Tunnel advanced geological forecast transient electromagnetic coil angle auxiliary device

Abstract

The utility model relates to the technical field of tunnel transient electromagnetic detection, and discloses a tunnel advanced geological forecast transient electromagnetic coil angle auxiliary device, which comprises two block bodies with the same structure, the two block bodies are mutually and symmetrically connected to two ends of a connecting rod, and are erected on a bottom plate in a tunnel through the bottom surfaces of the two block bodies; a plurality of blind holes are formed in each block body, the central axes of the blind holes extend towards the bottom surfaces of the block bodies, intersect at one point and are located on the same plane perpendicular to the connecting rod, and a certain angle is formed between every two adjacent blind holes; the two fixing rods are used for being inserted into the blind holes, in the same angle direction, in the two block bodies in a clearance fit mode respectively, and the two fixing rods are each provided with a plurality of binding connectors used for binding and fixing the same loop type coil between the two fixing rods. The device is used for tunnel transient electromagnetic detection and can quickly and accurately position the inclination angle of the coil, the deviation between the detection angle and the design angle is reduced, and the detection accuracy and efficiency are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel transient electromagnetic detection, in particular to a tunnel advanced geological forecast transient electromagnetic coil angle auxiliary device. Background Art

[0002] With the rapid development of my country's transportation construction industry and the continuous improvement of technological standards, the number of long and deep mountain tunnels is increasing. Tunnel excavation faces threats such as karst formations, mud and water inrush, faults, and landslides, which seriously impact the safety of personnel and equipment. Water inrush is the most serious geological hazard causing economic losses and casualties during tunnel construction. Major water inrush disasters in the tunnel construction industry have caused significant casualties and economic losses, severely hindering the rapid development of my country's transportation construction.

[0003] At present, the most effective and widely used method for advanced geological prediction of sudden water inrush in tunnels is the transient electromagnetic method, which uses an ungrounded return line or a grounded line source to emit a pulsed magnetic field into the ground. During the interval of the pulsed magnetic field, the coil is used to observe the secondary induced eddy current field caused in the underground medium to detect the medium resistivity, thereby identifying water-bearing geology such as karst caves and channels, coal mine goafs, deep irregular water bodies, etc. During implementation, several groups of measuring points are arranged in the horizontal direction near the tunnel face within a fan-shaped range of 90° to the left, straight ahead, and 90° to the right, based on the excavation centerline. For example, Figure 1 As shown in Figure 1, 4 groups of measuring points are arranged within a 90° left deviation, 3 groups of measuring points are arranged on the tunnel face, and 4 groups of measuring points are arranged within a 90° right deviation, for a total of 11 groups of measuring points. A transient electromagnetic coil (hereinafter referred to as the coil) is placed at each measuring point in sequence, and transient electromagnetic data of the coil at different inclination angles (the angle between the coil normal direction and the tunnel face) are detected and collected at each measuring point. For example, Figure 2 As shown, each measuring point detects the following seven directions in sequence: bottom plate 60°, bottom plate 45°, bottom plate 30°, along the layer, top plate 30°, top plate 45°, and top plate 60°; thus, according to the designed observation task, a total of 11*7=77 sets of transient electromagnetic data are collected (there are other observation designs in the prior art, which are not listed here one by one).

[0004] The precise coil inclination angle has a significant impact on the detection results. Currently, some methods manually locate the coil inclination angle. However, due to the complexity of the on-site environment and the differences in coil operation by personnel, the coil inclination angle positioning deviation is large during transient electromagnetic detection, and the detection angle deviates significantly from the designed angle, seriously affecting the accuracy and reliability of the detection results. In addition, manual positioning of the angle is inefficient. Some methods use a tripod to locate the coil angle. However, using this device, the coil is far away from the face and cannot contact the face. The layered stratum model can be equivalent to a series-parallel circuit of multiple inductors and capacitors. The transient electromagnetic method detects in layered strata, which is similar to the discharge and supply process of this series-parallel circuit. During the transient electromagnetic detection process, the coil is not in contact with the face, which is equivalent to a capacitor connected in series in the circuit. The detection accuracy and detection distance will be affected to a certain extent.

[0005] Therefore, it is necessary to design a tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device to solve the above problems. Utility Model Content

[0006] In view of the defects and shortcomings in the above-mentioned prior art, the present invention proposes a tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device to solve the problems of large coil inclination angle positioning deviation and low positioning efficiency in tunnel transient electromagnetic detection.

[0007] The above-mentioned purpose of the utility model is achieved through the following technical solutions:

[0008] A tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device comprises two blocks of identical structure, the two blocks being symmetrically connected to the two ends of a connecting rod and supported on the tunnel floor through the bottom surfaces of the two blocks;

[0009] Each block is provided with a plurality of blind holes, the central axes of which extend toward the bottom surface of the block and intersect at a point, and are located on the same plane perpendicular to the connecting rod, with a certain angle between two adjacent blind holes;

[0010] It also includes two fixing rods for respectively inserting into the blind holes of the same angle direction on the two blocks with clearance fit. The two fixing rods are each provided with a plurality of binding interfaces for binding and fixing the same loop coil between the two fixing rods.

[0011] Preferably, each block has 11 blind holes at intervals of 15° within the fan-shaped range of -90° to 90°, corresponding to 11 detection inclination angles of -75°, -60°, -45°, -30°, -15°, 0°, 15°, 30°, 45°, 60°, and 75°.

[0012] Preferably, each block includes a rectangular block and a semicircular block fixed on the rectangular block, and the plurality of blind holes are arranged on the semicircular block.

[0013] Preferably, the block is formed in one piece.

[0014] Preferably, each blind hole has a depth of 10 cm; and / or a hole diameter of 3 cm.

[0015] Preferably, the block is 20 cm high and / or 5 cm thick.

[0016] Preferably, a connecting through hole is provided in the middle of each block near the bottom surface for the connecting rod to be inserted and fixed with clearance fit.

[0017] Preferably, the block, connecting rod, fixing rod and binding interface are all made of non-metallic materials.

[0018] Compared with the prior art, the beneficial effects of the technical solution of the utility model are:

[0019] The utility model is a transient electromagnetic coil angle auxiliary device that can be detachably assembled through two approximately semicircular blocks (upper semicircle + lower rectangle), a connecting rod and a fixing rod. By opening a plurality of blind holes corresponding to different detection inclination angles at regular intervals in the semicircular part of the block, the coil inclination angle can be quickly and accurately located in the transient electromagnetic detection of the tunnel, the deviation between the detection angle and the design angle is reduced, the accuracy and reliability of the detection result are improved, and the on-site work efficiency is improved. The device has a simple structure, is easy to disassemble and assemble, is easy to carry, and has low cost, and has important engineering practice significance.

[0020] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the arrangement of transverse measuring points of the transient electromagnetic method in the prior art;

[0022] Figure 2 A schematic diagram of an arrangement of each detection inclination angle at a single measuring point using the transient electromagnetic method in the prior art;

[0023] Figure 3 A three-dimensional schematic diagram of a transient electromagnetic coil angle auxiliary device for tunnel advanced geological prediction according to an exemplary embodiment of the present utility model;

[0024] Figure 4 A side view schematic diagram of a transient electromagnetic coil angle auxiliary device for tunnel advanced geological prediction according to an exemplary embodiment of the present utility model;

[0025] In the figure: block 1, connecting rod 2, blind hole 3, fixing rod 4, binding interface 5, coil 6. DETAILED DESCRIPTION

[0026] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent;

[0027] In order to better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size;

[0028] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings;

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "setting" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, which can be said to be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", etc. are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0030] The technical solution of the present utility model is further described below with reference to the accompanying drawings and embodiments.

[0031] like Figure 3 、 Figure 4 As shown, the tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device of the exemplary embodiment of the utility model includes two blocks 1 with the same structure, which are symmetrically connected to each other at the two ends of the connecting rod 2 and stand on the bottom plate in the tunnel through the bottom surfaces of the two blocks 1.

[0032] Each block 1 has 11 blind holes 3 on its top surface. The central axes of the 11 blind holes extend toward the bottom surface of the block 1 and intersect at one point. They are located on the same plane perpendicular to the connecting rod 2. The 11 blind holes 3 are arranged on the block 1 at intervals of 15° within a fan-shaped range of -90° to 90°, corresponding to different detection inclination angles, namely: -75°, -60°, -45°, -30°, -15°, 0°, 15°, 30°, 45°, 60°, and 75°, a total of 11 detection inclination angles. It is well known in the art that the direction of the coil normal pointing upwards is positive (top plate detection) and downwards is negative (bottom plate detection). It should also be noted that the arrangement of the blind holes 3 is not limited to this, and the required angles and number of blind holes can be opened according to the detection requirements.

[0033] The device also includes two fixing rods 4, which are inserted into blind holes 3 with the same angle in the two blocks 1 with a clearance fit. Each of the two fixing rods 4 is provided with multiple binding interfaces 5 at intervals, which are used to bind and fix the same loop coil 6 between the two fixing rods 4. In this way, by inserting the lower ends of the two fixing rods 4 into the corresponding blind holes 3, the inclination angle of the coil 6 can be quickly and accurately determined. It should be noted that this device is suitable for tunnel transient electromagnetic detection using a single loop device (transmitting and receiving share the same coil). It has a simple and lightweight structure and high detection accuracy and efficiency.

[0034] When the device is specifically applied, the blind hole 3 can be selected according to the designed observation task. For example, the designed observation task is to detect transient electromagnetic data in seven inclination directions at each measuring point: bottom plate 60°, bottom plate 45°, bottom plate 30°, along the layer, top plate 30°, top plate 45°, and top plate 60°. In this case, the seven groups of blind holes of -60°, -45°, -30°, 0°, 30°, 45°, and 60° of the device are selected to locate the coil.

[0035] In some embodiments, the block 1 comprises a rectangular block and a semicircular block fixed to the rectangular block, with eleven blind holes 3 arranged in the semicircular block. This arrangement of blind holes at equal angles in the semicircular block facilitates fabrication, and the bottom rectangular block ensures the device stands stably on the tunnel floor. Optionally, the semicircular block and the rectangular block are aligned at their connecting surfaces. Furthermore, the block can be integrally formed.

[0036] Considering the possibility of water accumulation in front of the tunnel face, block 1 is set to a height of 20 cm (semicircle radius + rectangle height). To facilitate the arrangement of blind holes 3 and ensure a certain width at the bottom of block 1, block 1 is set to a thickness of 5 cm (in this embodiment, a bottom width of 5 cm). Optionally, each blind hole 3 is set to a depth of 10 cm and a diameter of 3 cm.

[0037] A connecting through hole is provided near the bottom of each block 1 for the connecting rod 2 to be inserted and fixed with clearance, so that the two blocks can be easily assembled and disassembled and are convenient to carry.

[0038] To avoid metal interference with transient electromagnetic detection, the block 1, connecting rod 2, fixing rod 4, and lashing interface 5 are all made of non-metallic materials. For example, the block can be made of plastic, the connecting rod and fixing rod can be made of PVC pipe, and the lashing interface can be made of polyethylene.

[0039] by Figure 1 、 Figure 2 Taking the design observation task shown in the figure as an example, the steps for using this device to perform tunnel transient electromagnetic detection are as follows:

[0040] Connect the two ends of the connecting rod to the two blocks respectively; fix the coil between the two fixing rods through the binding interface.

[0041] Insert the lower ends of the two fixing rods that have fixed the coils into the -60° blind holes of the two blocks, and then move the entire device to Figure 1 At the first measuring point on the far left, make the connecting rod perpendicular to the tunnel face, then connect the coil to the transient electromagnetic instrument to collect transient electromagnetic data of the first inclination angle of the measuring point. After collecting transient electromagnetic data of the first inclination angle, pull the lower ends of the two fixing rods out of the -60° blind hole and then insert them into the -45° blind hole to collect transient electromagnetic data of the second inclination angle of the measuring point. Repeat this operation, and after collecting transient electromagnetic data of 7 inclination angles of the measuring point, the collection of all data of the first measuring point is completed.

[0042] Next, move the entire device to the second measuring point, adjust the angle between the connecting rod and the tunnel face to 60°, insert the lower ends of the two fixing rods into the -60° blind hole, and collect transient electromagnetic data for the first inclination angle of the second measuring point. Repeat the above operations to complete the collection of all data at the second measuring point.

[0043] According to the above steps, complete the transient electromagnetic data collection of 7 inclination angles at each measuring point in a clockwise direction to complete the observation task.

[0044] It should be understood that the angle between the connecting rod and the tunnel face in this device represents the placement angle of the device at the measuring point. The device is placed at each measuring point according to the designed placement angle. At each measuring point, the coil changes the detection inclination angle, while the device placement angle remains unchanged.

[0045] For other matters not mentioned, please refer to the prior art.

[0046] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A transient electromagnetic coil angle auxiliary device for tunnel advanced geological prediction, characterized in that: It comprises two blocks of identical structure, the two blocks being symmetrically connected to the two ends of a connecting rod and standing on the tunnel floor through the bottom surfaces of the two blocks; Each block is provided with a plurality of blind holes, the central axes of which extend toward the bottom surface of the block and intersect at a point, and are located on the same plane perpendicular to the connecting rod, with a certain angle between two adjacent blind holes; It also includes two fixing rods for respectively inserting into the blind holes of the same angle direction on the two blocks with clearance fit. The two fixing rods are each provided with a plurality of binding interfaces for binding and fixing the same loop coil between the two fixing rods.

2. The tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device according to claim 1 is characterized in that: There are 11 blind holes on each block at intervals of 15° within the fan-shaped range of -90° to 90°, corresponding to 11 detection inclination angles of -75°, -60°, -45°, -30°, -15°, 0°, 15°, 30°, 45°, 60°, and 75°.

3. The tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device according to claim 1 is characterized in that: Each block includes a rectangular block and a semicircular block fixed on the rectangular block, and the plurality of blind holes are arranged on the semicircular block.

4. The tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device according to claim 3 is characterized in that: The block is integrally formed.

5. The tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device according to claim 1 is characterized in that: Each blind hole has a depth of 10 cm; and / or a hole diameter of 3 cm.

6. The tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device according to claim 1 is characterized in that: The block is 20 cm high and / or 5 cm thick.

7. The tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device according to claim 1 is characterized in that: A connecting through hole is provided in the middle of each block near the bottom surface for the connecting rod to be inserted and fixed with clearance fit.

8. The tunnel advanced geological prediction transient electromagnetic coil angle auxiliary device according to any one of claims 1 to 7, characterized in that: The blocks, connecting rods, fixing rods and binding interfaces are all made of non-metallic materials.

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