JPH04134091U - ground penetrating radar equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To ensure that surface propagation waves from the transmitting antenna section to the receiving antenna section pass through the ground, and to accurately determine the soil quality. [Structure] A transmitting antenna section 54a and a receiving antenna section 54b are attached and fixed to the protective plate surfaces 50a and 50b.
and the transmitting antenna section 54a and the receiving antenna section 5.
4b, and includes a first electromagnetic wave shielding part 56 provided around the 4b to prevent leakage of electromagnetic waves to the back side. This is an underground detection radar device that determines soil quality.
A second electromagnetic wave shielding part 60 is provided between the protective plate surfaces 50a and 50b located in front of the transmitting antenna part 54a and the receiving antenna part 54b, and this second electromagnetic wave shielding part 60 is extended to the back side of the protective face plate 50 to shield the electromagnetic wave leakage space between both antenna parts.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention uses a ground-penetrating radar device, especially for determining the soil quality in front of the ground from surface propagating waves. Concerning improvements to ground-penetrating radar equipment.

0002

[Conventional technology]

The shield method is widely used as a construction method for urban tunnels, etc. In the shield method, excavation conditions such as cutter rotation speed and load pressure on the face side are It is necessary to appropriately set the conditions and carry out safe and reliable construction.

0003 In order to optimize construction management, it is necessary to investigate the excavation route. Become. One such exploration method is to install a transmitting antenna on the face plate of the shield tunneling machine. A receiving antenna is installed to investigate the condition in front of the face and the soil quality by transmitting and receiving electromagnetic waves. A method has been developed to determine the

0004 Figure 2 shows the face plate of a shield tunneling machine equipped with such a transmitting and receiving antenna. A view of the unit from the front side is shown. As shown in the figure, the face plate 10 includes a casing. A transmitting antenna 30 and a receiving antenna 40 housed in a single antenna are arranged adjacent to each other. In addition to this, the face plate 10 also includes a cutter 12 and a cutter 12 for installing excavated earth and sand into the face plate part. slit 14 for entry, slit opening/closing device 16, opening/closing manhole 18, etc. It is equipped with various equipment. Therefore, the transmitting and receiving antennas 30 and 40 are near the outer periphery of the face plate 12 so as not to obstruct the installation of essential equipment. They are arranged adjacent to each other along the circumferential direction.

[0005] FIG. 3 shows a face detection radar using the transmitting antenna 30 and the receiving antenna 40. A diagram of the principle of the da system is shown (Japanese Unexamined Patent Publication No. 2-28586). This system The system controls a transmitting antenna 30 and a receiving antenna 40 provided on the face plate 10. , which transmits and receives high-frequency pulsed radio waves from the transmitting antenna 30 toward the front of the face. It is. The radio waves received at this time include reflections from a reflecting object 150 located underground. The emitted wave 200 and the surface transmission propagated directly from the transmitting antenna 30 to the receiving antenna 40. There is a broadcast wave 210.

[0006] FIG. 4 shows an example of this received waveform. Here, from the reflected wave 200, Reflective objects 150 (for example, buried trees, underground structures) existing underground can be captured. Furthermore, the soil quality of the face 12 can be determined from the surface propagating waves 210.

[0007] Surface propagating waves 210 can be generated by using separate transmitting antennas 30 and receiving antennas 40. This is what can be seen when it is formed. Since the propagation distance is the shortest, Figure 4 shows It is recorded at the beginning of the received waveform as shown. Surface propagating waves 210 However, depending on the distance between the antennas, experiments show that the distance between the antennas is 5. It has been confirmed that when the distance is 0 cm, the distance passes through the range of 20 to 25 cm. Surface layer ( Since the waves pass through the area of the face 22), they are always recorded regardless of the presence of reflective objects. It has the special feature of being

[0008] The forward detection circuit 24 detects the surface propagation wave 210 based on the propagation time and attenuation rate. For example, the soil type and moisture content are determined.

[0009] Here, in order to accurately determine the soil quality using surface propagating waves 210, it is necessary to The surface propagating wave 210 transmitted from the communication antenna 30 reliably passes through the face 22 and is received. It is necessary for the signal to be received by the communication antenna 40, and the signal must not pass through a location other than the face 22. If electromagnetic waves are included, the accuracy of soil type determination will decrease.

0010 For this reason, the conventional transmitting antenna 30 and receiving antenna 40, as shown in FIG. It is composed of

[0011] In other words, if there is a steel plate in front of the antenna, the electromagnetic waves will be reflected by the steel plate and Since the direction search becomes impossible, these transmitting antennas 30 and receiving antennas 40 are An opening 11 is provided in the face plate 10, and a protective plate surface 50 is attached to this opening 11. Both antennas 30 and 40 are attached and fixed to the back surface of a protective plate surface 50.

0012 Both the antennas 30 and 40 are each formed into a unit, and each of the antennas 30 and 40 is Physically, antenna containers 52a and 52 attached to the back side of the protective plate surface 50 b, and the antenna section 5 installed facing forward inside the antenna containers 52a and 52b. 4a and 54b. The protective plate surface 50 is protected against soil water pressure and rotation of the face plate 10. In order to sufficiently protect the antenna parts 54a and 54b from wear, the antenna parts 54a and 54b are made of a material having the same strength as iron. Materials with excellent durability that do not interfere with the transmission of electromagnetic waves, such as FRP It is formed using

[0013] In the transmitting antenna 30 and the receiving antenna 40, the antenna of the transmitting antenna 30 is Electromagnetic waves emitted from the inner part 54 go around to the back side of the antenna and are received by the receiving antenna 40. A radio wave absorbing material 56a is provided on the inner surface of the antenna containers 52a and 52b to prevent , 56b are provided.

[0014]

[Problem that the idea aims to solve]

In this way, with the conventional device, it is possible to sufficiently prevent wraparound to the back side. However, the signal passes from the transmitting antenna 30 through the protective plate surface 50 to the receiving antenna 40. The received electromagnetic waves 212, the protective plate surface 50 and the antenna parts 54a, 54b Since leakage electromagnetic waves 214 propagating through the air in gaps between The electromagnetic waves received as surface propagating waves at 40 are separated from the original surface propagating waves 210. It becomes a composite waveform with the leakage electromagnetic waves 212 and 214 that pass through parts other than the wings, so However, there was a problem in that soil quality could not be determined sufficiently.

[0015] In particular, compared to the surface propagating waves 210 passing through the face 22, electromagnetic waves passing through the air Since the propagation speed of the wave 214 is fast, the proportion of this electromagnetic wave 214 in the received waveform is If there are many cases, the soil quality discrimination accuracy may be significantly reduced.

[0016] The present invention was developed in view of these conventional problems, and its purpose is to The surface propagation waves from the transmitting antenna to the receiving antenna pass through the ground reliably, and the soil quality is accurately measured. An object of the present invention is to provide a ground-penetrating radar device that can perform discrimination.

[0017]

[Means to solve the problem]

In order to solve the above problems, the present invention: Transmitting antenna section and receiving antenna section installed and fixed on the back side of the protective plate surface and, At least the area around the transmitting antenna section should be designed to prevent electromagnetic waves from leaking to the back side. a first electromagnetic wave shielding section provided with a first electromagnetic wave shielding section; , and detects the ground by transmitting and receiving electromagnetic waves for detection forward through the protective plate surface. In ground-penetrating radar equipment that determines the soil quality in the middle, Between the protective plate surfaces located in front of the transmitting antenna section and the receiving antenna section , a second electromagnetic wave shielding part is provided to partition the two, and this second electromagnetic wave shielding part is It is recommended that it be extended to the back side of the protective face plate to shield the electromagnetic wave leakage space between both antenna parts. Features.

[0018]

[Effect]

With the above configuration, the receiving antenna is connected from the transmitting antenna section through the protective plate surface. from leakage electromagnetic waves propagating towards the antenna section and the gap between the protective plate surface and the antenna section. The leakage electromagnetic waves that propagate toward the receiving antenna through the air are transmitted to the transmitting antenna. The electromagnetic wave shielding part provided between the antenna part and the receiving antenna part ensures that the electromagnetic waves are shielded reliably. It becomes.

[0019] Therefore, all surface propagation waves from the transmitting antenna section to the receiving antenna section are underground. The soil quality can be determined from the received surface propagation waves. You can do different things accurately.

[0020]

【Example】 Next, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the conventional technique The same reference numerals are given to the members corresponding to the parts, and the explanation thereof will be omitted.

[0021] FIG. 1 shows a transmitting antenna 30 and A schematic cross-sectional view of a receiving antenna 40 and a receiving antenna 40 are shown.

[0022] In the device of this embodiment, a transmitting antenna 30 and a receiving antenna 4 are unitized. Electromagnetic waves formed using materials that do not pass electromagnetic waves, such as steel or cast iron, between 0 and 0 A shielding plate 60 is provided to shield leakage electromagnetic waves 212 and 214.

[0023] The electromagnetic wave shielding plate 60 is attached to the face plate 10 so as to divide the opening 11 of the face plate 10 into two. Fixed by welding. A transmitting antenna and a transmitting antenna are provided in each opening 11a and 11b. Protective plate surfaces 50a and 50b for the antenna and receiving antenna are attached and fixed. Also, The other end side of this electromagnetic wave shielding plate 60 is extended to the back side of the face plate 10 and is used to house the antenna. The inside of the box 28 is divided into two parts for a transmitting antenna and a receiving antenna.

[0024] With the above configuration, electromagnetic When a wave is transmitted, leakage electromagnetic waves that try to wrap around the back side of the antenna section 54a are It is absorbed by the magnetic wave absorbing material 56a and propagated within the protective plate surfaces 50a and 50b. Leakage electromagnetic waves 212 and protective plate surfaces 50a, 50 attempting to reach the antenna 40 The receiving antenna is connected to the receiving antenna via the space formed by the gap between The leakage electromagnetic waves 214 that try to propagate toward the electromagnetic wave shielding plate 60 are completely blocked by the electromagnetic wave shielding plate 60. covered. Therefore, from the antenna section 54a of the transmitting antenna 30 to the receiving antenna 40, The surface propagation wave toward the antenna portion 54b is the original electromagnetic wave 2 passing through the face 22. 10, and there is a face in the surface propagating wave 210 received by the receiving antenna 40. Information on 22 soil types will be accurately included.

[0025] In other words, the propagation time and attenuation amount of this surface propagating wave 210 clearly differ depending on the soil type. Therefore, the surface propagating wave 210 received by the receiving antenna 40 Accurately determine the soil quality of the face 22, such as type and water content, from the propagation time and attenuation amount. can be determined.

[0026] It should be noted that the present invention is not limited to the above-mentioned embodiments, but is within the scope of the gist of the present invention. Various modifications can be made within.

[0027] For example, in the above embodiment, a plate-shaped electromagnetic wave shielding member is provided between both antennas. However, the present invention is not limited to this, and the present invention is not limited to this. Any device that can reliably shield leakage electromagnetic waves 212, 214 propagating to 40 An electromagnetic wave shielding member having such a shape may also be used.

[0028] Furthermore, in the above embodiment, the ground penetrating radar device of the present invention was applied to a shield tunneling machine. Although the explanation has been given using an example where the device is used underground, the present invention is not limited to this. It can be used for a wide range of detection purposes.

[0029]

[Effect of the idea]

As explained above, according to the present invention, the display from the transmitting antenna to the receiving antenna is Since surface propagating waves reliably pass underground, the received surface propagating waves include The information will be included accurately, and the soil quality underground will be accurately determined. becomes possible.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a preferred example of a ground penetrating radar device to which the present invention is applied.

FIG. 2 is a schematic front view of a shield tunneling machine to which a transmitting antenna and a receiving antenna are attached.

FIG. 3 is a diagram explaining the principle of a ground-penetrating radar device.

FIG. 4 is a received waveform diagram of the ground penetrating radar device shown in FIG. 3;

FIG. 5 is a schematic cross-sectional explanatory diagram of a conventional ground-penetrating radar device.

[Explanation of symbols]

30 Transmitting antenna 40 Receiving antenna 50a, 50b Protective plate surface 52a, 52b Antenna container 54a, 54b Antenna section 56a, 56b Radio wave absorbing member 60 Electromagnetic wave shielding plate 210 Surface propagating wave
TD004202

──────────────────────────────────────────────── ─── Continuation of front page (72) Creator Yuji Tatekawa Toda Ken, 1-7-1 Kyobashi, Chuo-ku, Tokyo Inside the company (72) Creator Makoto Ukegawa Toda Ken, 1-7-1 Kyobashi, Chuo-ku, Tokyo Inside the company

Claims (1)

[Scope of utility model registration request] 1. A transmitting antenna section and a receiving antenna section that are attached and fixed to the back side of the protective plate surface, and a groove provided at least around the transmitting antenna section to prevent leakage of electromagnetic waves to the back side. 1, and the ground penetrating radar device determines soil quality in front of the ground by transmitting and receiving detection electromagnetic waves forward through the protective plate surface, the transmitting antenna section and the receiving antenna section. A second electromagnetic wave shielding part is provided between the protective plate surfaces located on the front side of the antenna, and this second electromagnetic wave shielding part is provided to extend to the back side of the protective plate to prevent electromagnetic waves between both antenna parts. A ground penetrating radar device characterized by shielding leakage space.