Prestressed anchor rod guide cap for high-pressure splitting grouting

Abstract

A prestressed anchor rod guide cap for high-pressure splitting grouting comprises a guide cap body and a connecting sleeve. The guide cap main body comprises a cylinder section and a conical cylinder section, and first slurry outlet holes are formed in the side wall of the guide cap main body at intervals; a horizontal partition plate is arranged in the guide cap body and located at the junction of the cylindrical section and the conical section. A through hole is formed in the middle of the plate surface of the horizontal partition plate; second slurry outlet holes are formed in the horizontal partition plate around the through hole at intervals; the connecting sleeve is arranged in the middle of the top of the horizontal partition plate and communicated with the through hole. A group of arc-shaped plates are arranged at the top of the horizontal partition plate and around the connecting sleeve at intervals along the circumferential direction; the arc-shaped plate is strip-shaped, and the horizontal section is arc-shaped; the notch direction of the arc-shaped plate faces one side deviating from the circle center of the guide cap main body; and puller bolts are arranged on the side wall of the cylindrical section and correspond to the arc-shaped plates. The pre-stressed anchor rod solves the technical problem that grout cannot be split at the position of the guide cap in the high-pressure splitting grouting process of the front end of the anchoring section of a traditional pre-stressed anchor rod.

Description

Technical Field

[0001] This utility model relates to the field of prestressed anchor construction technology, and in particular to a prestressed anchor guide cap for high-pressure splitting grouting. Background Technology

[0002] In prestressed anchor bolt construction, the guide cap primarily serves to protect the prestressed steel strands during threading. Installed at the front end of the steel strands, it mainly performs the following functions: 1. Guiding the drilling direction: The guide cap provides a clear direction of travel during anchor bolt drilling. In complex geological conditions, such as encountering soil layers of varying hardness or interspersed rock layers, the guide cap ensures the anchor bolt drills along a predetermined trajectory, avoiding deviation and ensuring the anchor bolt accurately reaches the designed position. 2. Reducing drilling resistance: When the anchor bolt advances through soil or rock, it encounters significant resistance. The special shape design of the guide cap, typically streamlined or conical, effectively reduces frictional resistance during anchor bolt advancement, making drilling smoother. 3. Protecting the anchor bolt end and grouting pipe: During drilling, the anchor bolt end is susceptible to impact and wear. Ordinary guide caps are closed; during high-pressure fracturing grouting at the anchoring section of the prestressed anchor bolt, the grout cannot fracture at the guide cap location.

[0003] Currently, there are no guide caps specifically designed for anchor bolts used in secondary high-pressure fracturing grouting. Ordinary anchor bolt guide caps consist of a first and a second housing for assembly. Each housing includes a body, a tip, and a tail. Both bodies include a semi-conical section, which, when assembled, forms a conical cylinder. The two tips are located at the apex of the conical cylinder and each has a tip hole. A first connector passes through these tips to connect and secure them. Both tails have grooves with tail holes on either side. A second connector passes through these tail holes to connect and secure the tails, pressing the anchor bolt body tightly between the two grooves. The anchor bolt guide cap, constructed from two assembled housings, securely locks the guide cap onto the anchor bolt body. As can be seen from the above technical solutions, the existing system uses first and second shells for assembly. Both shells include a cap body, a cap tip, and a cap tail. Both cap bodies include semi-conical shell sections. After assembly, they form a guide cap made of a conical cylinder. The grout splitting pipe is installed at the closed guide cap. During secondary fracturing grouting, it is impossible to split the cement at the guide cap. If the grout splitting pipe is not placed at the guide cap, and the grout splitting pipe is shorter than the anchor bolt length, the fracturing effect will not meet the design requirements. Utility Model Content

[0004] The purpose of this invention is to provide a prestressed anchor guide cap for high-pressure splitting grouting, which solves the technical problem that the grout cannot split at the guide cap position during high-pressure splitting grouting of the anchoring section of traditional prestressed anchors.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A prestressed anchor guide cap for high-pressure splitting grouting includes a guide cap body and a connecting sleeve. The guide cap body comprises an upper cylindrical section and a lower conical section, with first grout outlet holes spaced apart on the side wall of the guide cap body. A horizontal partition is provided inside the guide cap body at the junction of the cylindrical and conical sections. A through hole is provided in the center of the horizontal partition, and second grout outlet holes are spaced apart on the surface of the horizontal partition surrounding the through hole. The connecting sleeve is located at the top center of the horizontal partition, and its pipe communicates with the through hole. A set of arc-shaped plates are spaced circumferentially around the top of the horizontal partition and around the connecting sleeve. The arc-shaped plates are strip-shaped with an arc-shaped horizontal cross-section. The grooves of the arc-shaped plates face away from the center of the guide cap body. A tightening bolt is provided on the side wall of the cylindrical section at the position corresponding to each arc-shaped plate. The tightening bolt is threadedly connected to the side wall of the cylindrical section.

[0007] Preferably, the horizontal cross-section of the conical section is circular, and the diameter of the horizontal cross-section of the conical section gradually decreases from top to bottom; the length of the cylindrical section is 150mm~250mm, and the diameter of the cylindrical section is not less than 100mm; the length of the conical section is 80mm~150mm.

[0008] Preferably, the lower end of the connecting sleeve is welded to the horizontal partition; the upper end of the connecting sleeve extends beyond the top of the cylindrical section, and the length of the extended portion is not less than 30mm.

[0009] Preferably, the diameter of the circle containing the horizontal cross-section of the arc plate is adapted to the diameter of the steel strand to be installed, and the lower end of the arc plate is welded to the top of the horizontal partition; at least two tightening bolts are provided on the outer side of each arc plate and are arranged at intervals along the vertical direction; the tightening bolts are set in correspondence with the vertical axis of the arc plate.

[0010] Preferably, the arc-shaped plate has a protrusion on the side near the connecting sleeve; the side of the protrusion facing the connecting sleeve is an arc-shaped surface, and the protrusion is attached to and connected to the connecting sleeve.

[0011] Preferably, the spacing between adjacent first discharge holes is 10mm to 30mm.

[0012] Preferably, the inner diameter of the connecting sleeve is adapted to the outer diameter of the anchor rod, and the connecting sleeve is sleeved and connected to the lower end of the anchor rod.

[0013] Compared with the prior art, the present invention has the following features and beneficial effects.

[0014] 1. This application addresses the shortcomings of existing construction methods by designing a guide cap that guides the anchor cable into the predetermined position during anchor cable construction. This also ensures that the correct placement of the anchor cable and the subsequent anchoring effect of the second high-pressure fracturing grouting meet the design requirements. This approach expands the contact area between the anchor body and the soil and rock, strengthens the bond between them, improves the mechanical properties of the soil and rock surrounding the anchor body, and significantly increases the ultimate pull-out bearing capacity of the anchor rod.

[0015] 2. Using the prestressed anchor guide cap of this utility model, the splitting length of this device is longer than that of ordinary guide caps. Furthermore, due to the pre-drilled holes, the splitting extends outwards, resulting in more downward splitting than ordinary devices which tend to split downwards due to gravity. This leads to a more uneven splitting effect. The device also features a simple structure, convenient anchor cable installation, and enhanced anchoring effectiveness after splitting. This compact and flexible device is easy to use and operate, making it suitable for widespread application.

[0016] 3. This utility model's guide cap provides a standardized and tool-based construction method for secondary high-pressure splitting grouting anchor bolts under different geological conditions. It avoids the splitting grouting pipe end being shorter than the fabricated anchor cable, thus improving the quality of the splitting effect. The tool-based construction method allows anyone to achieve essentially consistent construction quality results after simple training. After secondary splitting grouting using this utility model, once the anchor bolt's solidified body reaches a strength of 15 MPa and 75% of its design strength, the anchor bolt is tensioned and locked. It was found that using this utility model's guide cap significantly increases the axial tensile force limit of the anchor bolt compared to using a conventional guide cap. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings.

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

[0019] Figure 2 This is a schematic diagram of the elevation structure of this utility model.

[0020] Figure 3 This is a schematic diagram of the vertical cross-sectional structure of this utility model.

[0021] Figure 4 This is a schematic diagram of the connection structure between the arc-shaped plate and the connecting sleeve in this utility model.

[0022] Figure 5 This is a cross-sectional view of the horizontal partition plate located at the junction of the cylindrical section and the conical section in this utility model.

[0023] Reference numerals in the attached drawings: 1-Guide cap body, 1.1-Cylindrical section, 1.2-Conical section, 2-Connecting sleeve, 3-Horizontal partition, 4-First slurry outlet hole, 5-Second slurry outlet hole, 6-Through hole, 7-Arc plate, 8-Tightening bolt, 9-Protruding strip, 10-Vertical strip hole. Detailed Implementation

[0024] like Figure 1-5 As shown, this high-pressure splitting grouting prestressed anchor guide cap includes a guide cap body 1 and a connecting sleeve 2; the guide cap body 1 includes an upper cylindrical section 2.1 and a lower conical section 2.2, and first grout outlet holes 4 are spaced apart on the side wall of the guide cap body 1; a horizontal partition 3 is provided inside the guide cap body 1 at the junction of the cylindrical section 2.1 and the conical section 2.2; a through hole 6 is provided in the middle of the plate surface of the horizontal partition 3, and second grout outlet holes 5 are spaced apart on the plate surface of the horizontal partition 3 around the through hole 6. The connecting sleeve 2 is located at the top center of the horizontal partition 3, and the pipe of the connecting sleeve 2 is connected to the through hole 6; a set of arc-shaped plates 7 are arranged circumferentially around the top of the horizontal partition 3 and around the connecting sleeve 2; the arc-shaped plates 7 are strip-shaped and have an arc-shaped horizontal cross-section; the groove of the arc-shaped plate 7 faces away from the center of the guide cap body 1; a tightening bolt 8 is provided on the side wall of the cylindrical section 2.1 at the position corresponding to each arc-shaped plate 7; the tightening bolt 8 is threadedly connected to the side wall of the cylindrical section 2.1.

[0025] In this embodiment, the horizontal cross-section of the conical section 2.2 is circular, and the diameter of the horizontal cross-section of the conical section 2.2 gradually decreases from top to bottom; the length of the cylindrical section 2.1 is 150mm~250mm, and the diameter of the cylindrical section 2.1 is not less than 100mm; the length of the conical section 2.2 is 80mm~150mm.

[0026] In this embodiment, the lower end of the connecting sleeve 2 is welded to the horizontal partition 3; the upper end of the connecting sleeve 2 extends beyond the top of the cylindrical section 2.1, and the length of the extended part is not less than 30mm; the upper end of the connecting sleeve 2 is sleeved on the lower part of the anchor rod, the anchor rod is a hollow grouting anchor rod, and the connecting sleeve 2 and the anchor rod are connected by binding; vertical holes 10 are provided at intervals on the side wall of the connecting sleeve 2.

[0027] In this embodiment, the diameter of the circle containing the horizontal cross-section of the arc plate 7 is adapted to the diameter of the anchor cable, and the lower end of the arc plate 7 is welded to the top of the horizontal partition 3; at least two of the tightening bolts 8 are provided on the outer side of each arc plate 7 and are arranged at intervals along the vertical direction; the tightening bolts 8 are set in correspondence with the vertical axis of the arc plate 7.

[0028] In this embodiment, the arc plate 7 is provided with a protrusion 9 on the side near the connecting sleeve 2; the side of the protrusion 9 facing the connecting sleeve 2 is an arc surface, and the protrusion 9 is attached and connected to the connecting sleeve.

[0029] In this embodiment, the distance between adjacent first slurry outlet holes 4 is 10mm~30mm.

[0030] In this embodiment, the inner diameter of the connecting sleeve 2 is adapted to the outer diameter of the anchor rod, and the connecting sleeve 2 is sleeved and connected to the lower end of the anchor rod.

[0031] In this embodiment, the wall thickness of the guide cap body 1, the arc plate 7, the horizontal partition 3, and the connecting sleeve 2 is not less than 2mm; the materials used for their manufacture are stainless steel as much as possible, but aluminum, iron, or hard plastic can also be used, and they are formed by welding or mold casting.

[0032] In this embodiment, the number of the arc-shaped plates 7 is adapted to the number of steel strands in the anchor cable, with a maximum of 6 plates. The steel strands are fixed in the groove of the arc-shaped plates 7 by tightening bolts 8.

[0033] In this embodiment, six arc-shaped plates 7 for connecting steel strands are set in the guide cap, which can be used for various types of anchor rods, such as steel bars and steel strands of different diameters, as well as single or multiple steel bars and steel strands. It is also suitable for the grouting requirements of various ordinary anchor rods, high-pressure splitting grouting anchor rods, and the splitting requirements of high-pressure splitting grouting anchor rods. Inside the guide cap, multiple holes are reserved, and the grout can split along the holes during high-pressure grouting, so that the splitting effect can be optimized.

[0034] The application of this high-pressure splitting grouting prestressed anchor guide cap is as follows: After the anchor hole is drilled, the qualified anchor cable is inserted into the anchor hole, and the guide cap is installed at the end of the anchor, so that the steel strands of the anchor cable are fixed at the arc plate. The guide cap can easily install the anchor cable to the design position. Then, the first grouting is performed into the duct. After the design requirements are met, high-pressure splitting grouting is performed into the anchor. The reserved holes on the guide cap can split the grout in all directions, increase the anchoring effect, expand the contact area between the anchor body and the rock and soil, strengthen the bonding between the two, improve the mechanical properties of the rock and soil around the anchor body, and greatly improve the ultimate pull-out bearing capacity of the anchor.

[0035] The above embodiments are not exhaustive examples of specific implementation methods, and other embodiments may also exist. The purpose of the above embodiments is to illustrate the present utility model, rather than to limit the protection scope of the present utility model. All applications derived from simple variations of the present utility model fall within the protection scope of the present utility model.

Claims

1. A prestressed anchor rod guide cap for high-pressure wedge grouting, comprising a guide cap main body (1) and a connecting sleeve (2); characterized in that: The guide cap body (1) includes an upper cylindrical section (2.1) and a lower conical section (2.2). A first slurry outlet hole (4) is spaced apart on the side wall of the guide cap body (1). A horizontal partition (3) is provided inside the guide cap body (1) at the junction of the cylindrical section (2.1) and the conical section (2.2). A through hole (6) is provided in the middle of the horizontal partition (3), and a second slurry outlet hole (5) is spaced apart on the horizontal partition (3) around the through hole (6). The connecting sleeve (2) is installed on the horizontal partition (3). At the top center of the ), the pipe of the connecting sleeve (2) is connected to the through hole (6); at the top of the horizontal partition (3), a set of arc plates (7) are arranged around the connecting sleeve (2) in a circumferential manner; the arc plate (7) is strip-shaped and the horizontal cross-section is arc-shaped; the groove of the arc plate (7) faces away from the center of the guide cap body (1); on the side wall of the cylindrical section (2.1), a tightening bolt (8) is provided at the position corresponding to each arc plate (7); the tightening bolt (8) is threadedly connected to the side wall of the cylindrical section (2.1).

2. A prestressed anchor rod guide cap for high-pressure wedge splitting grouting according to claim 1, characterized in that: The horizontal cross-section of the conical section (2.2) is circular, and the diameter of the horizontal cross-section of the conical section (2.2) gradually decreases from top to bottom; the length of the cylindrical section (2.1) is 150mm~250mm, and the diameter of the cylindrical section (2.1) is not less than 100mm; the length of the conical section (2.2) is 80mm~150mm.

3. A prestressed anchor rod guide cap for high-pressure wedge splitting grouting according to claim 1, characterized in that: The lower end of the connecting sleeve (2) is welded to the horizontal partition (3); the upper end of the connecting sleeve (2) extends beyond the top of the cylindrical section (2.1), and the length of the extended part is not less than 30mm.

4. A high-pressure wedge-splitting grouting prestressed anchor rod guide cap according to claim 1, characterized in that: The diameter of the circle containing the horizontal cross section of the arc plate (7) is adapted to the diameter of the steel strand to be installed. The lower end of the arc plate (7) is welded to the top of the horizontal partition (3). At least two of the tightening bolts (8) are provided on the outside of each arc plate (7) and are arranged at intervals along the vertical direction. The tightening bolts (8) are set in correspondence with the vertical axis of the arc plate (7).

5. A high-pressure wedge-splitting grouting prestressed anchor rod guide cap according to claim 1, characterized in that: The arc plate (7) has a protrusion (9) on the side near the connecting sleeve (2); the side of the protrusion (9) facing the connecting sleeve (2) is an arc surface, and the protrusion (9) is attached to and connected to the connecting sleeve.

6. A high-pressure wedge-splitting grouting prestressed anchor rod guide cap according to claim 1, characterized in that: The distance between adjacent first discharge holes (4) is 10mm~30mm.

7. The prestressed anchor guide cap for high-pressure fracturing grouting according to claim 1, characterized in that: The inner diameter of the connecting sleeve (2) is adapted to the outer diameter of the anchor rod, and the connecting sleeve (2) is sleeved and connected to the lower end of the anchor rod.

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