NPR ANCHOR ROD

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of concrete-related new materials, in particular to an NPR (Negative Poisson's Ratio) rock bolt.

BACKGROUND

[0002] In the prior art, in the support of coal mine roadways and tunnels, rock bolts are the most used support equipment in terms of both scope and quantity. With the continuous increase of coal mining depth, the roadway-surrounding rock often shows the characteristics of large deformation, such as large deformation of soft rock, large deformation of rock burst, large deformation of impact, large deformation of gas outburst. In the current supporting rock bolts, the bolt body has a low elongation and is not suitable for the nonlinear large-scale deformation and failure characteristics of surrounding rock in deep roadways. Under the action of impact loads, the rock bolt may reach its yield strength instantaneously, then fracture and failure occur, and its bearing and protection capabilities are lost, which leads to destructive situations such as repeated repairation of the roadway, distortion of the steel frame, and cracking of the poured concrete.

[0003] Document CN104 343 460 A, according to its abstract, discloses a surrounding rock support method adopting tensioning type pre-tightening anchor rod. The method comprises the steps as follows: a tensioning machine is adopted to tension the anchor rod (1) and apply pre-tightening force to the anchor rod (1), and the anchor rod is locked by anchor rod locks such as an anchor rod support plate (4), an anchor ring (3) and a clamping piece (2). The method is applicable to the support way of reinforcing the surrounding rock of a roadway by mounting of various specifications of anchor rods with pre-tightening force, the used anchor rod is directly cut out from a reinforcing steel bar according to a required length, and the processing and manufacturing process of the anchor rod is simple; after the anchor rod stirs an anchoring agent (5), an anchor rod tray and the anchor rod locks can be directly pushed to the surrounding rock surface along the anchor rod, an anchor drilling machine can be withdrawn after the anchoring agent is solidified, and rapid mounting is realized while a top plate is protected in time; the conditions of insufficient anchor rod torque force due to human factors and torsion failure of the anchor rod due to overlarge torque force can be avoided, and the labor intensity of a construction worker can be reduced simultaneously; and besides, the pre-tightening force can be recovered by tensioning the faulty anchor rod again, the anchor rod cost can be reduced, and the anchor rod locks can be recovered and recycled.

[0004] Document CN108 754 339 A, according to its abstract, discloses an NPR anchor rod steel material and manufacturing method thereof. The NPR anchor rod steel material comprises, by weight, 0.4-0.7% of C, 15-20% of Mn, less than or equal to0.1% of Si, less than or equal to 0.03% of Cu, less than or equal to 0.01% of Cr, less than or equal to 0.02% of Ni, less than or equal to 0.001% of S, less than or equal to 0.001% of P and the balance Fe and unavoidable impurity elements. The NPR anchor rod steel material and the manufacturing method thereof effectively solve the problems that in the prior art, tensile strength and effective elongation of the anchor rod are low. The yield strength of the NPR anchor rod steel material is adjustable in the range of 500-1100 MPa, and the elongation is adjustable in the range of 10-80%.

SUMMARY

[0005] An embodiment of the present disclosure provides an NPR rock bolt to solve the problem in the prior art that the conventional rock bolts have a low elongation and cannot meet the requirement of large deformation of the surrounding rock.

[0006] In order to achieve the above object, the present disclosure provides an NPR rock bolt according to claim 1.

[0007] Further, the tail of the NPR spiral steel bar is untreated.

[0008] Further, a nominal diameter of the NPR bolt is 14-26 mm.

[0009] Further, the tray is a metal butterfly tray.

[0010] Further, the lock comprises a metal lock piece and a lock sleeve that cooperate with each other.

[0011] Further, the spiral ribs extend along an axial direction of the NPR spiral steel bar.

[0012] Further, the quantity of the spiral ribs is 3-6.

[0013] Further, a number of the spiral ribs are evenly disposed along a circumferential direction of the NPR spiral steel bar.

[0014] The NPR rock bolt according to the present disclosure can achieve uniform elongation (200-350 mm/m) when the roadway-surrounding rock deforms greatly, and maintain a substantially stable working resistance. Therefore, the NPR bolt according to the present disclosure can absorb the energy of the surrounding rock by means of transverse resistance and large deformation, so as to still have a good supporting effect under the condition of large deformation of the surrounding rock to ensure the stability of the roadway.

BRIEF DESCRIPTION OF DRAWINGS

[0015] 

FIG. 1 is a schematic diagram of the structure of an NPR rock bolt according to an embodiment of the present disclosure; and

FIG. 2 is a schematic diagram of a stress-strain curve of the NPR rock bolt according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0016] The present disclosure will be described in further detail below with reference to the drawings and specific embodiments, but they are not intended to limit the present disclosure.

[0017] Referring to FIG. 1 and FIG. 2, according to an embodiment of the present disclosure, a NPR rock bolt with constant resistance and large deformation is provided. The NPR rock bolt comprises a bolt body 1, a tray 2 and a lock 3. The bolt body 1 is an NPR spiral steel bar, an outer surface of the NPR spiral steel bar is provided with a number of convex spiral ribs, and the spiral ribs have a spiral structure. The tray 2 and the lock 3 are directly sleeved on a tail of the NPR spiral steel bar.

[0018] The NPR rock bolt according to the present disclosure can achieve uniform elongation (200-350 mm/m) when the roadway-surrounding rock deforms greatly, and maintain a substantially stable working resistance. Therefore, the NPR bolt according to the present disclosure can absorb the energy of the surrounding rock by means of transverse resistance and large deformation, so as to still have a good supporting effect under the condition of large deformation of the surrounding rock to ensure the stability of the roadway.

[0019] Preferably, the tail of the NPR spiral steel bar is untreated. For example, the tail of the NPR spiral steel bar is not subject to any treatment such as thread rolling. Such structure has the advantage of avoiding the stress concentration at the tail thread, thereby avoiding the occurrence of tail thread cracking, and effectively improving the elongation of the rock bolt.

[0020] Refer to the schematic diagram of stress-strain curve shown in FIG. 2, in the present embodiment, the NPR spiral steel bar has a yield strength of 800-950 MPa and a tensile strength of 900-1050 MPa, and the deformation displacement of the NPR spiral steel bar is 200-350 mm/m. The maximum stress of bolt body is >210 KN, the elongation is >20%, the anchoring force of bolt body is >200 KN, the anchoring length is >1 m, the bearing capacity of bolt lock is >210 KN, and the bearing capacity of tray is >210 KN.

[0021] Preferably, the nominal diameter of the NPR bolt is 14-26 mm. As shown in FIG. 1, the tray 2 is a metal butterfly tray. The lock 3 comprises a metal lock piece and a lock sleeve that cooperate with each other. A hole is formed at the center part of the tray 2 for the bolt body 1 to pass through. The metal lock piece is sleeved on the tail of the bolt body and cooperates with the lock sleeve to form a lock 3.

[0022] The structure of the bolt body 1 is as follows. The spiral ribs extend along the axial direction of the NPR spiral steel bar. The quantity of spiral ribs is 3-6. A number of spiral ribs are evenly disposed along the circumferential direction of the NPR spiral steel bar.

[0023] The NPR bolt according to the present disclosure can realize constant resistance and large deformation, and in the roadway where the NPR bolt according to the present disclosure is used as a supporting equipment, when the roadway-surrounding rock is subject to a certain deformation, the NPR bolt will be evenly stretched and the deformation energy in the surrounding rock can be released, and when there is large tensile deformation, the relatively stable working resistance can be maintained, the stability of the roadway can be realized, and the hidden safety hazards such as roof fall and collapse can be eliminated.

[0024] It should be noted that the terminology used herein is only for describing specific embodiments and is not intended to limit the exemplary embodiments according to the present disclosure. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that when the terms "include" and/or "comprise" are used in this specification, they indicate there are features, steps, operations, devices, components, and/or combinations thereof.

[0025] It should be noted that the terms "first" and "second" in the specification, claims and drawings of the present disclosure are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0026] Of course, the above are only preferable embodiments of the present disclosure. It should be noted that those skilled in the art can make improvements and modifications without departing from the basic principles of the present disclosure, and these improvements and modifications shall also fall within the protection scope of the present disclosure. It is noted that the scope of protection of the current invention is defined by the appended claims.

Claims

1. A negative poisson's ratio rock bolt, comprising a bolt body (1), a tray (2) and a lock (3), the tray (2) and the lock (3) are directly sleeved on a tail of the negative poisson's ratio spiral steel bar, characterized in that the bolt body (1) is a negative poisson's ratio spiral steel bar, an outer surface of the negative poisson's ratio spiral steel bar is provided with a number of convex spiral ribs, and the spiral ribs have a spiral structure; the negative poisson's ratio spiral steel bar has a yield strength of 800-950 MPa and a tensile strength of 900-1050 MPa, and a deformation displacement of the negative poisson's ratio spiral steel bar is 200-350 mm/m.

2. The negative poisson's ratio bolt according to claim 1, wherein the tail of the negative poisson's ratio spiral steel bar is untreated.

3. The negative poisson's ratio bolt according to claim 1, wherein a nominal diameter of the negative poisson's ratio bolt is 14 -26 mm.

4. The negative poisson's ratio rock bolt according to claim 1, wherein the tray (2) is a metal butterfly tray.

5. The negative poisson's ratio rock bolt according to claim 1, wherein the lock (3) comprises a metal lock piece and a lock sleeve that cooperate with each other.

6. The negative poisson's ratio rock bolt according to claim 1, wherein the spiral ribs extend along an axial direction of the negative poisson's ratio spiral steel bar.

7. The negative poisson's ratio bolt according to claim 1, wherein the quantity of the spiral ribs is 3-6.

8. The negative poisson's ratio rock bolt according to claim 1, wherein a number of the spiral ribs are evenly disposed along a circumferential direction of the negative poisson's ratio spiral steel bar.

Ansprüche

1. Gebirgsanker mit negativer Poissonzahl, der einen Ankerkörper (1), eine Scheibe (2) und eine Sicherung (3) umfasst, wobei die Scheibe (2) und die Sicherung (3) direkt auf den Schwanz des spiralförmigen Stahlstabs mit negativer Poissonzahl aufgeschoben werden, dadurch gekennzeichnet, dass der Ankerkörper (1) ein spiralförmiger Stahlstab mit negativer Poissonzahl ist, eine Außenfläche des spiralförmigen Stahlstabs mit negativer Poissonzahl mit einer Reihe von konvexen Spiralrippen versehen ist und die Spiralrippen eine spiralförmige Struktur aufweisen; der spiralförmige Stahlstab mit negativer Poissonzahl eine Streckgrenze von 800-950 MPa und eine Zugfestigkeit von 900-1050 MPa aufweist und die Verformungsverschiebung des spiralförmigen Stahlstabs mit negativer Poissonzahl 200-350 mm/m beträgt.

2. Gebirgsanker mit negativer Poissonzahl nach Anspruch 1, wobei der Schwanz des spiralförmigen Stahlstabs mit negativer Poissonzahl unbehandelt ist.

3. Gebirgsanker mit negativer Poissonzahl nach Anspruch 1, wobei der Nenndurchmesser des Gebirgsankers mit negativer Poissonzahl 14-26 mm beträgt.

4. Gebirgsanker mit negativer Poissonzahl nach Anspruch 1, wobei die Scheibe (2) eine Schmetterlingsscheibe aus Metall ist.

5. Gebirgsanker mit negativer Poissonzahl nach Anspruch 1, wobei die Sicherung (3) ein Metallsicherungsstück und eine Sicherungshülse umfasst, die zusammenwirken.

6. Gebirgsanker mit negativer Poissonzahl nach Anspruch 1, wobei sich die Spiralrippen entlang der Axialrichtung des spiralförmigen Stahlstabs mit negativer Poissonzahl erstrecken.

7. Gebirgsanker mit negativer Poissonzahl nach Anspruch 1, wobei die Anzahl der Spiralrippen 3-6 beträgt.

8. Gebirgsanker mit negativer Poissonzahl nach Anspruch 1, wobei eine Anzahl der Spiralrippen gleichmäßig entlang der Umfangsrichtung des spiralförmigen Stahlstabs mit negativer Poissonzahl angeordnet ist.

Revendications

1. Boulon de roche à coefficient de Poisson négatif, comprenant un corps de boulon (1), un plateau (2) et un verrou (3), le plateau (2) et le verrou (3) sont directement manchonnés sur une queue de la barre d'acier en spirale à coefficient de Poisson négatif, caractérisé en ce que le corps de boulon (1) est une barre d'acier en spirale à coefficient de Poisson négatif, une surface extérieure de la barre d'acier en spirale à coefficient de Poisson négatif est pourvue d'un certain nombre de nervures en spirale convexes, et les nervures en spirale présentent une structure en spirale ; la barre d'acier en spirale à coefficient de Poisson négatif présente une limite d'élasticité de 800 à 950 MPa et une résistance à la traction de 900 à 1050 MPa, et un déplacement de déformation de la barre d'acier en spirale à coefficient de Poisson négatif est de 200 à 350 mm/m.

2. Boulon à coefficient de Poisson négatif selon la revendication 1, dans lequel la queue de la barre d'acier en spirale à coefficient de Poisson négatif n'est pas traitée.

3. Boulon à coefficient de Poisson négatif selon la revendication 1, dans lequel un diamètre nominal du boulon à coefficient de Poisson négatif est de 14 à 26 mm.

4. Boulon de roche à coefficient de Poisson négatif selon la revendication 1, dans lequel le plateau (2) est un plateau à papillon métallique.

5. Boulon de roche à coefficient de Poisson négatif selon la revendication 1, dans lequel le verrou (3) comprend une pièce de verrou métallique et un manchon de verrou qui coopèrent l'un avec l'autre.

6. Boulon de roche à coefficient de Poisson négatif selon la revendication 1, dans lequel les nervures en spirale s'étendent le long d'une direction axiale de la barre d'acier en spirale à coefficient de Poisson négatif.

7. Boulon à coefficient de Poisson négatif selon la revendication 1, dans lequel la quantité de nervures en spirale est de 3 à 6.

8. Boulon de roche à coefficient de Poisson négatif selon la revendication 1, dans lequel un certain nombre des nervures en spirale sont disposées de manière régulière le long d'une direction circonférentielle de la barre d'acier en spirale à coefficient de Poisson négatif.

Drawing