Long exposed tension anchor rod

Abstract

The utility model relates to the technical field of tension anchor rods, and provides a long exposed tension anchor rod which comprises a tension anchor rod, an auxiliary rod parallel to the tension anchor rod, an isolation device and a protection structure. The orifice section of the tension anchor rod is sequentially coated with an anti-rust paint layer, an asphalt layer and an outer sleeve heat shrink tube to form a composite protective layer, so that a corrosive medium is effectively isolated, and the stress concentration of a contact surface is reduced; the auxiliary rod and the tension anchor rod are fixed at intervals through the isolation device, the exposed length is smaller than or equal to 15 cm, and waveform interference is avoided when a sound wave reflection method is used for detection. The tension anchor rod and the auxiliary rod are made of the same material, the diameter of the auxiliary rod is 1 / 4-1 / 5 of that of the tension anchor rod, the tension anchor rod and the auxiliary rod are bound through an iron wire and keep a non-contact state through an isolation device, and it is ensured that the auxiliary rod serves as an independent signal transmission path during nondestructive testing. Safety and stability of a concrete structure, a contact surface and surrounding rock nearby are enhanced, and meanwhile effective quality detection of the long exposed tension anchor rod is achieved.

Description

Technical Field

[0001] This utility model relates to the field of tension anchor technology, and in particular to a long exposed tension anchor. Background Technology

[0002] Underground caverns in water conservancy and hydropower projects are often designed with concrete structures, such as gate chambers, rock wall crane beams, and space frame rock wall beams. These structures require tension anchors to form a stable overall structure with the deep rock mass. Tension anchors are placed between the concrete structure, the surrounding rock, and the contact surface, and are anchored to the borehole wall through anchoring agents or cement mortar, forming a complete and stable pull-out stress structure. However, during operation, after the concrete structure is subjected to operating loads, such as frequent gate lifting or lowering in the gate chamber, long-term stress on the supports and protective trusses of the space frame rock wall beams after construction, and dynamic loads generated by the permanent bridge cranes on the rock wall crane beams, the stress in the tension anchors reaches its maximum at the concrete-to-rock interface. The stress distribution of the tension anchors changes significantly, and a significant stress concentration failure zone appears in the surrounding rock near the contact surface. However, the stress value in the deeper surrounding rock is lower, and the tensile strength of the anchors is not significant, affecting the safety and stability of the concrete structure, the contact surface, and the nearby surrounding rock.

[0003] Meanwhile, the tension anchors commonly found in the aforementioned locations require non-destructive testing of anchorage quality due to the unique stress structure of these anchors, and the exposed length of these tension anchors can reach 1m to 2m. However, excessively long exposed anchor lengths can lead to distortion of the results obtained using the currently commonly used acoustic reflection method.

[0004] Therefore, there is an urgent need to develop a long exposed tension anchor bolt to overcome the shortcomings of existing technologies. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a long exposed tension anchor rod to enhance the safety and stability of concrete structures, contact surfaces, and surrounding rock, while also enabling effective quality inspection of the long exposed tension anchor rod.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A long exposed tension anchor bolt includes: a tension anchor bolt, a rust-proof paint layer surrounding the anchor bolt bore, an asphalt layer surrounding the rust-proof paint layer, an outer heat-shrink tubing surrounding the asphalt layer, and a secondary rod arranged parallel to the tension anchor bolt; several isolation devices are provided between the tension anchor bolt and the secondary rod, and the isolation devices are sleeved on the tension anchor bolt; the rock penetration length of the secondary rod is the same as that of the tension anchor bolt and must not be interrupted in the middle, and the exposed length of the secondary rod is less than 15cm.

[0008] Preferably, the width of the isolation device is 3-5cm, and the distance between several isolation devices is 60cm.

[0009] Preferably, the tension anchor rod, the auxiliary rod, and the isolation device are bound together as one unit by wire.

[0010] Preferably, the tension anchor rod is made of threaded steel bar.

[0011] Preferably, the diameter of the auxiliary rod is 1 / 4 to 1 / 5 of the diameter of the tension anchor rod.

[0012] This utility model discloses a long exposed tension anchor rod, which has the following beneficial effects.

[0013] This utility model includes a tension anchor, a secondary rod arranged parallel to the tension anchor, an isolation device, and a protective structure. The opening section of the tension anchor is sequentially covered with an anti-rust paint layer, an asphalt layer, and an outer heat-shrink tubing to form a composite protective layer, effectively isolating corrosive media and reducing stress concentration at the contact surface. The secondary rod is fixed to the tension anchor at intervals via the isolation device, with an exposed length ≤15cm, avoiding waveform interference during acoustic reflection testing. The tension anchor and the secondary rod are made of the same material, with the secondary rod's diameter being 1 / 4 to 1 / 5 of the tension anchor's. They are bound together with wire and kept in a non-contact state by the isolation device, ensuring the secondary rod serves as an independent signal transmission path during non-destructive testing. This enhances the safety and stability of the concrete structure, contact surface, and surrounding rock, while simultaneously enabling effective quality inspection of long exposed tension anchors. Attached Figure Description

[0014] Figure 1 This is a front view structural diagram of the present invention.

[0015] Figure 2 This is a side view of the structure of this utility model.

[0016] In the attached diagram: 1. Tension anchor; 2. Anti-rust paint layer; 3. Asphalt layer; 4. Outer heat shrink tubing; 5. Secondary anchor; 6. Surrounding rock; 7. Isolation device; 8. Wire; 9. Contact surface. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0018] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this utility model. Example 1

[0019] Reference Figures 1 to 2 A long exposed tension anchor bolt includes: a tension anchor bolt 1, a rust-proof paint layer 2 surrounding the borehole section of the tension anchor bolt 1, an asphalt layer 3 surrounding the rust-proof paint layer, an outer heat-shrink tubing 4 surrounding the asphalt layer 3, and a secondary rod 5 arranged parallel to the tension anchor bolt 1; several isolation devices 7 are provided between the tension anchor bolt 1 and the secondary rod 5, and the isolation devices 7 are sleeved with the tension anchor bolt 1; the rock penetration length of the secondary rod 5 is the same as that of the tension anchor bolt 1, and there should be no interruption in the middle, and the exposed length of the secondary rod 5 is less than 15cm. It should be noted that the secondary rod 5 and the tension anchor bolt 1 are made of the same material; the isolation devices 7 prevent direct contact between the secondary rod 5 and the tension anchor bolt 1, and prevent mutual interference between the secondary rod 5 and the tension anchor bolt 1 during testing, which would lead to unstable test waveforms.

[0020] In this embodiment, the long exposed tension anchor 1 is applied to the overall stable structure formed by the concrete structure and deep rock mass of the underground cavern of the water conservancy and hydropower project. The tension anchor 1 is placed between the concrete structure, the surrounding rock 6 and the contact surface 9 and is anchored to the borehole wall by anchoring agent or cement mortar. The anti-rust paint layer 2, the asphalt layer 3, and the outer heat shrink tube 4 provided around the borehole section of the tension anchor 1 can enhance the safety and stability of the concrete structure, the contact surface 9 and the surrounding rock 6, effectively reduce the stress on the contact surface 9 and ensure the safety of the project during operation. It should be noted that in this embodiment, the anti-rust paint layer 2 is applied in multiple layers. Each layer of anti-rust paint layer 2 is applied and dried before the next layer is applied to achieve the specified thickness requirement of the anti-rust paint layer 2. When applying the asphalt layer 3, the thickness of the applied asphalt should be uniform in order to effectively isolate the external environment from the corrosion of the hole section of the tension anchor rod 1. The outer heat shrink tube 4 is tightly fitted around the asphalt layer 3. After the outer heat shrink tube 4 is heat-shrinked, it fits tightly with the surface of the tension anchor rod 1 and the asphalt layer 3 without gaps.

[0021] Preferably, in this embodiment, the isolation device 7 is made of PE pipe, the width of the isolation device 7 is 3-5cm, and the distance between adjacent isolation devices 7 is 60cm.

[0022] Preferably, in this embodiment, the tension anchor 1, the auxiliary rod 5, and the isolation device 7 are bound together as one unit by wire 8.

[0023] Preferably, in this embodiment, the tension anchor 1 is made of threaded steel bar.

[0024] Preferably, in this embodiment, the diameter of the secondary rod 5 is 1 / 4 to 1 / 5 of the diameter of the tension anchor rod 1.

[0025] This embodiment also provides a non-destructive testing method for long exposed tension anchor rods. First, it is necessary to confirm that the length of the secondary rod 5 meets the limit requirement of the exposed length of the non-destructive testing equipment.

[0026] Then, the auxiliary rod 5 is connected to the exposed part of the long exposed tension anchor rod 1, and isolation measures are adopted at the connection to prevent mutual interference between the auxiliary rod 5 and the long exposed tension anchor rod 1 during the test.

[0027] Next, the commonly used acoustic reflection method was used to perform non-destructive testing on the anchor rod connected to the secondary rod 5, and the corresponding waveforms were obtained through different excitation and reception methods;

[0028] Further analysis of the waveform characteristics, spectral characteristics, and attenuation characteristics of the received wave train, based on the regularity of the waveform, the amount of reflected clutter, the frequency and concentration, the amplitude and attenuation rate, can help determine whether the anchor bolt has under-saturated, unsaturated, or empty grouting.

[0029] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Substitutions may include replacements for some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made based on the technical solution and inventive concept of this utility model should all be covered within the scope of protection of this utility model.

Claims

1. A long exposed tension anchor bolt, characterized in that, include: The anchor rod (1) is a tension anchor, a rust-proof paint layer (2) is provided around the hole section of the tension anchor (1), an asphalt layer (3) is provided around the rust-proof paint layer (2), an outer heat shrink tube (4) is provided around the asphalt layer (3), and a secondary rod (5) is arranged parallel to the tension anchor (1). Several isolation devices (7) are provided between the tension anchor (1) and the secondary rod (5), and the isolation devices (7) are sleeved with the tension anchor (1). The rock penetration length of the secondary rod (5) is consistent with that of the tension anchor (1), and there shall be no interruption in the middle. The exposed length of the secondary rod (5) is less than 15cm.

2. The long exposed tension anchor bolt according to claim 1, characterized in that, The isolation device (7) has a width of 3 to 5 cm and the distance between several isolation devices (7) is 60 cm.

3. A long exposed tension anchor bolt according to claim 1 or 2, characterized in that, The tension anchor (1), the auxiliary rod (5) and the isolation device (7) are bound together as one unit by wire (8).

4. A long exposed tension anchor bolt according to claim 1, characterized in that, The tension anchor (1) is made of threaded steel bar.

5. A long exposed tension anchor bolt according to claim 1, characterized in that, The diameter of the auxiliary rod (5) is 1 / 4 to 1 / 5 of the diameter of the tension anchor rod (1).

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