Prefabricated spiral drilling expanded body pre-stressed anchor cable device

Abstract

The utility model belongs to the technical field of constructional engineering, and particularly relates to a prefabricated spiral drilling expanded body pre-stressed anchor cable device which comprises a variable-diameter end pipe, a locking anchorage device is arranged in the variable-diameter end pipe, and the locking anchorage device is connected with an outer anchorage device through a plurality of unbonded steel strands. A metal grouting pipe communicated with the grouting cavity and the high-pressure grouting pipe is arranged in the variable-diameter end pipe in advance, a spiral expanded-base bearing ring is welded to the outer side of the variable-diameter end pipe, and the section area of the end is increased by arranging the prefabricated spiral expanded anchor head capable of conveniently drilling, so that the anti-pressure capacity of soil can be fully exerted; and meanwhile, lateral confinement and constraint are increased by high-strength grouting materials through the variable-diameter end pipe with the top shrunk, the deformation amount of the anchor head is extremely small, and by combining high-pressure grouting of soil around the end of the anchor rod, the anti-pulling bearing capacity of the single anchor rod is greatly improved, and the prestress loss of the anchor cable is greatly reduced.

Description

Technical Field

[0001] This utility model belongs to the field of building engineering technology, and in particular relates to a prefabricated spiral drilling expansion prestressed anchor cable device. Background Technology

[0002] In the fields of anti-buoyancy in building engineering, foundation pit support, and slope support, there is a need for large-scale use of anti-buoyancy anchors, prestressed anchor cables / anchors, etc. Traditional anchors are mainly equal-diameter anchors, whose pull-out bearing capacity is controlled by the bond strength between the anchor body and the soil. They have low pull-out bearing capacity, large displacement, and are prone to deformation, which can cause prestress loss.

[0003] For example, patent application number CN202023126458.1 describes a prestressed anchor cable, including an anchor head, a spring, and a grouting pipe. The inner wall of the anchor head is connected to a limiting block, and an anchor bar is connected through the limiting block. A connecting ring is connected to the outer wall of the anchor bar, and a bolt is connected through the limiting block. The spring is connected to one side of the anchor head, and a locking block is fixed to the surface of the connecting ring. A locking block is also connected to the outer wall of the grouting pipe. The inner wall of the locking block's opening end is arc-shaped, tangent to the outer wall of the grouting pipe, forming a locking connection between the grouting pipe and the locking block. A threaded connection is formed between the connecting ring and the anchor bar. The connecting ring is fixed by rotating it into the outer wall of the anchor bar, and the anchor bar is then inserted into the ground after the grouting pipe is inserted into the locking block. However, the disadvantage of this technical solution is that the anchor head of the prestressed anchor cable has a uniform diameter and is not enlarged, resulting in low pull-out bearing capacity and easy deformation leading to prestress loss. Utility Model Content

[0004] The purpose of this utility model is to provide a prefabricated spiral drilling prestressed anchor cable device to solve the problems in the prior art. The specific technical solution is as follows:

[0005] A prefabricated spiral drilling prestressed anchor cable device includes a variable diameter end pipe, a locking anchor inside the variable diameter end pipe, the locking anchor being connected to an outer anchor via multiple unbonded steel strands, a metal grouting pipe pre-installed inside the variable diameter end pipe connecting the grouting cavity and the high-pressure grouting pipe, and a spiral expansion bearing ring welded to the outside of the variable diameter end pipe.

[0006] Furthermore, the lower end of the variable diameter end pipe is provided with a guide pile tip, and the variable diameter end pipe is connected to the end of the drill rod of the drilling rig through the connecting flange provided at its upper end.

[0007] Furthermore, the locking anchor is provided with a metal pressure plate at its front end. The locking anchor, the metal pressure plate, the unbonded steel strand located inside the variable diameter end pipe, and the metal grouting pipe are all encapsulated in the variable diameter end pipe with high-strength grouting material.

[0008] Furthermore, the connection between the variable diameter end tube and the connecting flange is tapered inward.

[0009] Furthermore, the lower end of the variable diameter end pipe is provided with four equidistant post-grouting outlet holes, and the grouting cavity is connected to the outside of the variable diameter end pipe through the four post-grouting outlet holes.

[0010] Furthermore, the unbonded steel strand is covered by a sleeve, and the space between the sleeve and the unbonded steel strand is filled with grease.

[0011] Furthermore, the cement grout in the grouting cavity overflows to the outside of the variable diameter end pipe through four post-grouting outlet holes, forming a high-pressure grouting body for the anchor head. After the high-pressure grouting body for the anchor head solidifies, it forms an integral whole with the variable diameter end pipe and the spiral expansion bearing ring.

[0012] Furthermore, the end of the external anchor rests against the foundation slab, a waterproof layer is provided between the foundation slab and the foundation pad, and the foundation pad rests against the ground.

[0013] Furthermore, a steel pad is provided between the external anchor and the foundation plate.

[0014] The advantages of this utility model are:

[0015] 1. The prestressed anchor cable device with a spiral-expanded bearing ring is mechanically drilled to a predetermined depth in the soil using a drilling rig. The spiral-expanded bearing ring allows the variable-diameter end pipe to be drilled quickly into the preset position. Cement grout is injected into the grouting cavity through a high-pressure grouting pipe. The cement grout is then injected into the soil around the variable-diameter end pipe through the post-grouting outlet hole to form a reinforcing body. The spiral-expanded anchor head on the outside of the variable-diameter end pipe increases the end cross-sectional area, which can fully utilize the compressive strength of the soil. The deformation of the anchor head is minimal, which greatly improves the pull-out bearing capacity of a single anchor rod and significantly reduces the prestress loss of the anchor cable.

[0016] 2. This anchor cable device has the main advantages of convenient construction, high strength, short curing period or no curing period required, reliable structure, high pull-out bearing capacity, and environmental protection. It can be widely used in structural anti-buoyancy, foundation pit and slope support anchoring and other fields. By expanding the anchor head, the end bearing capacity of the soil is fully utilized. Combined with high-pressure grouting of the soil around the anchor rod end, the pull-out bearing capacity of the single anchor is further improved. It is applicable to a wide range of strata, including fill, cohesive soil, silt, loess, sand, angular gravel, round gravel, crushed stone, pebbles, completely weathered rock and strongly weathered rock.

[0017] 3. The spiral drilling prestressed anchor cable device in this application has high compatibility with pile driving machinery. It can be constructed using ordinary anchor drilling rigs with special tool-section drill rods. It has high construction efficiency, low maintenance requirements, and no environmental pollution during construction. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle;

[0020] Figure 3 for Figure 1 Enlarged view of a section at point B in the middle;

[0021] Explanation of markings in the diagram:

[0022] 1. Variable diameter end pipe; 2. Guide pile tip; 3. Spiral expanded bottom bearing ring; 4. Post-grouting outlet hole; 5. Grouting cavity; 6. High-strength grouting material; 7. Locking anchor; 8. Metal bearing plate; 9. Connecting flange; 10. Unbonded steel strand; 11. Metal grouting pipe; 12. High-pressure grouting pipe; 13. Anchor head high-pressure grouting body; 14. External anchor; 15. Steel pad; 16. Foundation cushion layer; 17. Waterproof layer; 18. Foundation base plate. Detailed Implementation

[0023] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Example 1

[0026] like Figures 1-3 As shown, a prefabricated spiral drilling prestressed anchor cable device includes a variable diameter end pipe 1, a locking anchor 7 is provided inside the variable diameter end pipe 1, the locking anchor 7 is connected to the outer anchor 14 through multiple unbonded steel strands 10, a metal grouting pipe 11 is pre-installed inside the variable diameter end pipe 1 to connect the grouting cavity 5 and the high pressure grouting pipe 12, and a spiral expansion bearing ring 3 is welded to the outside of the variable diameter end pipe 1;

[0027] The working principle of the above technical solution is as follows: The grouting cavity 5 is located inside the variable diameter end pipe 1. One end of the metal grouting pipe 11 is inserted into the grouting cavity 5, and the other end of the metal grouting pipe 11 is fixed to the end of the high pressure grouting pipe 12 with a detachable pressure self-tightening joint. The variable diameter end pipe 1 is mechanically drilled into the soil layer to a predetermined depth by a drilling rig. Cement grout is injected into the grouting cavity 5 through the high pressure grouting pipe 12. The cement grout is injected into the soil around the variable diameter end pipe 1 through the post-grouting outlet hole 4 to form a reinforced body. The spiral expansion of the anchor head on the outside of the variable diameter end pipe increases the end cross-sectional area, which can give full play to the compressive strength of the soil. The deformation of the anchor head is minimal, which greatly improves the pull-out bearing capacity of a single anchor rod and significantly reduces the prestress loss of the anchor cable.

[0028] Compared with other existing enlarged head anchor cable technologies, the prefabricated spiral drilling enlarged body prestressed anchor cable device used in this application has high strength, reliable structure, and the enlarged head size can be fully guaranteed. It overcomes the possible defects caused by the uncontrollable enlarged hole size when enlarging holes using mechanical hole enlargement or high-pressure jet grouting technology, and overcomes the problems of relatively low strength and poor strength uniformity of the grout body of the anchor head of general enlarged head anchor cables.

[0029] This anchor cable device boasts advantages such as convenient construction, high strength, reliable structure, high pull-out bearing capacity, and environmental friendliness. It can be widely used in structural anti-buoyancy, foundation pit and slope support anchoring, and other fields. By fully utilizing the end bearing capacity of the soil through anchor head expansion and combining it with high-pressure grouting of the soil surrounding the anchor rod end, the pull-out bearing capacity of a single anchor is further improved, reaching 400-2000KN. Because it employs mechanical drilling, it is suitable for a wide range of geological formations, including fill, cohesive soil, silt, loess, sand, angular gravel, rounded gravel, crushed stone, pebbles, completely weathered rock, and strongly weathered rock.

[0030] The precast spiral drilling prestressed anchor cable device in this application has high compatibility with piling machinery, high construction efficiency, low maintenance requirements, and no environmental pollution during construction.

[0031] Example 2

[0032] like Figures 1-3 As shown, the lower end of the variable diameter end pipe 1 is provided with a guide pile tip 2, and the variable diameter end pipe 1 is connected to the end of the drill rod of the drilling rig through the connecting flange 9 provided at its upper end.

[0033] The working principle of the above technical solution is as follows: the guide pile tip 2 facilitates the drilling of the variable diameter end pipe 1 into the soil layer, and the connecting flange 9 is a special self-locking flange, which facilitates the connection of the variable diameter end pipe 1 with the drilling rig.

[0034] Example 3

[0035] like Figures 1-3As shown, the locking anchor 7 is provided with a metal pressure plate 8 at its front end. The locking anchor 7, the metal pressure plate 8, the unbonded steel strand 10 located in the variable diameter end pipe 1 and the metal grouting pipe 11 are all encapsulated in the variable diameter end pipe 1 by high-strength grouting material 6.

[0036] The working principle of the above technical solution is as follows: multiple unbonded steel strands 10 are passed through the metal pressure plate 8 and locked to the anchor 7. High-strength grout 6 is placed inside the variable diameter end pipe 1. After the high-strength grout 6 is cured, the locking anchor 7, the metal pressure plate 8, and the metal grouting pipe 11 are sealed inside the variable diameter end pipe 1. The lower end of the metal grouting pipe 11 is inserted into the grouting cavity 5. During construction, the upper end of the metal grouting pipe 11 is connected to the high-pressure grouting pipe 12 using a detachable pressure self-tightening joint, thereby completing the prefabrication of the front end part of the spiral drilling expanded prestressed anchor cable device.

[0037] Example 4

[0038] like Figures 1-3 As shown, the connection between the variable diameter end tube 1 and the connecting flange 9 tapers inward;

[0039] The working principle of the above technical solution is as follows: the upper end of the variable diameter end pipe 1 contracts inward to prevent the high-strength grout 6 from being easily pulled out of the variable diameter end pipe 1, and to prevent the locking anchor 7 and the metal pressure plate 8 from being pulled out of the variable diameter end pipe 1, thereby further increasing the strength of the overall structure.

[0040] The outer sides of the locking anchor 7, the metal pressure plate 8, and the outer anchor 14 are all coated with anti-corrosion paint.

[0041] Example 5

[0042] like Figures 1-3 As shown, four grouting outlet holes 4 are provided at equal intervals at the lower end of the variable diameter end pipe 1, and the grouting chamber 5 is connected to the outside of the variable diameter end pipe 1 through the four grouting outlet holes 4.

[0043] The working principle of the above technical solution is as follows: Cement grout is injected into the grouting cavity 5 under high pressure through the high-pressure grouting pipe 12 and the metal grouting pipe 11. The cement grout is injected into the soil around the variable diameter end pipe 1 under high pressure through the four post-grouting outlet holes 4 to form a reinforcing body. This can further solidify and strengthen the soil around the anchor head, further improve the soil's compressive strength, thereby improving the pull-out bearing capacity of the anchor rod and significantly reducing the prestress loss of the anchor cable.

[0044] Example 6

[0045] like Figures 1-3 As shown, the unbonded steel strand 10 is covered with a sleeve, and the space between the sleeve and the unbonded steel strand 10 is filled with grease.

[0046] The working principle of the above technical solution is as follows: The unbonded steel strand 10 is wrapped with a sleeve, which isolates the unbonded steel strand 10 from the external environment, effectively preventing corrosion and oxidation and extending the service life of the material. The unbonded steel strand 10 can freely expand and contract during the tensioning process and is not affected by the shrinkage and creep of concrete, which simplifies the tensioning process and improves construction efficiency. In the event of natural disasters such as earthquakes, the unbonded steel strand 10 allows the concrete to undergo relative displacement, effectively absorbing and dispersing seismic energy and reducing the damage to the structure.

[0047] Example 7

[0048] like Figures 1-3 As shown, the lower end of the high-pressure grouting pipe 12 is fixed to the metal grouting pipe 11 by a detachable pressure self-tightening joint. The metal grouting pipe 11 is encapsulated in the high-strength grouting material 6, and the grout outlet of the metal grouting pipe 11 is located in the grouting cavity 5.

[0049] The cement grout in the grouting cavity 5 overflows to the outside of the variable diameter end pipe 1 through four post-grouting outlet holes 4, forming the anchor head high pressure grouting body 13. After the anchor head high pressure grouting body 13 is cured, it forms an integral whole with the variable diameter end pipe 1 and the spiral expansion bearing ring 3.

[0050] The working principle of the above technical solution is as follows: After the variable diameter end pipe 1 is mechanically drilled into the soil to a predetermined depth by a drilling rig, cement grout is injected into the grouting cavity 5 through the high-pressure grouting pipe 12 and the metal grouting pipe 11. The metal grouting pipe 11 has high strength, which increases durability. The cement grout in the grouting cavity 5 overflows into the soil around the variable diameter end pipe 1 through four post-grouting outlet holes 4, forming the anchor head high-pressure grouting body 13. After the anchor head high-pressure grouting body 13 is cured, it forms an integral whole with the variable diameter end pipe 1 and the spiral expansion bearing ring 3, which greatly improves the pull-out bearing capacity of a single anchor rod and significantly reduces the prestress loss of the anchor cable.

[0051] Example 8

[0052] like Figures 1-3 As shown, the end of the external anchor 14 abuts against the foundation plate 18, and a waterproof layer 17 is provided between the foundation plate 18 and the foundation pad 16, with the foundation pad 16 abutting against the foundation.

[0053] A steel pad 15 is provided between the external anchor 14 and the foundation plate 18;

[0054] The working principle of the above technical solution is as follows: The waterproof layer 17 can prevent water from seeping into the foundation around the spiral drilling expansion prestressed anchor cable device, causing soil collapse, causing the outer anchor 14 to shift, reducing the tension of the unbonded steel strand 10, and causing loss of anchor cable prestress.

[0055] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A precast augercast pile ground improvement prestressed cable device, characterized by, The variable diameter end pipe (1) is internally provided with a locking anchor (7) connected with an outer anchor (14) through a plurality of unbonded steel strands (10), and is externally welded with a spiral expanding bottom bearing ring (3).

2. A pre-fabricated auger drilling expander prestressed cable device according to claim 1, characterized in that, The lower end of the variable diameter end pipe (1) is provided with a guide pile tip (2), and the variable diameter end pipe (1) is connected with the end of a drill rod of a drilling machine through a connecting flange (9) arranged at the upper end thereof.

3. A pre-fabricated auger drilling expander prestressed cable device according to claim 2, wherein, The front end of the locking anchor (7) is provided with a metal pressure bearing disc (8), and the locking anchor (7), the metal pressure bearing disc (8), the unbonded steel strands (10) and the metal grouting pipe (11) located in the variable diameter end pipe (1) are encapsulated in the variable diameter end pipe (1) by high-strength grouting material (6).

4. A pre-fabricated auger drilling expander prestressed cable device according to claim 2, wherein, The connecting portion of the variable diameter end pipe (1) and the connecting flange (9) is inwardly contracted.

5. A pre-fabricated auger drilling expander prestressed cable device according to claim 3, wherein, The lower end of the variable diameter end pipe (1) is equidistantly provided with four rear pressure grouting outlets (4), and the grouting cavity (5) is communicated with the outside of the variable diameter end pipe (1) through the four rear pressure grouting outlets (4).

6. A pre-fabricated auger drilling expander prestressed cable device according to claim 1, wherein, The unbonded steel strands (10) are externally sleeved with sleeves, and the sleeves are filled with lubricating grease.

7. A pre-fabricated auger drilling expander prestressed cable device according to claim 5, wherein, The cement slurry in the grouting cavity (5) is overflowed to the outside of the variable diameter end pipe (1) through the four rear pressure grouting outlets (4) to form an anchor head high pressure grouting body (13), and the anchor head high pressure grouting body (13) is integrated with the variable diameter end pipe (1) and the spiral expanding bottom bearing ring (3) after solidification.

8. A pre-fabricated auger drilling expander prestressed cable device according to claim 1, wherein, The end of the outer anchor (14) abuts against a foundation bottom plate (18), and a waterproof layer (17) is arranged between the foundation bottom plate (18) and a foundation cushion layer (16), and the foundation cushion layer (16) abuts against a foundation.

9. A pre-fabricated auger drilling expander prestressed cable device according to claim 8, wherein, A steel cushion plate (15) is arranged between the outer anchor (14) and the foundation bottom plate (18). The end of the outer anchor (14) abuts against a foundation bottom plate (18), and a waterproof layer (17) is arranged between the foundation bottom plate (18) and a foundation cushion layer (16), and the foundation cushion layer (16) abuts against a foundation.

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