Static pressure extrusion and compacting hole expanding anchor rod body construction equipment

Abstract

This utility model discloses a static pressure compaction and expansion anchor bolt construction device, including an expansion body and an expansion component. The expansion body is a tubular structure with 8 to 12 expansion holes of 15° to 35° spiral angle on its sidewalls from bottom to top. The axial center-to-center distance between adjacent holes is 0.8 to 1.0 times the diameter of the anchor hole. The expansion component is located inside the body and includes a four-bar hinge mechanism (first fixed plate, first movable plate, second movable plate, and second fixed plate). When the load top plate is pressed down, the first movable plate and the second movable plate hinge and rotate to form a forming corner, radially extruding the expansion holes. A positioning tip is set at the bottom of the device to ensure accurate positioning of the hole bottom. The outward convex height of the forming corner is 0.3 to 0.5 times the diameter of the anchor hole, forming a continuous spiral jujube-shaped expansion cavity through static pressure compaction. This device replaces the cutting process with static pressure compaction, forming a reinforced compression zone around the hole, optimizing stress distribution, and improving the anchoring force in weak strata. Tests show that the bearing capacity of spiral jujube-shaped anchor bolts is 2.11 times that of ordinary anchor bolts.

Description

Technical Field

[0001] This utility model relates to a static pressure compaction and hole expansion anchor body construction device, belonging to the field of anchor body technology. Background Technology

[0002] Anchor bolts (cables) are a key engineering measure in geotechnical anchoring projects. Studies have shown that after a certain limit is reached, further increases in the anchorage length have little effect on improving the anchoring force. Therefore, improving the anchoring force of anchor bolts (cables) in weak strata such as loess, soil-like materials, or soft rock is of significant practical importance for engineering safety, cost savings, energy conservation, emission reduction, and environmental protection. The principle of existing enlarged-hole anchor bolt (cable) technology is to use cutting blades to cut away the soil or soft rock from the anchorage section's borehole wall, thereby increasing the borehole diameter and thus improving the anchoring force. However, when cutting away the soil or soft rock from the anchorage section's borehole wall, the borehole wall is not compacted, resulting in a less dense anchorage section. The increase in anchoring force is mainly due to the increased borehole diameter; the lateral resistance per unit area between the grout and the borehole wall does not increase. Therefore, improving the anchoring force solely through soil cutting has a limited range of effect. Utility Model Content

[0003] In view of this, the present invention discloses a construction device for a static pressure borehole-expanding anchor body that can be continuously spirally compacted, so as to solve the problems existing in the above-mentioned background technology.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A static pressure compaction and hole-expanding anchor bolt construction device, comprising:

[0006] The extrusion body is a tubular structure extending from bottom to top. The extrusion body has an upper opening and a lower opening. The lower opening is provided with a sealing plate to close the lower opening. The side wall of the extrusion body is provided with a plurality of extrusion holes from bottom to top. The extrusion holes are arranged in a spiral shape along the height direction of the extrusion body, and the spiral angle of the extrusion holes is 15°~30°.

[0007] The helical helix angle design creates a continuous, gradually changing trajectory for the extrusion boreholes in both the axial and circumferential directions, ensuring that the extruded cavity constructs a helical, synergistic load-bearing arch network within the soil. Simulation tests show that when the helical helix angle α = 15°~30°, the load-bearing capacity of the helical extrusion anchor is relatively high, with the maximum and consistent capacity occurring between α = 15°~25°. This indicates that when the helical helix angle α = 15°~25°, the synergistic effect between the extruded anchor and the surrounding soil and rock is optimal, resulting in the maximum load-bearing capacity of the anchor. When the helical helix angle α is small (α = 5° and α = 10°), the stress-bearing areas of the extruded anchor overlap, leading to additional displacement of the soil between the discs and significant stress concentration, failing to fully utilize the load-bearing effect of the interaction between the extruded anchor and the soil. As the helical helix angle increases (α = 15°~30°), the mutual influence between the extruded anchors decreases, and each extruded anchor can interact with the surrounding soil and rock, fully utilizing their synergistic performance. However, a larger helix angle does not necessarily mean a greater pull-out bearing capacity of the anchor. When the helix angle exceeds 30° (α=35° and α=40°), the bearing capacity of the anchor body actually decreases. In practical engineering, the helix angle of the spiral-shaped extrusion anchor can be controlled between α=15° and 30° to fully utilize the synergistic effect between the extrusion body and the surrounding soil and rock, thereby improving the bearing capacity of the anchor body.

[0008] An extrusion expansion component, located within an extrusion expansion body, includes an extrusion expansion side plate fixed to a sealing plate, and a load top plate fixed to the other end of the extrusion expansion side plate. The extrusion expansion side plate includes a first fixed plate, a first movable plate, a second movable plate, and a second fixed plate that are sequentially hinged to each other from bottom to top. The first fixed plate is fixedly connected to the sealing plate, and the second fixed plate is fixedly connected to the load top plate. When the load top plate is pressed down, the first movable plate and the second movable plate hinge and rotate to form an outwardly raised forming corner, and extend out a corresponding extrusion expansion hole.

[0009] Furthermore, the number of extrusion holes is 8 to 12, and the center-to-center distance between adjacent extrusion holes along the axial direction is 0.8 to 1.0 times the diameter of the anchor hole. The diameter of the extrusion holes is 0.3 to 0.4 times the designed anchor hole diameter; the outward convex height of the formed corner is 0.3 to 0.5 times the designed anchor hole diameter. This combination of parameters ensures that adjacent extrusion cavities are tightly connected, forming a continuous jujube-shaped enlarged cavity, avoiding excessive dispersion between extruded bodies and the formation of unreinforced areas.

[0010] Furthermore, the cross-section of the extrusion body is square or circular, compatible with different drilling tool hole shapes.

[0011] Furthermore, the bottom of the extrusion body is provided with a positioning tip to accurately abut against the rock surface at the bottom of the hole, preventing deviation during the extrusion process.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. Static pressure compaction to form a cavity

[0014] The shaped corner is driven by axial load to be radially extruded. Through continuous compression rather than cutting, the soil around the hole is plastically compacted, forming a date-shaped reinforcing compression band on the hole wall, which significantly enhances the micro-interlocking effect of the slurry-soil interface.

[0015] 2. Spiral arrangement structure of date pits

[0016] The continuously spirally distributed jujube-shaped cavities construct a spatially coordinated load-bearing arch network in the soil, transforming the pull-out resistance of the anchor body from a discrete point distribution to a continuous band distribution, significantly reducing the risk of stress concentration in the anchor (cable) hole wall under pull-out loads. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the main structure of the static pressure compaction and expansion anchor bolt construction equipment of this utility model.

[0018] Figure 2 This is a cross-sectional view of the extrusion and expansion component of the static pressure compaction and expansion anchor bolt construction equipment of this utility model.

[0019] Figure 3 for Figure 2 A schematic diagram of the structure under pressure of the extruded expansion component.

[0020] Figure 4 This is a schematic diagram of the test anchor bolt arrangement in Embodiment 3 of this utility model.

[0021] In the figure, 1-extrusion body, 11-upper pipe opening, 12-lower pipe opening, 13-sealing plate, 14-extrusion hole, 2-extrusion part, 21-extrusion side plate, 22-load top plate, 211-first fixed plate, 212-first movable plate, 213-second movable plate, 214-second fixed plate, 23-forming corner, 3-positioning tip. Detailed Implementation

[0022] The present invention will be further explained below with reference to the accompanying drawings.

[0023] Example 1

[0024] Combination Figure 1-3 Explain the structural implementation details of this equipment:

[0025] Assembly of extrusion body 1:

[0026] A Q345 seamless steel pipe with a wall thickness of 12mm (circular cross section, outer diameter 120mm) is selected, and 12 extrusion and expansion holes 14 are milled from the bottom to the top.

[0027] The diameter of the extrusion hole 14 is 40mm, arranged in a right-hand spiral, with a helix angle α=25°, and the center distance between adjacent holes in the axial direction is 110mm;

[0028] Weld a Φ120mm×10mm sealing plate 13 to the bottom and a conical positioning tip 3 (cone angle 60°, height 50mm) to the center.

[0029] Extrusion Part 2 Reinforcement Design:

[0030] The extruded side plate 21 adopts a four-bar hinge mechanism:

[0031] The first fixing plate 211 is welded to the sealing plate 13 (plate thickness 15mm);

[0032] A 10mm thick ear plate is welded at the hinge point between the first movable plate 212 and the second movable plate 213;

[0033] The convex height of the shaped corner 23 is 52mm;

[0034] Tolerance control: The deviation between the center line of the forming corner 23 and the axis of the extrusion hole (14) is ≤0.5mm (to ensure accurate extrusion).

[0035] Example 2

[0036] The specific applications of this utility model are as follows:

[0037] Anchor hole formation:

[0038] Drill Φ130mm anchor holes to the design depth, clean the holes with high-pressure air (pressure 0.4MPa×2min), and the sediment at the bottom of the hole is ≤30mm;

[0039] Positioning tip 3 abuts against the rock surface at the bottom of the hole to prevent the equipment from tilting.

[0040] Spiral extrusion cavity formation:

[0041] Apply an axial pressure of 28MPa (corresponding to the range of 8~35MPa) to the load top plate 22, with a loading rate of 0.5MPa / s, hold the pressure for 300 seconds, release the pressure, lift the equipment 110mm (axial hole distance), and repeat the extrusion expansion operation;

[0042] Grouting Synergistic Enhancement:

[0043] Lower Φ32mm ribbed anchor bolts, and set up positioning brackets (outer diameter Φ100mm) every 2m.

[0044] A cement grout with a water-cement ratio of 0.45 was injected in one go, and the final pressure was 2.0 MPa, which was then stabilized for 3 minutes.

[0045] Example 3

[0046] Field pull-out tests were conducted on ordinary anchor bolts, tandem date-shaped extruded anchor bolts (CN118911128A), and spiral date-shaped extruded anchor bolts based on the reconstruction and expansion project of the Shantou-Meizhou Expressway in Guangdong Province. The test location was the cut slope from LK0+154 to LK0+496. The topography and strata of the test site are as follows:

[0047] (1) Topography and landforms

[0048] This section of the slope is located in a low mountain and hilly terrain (I2 area), with a relatively steep terrain and dense vegetation, mainly artificially planted eucalyptus trees. The natural slope ratio is 20-30°. The terrain is quite undulating, with ground elevations ranging from 236 to 265 m, and a relative height difference of approximately 29 m.

[0049] (2) Stratigraphy

[0050] The slope strata mainly consist of Quaternary silty clay and Upper Jurassic Douling Group (J3) a Composed of tuff. Based on the depth revealed, from top to bottom, it consists of Quaternary residual slope deposits (Q). el+dl ) layer and Upper Jurassic Douling Group (J3) d The tuff exhibits a distinct layered structure and differences in mechanical properties.

[0051] A total of 6 anchor bolts were used in the experiment: 2 ordinary anchor bolts, 2 tandem date-shaped expansion anchor bolts, and 2 spiral date-shaped expansion anchor bolts. The arrangement is as follows: Figure 4 As shown, all anchor bolts have an angle of 20° with the horizontal plane. Among them, 1-1 and 1-2 are ordinary anchor bolts, 1-3 and 1-4 are tandem jujube-shaped expansion anchor bolts, and 1-5 and 1-6 are spiral jujube-shaped expansion anchor bolts.

[0052] The test results are as follows:

[0053] Load-displacement relationship: 1-1 The ultimate bearing capacity of ordinary anchor bolt is 454 kN and the ultimate displacement is 41 mm; 1-2 The ultimate bearing capacity of ordinary anchor bolt is 414 kN and the ultimate displacement is 38 mm; 1-3 The ultimate bearing capacity of series jujube-shaped extrusion anchor bolt is 626 kN and the ultimate displacement is 52 mm; 1-4 The ultimate bearing capacity of series jujube-shaped extrusion anchor bolt is 750 kN and the ultimate displacement is 28.8 mm; 1-5 The ultimate bearing capacity of spiral jujube-shaped extrusion anchor bolt is 920 kN and the ultimate displacement is 49.6 mm; 1-6 The ultimate bearing capacity of spiral jujube-shaped extrusion anchor bolt is 910 kN and the ultimate displacement is 34 mm.

[0054] Bearing capacity comparison: The average ultimate bearing capacity of ordinary anchor bolts is 434 kN; the average ultimate bearing capacity of tandem date-shaped extrusion anchor bolts is 688 kN; and the average ultimate bearing capacity of spiral date-shaped extrusion anchor bolts is 915 kN. The average ultimate bearing capacity of spiral date-shaped extrusion anchor bolts is 2.11 times that of ordinary anchor bolts and 1.33 times that of tandem date-shaped extrusion anchor bolts; the average ultimate bearing capacity of tandem date-shaped extrusion anchor bolts is 1.59 times that of ordinary anchor bolts. Spiral date-shaped extrusion anchor bolts have a greater bearing capacity, avoid the problem of discrete stress concentration in tandem date-shaped extrusion anchor bolts, and significantly improve the anchoring performance in weak strata.

Claims

1. A static pressure extruded expanding anchor body construction apparatus, characterized by, include: The extrusion body (1) is a tubular structure extending from bottom to top. The extrusion body has an upper pipe opening (11) and a lower pipe opening (12). The lower pipe opening (12) is provided with a sealing plate (13) to close the lower pipe opening (12). The side wall of the extrusion body is provided with a plurality of extrusion holes (14) from bottom to top. The extrusion holes (14) are arranged in a spiral shape along the height direction of the extrusion body, and the spiral angle of the extrusion holes (14) is 15°~35°. The extrusion part (2) is located inside the extrusion body (1) and includes an extrusion side plate (21) fixed to the sealing plate (13). The other end of the extrusion side plate (21) is fixed with a load top plate (22). The extrusion side plate (21) includes a first fixed plate (211), a first movable plate (212), a second movable plate (213), and a second fixed plate (214) that are hinged to each other from bottom to top. The first fixed plate (211) is fixed to the sealing plate (13), and the second fixed plate (214) is fixed to the load top plate (22). When the load top plate (22) is pressed down, the first movable plate (212) and the second movable plate (213) are hinged and rotated to form an outwardly raised forming corner (23) and extend out the corresponding extrusion hole (14).

2. The jacking-in compaction underreaming anchor body construction apparatus of claim 1, wherein, The number of the extrusion holes (14) is 8 to 12, and the center-to-center distance between adjacent extrusion holes along the axial direction is 0.8 to 1.0 times the designed anchor hole diameter.

3. The jacking-in expanding anchor body construction apparatus according to claim 1, wherein The diameter of the extrusion hole (14) is 0.3 to 0.4 times the designed anchor hole diameter; the convex height of the formed corner (23) is 0.3 to 0.5 times the designed anchor hole diameter.

4. The jacking-in compaction underreaming anchor body construction apparatus of claim 1, wherein, The cross-section of the extrusion body (1) is square or circular.

5. The jacking-in expanding anchor body construction apparatus according to claim 1, wherein The bottom of the extrusion body (1) is provided with a positioning tip (3).

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