A device for sealing the anchor bolt hole and controlling the exposed length of the anchor bolt.

Abstract

This utility model provides a device for grout sealing at anchor bolt holes and controlling the exposed length of anchor bolts, belonging to the technical field of underground cavern excavation support in power and water conservancy engineering. The device includes a fixed support, a connector, and an adsorption component. The fixed support consists of a base plate, an inner sleeve, and an outer sleeve. The support is a hollow columnar structure, located entirely on the outside of the device. The base plate is a centrally open disc installed at both ends of the fixed support. One end of the connector is connected to the outer sleeve of the fixed support, and the other end is connected to the inner sleeve. The adsorption component is placed within the cavity formed by the inner and outer sleeves of the fixed support. During construction using this utility model, the adsorption component adheres to the inner sleeve of the fixed support, and the fixed support forms a closed space at the anchor bolt hole, preventing mortar overflow during anchor bolt insertion. By adjusting the length of the device, the exposed length of the anchor bolt can be ensured to meet design requirements. After the anchor bolt is installed, the device can be removed and reused.

Description

Technical Field

[0001] This utility model relates to the field of underground cavern support technology in power and water conservancy projects, and in particular to a device for grout sealing at anchor bolt holes and controlling the exposed length of anchor bolts. Background Technology

[0002] As a key support measure in the New Austrian Tunneling Method (NATM), shotcrete anchoring is widely used in tunnel excavation projects. Unlike other cavern support methods, shotcrete anchoring fully utilizes the self-supporting capacity of the surrounding rock. By driving anchor bolts into the surrounding rock mass, followed by wire mesh and shotcrete application, it minimizes disturbance to the surrounding rock, making the surrounding rock an integral part of the support system. In shotcrete anchoring, the quality of anchor bolt construction is crucial to the support effect. The density of the grouting and the exposed length of the anchor bolts are key parameters affecting the quality of anchor bolt construction; therefore, effective measures must be taken to control them during the anchor bolt construction process.

[0003] Based on the sequence of anchor bolt insertion and grouting, anchor bolt construction is typically divided into two processes: "inserting the bolt first and then grouting" and "grouting first and then inserting the bolt." For anchor bolts longer than 6m, the "inserting the bolt first and then grouting" method is generally used to ensure anchoring effectiveness. When using this method, grouting pipes and venting pipes need to be tied to the anchor bolt. To ensure the thickness of the anchor bolt protective layer, a centering ring is also required. During the bolt insertion process, grouting pipe extrusion can easily occur, leading to rework. Therefore, the "inserting the bolt first and then grouting" process is more complex, takes longer, and has higher costs. In actual field construction, for anchor bolts shorter than 6m, the "grouting first and then inserting the bolt" process is usually used.

[0004] When using the "grouting before bolt insertion" process to install anchor bolts, mortar is first injected into qualified anchor bolt holes, and then the anchor bolt is inserted into the mortar-filled holes. When inserting anchor bolts into horizontal anchor bolt holes or anchor bolt holes with an upward angle, mortar overflows from the anchor bolt holes. The reason for the mortar overflow is the lack of a grout-stopping device at the hole opening. The amount of mortar overflow is mainly affected by the consistency of the mortar and the insertion speed of the anchor bolt. Generally, when the mortar consistency is constant, the faster the anchor bolt insertion speed, the more mortar overflows. When the anchor bolt insertion speed is constant, the thicker the mortar, the less overflows. In actual construction, control often relies on the experience of the operators, making it difficult to guarantee the compactness of the anchor bolt. In addition, the exposed length of the anchor bolt is a key point for construction quality control. Since anchor bolt installation generally uses mechanical pushing, the installation quality is also greatly affected by the operators. Therefore, simply marking the position to control the exposed length is not very effective. Utility Model Content

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a device for stopping grout at the anchor bolt hole and controlling the exposed length of the anchor bolt. When using this device for construction, the adsorption component is adsorbed onto the inner sleeve of the fixed bracket, and the fixed bracket forms a closed space at the anchor bolt hole. This prevents grout from overflowing from the anchor bolt hole during the anchor bolt insertion process. By adjusting the length of the device, it can be ensured that the exposed length of the anchor bolt meets the design requirements. After the anchor bolt is installed, the device can be removed and reused, thus effectively solving the problem of insufficient compaction caused by grout overflow during the anchor bolt insertion process and the difficulty in accurately controlling the exposed length of the anchor bolt in the existing technical solutions.

[0006] To achieve the above-mentioned technical features, the purpose of this utility model is as follows: a device for stopping grout at the anchor bolt hole and controlling the exposed length of the anchor bolt, comprising a fixing bracket, a connector and an adsorption component; The fixed bracket consists of an inner sleeve, an outer sleeve, an upper base plate, and a lower base plate, forming a columnar structure. The inner sleeve and the outer sleeve are connected by a connector and arranged coaxially. The upper base plate and the lower base plate are respectively located at the upper and lower ends of the inner sleeve and the outer sleeve. The adsorption elements are distributed around the outer wall of the inner sleeve; Preferably, the inner sleeve is fitted onto the outer end of the anchor rod.

[0007] Preferably, the outer sleeve is in the shape of a hollow cylinder, and the inner wall of the outer sleeve is fixedly connected to the outer side of the connector.

[0008] Preferably, the inner sleeve is in the shape of a hollow cylinder, the inner side of the connector is fixedly connected to the outer wall of the inner sleeve, and the diameter of the inner sleeve is larger than the diameter of the anchor rod.

[0009] Preferably, the upper base plate is a circular ring structure, with the outer diameter of the upper base plate being the same as the diameter of the outer sleeve, and the inner diameter of the upper base plate being the diameter of the anchor rod. The upper base plate is movably connected to the top of the outer sleeve. The lower base plate is a disc structure, with the diameter of the lower base plate being the same as the diameter of the outer sleeve. The lower base plate is movably connected to the bottom of the outer sleeve.

[0010] Preferably, the connector is a square plate structure with the same length as the sleeve. Preferably, the number of connectors is at least two sets.

[0011] Preferably, the adsorption element has a fan-shaped cross-section with a fan-shaped diffusion angle of 30°, and the adsorption element is tightly attached to the outside of the inner sleeve to adsorb and fix the inner sleeve and the anchor rod.

[0012] Preferably, the fixing bracket is installed on the top of the anchor bolt before the anchor bolt is installed. During the installation of the anchor bolt, the fixing bracket moves along the anchor bolt. After the anchor bolt is inserted to the designed depth, the bottom plate of the fixing bracket is tightly attached to the anchor bolt hole.

[0013] Preferably, the inner sleeve is machined with a certain width of slit along the axial direction, and the overlapping part of the steel plates at both ends of the opening slit of the inner sleeve is connected by an adsorption component.

[0014] Preferably, the connector is made of rubber material.

[0015] Preferably, the upper base plate is made of polyethylene material and is bonded to the outer sleeve using epoxy resin adhesive.

[0016] The present invention has the following beneficial effects: 1. When using the device provided by this utility model for anchor bolt insertion, the bottom plate of the device fits tightly with the hole, effectively preventing the anchor bolt grout from flowing out and ensuring the density and anchoring effect of the anchor bolt.

[0017] 2. The length of the device is the same as the exposed length of the anchor bolt. As the anchor bolt enters the anchor bolt hole, the device gradually moves to the end of the anchor bolt. The fixed bracket restricts the movement of the end anchor bolt into the hole, so that the exposed length of the anchor bolt meets the requirements, ensuring the bonding area between the anchor bolt and the shotcrete and improving the overall integrity of the anchor-shotcrete support.

[0018] 3. The inner sleeve of the device has an adjustable volume, which can be used for anchor bolts of different diameters. The outer sleeve has an adjustable length, which can be used for anchor bolts of different exposed lengths. The device has high applicability.

[0019] 4. Using the device can effectively reduce the amount of grouting work in the anchor bolt holes. After the anchor bolt insertion is completed, the device can be removed and reused, reducing the cost of anchor bolt construction. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0022] Figure 2 This is a cross-sectional view of the present invention.

[0023] Figure 3 This is a schematic diagram of the working state of this utility model.

[0024] In the diagram: 1. Adsorption component; 2. Fixing bracket; 21. Outer sleeve; 22. Inner sleeve; 23. Upper base plate; 24. Lower base plate; 3. Connector; 4. Anchor bolt; 5. Bedrock surface; 6. Anchor bolt hole. Detailed Implementation

[0025] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0026] like Figure 1-3As shown, a device for stopping grouting at anchor bolt holes and controlling the exposed length of anchor bolts includes an adsorption element 1, a fixed bracket 2, and a connector 3. The adsorption element 1 is attached to the inside of the fixed bracket 2. The fixed bracket 2 is composed of an outer sleeve 21, an inner sleeve 22, an upper base plate 23, and a lower base plate 24. The inner sleeve 22 is located in the middle of the fixed bracket 2. The outer sleeve 21 and the inner sleeve 22 have the same axis. The outer sleeve surrounds and forms the device space. The upper base plate 23 is connected to the top of the outer sleeve 21, and the lower base plate 24 is movably connected to the bottom of the outer sleeve 21. The connector 3 is welded to the outer sleeve 21 on the outside and connected to the outside of the inner sleeve 22 on the inside. Multiple sets of adsorption elements 1 are arranged around the inner sleeve 22 along its length. The device is columnar in shape. The anchor bolt 4 passes through the inner sleeve 22 and is connected to the device through the adsorption element 1.

[0027] Furthermore, the adsorption element 1 is a fan-shaped permanent magnet with the same length as the inner sleeve 22 and a thickness of 3-5 cm. The fan-shaped diffusion angle is 30°. When the grout-stopping device is installed, the adsorption element 1 is adsorbed on the outside of the inner sleeve. Under the action of magnetic attraction, the inner sleeve and the anchor rod 4 are further adsorbed. In other embodiments, the adsorption element 1 can be an electromagnet. The installation and disassembly of the anchor rod 4 and the device are controlled by a switching circuit.

[0028] Furthermore, the outer sleeve 21 is a hollow cylindrical structure with a wall thickness of 2cm, an inner diameter of 30cm, and a length of 25cm. It is made of steel profiles. For anchor rods with a designed exposed length of 15cm, after the device is installed, a 10cm thick sand belt is filled into the outer sleeve 21. For anchor rods with other exposed lengths, multiple outer sleeves 21 can be spliced ​​together for adjustment. In other embodiments, to reduce the weight of the device, the outer sleeve 21 can be made of polyethylene material with a sleeve wall thickness of 5cm.

[0029] Preferably, the outer sleeve 21 can also be configured as a telescopic structure containing two sleeves, an inner sleeve and an outer sleeve. The outer diameter of the inner sleeve is the same as the inner diameter of the outer sleeve, and the length of both the inner and outer sleeves is 15cm. For anchor rods with different exposed lengths, the telescopic length of the inner sleeve can be controlled.

[0030] Preferably, the inner sleeve 22 is a hollow thin-walled cylindrical structure made of 3mm thick steel sheet, with a 1mm wide slit along the axial direction of the inner sleeve. The inner sleeve has a diameter of 32mm. For anchor rods with diameters of 25mm and 28mm, when using the device, one end of the opening slit of the inner sleeve is rolled into the sleeve, and the other end contains this part of the steel sheet inside. The overlapping part of the steel sheet at both ends of the opening slit of the inner sleeve 22 is connected by adsorption component 1. For other anchor rods with a diameter greater than 32mm, when using the device, the steel sheets at both ends of the opening slit are kept away from each other to ensure that the device can be used for anchor rods of different diameters.

[0031] Preferably, the upper base plate 23 is a 5mm thick circular steel plate with the same inner diameter as the anchor rod. When installing the control device, the upper base plate 23 is in close contact with the bedrock surface 5 and is bonded to the outer sleeve 21 with epoxy resin. For the upward anchor rod, connection holes are provided around the base plate. Insertion bars are driven around the anchor rod holes 6 and pass through the connection holes to fix the upper base plate 23. In other embodiments, to reduce the weight of the device, the upper base plate 23 can be made of polyethylene material with a wall thickness of 1cm.

[0032] Preferably, the bottom plate 24 is a 3mm thick circular steel plate or plastic plate. After the device is installed, epoxy resin is used to fix the bottom plate and the outer sleeve to restrict the displacement of the internal filling material of the device to the outside. When the length of the outer sleeve is the same as the exposed length of the anchor rod, the bottom plate 24 does not need to be installed when using the control device.

[0033] Furthermore, the connector 3 is disposed between the outer sleeve 21 and the inner sleeve 22. When the outer sleeve is made of steel, the connector 3 is bonded to the outer sleeve. When the outer sleeve is made of polyethylene, it is connected by drilling a threaded hole. The connector 3 is fixedly connected to the inner sleeve 22. The length of the connector is the same as or slightly less than the length of the outer sleeve, the width is 0.5 times the difference in diameter between the inner and outer sleeves, and the thickness is 1 cm.

[0034] Preferably, the connector 3 is made of elastic materials such as rubber. For anchor rods of different diameters, the working diameter of the inner sleeve 21 is different. The connector can generate a certain displacement to adapt to the change in the inner sleeve diameter, ensuring that the device can be used for various types of anchor rods.

[0035] Furthermore, the number of connectors 3 can be 2, 4 or more, and the number of connectors forming the cavity and the number of adsorption components 1 can be 2, 4 or more. The number of adsorption components 1 and connectors 3 can be selected according to the required adsorption force.

[0036] The working process and principle of this utility model: When the device is in operation, the inner sleeve 21 and the anchor rod 4 are adsorbed by the adsorption component 1, and the force is transmitted to the outer sleeve 22 by the connecting component 3. During the process of inserting the anchor rod 4 into the anchor rod hole, the device is pressed against the bedrock surface 5, and the upper bottom plate 23 and the anchor rod hole 6 form a closed space to achieve the grouting stop effect and effectively control the density of the anchor rod.

[0037] In this embodiment, the anchor rod 4 is made of HRB400 or HRB500 grade hot-rolled threaded steel bar with a diameter of 25-32mm. The length of the anchor rod is determined according to the design requirements and is made by processing steel bars of a specified type. The control device is carried out synchronously with the anchor rod processing. In order to improve construction efficiency, multiple devices can be used to install the anchor rod simultaneously.

Claims

1. A device for sealing and controlling the exposed length of an anchor rod, characterized in that, It includes a fixed bracket (2), a connector (3), and an adsorption component (1); The fixed bracket (2) is composed of an inner sleeve (22), an outer sleeve (21), an upper base plate (23) and a lower base plate (24), and is a columnar structure. The inner sleeve (22) and the outer sleeve (21) are connected by a connector (3) and are arranged coaxially. The upper base plate (23) and the lower base plate (24) are respectively set at the upper and lower ends of the inner sleeve (22) and the outer sleeve (21). The adsorption element (1) is distributed around the outer wall of the inner sleeve (22); The inner sleeve (22) is fitted onto the outer end of the anchor rod (4).

2. The device for stopping grout and controlling the exposed length of the anchor rod at the anchor rod hole according to claim 1, characterized in that: The outer sleeve (21) is in the shape of a hollow cylinder, and the inner wall of the outer sleeve (21) is fixedly connected to the outer side of the connector (3).

3. The device for sealing and controlling the exposed length of the anchor rod according to claim 1, characterized in that: The inner sleeve (22) is in the shape of a hollow cylinder. The inner side of the connector (3) is fixedly connected to the outer wall of the inner sleeve (22). The diameter of the inner sleeve (22) is larger than the diameter of the anchor rod (4).

4. The device for stopping grout and controlling the exposed length of the anchor rod at the anchor rod hole according to claim 1, characterized in that: The upper base plate (23) is a circular structure. The outer diameter of the upper base plate (23) is the same as the diameter of the outer sleeve (21). The inner diameter of the upper base plate (23) is the diameter of the anchor rod (4). The upper base plate (23) is movably connected to the top of the outer sleeve (21). The lower base plate (24) is a disc structure. The diameter of the lower base plate (24) is the same as the diameter of the outer sleeve (21). The lower base plate (24) is movably connected to the bottom of the outer sleeve (21).

5. The device for sealing and controlling the exposed length of the anchor rod according to claim 1, characterized in that: The connector (3) is a square plate structure with the same length as the sleeve. The number of connectors (3) is at least 2 sets.

6. The device for sealing and controlling the exposed length of the anchor rod according to claim 1, characterized in that: The adsorption element (1) has a fan-shaped cross section with a fan-shaped diffusion angle of 30°. The adsorption element (1) is wrapped tightly around the outside of the inner sleeve (22) and is used to adsorb and fix the inner sleeve (22) and the anchor rod (4).

7. The device for sealing and controlling the exposed length of the anchor rod according to claim 1, characterized in that: Before the construction of the anchor rod (4), the fixing bracket (2) is installed on the top of the anchor rod (4). During the installation of the anchor rod, the fixing bracket (2) moves along the anchor rod. After the anchor rod is inserted to the designed depth, the bottom plate of the fixing bracket (2) is tightly attached to the anchor rod hole.

8. The device for sealing and controlling the exposed length of the anchor rod according to claim 1, characterized in that: The inner sleeve (22) has a certain width of gap processed along the axial direction. The steel plates at both ends of the opening gap of the inner sleeve (22) are connected by adsorption components (1).

9. The device for sealing and controlling the exposed length of the anchor rod according to claim 1, characterized in that: The connector (3) is made of rubber material.

10. The device for sealing and controlling the exposed length of the anchor rod according to claim 1, characterized in that: The upper base plate is made of polyethylene material and is bonded to the outer sleeve (21) with epoxy resin adhesive.

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