Expansion anchor assembly and anchoring method

Abstract

The present invention discloses an expansion anchor assembly, including an anchor, an expandable sleeve is sleeved on one end of the anchor, an expandable support device is arranged between the expandable sleeve and the anchor, a first temperature control device for roughly adjusting the expansion state of the expandable sleeve is arranged in the expandable sleeve, and a second temperature control device for adjusting the expansion state of the expandable support device to further adjust the expansion state of the expandable sleeve is arranged in the expandable support device. The present invention also provides an anchoring method of the expansion anchor assembly. The expansion anchor assembly and the anchoring method of the present invention have the advantages of good anchoring effect, strong pull-out bearing capacity, simple construction process, etc.

Description

Technical Field

[0001] The invention belongs to the field of geotechnical engineering support structures, and in particular relates to an anchor rod assembly and an anchoring method. Background Art

[0002] At present, with the continuous development of anchor reinforcement technology, anchors are widely used in the field of disaster prevention and control of underground projects such as slope tunnels and tunnels. However, due to its own technical defects, inflexible anchoring force characteristics, limited pull-out bearing capacity, and inability to adapt to complex and changeable forces, traditional anchors cannot provide greater anchoring force in the face of sudden natural disasters and are easily broken and fail, resulting in the collapse of underground projects such as tunnels and slopes, causing a large number of life threats and property losses. Therefore, the disaster prevention and control of underground projects first needs to address the problems of insufficient anchor support effect and poor bearing capacity. At the same time, after the support project is completed, a large number of anchors are buried underground, resulting in a large waste of materials. Therefore, in order to cope with the current situation, the development of recyclable anchors with good anchoring effect has become a hot topic in the field of geotechnical anchoring technology. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology, and to provide an expandable anchor assembly and an anchoring method of the anchor assembly with good anchoring effect, strong pull-out bearing capacity and recoverability, which can solve the technical problems existing in the prior art of insufficient anchoring between the anchor and the surrounding rock, poor support effect and complicated recovery.

[0004] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0005] An expandable anchor rod assembly comprises an anchor rod, one end of which is sleeved with an expandable sleeve, an expandable support device is arranged between the expandable sleeve and the anchor rod, the expandable sleeve is provided with a first temperature control device for roughly adjusting the expansion state of the expandable sleeve, and the expandable support device is provided with a second temperature control device for adjusting the expansion state of the expandable support device to further adjust the expansion state of the expandable sleeve.

[0006] In the above-mentioned expandable anchor assembly, preferably, the expandable sleeve includes a plurality of shape memory alloy expansion plates, and the first temperature control device is arranged in the shape memory alloy expansion plates; and in the expanded state, the plurality of shape memory alloy expansion plates are trumpet-shaped, and in the non-expanded state, the plurality of shape memory alloy expansion plates are attached to the expandable support device. In the expanded state, the plurality of shape memory alloy expansion plates are trumpet-shaped, conforming to the optimal curve shape, having better pull-out bearing capacity, and good anchoring effect. In the non-expanded state, the plurality of shape memory alloy expansion plates are attached to the expandable support device to facilitate the placement of the anchor assembly into the anchor hole.

[0007] In the above-mentioned expansion anchor assembly, preferably, the expandable support device is a shape memory alloy spring, and the second temperature control device is arranged in the shape memory alloy spring; and in the expanded state, the shape memory alloy spring is trumpet-shaped to support the expandable sleeve, and in the non-expanded state, the shape memory alloy spring is attached to the anchor. The above-mentioned shape memory alloy spring can be fixed at one end of the anchor. In the expanded state, the shape memory alloy spring is trumpet-shaped to facilitate further adjustment of the shape of the shape memory alloy expansion plate to meet the optimal curve shape, and in the non-expanded state, the shape memory alloy spring is attached to the anchor to facilitate the placement of the anchor assembly into the anchor hole.

[0008] In the above-mentioned expansion anchor assembly, preferably, the first temperature control device includes a first temperature control wire, which is arranged in a wire groove in the expandable sleeve, and the second temperature control device includes a second temperature control wire, which is arranged in a wire groove in the expandable support device, and the first temperature control wire and the second temperature control wire are both connected to a temperature control device. The above-mentioned first temperature control wire and the second temperature control wire are respectively used to control the temperature of the shape memory alloy expansion plate and the shape memory alloy spring to control the deformation of the two. The first temperature control wire and the second temperature control wire can share the same set of temperature control devices, and of course, different temperature control devices can also be used respectively. The above-mentioned first temperature control wire and the second temperature control wire are evenly distributed in the shape memory alloy expansion plate and the shape memory alloy spring to better control the temperature of the two.

[0009] In the above-mentioned expandable anchor rod assembly, preferably, a fixing sleeve is provided on the anchor rod, and the expandable sleeve is fixed on the fixing sleeve.

[0010] In the above-mentioned expandable anchor assembly, preferably, the inner cavity of the fixing sleeve is provided with an internal thread, the outer wall of the anchor is provided with an external thread, and the fixing sleeve and the anchor are connected through internal and external threads; the outer wall of the fixing sleeve is provided with an external thread, the inner cavity of the expandable sleeve is provided with an internal thread, the fixing sleeve and the expandable sleeve are both provided with screw holes, and the expandable sleeve is provided on the fixing sleeve through internal and external threads and bolts. The fixing sleeve and the anchor are connected through internal and external threads, which is convenient for subsequent recovery of the anchor.

[0011] In the above-mentioned expansion anchor assembly, preferably, the anchor is a hollow structure, and a peelable coating or isolation film is provided on the inner wall of the hollow structure for preventing direct contact between cement mortar and the anchor during grouting. The hollow structure is convenient for grouting, and the peelable coating or isolation film is used to prevent direct contact between the anchor and the grout, so as to facilitate subsequent recovery of the anchor.

[0012] In the above-mentioned expandable anchor assembly, preferably, the expandable sleeve is evenly provided with a plurality of patterned grooves. Adding patterned grooves can increase the pull-out bearing capacity of the anchor assembly.

[0013] In the above-mentioned expandable anchor assembly, preferably, the end of the anchor away from the expandable sleeve is set as a hexagonal block, and the end is anchored by a high-strength nut and a high-strength gasket. The above-mentioned hexagonal block facilitates the subsequent recovery of the anchor. Both ends of the anchor are provided with threads, one end is used to connect with the fixed sleeve, and the other end is used for fixing with a high-strength nut.

[0014] As a general technical concept, the present invention also provides an anchoring method of the above-mentioned expandable anchor assembly, comprising the following steps:

[0015] S1: drilling a hole at a location to be anchored to form an anchor hole, and expanding the bottom of the anchor hole into a trumpet hole matching the expandable sleeve in an expanded state;

[0016] S2: keeping the expandable sleeve in a non-expanded state by the first temperature control device, keeping the expandable support device in a non-expanded state by the second temperature control device, and placing the expandable anchor assembly into the anchor hole;

[0017] S3: using the first temperature control device to roughly adjust the expansion state of the expandable sleeve so that the expandable sleeve remains in the expanded state, and then using the second temperature control device to adjust the expansion state of the expandable support device to further adjust the expansion state of the expandable sleeve so that the expansion end of the expandable sleeve fits with the horn hole;

[0018] S4: Grouting, maintenance, and anchoring.

[0019] In the above anchoring method, preferably, using the first temperature control device to adjust the expansion state of the expandable sleeve comprises the following steps: determining the shape change temperature of the expandable sleeve, powering on the first temperature control device to increase the temperature of the expandable sleeve to a temperature higher than the shape change temperature, so that the expandable sleeve remains in a non-expanded state; after being placed in the anchoring hole, powering off the first temperature control device to reduce the temperature of the expandable sleeve to a temperature lower than the shape change temperature, so that the expandable sleeve remains in an expanded state, and a rough adjustment of the expansion state of the expandable sleeve is completed;

[0020] The expansion state of the expandable support device is adjusted by the second temperature control device to further adjust the expansion state of the expandable sleeve, including the following steps: determining the shape change temperature of the expandable support device, powering on the second temperature control device to increase the temperature of the expandable support device to a temperature higher than the shape change temperature, so that the expandable support device remains in a non-expanded state; after being placed in the anchor hole, the second temperature control device is powered off to reduce the temperature of the expandable support device to a temperature lower than the shape change temperature, so that the expandable support device remains in an expanded state and further supports the expandable sleeve, thereby completing the further adjustment of the expansion state of the expandable sleeve by the expandable support device.

[0021] In the above anchoring method, it is more preferred to take the expandable support device as an example, which is described in more detail as follows: using the second temperature control device to adjust the expansion state of the expandable support device, including the following steps: determining the shape change temperature of the expandable support device, the second temperature control device is powered on, so that the expandable support device is heated to a temperature higher than the shape change temperature, so that the expandable support device is kept in a non-expanded state, at this time it is an austenite phase, applying external force to process the expandable support device into an expanded state, and quickly placing the expandable support device in a coolant for quenching and cooling, so that it is quickly transformed into a martensite phase, thereby fixing the expanded state after deformation; the second temperature control device is powered on, so that the expandable support device is heated to a temperature higher than the shape change temperature, so that the expandable support device is kept in a non-expanded state, after being placed in the anchor hole, the second temperature control device is powered off, so that the expandable support device is cooled to a temperature lower than the shape change temperature, so that the expandable support device is kept in an expanded state and further supports the expandable sleeve, completing the further adjustment of the expansion state of the expandable sleeve by the expandable support device so that it meets the optimal curve shape.

[0022] In the present invention, the fixed sleeve is a hollow cylindrical shape, the interior of which is connected to the anchor rod, the front end of the fixed sleeve is fixed to the shape memory alloy spring, the outer wall of the fixed sleeve is connected to the expandable sleeve, the expandable sleeve is composed of a plurality of shape memory alloy expansion plates, the temperature control device adjusts the temperature of the wire to control the shape memory alloy expansion plate and the shape memory alloy spring to expand and non-expand (i.e., closed) two states, coarse adjustment and fine adjustment are used to make the shape memory alloy expansion plate and the shape memory alloy spring expand and fully unfold according to a pre-set optimal curve shape, and the expanded shape memory alloy spring is spirally wrapped around the inner wall of the shape memory alloy expansion plate and supported so that it meets the optimal curve shape.

[0023] The above-mentioned coarse adjustment and fine adjustment adopt step-by-step control. First, coarse adjustment is performed. The temperature of the first temperature control wire is controlled by the first temperature control device to control the shape memory alloy expansion plate to expand according to the preset curve. Due to the influence of external factors, coarse adjustment is difficult to control the shape memory alloy expansion plate to conform to the optimal curve shape after expansion. Therefore, the above-mentioned fine adjustment is further adjusted. The fine adjustment controls the cooling of the second temperature control wire connected to the shape memory alloy spring by the second temperature control device. The shape memory alloy spring expands and deforms in sequence according to the preset bending inflection point, and the gradual support of the inner wall of the shape memory alloy expansion plate reaches the maximum value, so that the geometric shape of the shape memory alloy expansion plate conforms to the optimal curve shape. The main function of coarse adjustment and fine adjustment is to make the shape memory alloy expansion plate reach the optimal curve shape. In the process of coarse adjustment, because the shape memory alloy expansion plate has a certain error when deforming according to the preset shape, coupled with the complex underground environment and the obstruction of the soil around the borehole, the shape memory alloy expansion plate cannot return to the preset bending shape. Combined with further fine adjustment, the coarse adjustment is corrected so that the shape memory alloy expansion plate can conform to the shape of the optimal curve to the greatest extent after the expansion is completed, and the pull-out bearing capacity is stronger and the anchoring effect is better. At the same time, after the fine-tuning is completed, the shape memory alloy spring spirally surrounds the inner wall of the shape memory alloy expansion plate and supports the shape memory alloy expansion plate, which is not easy to deform, making the structure more solid and increasing the anti-pulling bearing capacity of the anchor rod.

[0024] In the present invention, the optimal curve shape of the shape memory alloy expansion plate can be understood as solving the minimum rotation surface of the destruction body by using the variational method of the classical Euler equation, and the destruction body is regarded as a rotating wedge with the center line of the anchor plug body as the axis. The angles between the generatrix of the wedge body and the slope surface and the bottom plane of the anchor plug body are specific angles, and the destruction surface is the minimum rotation surface, and the generatrix equation of the rotation surface is determined. This surface plays a key role in calculating the ultimate pull-out bearing capacity. It is derived by mathematical methods to reflect the optimal geometric shape when the anchor rod is destroyed and has a higher pull-out upper limit value in experimental analysis, and has high reliability.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] The expandable anchor rod assembly of the present invention comprises an expandable sleeve and an expandable supporting device. The expansion state of the expandable sleeve is roughly adjusted by a first temperature control device, and the expansion state of the expandable supporting device is adjusted by a second temperature control device to further adjust the expansion state of the expandable sleeve. The expandable sleeve can be made to present an optimal curved shape in the expanded state, with better anchoring effect and stronger pull-out bearing capacity, thereby improving the safety of tunnel and slope engineering.

[0027] The anchoring method of the expansion anchor rod assembly of the present invention has the advantages of good anchoring effect, strong pull-out bearing capacity, simple construction process, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure of the expandable anchor assembly of the present invention in an expanded state.

[0030] Figure 2 It is a schematic diagram of the three-dimensional structure of the expandable anchor assembly of the present invention in a non-expanded state.

[0031] Figure 3 It is a cross-sectional structural diagram of the front end of the expansion anchor assembly of the present invention.

[0032] Figure 4 for Figure 2 Right view of .

[0033] Figure 5 It is a schematic diagram of the application of the expansion anchor assembly of the present invention.

[0034] Legend

[0035] 1. Anchor rod; 2. Fixed sleeve; 3. Expandable sleeve; 4. Shape memory alloy expansion plate; 5. Expandable support device; 6. Temperature control device; 71. First temperature control wire; 72. Second temperature control wire; 8. Wire groove; 9. Bolt; 10. Anchor hole; 11. Hexagonal block; 13. Concrete; 14. High-strength nut; 15. High-strength pad; 23. Patterned groove; 24. Isolation membrane. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0037] It should be noted that when an element is described as being "fixed, fixed, connected or connected to" another element, it can be directly fixed, fixed, connected or connected to the other element, or it can be indirectly fixed, fixed, connected or connected to the other element through other intermediate connectors.

[0038] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0039] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0040] Example:

[0041] like Figure 1-Figure 4 As shown, the expandable anchor rod assembly of this embodiment includes an anchor rod 1, a fixed sleeve 2 is provided on the anchor rod 1, an expandable sleeve 3 is sleeved on one end of the anchor rod 1, the expandable sleeve 3 is fixed on the fixed sleeve 2, an expandable support device 5 is provided between the expandable sleeve 3 and the anchoring end of the anchor rod 1, the expandable sleeve 3 is provided with a first temperature control device for roughly adjusting the expansion state of the expandable sleeve 3, and the expandable support device 5 is provided with a second temperature control device for adjusting the expansion state of the expandable support device 5 to further adjust the expansion state of the expandable sleeve 3.

[0042] In this embodiment, the expandable sleeve 3 includes a plurality of shape memory alloy expansion plates 4, and the first temperature control device is disposed in the shape memory alloy expansion plates 4; and in the expanded state, the plurality of shape memory alloy expansion plates 4 are horn-shaped (such as Figure 1 As shown, in the non-expanded state, a plurality of shape memory alloy expansion plates 4 are attached to the expandable support device 5 (as shown in Figure 2 As shown). In this embodiment, the number of shape memory alloy expansion plates 4 is four, and in other embodiments, the number can be adjusted according to demand.

[0043] In this embodiment, the expandable support device 5 is a shape memory alloy spring, and the second temperature control device is arranged in the shape memory alloy spring; and in the expanded state, the shape memory alloy spring is trumpet-shaped (such as Figure 1 As shown), it is used to support the expandable sleeve 3. In the non-expanded state, the shape memory alloy spring is attached to the anchor rod 1 (as shown in FIG. Figure 2 as shown).

[0044] like Figure 1 , Figure 3 As shown, in this embodiment, the first temperature control device includes a first temperature control wire 71, which is arranged in the wire groove 8 in the expandable sleeve 3, and the second temperature control device includes a second temperature control wire 72, which is arranged in the wire groove 8 in the expandable support device 5, and the first temperature control wire 71 and the second temperature control wire 72 are both connected to the temperature control device 6.

[0045] In this embodiment, the inner cavity of the fixed sleeve 2 is provided with an internal thread, and the outer wall of the anchor rod 1 is provided with an external thread, and the fixed sleeve 2 and the anchor rod 1 are connected by the internal and external threads; the outer wall of the fixed sleeve 2 is provided with an external thread, and the inner cavity of the expandable sleeve 3 is provided with an internal thread, and screw holes are provided on the fixed sleeve 2 and the expandable sleeve 3, and the expandable sleeve 3 is provided on the fixed sleeve 2 by internal and external threads and bolts 9.

[0046] In this embodiment, the anchor rod 1 is a hollow structure, and a peelable coating or isolation film 24 is provided on the inner wall of the hollow structure to prevent the cement mortar from directly contacting the anchor rod 1 during grouting.

[0047] In this embodiment, a plurality of patterned grooves 23 are evenly arranged on the expandable sleeve 3 .

[0048] In the expansion anchor assembly of this embodiment, the anchor 1 is a cylindrical structure and is a recyclable main body. Both ends of the anchor are provided with threads. The anchoring end is connected to the fixed sleeve 2, and the other end thread cooperates with the high-strength nut 14. The high-strength nut 14 is tightened to apply pressure to the high-strength pad 15 so that the anchor 1 is pressed tightly against the surrounding rock. The non-anchoring section of the anchor 1 is set as a hexagonal block 11. After the project is completed, the hexagonal block 11 can be directly screwed to take out the anchor 1 for recycling. The anchoring section of the anchor 1 is optimized as follows: the anchor 1 and the fixed sleeve 2 are designed to be detachable threaded connection, which can be convenient for installation and recycling; the fixed sleeve 2 and the shape memory alloy spring are welded and fixed as one body, and the expandable sleeve 3 and the fixed sleeve 2 are designed to be connected by internal and external threads and bolts 9, which also meet the detachable requirements. At the same time, the shape memory alloy expansion plate 4 and the shape memory alloy spring meet certain strength requirements and can continue to bear axial loads without breaking after expansion. The shape memory alloy expansion plate 4 and the shape memory alloy spring are adjusted by the temperature control device 6 to expand or not.

[0049] The anchoring method of the expansion anchor assembly of this embodiment comprises the following steps:

[0050] S1: drilling a hole 10 at the location to be anchored, and expanding the bottom of the anchor hole 10 into a trumpet hole matching the expandable sleeve 3 in the expanded state;

[0051] S2: Keep the expandable sleeve 3 in a non-expanded state by a first temperature control device, keep the expandable support device 5 in a non-expanded state by a second temperature control device, and place the expandable anchor assembly into the anchor hole 10;

[0052] S3: using the first temperature control device to roughly adjust the expansion state of the expandable sleeve 3 so that the expandable sleeve 3 remains in the expanded state, and then using the second temperature control device to adjust the expansion state of the expandable support device 5 to further adjust the expansion state of the expandable sleeve 3, so that the expansion end of the expandable sleeve 3 fits the horn hole, and the shape memory alloy expansion plate 4 meets the optimal curve shape requirement;

[0053] S4: Grouting, curing, anchor bolt 1 anchoring.

[0054] More specifically, the expansion state of the expandable sleeve 3 is adjusted by using the first temperature control device, including the following steps: determining the shape change temperature of the expandable sleeve 3, the first temperature control device is powered on, so that the expandable sleeve 3 is heated to a temperature higher than the shape change temperature, so that the expandable sleeve 3 remains in a non-expanded state; after being placed in the anchor hole 10, the first temperature control device is powered off, so that the expandable sleeve 3 is cooled to a temperature lower than the shape change temperature, so that the expandable sleeve 3 remains in an expanded state, and a rough adjustment of the expansion state of the expandable sleeve 3 is completed; the expansion state of the expandable support device 5 is adjusted by using the second temperature control device The state is used to further adjust the expansion state of the expandable sleeve 3, including the following steps: determining the shape change temperature of the expandable support device 5, powering on the second temperature control device, heating the expandable support device 5 to a temperature higher than the shape change temperature, and keeping the expandable support device 5 in a non-expanded state; after being placed in the anchor hole 10, the second temperature control device is powered off, cooling the expandable support device 5 to a temperature lower than the shape change temperature, and keeping the expandable support device 5 in an expanded state and further supporting the expandable sleeve 3, thereby completing the further adjustment of the expansion state of the expandable sleeve 3 by the expandable support device 5.

[0055] More specifically, Figure 5 As shown, the anchoring method of the expansion anchor assembly of this embodiment has the following construction process: assembling the anchor assembly → drilling → power on and closing → placing the anchor assembly → power off and expanding → grouting → curing → anchoring → recycling; including the following steps:

[0056] (1) Assembling anchor rod components

[0057] The shape memory alloy spring is fixed to the front end of the fixing sleeve 2, and then the anchor rod 1 and the expandable sleeve 3 are connected to the fixing sleeve 2 through threads so that the axes coincide with each other.

[0058] (2) Clean up the site

[0059] Determine the anchoring position on the slope and clear the area around the anchoring position.

[0060] (3) Drilling

[0061] An anchor hole 10 perpendicular to the slope is drilled on the slope surface, and equal diameter drilling is adopted. The drilling depth and diameter must meet the design requirements, and then the anchor section is expanded into a trumpet hole with an optimal curved shape.

[0062] (4) Clearing the hole

[0063] Clean the anchoring section of the drilled hole and remove debris from the hole.

[0064] (5) Power on and close

[0065] Determine that the temperature change of the shape memory alloy material is between 60-100°. Before placing the anchor assembly in the hole, power is supplied to the first temperature control device and the second temperature control device to raise the temperature of the shape memory alloy expansion plate 4 and the shape memory alloy spring to 80°, so that the shape memory alloy expansion plate 4 and the shape memory alloy spring are in a non-expanded state (state such as Figure 2 as shown).

[0066] (6) Place anchor rod assembly

[0067] The anchor rod assembly is placed in the hole, and after the anchoring section reaches the specific hole, the high-strength nut 14 is tightened to apply pressure to the high-strength pad 15 to complete the initial fixation of the anchor rod assembly in the hole.

[0068] (7) Power failure expansion

[0069] After the anchor rod assembly is installed, the shape memory alloy expansion plate 4 and the shape memory alloy spring are gradually expanded by coarse adjustment and fine adjustment. During coarse adjustment, the power supply of the first temperature control device is turned off to cool down for 30 minutes, and the shape memory alloy expansion plate 4 immediately begins to recover its shape. However, due to the obstruction of the soil around the borehole, the shape memory alloy expansion plate 4 cannot return to the preset bending shape of the optimal curve, so further fine adjustment is required. During fine adjustment, the power supply of the second temperature control device is turned off to cool down for 30 minutes, and the shape memory alloy spring begins to recover its shape according to the preset four inflection point heights to support the shape memory alloy expansion plate 4. When the expansion of the shape memory alloy spring reaches the set maximum value, the shape memory alloy expansion plate 4 is fully expanded according to the geometric shape of the preset optimal curve under the action of external force, and the expanded shape memory alloy expansion plate 4 fits the above-mentioned horn hole (the state is as shown in FIG. Figure 1 As shown in the figure), after the expansion is completed, the first and second temperature control devices are no longer powered.

[0070] (8) Grouting

[0071] Cement mortar is injected into the anchoring section. During grouting, the main structure of the anchor rod 1 is not in direct contact with the cement mortar, which is convenient for recovery.

[0072] (9) Anchor bolt assembly maintenance and anchoring

[0073] After grouting, the shape memory alloy expansion plate 4 remains in a fully expanded state, and the anchoring construction is completed when the concrete 13 obtained by curing the cement mortar is fixed.

[0074] (10) Recycling

[0075] The recovered part is the anchor rod 1, and the non-recoverable part includes the fixed sleeve 2, the expandable sleeve 3, the shape memory alloy expansion plate 4, and the shape memory alloy spring. When recovering, the hexagonal block 11 at the front end of the anchor rod 1 is screwed counterclockwise, and the anchor rod 1 moves backward. When the anchor rod 1 is separated from the fixed sleeve 2, the anchor rod 1 is taken out to complete the recovery.

[0076] In summary, the above technical solution of this embodiment not only improves the support effect of the anchor assembly in the tunnel or slope engineering, increases the anchoring force of the anchor assembly in the surrounding rock, but also facilitates the recovery of the anchor 1, saves resources, and reduces the danger and property loss of underground engineering. Compared with the case where only the expandable sleeve 3 and the shape memory alloy expansion plate 4 are used without the shape memory alloy spring, the anchoring effect will be significantly better.

[0077] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An expansion anchor assembly, comprising an anchor (1), characterized in that: An expandable sleeve (3) is sleeved on one end of the anchor rod (1); an expandable support device (5) is provided between the expandable sleeve (3) and the anchor rod (1); a first temperature control device for roughly adjusting the expansion state of the expandable sleeve (3) is provided in the expandable sleeve (3); and a second temperature control device for adjusting the expansion state of the expandable support device (5) to further adjust the expansion state of the expandable sleeve (3) is provided in the expandable support device (5); The expandable sleeve (3) comprises a plurality of shape memory alloy expansion plates (4), and the first temperature control device is arranged in the shape memory alloy expansion plates (4); and in an expanded state, the plurality of shape memory alloy expansion plates (4) are trumpet-shaped, and in a non-expanded state, the plurality of shape memory alloy expansion plates (4) are attached to the expandable support device (5); The expandable support device (5) is a shape memory alloy spring, and the second temperature control device is arranged in the shape memory alloy spring; and in the expanded state, the shape memory alloy spring is trumpet-shaped to support the expandable sleeve (3), and in the non-expanded state, the shape memory alloy spring is attached to the anchor rod (1); The first temperature control device comprises a first temperature control wire (71), the first temperature control wire (71) being arranged in a wire groove (8) in the expandable sleeve (3), the second temperature control device comprises a second temperature control wire (72), the second temperature control wire (72) being arranged in a wire groove (8) in the expandable support device (5), and the first temperature control wire (71) and the second temperature control wire (72) are both connected to a temperature control device (6); The anchor rod (1) is provided with a fixed sleeve (2), and the expandable sleeve (3) is fixed on the fixed sleeve (2); The anchor rod (1) is a hollow structure, and a peelable coating or isolation film (24) is provided on the inner wall of the hollow structure to prevent direct contact between cement mortar and the anchor rod (1) during grouting.

2. The expandable anchor assembly according to claim 1, characterized in that: The inner cavity of the fixing sleeve (2) is provided with an internal thread, the outer wall of the anchor rod (1) is provided with an external thread, and the fixing sleeve (2) and the anchor rod (1) are connected via internal and external threads; the outer wall of the fixing sleeve (2) is provided with an external thread, the inner cavity of the expandable sleeve (3) is provided with an internal thread, both the fixing sleeve (2) and the expandable sleeve (3) are provided with screw holes, and the expandable sleeve (3) is arranged on the fixing sleeve (2) via internal and external threads and bolts (9).

3. The expandable anchor assembly according to claim 1 or 2, characterized in that: The expandable sleeve (3) is evenly provided with a plurality of patterned grooves (23).

4. An anchoring method for an expansion anchor assembly according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: drilling a hole at a location to be anchored to form an anchor hole (10), and expanding the bottom of the anchor hole (10) into a trumpet hole that matches the expandable sleeve (3) in an expanded state; S2: maintaining the expandable sleeve (3) in a non-expanded state by means of the first temperature control device, maintaining the expandable support device (5) in a non-expanded state by means of the second temperature control device, and placing the expandable anchor assembly into the anchor hole (10); S3: using the first temperature control device to roughly adjust the expansion state of the expandable sleeve (3) so that the expandable sleeve (3) remains in the expanded state, and then using the second temperature control device to adjust the expansion state of the expandable support device (5) to further adjust the expansion state of the expandable sleeve (3) so that the expansion end of the expandable sleeve (3) fits the horn hole; S4: Grouting, curing, anchor bolt (1) anchoring.

5. The anchoring method according to claim 4, characterized in that: The expansion state of the expandable sleeve (3) is adjusted by using the first temperature control device, comprising the following steps: determining the shape change temperature of the expandable sleeve (3), powering on the first temperature control device to raise the temperature of the expandable sleeve (3) to a temperature higher than the shape change temperature, so that the expandable sleeve (3) remains in a non-expanded state; after being placed in the anchor hole (10), powering off the first temperature control device to lower the temperature of the expandable sleeve (3) to a temperature lower than the shape change temperature, so that the expandable sleeve (3) remains in an expanded state, thereby completing a rough adjustment of the expansion state of the expandable sleeve (3); The expansion state of the expandable support device (5) is adjusted by using the second temperature control device to further adjust the expansion state of the expandable sleeve (3), comprising the following steps: determining the shape change temperature of the expandable support device (5), energizing the second temperature control device to increase the temperature of the expandable support device (5) to a temperature higher than the shape change temperature, so that the expandable support device (5) remains in a non-expanded state; after being placed in the anchor hole (10), the second temperature control device is de-energized to reduce the temperature of the expandable support device (5) to a temperature lower than the shape change temperature, so that the expandable support device (5) remains in an expanded state and further supports the expandable sleeve (3), thereby completing the further adjustment of the expansion state of the expandable sleeve (3) by the expandable support device (5).

Images