedrock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel friction type bolt which exerts a fixing force immediately after construction when reinforcing a wall of a tunnel or the like having a relatively soft ground.

[0002]

2. Description of the Related Art When constructing a tunnel or the like, the ground begins to loosen immediately after excavation. For this reason, the inner wall of the tunnel is reinforced with segments or the like, but it is normal practice to temporarily support with bolts or the like from excavation to reinforcement with the segments. At this time, if the ground is solid rock, fix it by driving in friction-type bolts, but if the ground is relatively soft, fix it by inserting bolts after drilling bolt holes, then injecting mortar etc. .

[0003]

However, it takes several hours for the mortar to harden and exert the fixing power, and it is necessary to wait for the mortar to be hardened, which significantly reduces the working efficiency. It is also conceivable to excavate a tunnel after the ground has been improved by injecting a chemical solution in advance, but this method requires a huge amount of time and cost. A failure of the tunnel plan for these reasons could lead to social problems. The present invention has been devised in view of the above circumstances, and an object of the present invention is to exert a fixing force immediately after construction, even in a soft ground where friction due to driving can not be expected, and to provide a permanent segment. It is an object of the present invention to provide a friction bolt capable of exerting a sufficient effect as temporary reinforcement until construction is performed.

[0004]

According to the present invention, there is provided a friction type bolt inserted into a hole excavated in a ground and integrated with the ground, wherein the bolt is inserted into the excavated hole. A cylindrical outer member formed with an outer diameter, a cylindrical inner member inserted into the outer member and integrated with the outer member, and a plurality of portions spaced apart in the longitudinal direction of the inner member A guide hole, an insertion member inserted into each of the guide holes, and an axial member inserted into the inside member, wherein the outer member is inserted through the guide hole. The inner member is formed of a material having a tensile strength, which allows insertion of the member and can maintain the inserted state, and the insertion member is radially outward of the inner member from the inside of the inner member. To the outer member through the guide hole And the insertion member and the shaft-shaped member are inserted into the inside of the inner member while the tip of the shaft member is held by the outer member in a state in which the tip is positioned radially inward of the outer peripheral surface of the outer member. As the base of the insertion member comes into contact with the shaft-like member due to the contact with the shaft-like member accompanying with the above, the base of the insertion member is pushed outward in the radial direction of the inner member until the base of the insertion member is located on the inner peripheral surface of the inner member. The insertion member is formed in such a length that the tip of the insertion member protrudes radially outward from the outer peripheral surface of the outer member in the pushed-out state. In the present invention, the base in the longitudinal direction of the inner member is disposed so as to protrude in the longitudinal direction from the base in the longitudinal direction of the outer member, and a male screw is formed on the outer peripheral surface of the base of the inner member. Features. Further, according to the present invention, the tip of the shaft-shaped member is formed by a tapered conical tapered surface, and with the insertion of the shaft-shaped member into the inside of the inner member, the tapered surface and the base of the insertion member are formed. And the insertion member is pushed out in the radial direction of the inner member, and the outer peripheral surface of the shaft-shaped member comes into contact with the base of the insertion member. A state in which it protrudes outward is maintained.

In the friction type bolt according to the present invention, when the shaft member is inserted into the inside member after the integrated outside member and inside member are inserted into the excavation hole, the tip of the insertion member becomes the outside member. Projecting radially outward from the outer peripheral surface, the tips of the plurality of insertion members enter the ground, and the intruded state of the tips is maintained. Therefore, the fixing force is reliably exerted immediately after the insertion of the shaft-shaped member.

[0006]

Next, an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view of an integrated outer member and an inner member, and FIG. 2 is a cross-sectional view of a state where a shaft-like member is inserted inside the inner member. The friction type bolt 2 includes an outer member 4, an inner member 6, an insertion member 8, a shaft-shaped member 10, and the like. The outer member 4 is, as shown in FIG.
An outer diameter inserted into a borehole 14 excavated in the ground 12,
Further, it is formed in a cylindrical shape with a length corresponding to the depth of the excavation hole 14. A tapered surface 402 having a tapered shape is formed on the outer periphery of a tip portion on the side where the outer member 4 is inserted into the drilling hole 14 so that the outer member 4 can be easily inserted into the drilling hole 14.

The inner member 6 is also formed in a cylindrical shape, and is inserted into the outer member 4 to be integrated with the outer member 4.
The tip of the inner member 6, which is the side to be inserted into the borehole 14, is disposed so as to coincide with the tip of the outer member 4, and the base of the inner member 6 projects more in the longitudinal direction than the outer member 4. An annular member 16 is attached to the annular member 16, and a male screw 18 is formed on the outer periphery of the annular member 16. A plurality of guide holes 20 are provided at a plurality of locations spaced apart in the longitudinal direction of the inner member 6.
Are formed. A plurality of the guide holes 20 may be formed at a plurality of locations spaced apart in the longitudinal direction at intervals in the circumferential direction.
Degrees or 180 degrees.

The insertion member 8 includes a shaft 802 inserted into the guide hole 20 and a base 804 formed at the base end of the shaft 802 in a disk shape with a larger cross-sectional area than the shaft 802. ing. Note that the inner diameter of the guide hole 20 is the shaft portion 802.
Are formed with dimensions slightly larger than the outer diameter of the shaft portion 802.
Is smoothly inserted into the guide hole 20, and the shaft portion 802 does not rattle in the guide hole 20.
The shaft-shaped member 10 has an outer diameter inserted into the inner member 6 and is formed in a hollow shape with a length larger than that of the inner member 6. Shaft-shaped member 1 on the side to be inserted into borehole 14
A tapered conical tapered surface 1002 is formed at the tip of the zero.

The inner member 6 is made of a material having a tensile strength such as steel or the like. In the embodiment, a steel pipe is used. The insertion member 8 is formed of a material having the same strength as the inner member 6 or a material having a higher strength so as not to be deformed, and is made of steel in the embodiment. The outer member 4 is made of, for example, a material such as a synthetic resin that allows the shaft portion 802 of the insertion member 8 to be inserted and can maintain the inserted state. Acrylic is used so that it can be inserted.

The insertion member 8 is inserted into the outer member 4 from the inside of the inner member 6 toward the radial outside of the inner member 6 from the guide hole 20, and the tip of the insertion member 8 is formed on the outer peripheral surface of the outer member 4. The insertion member 8 is disposed by being held by the outer member 4 while being positioned on the radially inner side, and the arrangement of the insertion member 8 is appropriately performed using a jig. Insert member 8 and shaft-shaped member 10
The insertion member 8 moves radially outward of the inner member 6 due to the contact between the tapered surface 1002 and the base 804 due to the insertion of the shaft-shaped member 10 into the inside of the inner member 6, and the base 804 Is formed so as to be pushed radially outward to a position where it comes into contact with the inner peripheral surface of the shaft member 10 while the shaft member 10 is inserted into the inner member 6. The surface and the base 804 are held by contact with each other. The insertion member 8 is formed to have a length such that the tip of the insertion member 8 protrudes radially outward from the outer peripheral surface of the outer member 4 in a state of being pushed out by the shaft-shaped member 10.

Next, a method of using the friction type bolt 2 will be described with reference to FIG. First, as shown in FIG. 3A, a drill hole 14 is drilled in the ground 12. Next, FIG.
As shown in (B), the outer member 4 and the inner member 6 that are integrated with each other are inserted into the borehole 14. Note that, in this case, as shown in FIG.
The insertion member 8 is disposed over the inner member 6 and the outer member 4 with the base 804 positioned inside the inner member 6. Further, the male screw 18 is inserted through the fixing plate 30, and the fixing plate 30 is applied to the wall surface of the ground 12. Next, as shown in FIG. 3C, the shaft-shaped member 10 is inserted into the inside of the inner member 6. Thereby, the tapered surface 1002
The insertion member 8 moves outward in the radial direction of the inner member 6 due to the contact between the inner member 6 and the base portion 804, and the shaft portions 802 of the plurality of insertion members 8 are moved.
Project radially outward from the outer peripheral surface of the outer member 4 and enter the ground 12. In addition, the state of the insertion member 8 entering the ground 12 is maintained by the contact between the outer peripheral surface of the shaft-shaped member 10 and the base 804 while the shaft-shaped member 10 is inserted into the inside of the inner member 6. Is done. Next, as shown in FIG. 3 (D), a nut 32 is screwed into the male screw 18 and the fixing plate 30 is fastened to the wall surface of the ground 12 with the nut 32, thereby completing the operation.

In the friction type bolt 2 of this embodiment, when the integrated outer member 4 and inner member 6 are inserted into the excavation hole 14, there is no projection on the outer peripheral portion of the outer member 4. Insertion into the device is performed smoothly. When the shaft-shaped member 10 is inserted into the inside member 6, the shaft portion 802 of the insertion member 8 protrudes radially outward from the outer peripheral surface of the outside member 4, and the shaft portions 802 of the plurality of insertion members 8 are The shaft portion 802 enters the ground 12, and the intrusion state of the shaft portion 802 is maintained. Therefore, even in the case of the soft ground 12 where the frictional force of the bolt due to the driving can not be expected, the fixing force is increased immediately after the insertion of the shaft-shaped member 10 by the plurality of shaft portions 802 entering the ground 12. Demonstrated reliably. As a result, it is not necessary to wait until the mortar is hardened as in the prior art, or it is not necessary to improve the ground of the ground 12 in advance. It becomes possible. Further, since the anchoring force is exerted immediately after the construction, it is advantageous in preventing a falling accident due to loosening of the ground 12 immediately after the excavation.

[0013]

As is apparent from the above description, according to the friction type bolt of the present invention, after the integrated outer member and inner member are inserted into the excavation hole, the shaft member is inserted inside the inner member. Upon insertion, the plurality of insertion members invade the ground, and this intrusion state is maintained. Therefore, even in the case of a soft ground where the frictional force of the bolt due to driving cannot be expected, the anchorage will be exerted immediately after construction without the need for ground improvement, etc., and temporary reinforcement until the construction of the permanent segment will be performed It is also effective in preventing a falling accident due to loosening of the ground immediately after excavation.

[Brief description of the drawings]

FIG. 1 is a sectional view of an integrated outer member and inner member.

FIG. 2 is a cross-sectional view showing a state where a shaft-like member is inserted into an inner member.

FIGS. 3A to 3D are explanatory diagrams of a method of using a friction bolt.

[Explanation of symbols]

 2 Friction bolt 4 Outer member 6 Inner member 8 Insertion member 10 Shaft-like member 12 Ground 14 Drilling hole

Claims (3)

[Claims] 1. A friction type bolt inserted into a hole excavated in a ground and integrated with the ground, comprising: a cylindrical outer member having an outer diameter inserted into the excavated hole; A cylindrical inner member inserted into the outer member and integrated with the outer member; guide holes formed at a plurality of locations spaced apart in the longitudinal direction of the inner member; inserted into each of the guide holes And a shaft-shaped member inserted into the inner member, wherein the outer member allows insertion of the insertion member inserted from the guide hole and can maintain the inserted state. The inner member is formed of a material having a tensile strength, and the insertion member is inserted from the inside of the inner member to the outer member from the guide hole toward the radial outside of the inner member, and is inserted into the outer member. The tip is radially inward of the outer peripheral surface of the outer member The insertion member and the shaft-like member are arranged while being held by an outer member in a state where the insertion member is in contact with the shaft-like member accompanying the insertion of the shaft-like member into the inside of the inner member. Is formed so as to be pushed out in the radial direction of the inner member until the base of the insertion member comes into contact with the shaft-shaped member and the base portion of the insertion member is located on the inner peripheral surface of the inner member, and the insertion member is in the pushed-out state. A friction-type bolt, wherein the tip of the insertion member has a length protruding radially outward from the outer peripheral surface of the outer member. 2. The base member in the longitudinal direction of the inner member is disposed so as to protrude in the longitudinal direction from the base member in the longitudinal direction of the outer member, and a male screw is formed on the outer peripheral surface of the base of the inner member. The described friction type bolt. 3. The tip of the shaft-shaped member is formed as a conical tapered surface, and the tapered surface comes into contact with the base of the insertion member as the shaft-shaped member is inserted into the inner member. As a result, the insertion member is pushed radially outward of the inner member, and due to the contact between the outer peripheral surface of the shaft-shaped member and the base of the insert member, the tip of the insert member is more radially outward than the outer peripheral surface of the outer member. The friction type bolt according to claim 1, wherein the projecting state is maintained.