RU2668953C1 - Method for determining bearing capacity of tubular anchor and installation for implementation thereof - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to the mining industry and can be used for quality control of the workings of pipe-work with friction-type tubular anchors. Method is proposed for determining the bearing capacity of a tubular anchor, which is realized as a result of a sequence of actions: inserting into tubular anchor 1 of spacers 3, the axial movement of traction element 4 is performed by screwing nut 6 on thread 7 to fix spacers 3 on inner surface 8 of the tubular anchor, installing support frame 9, installing loading device 12, axial loading of pulling member 4 through loading device 12.

EFFECT: ensuring the force loading of the tubular anchor installed in the hole.

8 cl, 10 dwg

Description

Technical field

The invention relates to the mining industry, and in particular to devices for securing mine workings.

State of the art

The known method of full-scale testing of fasteners and the rules for determining the bearing capacity of anchors with respect to longitudinal axial pulling loads in relation to a real building foundation (STO-44416204-010-2010 "Determination of the bearing capacity of the anchor"). The essence of the method lies in the fact that, by conducting tests of anchor fastenings for a tensile load applied to the anchor along its axis, the fastening resistance to the load and deformation corresponding to its characteristic ultimate states is determined, and then, by processing the test results, the tensile strength of this type of anchors is calculated. In this case, the following sequence of actions is performed: connecting the gripper to the anchor head on its outer surface protruding above the building structure, connecting the gripper to the traction element, installing the support frame, connecting the traction element to the loading device interacting with the supporting frame, implementing the working stroke of the loading device, registration of created forces by the loading device.

During testing, an installation is used consisting of: a support frame, a traction element equipped with a device for gripping the head of the anchor, a jack or other device for creating a load, instruments for measuring the forces applied to the anchor and the deformations of the anchor fastening.

A disadvantage of the known solution is the limited functionality determined by the possibility of using only for testing anchors with a clearly protruding part of its head (STO-44416204-010-2010. Fig. 1).

A feature of the installation of a tubular anchor is the tight coupling of its head with the surface of the excavation (building structure) or with a base plate. When using a base plate, the head of the tubular anchor deforms the base plate and is located out of reach of the grippers.

Thus, the known method does not allow to determine the bearing capacity of the tubular anchor.

The technical problem to which the invention is directed, is to enable testing to determine the bearing capacity of the tubular anchor.

The closest analogue to the claimed invention is a device for testing the holding ability of a building anchor in a material, including a power exciter, a loading handle, a connecting cable, a base plate with adjusting screws, a handle fixing screw, an exciter screw, a connector, a fork and an electronic unit, a special bolt, equipped with an internal screw thread on one end and hot flashes on the other (see Patent PM RF No. 95840, 03/23/2010, G01N 3/02).

A special bolt is screwed onto the thread of the tested anchor (the anchor is placed in the well of the building material, i.e., is in the working position). Next, the forks of the exciter are started on the tides of a special bolt and the anchor is loaded. A disadvantage of the known solution is the impossibility of its application for testing the bearing capacity of a tubular anchor. The device can only be used to test anchors having a helical surface.

The technical problem to which the invention is directed, is to enable testing to determine the bearing capacity of the tubular anchor.

Disclosure of invention

The technical problem is solved in that in order to determine the bearing capacity of the tubular anchor into its cavity, spacers are introduced from the open end, installed with the possibility of movement relative to the traction element and the washer, axial movement of the traction element fixes the spacer on the walls of the anchor. Then, the support frame is installed, before interacting with the surface to be strengthened, and the stationary part of the loading device is installed on the support frame, and the movable part is connected to the traction element. Next, the axial loading of the movable part of the loading device is provided, and the load bearing capacity of the tubular anchor is determined by the readings of the monitoring devices of its operating parameter.

A possible implementation of the method may be the implementation of the axial movement of the traction element, while fixing the spacers, due to the rotation of the nut through a thread cut into its cylindrical part. In this case, the nut is axially fixed on the end surface of the tubular anchor or on the washer mounted on the end surface of the anchor.

An installation that implements the proposed method includes a loading device based on a frame equipped with length-adjustable supports, a traction element with a screw surface, and a device for monitoring the generated force. The traction element is connected to the anchor through spacers installed with the possibility of interaction with the inner surface of the tubular anchor. In this case, the traction element forms a movable connection with spacers, along surfaces inclined to its longitudinal axis, and freely passes through the support washer.

The washer has two working surfaces, each of which has the ability to interact: the first with the end face of the tubular anchor, the second with a nut mounted on the screw.

Spacers form kinematic pairs with the washer. In this case, there are possible options for the implementation of kinematic pairs in the form of: translational, rotational, and pairs that allow the rotation of the thrust in a plane passing through the longitudinal axis of the washer and its progressive movement along the washer.

The surfaces of the spacers in contact with the inner surface of the tubular anchor can be corrugated, and the end surface of the spacer is conical in shape. The number of struts is performed more than two: three, four or five.

The mating surfaces of the traction element and struts are flat.

The introduction to the anchor from the open side of the struts is unknown.

The installation of spacers with the possibility of movement relative to the traction element and the washer is also unknown.

The fixing of spacer sleeves due to the axial movement of the traction element is known (see PI No. 21117190, 09.20.1995, F16B 13/06). In the known solution, the spacer sleeves are fixed on a fixed surface, which eliminates the possibility of their subsequent movement in the axial direction without violating the integrity of the surface.

In the proposed solution, the spacers are fixed on the inner walls of the anchor. This allows, with their axial loading, the anchor to move relative to the hole (fixed surface) without violating its integrity.

The installation of the stationary part of the loading device on the supporting surface is known (see STO-44416204-010-2010 "Determination of the bearing capacity of the anchor"). The performed action in the proposed method coincides with the intended purpose.

The axial loading of the movable part of the power device and the monitoring of the bearing capacity readings are known (see PKA1 BAR EXTENDER. Passport for PKA1.00PS. Manufacturer Ruspodshipnik LLC). The performed action in the proposed method coincides with the intended purpose.

Axial loading of the traction element is known (see PI No. 2374522 11/27/2009, F16G 11/12). At the same time, the creation of axial tension of the parts associated with the traction element is ensured.

In the proposed solution, axial loading provides radial movement of the struts.

The axial fixation of the nut on the washer installed with the possibility of contact with the end surface of the anchor is unknown.

The connection of the traction element with the anchor through spacers installed with the possibility of interaction with the inner surface of the tubular anchor is unknown.

The installation of a traction element forming a movable connection with spacers along surfaces inclined to its longitudinal axis is known (see PI No. 2078257, F16G 13/06). The performed action in the proposed method coincides with the intended purpose.

Passage of the traction element through the washer is known (see Dunaev PF, Lelikov OP Machine parts. Course design. - M.: Higher school, 1984. Fig. 6.35, p. 107). In a known solution, the washer eliminates damage to the bearing cage when tightening the nut on the threaded end of the shaft.

In the proposed technical solution, the washer provides axial fixation of the nut relative to the anchor.

The execution of the working surface of the washer, with the possibility of interaction, with one end of the tubular anchor is unknown.

The organization of the movable connection of the washer with spacers is not known.

Possible options for connecting the struts with the washer in the form of: translational, rotational pairs or couples allowing the rotation of the strut in a plane passing through the longitudinal axis of the washer and its translational movement along the washer is unknown.

The execution of the mating surfaces flat is known (see PI No. 2620113, 12.24.2015, F42D 1/08). This ensures the creation of significant effort in the direction perpendicular to the mating surface.

In the proposed technical solution, the implementation of the mating surfaces flat excludes the rotational movement of the traction element relative to the spacers. As a result, the directional movement of the traction element along its axis is realized.

The stated combination of known and unknown features ensures the achievement of a new technical effect - the possibility of testing to determine the bearing capacity of a tubular anchor.

Brief Description of the Drawings

The invention is illustrated by the images:

- In FIG. 1, 2, 4 are kinematic diagrams explaining successively the stages of the implementation of the method

- In FIG. 3 is a kinematic diagram of a device ready to determine the bearing capacity of a tubular anchor.

- In FIG. 5 is a kinematic diagram reflecting the implementation of the device in accordance with paragraph 2

- In FIG. 6 is a kinematic diagram reflecting the implementation of the device in accordance with paragraph 6

- In FIG. 7 is a kinematic diagram reflecting the implementation of the device in accordance with paragraph 7

- In FIG. 8 - constructive implementation of the complete device (section along the axis of symmetry) in accordance with paragraph 5.

- In FIG. 9 - constructive implementation of the device assembly (section along the axis of symmetry) in accordance with paragraph 7.

- In FIG. 10 - constructive implementation of the device assembly (section along the axis of symmetry), in accordance with paragraph 6

A method for determining the bearing capacity of a tubular anchor is implemented as a result of a sequence of actions.

In the tubular anchor 1, from the open end 2 enter the spacers 3, made with the possibility of interaction with the traction element 4 and the washer 5 (Fig. 1). Spacers 3 form movable joints with washer 5. The traction element 4 can freely move relative to the struts 3.

Spacers 3 are inserted into the tubular anchor 1 until the washer 5 stops in the open end 2, in accordance with paragraph 3 (Fig. 1) or until the washer 5 enters the internal cavity of the tubular anchor - the implementation of paragraph 2 (Fig. 4).

Next, the axial movement of the traction element 4 (Fig. 2, 4) is carried out by screwing the nut 6 along the thread 7 made on the cylindrical end of the traction element 4. In this case, the nut 6 interacts with the washer 5.

The traction element 4, acting on the struts 3, carries out their movement in the radial direction to the axis of the tubular anchor 1. The axial movement of the traction element 4 is carried out before fixing the spacers 3 on the inner surface 8 of the tubular anchor 1.

The next step is to install the support frame 9, along the axis of the traction element 4 (Fig. 3). The supporting frame 9 is equipped with supports 10. Due to their extension, its contact with the surface of the mine 11 is provided.

Further, a loading device 12 is mounted on the support frame 9. As such, a hydraulic cylinder, for example, of a special design (rod extractor type PKA 3) can be used. The rod 13 of the hydraulic cylinder is connected to the traction element 4 directly (Fig. 6), or through a transition sleeve 14 (Fig. 3).

As the loading device, a nut 15 can be used, screwed onto the thread 7, and interacting with the supporting frame 8 (Fig. 5).

The axial loading of the traction element 4 is performed due to the movement of the rod 13 (or rotation of the nut 15). The traction element 4 through the spacers 3 provides axial loading of the tubular anchor 1. Reactive force from the loading device 12, through the support frame 9 (supports 10), is transmitted to the surface of the mine 11.

The registration of the loading force is carried out using instruments for monitoring the operating parameter. When using the hydraulic cylinder according to the manometer 16. When loading through the nut 15 - according to the torque wrench (not shown conventionally in Fig.).

The axial loading of the tubular anchor 1 with the registration of the force on the gauge 16 or a torque wrench provides a test of the bearing capacity of the tubular anchor.

Installation for determining the bearing capacity of the tubular anchor includes spacers 3, traction element 4, washer 5, nut 6, support frame 9, stops 10, load device 12 (Fig. 3), the device for monitoring the force created 16. The support frame 9 is equipped with adjustable length supports 10.

Spacers 3 are installed in the washer 5 with the possibility of radial movement relative to the tubular anchor 1 (Fig. 1). At the same time, they are secured from axial movement (Fig. 8).

The washer 5 is installed with the possibility of interaction through the working surfaces 17 and 18 (Fig. 8), respectively, with the open end 2 and the nut 6, respectively.

The traction element 4 passes through the spacers 3, forms a movable connection with them along the inclined surfaces 20 to the axis 19, and has the ability to move relative to them in the axial direction. Surfaces 20 are made flat, in the form of a surface inclined to its longitudinal axis 19.

The surface 21, the spacers 3 have the ability to interact with the inner surface 8 of the tubular anchor 1 and can be corrugated (Fig. 2, 8).

The movable connection of the struts 3 with the washer 5 can be carried out in several versions: in the form of a translational pair 22 (Fig. 1, 8), in the form of a rotational pair 23 (Fig. 6, 10), in the form of a joint 24 that allows rotation and displacement in the radial direction (Fig. 5, 9).

In the translational pair 22, the movement of the struts 3 is provided along the washer 5 along its guides 25 passing through the axis 19. At the same time, a gap h is maintained between the surfaces 26 (washer 5) and 27 (spacer 3), which eliminates jamming during operation.

In the rotary pair 23, the axis of rotation 28 (Fig. 10) lies in the plane perpendicular to the axis 19.

In connection 24 (Fig. 9), the surface of the spacer 29 is made along the radius R, which allows rotation in a plane passing through the axis 19.

The spacers 3 have bevels 30 facilitating their entry into the tubular anchor 1. The surfaces of the spacers 31 in contact with the surfaces 20 are made flat.

A device for determining the bearing capacity of a tubular anchor operates as follows.

The device is being prepared for operation.

The assembly is pre-assembled due to the fact that with the washer 5 a movable connection of the spacers 3 is organized. In the variants in the form of a translational pair 22, and in the form of a connection 24, the spacers 3 are inserted into the guides 25. In the embodiment with rotational pairs, the connection is organized through the axis of rotation 28.

A traction element 4 is introduced into the space between the struts 3 until the surfaces 20 and 31 are mated. A nut 6 is screwed onto the screw part 7 of the traction element 4.

The assembled assembly is inserted into the tubular anchor until the surface 17 abuts against the end of the anchor (implementation of p. 3).

When implementing the invention in accordance with paragraph 2, the assembled assembly is inserted into the tubular anchor together with the washer 5 (Fig. 4).

The nut 6 is tightened along the screw surface 7. This results in the axial movement of the traction element 4 relative to the washer 5. The surfaces 20 interact with the surfaces 31 and provide radial movement of the spacers along the guides 25, combined with rotation (Fig. 9), or rotation about the axis 28 (Fig. 10). The surfaces 21 come into contact with the surface 8. The corrugation made on the surface 21 provides an increased adhesion coefficient between the spacers 3 and the tubular anchor 1.

The presence of a gap h in the translational pair 22 (Fig. 8) provides for self-installation of surfaces 20 and 31. As a result, pairing is realized over the entire surface area 31.

Spacers 3 are fixed on the inner surface 8, of the tubular anchor 1.

The support frame 9 is installed. The supports 10 are adjusted to ensure a central location relative to the traction element 4.

The loading device through a special sleeve 14 is connected to the screw part 7 of the traction element 4. In this case, the housing of the loading device interacts with the supporting frame 9.

The unit is ready for testing to determine the bearing capacity of the tubular anchor.

Claims (8)

1. The method of determining the bearing capacity of a tubular anchor, which consists in the fact that in the cavity of the anchor, from the open end, introducing spacers installed with the possibility of movement relative to the traction element and the washer, axial movement of the traction element fix the spacers on the walls of the anchor, install the support frame, up to interacting with the surface being strengthened, the stationary part of the loading device is installed on the support frame, and the moving part is connected to the traction element, and axial loading of the moving part of the device is ensured loading and according to the testimony of control devices of its operating parameter determine the bearing capacity of the tubular anchor. 2. A method for determining the bearing capacity of a tubular anchor according to claim 1, characterized in that the axial movement of the traction element, when fixing the struts, is carried out by rotating the nut along a thread cut into a cylindrical part and axial fixing of the nut on the washer. 3. A method for determining the bearing capacity of a tubular anchor according to claim 2, characterized in that the axial fixation of the nut is performed on a washer mounted with the possibility of contact with the end surface of the anchor. 4. Installation for determining the bearing capacity of a tubular anchor, including a loading device, a support frame equipped with length-adjustable supports, a traction element with a screw surface, mounted to interact with the anchor and a loading device, a force control device, characterized in that the traction connection the element with the anchor is made through spacers installed with the possibility of interaction with the inner surface of the tubular anchor, the traction element forms a movable connection e with spacers, along surfaces inclined to its longitudinal axis, passes through a washer, the working surfaces of which are made to interact, the first with the end of the tubular anchor, and the second with a nut mounted on the screw surface of the traction element, while the spacers form movable joints with the washer . 5. Installation for determining the bearing capacity of a tubular anchor according to claim 4, characterized in that the connection of the spacers with the washer is made in the form of translational pairs. 6. Installation for determining the bearing capacity of a tubular anchor according to claim 4, characterized in that the connection of the spacers with the washer is made in the form of rotational pairs. 7. Installation for determining the bearing capacity of a tubular anchor according to claim 4, characterized in that the connection of the spacers with the washer is made with the possibility of their rotation in the plane passing through the longitudinal axis of the washer and translational motion. 8. Installation for determining the bearing capacity of a tubular anchor according to claim 4, characterized in that the mating surfaces of the traction element and the spacer are made flat.

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