Shield cutter head integrated ground penetrating radar antenna device

Abstract

The invention relates to a shield cutterhead integrated ground penetrating radar antenna device which comprises a shield cutterhead, a ground penetrating radar antenna and a front protection plate, a semi-ellipsoidal concave cavity is formed in the shield cutterhead, the shield cutterhead and the semi-ellipsoidal concave cavity are integrally machined, and the ground penetrating radar antenna is located in the semi-ellipsoidal concave cavity and fixedly connected with the front protection plate. And the front protection plate is fixedly connected with the shield cutter head and covers the semi-ellipsoidal concave cavity. Compared with the prior art, the invention has the advantages of simple installation, compact structure, good sealing performance and the like.

Description

Technical Field

[0001] The present invention relates to a geological exploration device for tunnel engineering, and more particularly to a shield cutterhead integrated ground penetrating radar antenna device. Background Art

[0002] At present, the geological advance prediction during the construction of shield tunnels mainly relies on surface geological exploration means. As the burial depth of shield tunnels continues to increase, the means of using the surface for geological exploration can no longer meet the detection accuracy requirements for shield tunneling. Conducting exploration of the strata ahead inside the shield tunnel has become a hot topic of concern for more and more researchers.

[0003] Different from mine tunnels or TBM tunnels, there are reinforced concrete segments between the shield tunnel and the surrounding strata, which limits the direct contact between the sensor and the strata, making many detection methods that can be used in mine tunnels or TBM tunnels unable to be directly applied in shield tunnels. At present, in the field of shield tunnel advance detection, in addition to the drilling method with an advanced drill rig, the detection methods using the differences in the geophysical properties of rock and soil masses mainly include seismic wave method, resistivity method, ground penetrating radar method, acoustic wave method, etc. Among them, the ground penetrating radar method has the advantages of high detection efficiency and high detection accuracy. However, for the ground penetrating radar equipment mounted on the shield, the currently relatively mature equipment is the borehole radar, and its working method is to drill a hole into the strata ahead when the shield cutterhead stops tunneling, and then extend the radar antenna into the hole for detection. This method increases the detection cost because drilling is required for each detection; and tunneling needs to be stopped for each drilling, and detection cannot be carried out when the shield is tunneling, which does not match the characteristics of the high-efficiency tunneling of the shield machine.

[0004] Therefore, another detection method has been proposed: installing the ground penetrating radar on the shield cutterhead, and while the shield cutterhead is rotating, the ground penetrating radar conducts real-time detection. The currently proposed installation methods for the ground penetrating radar antenna on the shield machine cutterhead are all to open holes on the cutterhead panel of the shield machine, then encapsulate the ground penetrating radar antenna, and then fix the ground penetrating radar antenna at the position of the hole on the cutterhead. For example, the shield construction forward geological detection technology and system scheme design proposed by Tongji University and Shanghai Metro Shield Equipment Engineering Co., Ltd. in 2009, and the ground penetrating radar antenna design mounted on the TBM cutterhead designed by IDS Company in Italy in 2016, all adopt this method.

[0005] When the shield machine cutterhead is working, it needs to withstand the water and soil pressure and friction in front of it. When encountering isolated rocks or bedrock formations, it will also be hit by rocks. The method of opening a hole on the cutterhead to install the ground-penetrating radar antenna is easy to cause stress concentration around the hole position when the cutterhead is working. On the one hand, it is not conducive to the overall strength and safety of the cutterhead, and on the other hand, it is not conducive to the safety of the installed ground-penetrating radar antenna device. Once the ground-penetrating radar antenna is damaged by external forces, the entire ground-penetrating radar detection system will fail. Therefore, it is necessary to consider designing a safer device for integrating the ground-penetrating radar antenna with the shield cutterhead.

[0006] Patent CN201730623U discloses a shield forward detection radar protection structure, in which the radar antenna is placed in a protection box that is adapted to the shape and size of the radar antenna, the radar antenna is fixed inside it, a rectangular hole with a shape and size matching the protection box is excavated on the cutter head in front of the shield, the entire radar antenna is placed in the rectangular hole, and the outside of the hole is covered by a protective plate to keep the cutter head intact. This solution performs a hole digging operation on the finished cutter head, and the integrity and sealing of the dug hole are insufficient. Therefore, in order to ensure the sealing, a radar antenna protected by a protective shell is required, which increases the complexity and volume of the device structure. At the same time, the stress of the rectangular hole is large and unbalanced, and the overall reliability of the device is poor. Summary of the invention

[0007] The purpose of the present invention is to provide a shield cutterhead integrated ground penetrating radar antenna device in order to overcome the defects of complex structure and low reliability in the above-mentioned prior art.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] The present invention provides a shield cutter integrated ground penetrating radar antenna device, comprising a shield cutter, a ground penetrating radar antenna and a front protection plate. The shield cutter is provided with a semi-ellipsoidal recessed cavity, the shield cutter and the semi-ellipsoidal recessed cavity are integrally processed, the ground penetrating radar antenna is located in the semi-ellipsoidal recessed cavity and is fixedly connected to the front protection plate, the front protection plate is fixedly connected to the shield cutter and covers the semi-ellipsoidal recessed cavity.

[0010] Furthermore, the cavity wall of the semi-ellipsoidal concave cavity is filled with absorbing material.

[0011] Furthermore, the shield cutter head includes spokes and panels, the panel is a fan-shaped plate, there are multiple spokes and panels, the spokes are distributed radially from the center to the surroundings, and the panels are staggered between two adjacent spokes.

[0012] Furthermore, the semi-ellipsoidal concave cavity is located on the panel, and the short axis points to the center of the shield cutter head.

[0013] Furthermore, a sealing ring is provided on the inner side where the front protection plate contacts the panel.

[0014] Further, it also includes a transmission cable for signal and power transmission. One end of the transmission cable is connected to the ground penetrating radar antenna in the semi-elliptical concave cavity, and the other end passes through the shield cutter head and is connected to external equipment.

[0015] Further, the front protection plate is made of a ceramic matrix composite material.

[0016] Further, the shape of the front protection plate is the same as the outer edge of the concave opening of the semi-elliptical concave cavity, and the area is larger than the outer edge of the concave opening of the semi-elliptical concave cavity.

[0017] Furthermore, a plurality of bolt holes are provided at the edge of the front protection plate, and threaded holes are provided at the positions of the semi-elliptical concave cavity corresponding to the bolt holes. The front protection plate and the semi-elliptical concave cavity are connected by bolts.

[0018] Further, the number of ground penetrating radar antennas is one or more.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. When designing and manufacturing the shield cutter head panel of the present invention, the installation position of the ground penetrating radar antenna is considered, and the local panel is specially designed. When the panel is cast and formed, the panel at the installation position of the ground penetrating radar antenna is recessed inward to form a semi-elliptical concave cavity, and the ground penetrating radar antenna is located in the semi-elliptical concave cavity; the integrated structure of the semi-elliptical concave cavity and the shield cutter head avoids the later transformation of the shield cutter head. Compared with the holes obtained by digging holes on the finished shield cutter head, it has better structural integrity and sealing performance, and can avoid the influence of water, soil, rocks, etc. from the cavity wall direction; at the same time, the original shield cutter head panel is utilized, reducing the difficulty of designing and installing the ground penetrating radar antenna, which is beneficial to the actual application of the ground penetrating radar antenna on the shield cutter head.

[0021] 2. The recessed shape for placing the ground penetrating radar antenna in the present invention is an ellipsoidal shape. Compared with a rectangular hole, the semi-elliptical structure reduces the stress concentration phenomenon of the panel structure around the concave cavity and reduces the adverse impact on the panel structure strength.

[0022] 3. The present invention selects a ceramic composite material as the front protection plate of the ground penetrating radar antenna, so that the front protection plate has the advantages of high strength, wear resistance, high temperature resistance, and small electromagnetic loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the installation position of the ground penetrating radar antenna on the shield cutter head in the present invention;

[0024] Figure 2 It is a side view of the installation of the integrated ground penetrating radar antenna device on the shield cutter head in the present invention;

[0025] Figure 3 It is a schematic diagram of the fixing method of the shield cutterhead integrated ground penetrating radar antenna device in the present invention.

[0026] In the figure: 1. Shield cutter head, 2. Spokes, 3. Panel, 4. Semi-ellipsoidal recessed cavity, 5. Ground penetrating radar antenna, 6. Antenna protection plate, 7. Sealing ring, 8. Bolts, 9. Absorbing material, 10. Transmission cable. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] The shield cutterhead integrated ground penetrating radar antenna device involved in the present invention comprises a shield cutterhead 1, a panel 3, a semi-ellipsoidal concave cavity 4, a ground penetrating radar antenna 5, a front protection plate 6, a sealing ring 7, an absorbing material 9 and a transmission cable 10. The shield cutterhead 1 is mainly used to cut the front soil obliquely and is the main mechanical structure used to ensure that the shield machine can move forward. Figure 1 As shown, the common shield machine cutter head 1 comprises a plurality of spokes 2 and panels 3 staggeredly installed between the spokes 2 .

[0029] In this embodiment, the ground penetrating radar antenna 5 is installed on the panel 3, and the panel 3 at the installation position is recessed inward to form a semi-ellipsoidal recessed cavity 4 as the background cavity of the ground penetrating radar antenna 5, and the short axis points to the center of the shield cutter head 1. In this embodiment, a gap is provided between the spoke 2 and the panel 3 to allow the cut soil to pass through the cutter head and enter the soil bin or mud water bin to be transported out. The spoke 2 is the main force-bearing structure of the shield cutter head 1 and is not suitable for modification. Therefore, the installation position of the ground penetrating radar antenna is placed on the panel 3.

[0030] The shield cutter head 1 is usually formed by casting using a mold. In particular, the semi-ellipsoidal recessed cavity 4 described in the present embodiment is formed integrally with the shield cutter head 1 during casting, thereby avoiding reprocessing of the finished shield machine cutter head 1 for the purpose of installing the ground penetrating radar antenna 5. At the same time, the integrated semi-ellipsoidal recessed cavity 4 has better structural integrity and sealing than the holes obtained by digging on the finished shield machine cutter head 1, and can avoid the influence of water, soil, rock, etc. from the direction of the cavity wall.

[0031] As described above, the panel 3 at the installation position of the ground penetrating radar antenna 5 is specially designed. When the panel 3 is cast and formed, the panel 3 at the installation position of the ground penetrating radar antenna is recessed inward, and the recessed shape is an ellipsoidal shape, so as to form a semi-ellipsoidal recess cavity 4, as Figure 2 and Figure 3 shown. As a preferred embodiment, the recess cavity is filled with an electromagnetic wave absorbing material 9 to ensure that the detection direction of the ground penetrating radar antenna 5 is in front of the cutter head 1 of the shield machine.

[0032] In this embodiment, the ground penetrating radar antenna 5 is located in the semi-ellipsoidal recess cavity 4, and the cavity opening is covered by the front protection plate 6. The ground penetrating radar antenna 5 is fixedly connected to the front protection plate 6, and the front protection plate 6 is fixedly connected to the shield cutter head 1. The number of the ground penetrating radar antennas 5 is one or more, preferably two, one for transmitting electromagnetic waves and one for receiving electromagnetic waves. The transmission cable 10 is connected to the ground penetrating radar antenna 5 in the semi-ellipsoidal recess cavity 4 and buried in the panel 3 for connecting external devices to transmit signals and power. Most of the transmission cable 10 is pre-buried in the panel 3, and a part is left in the semi-ellipsoidal recess cavity 4 to be connected to the ground penetrating radar antenna 5 to control the ground penetrating radar antenna 5 to transmit and receive electromagnetic waves.

[0033] As a preferred embodiment, a ceramic composite material is selected as the front protection plate 6 of the antenna. The ceramic matrix composite material has the advantages of high strength, wear resistance, high temperature resistance, and small electromagnetic loss. The ground penetrating radar antenna 5 is fixed on one side of the front protection plate 6. A sealing ring 7 is placed on the inner side where the front protection plate 6 contacts the panel 3 to prevent mud or soil slag from leaking into the semi-ellipsoidal recess cavity 4.

[0034] As a preferred embodiment, the size of the front protection plate 6 needs to cover the periphery of the semi-ellipsoidal recess cavity 4. Bolt holes are opened in a circle of the front protection plate 6, and threaded holes are opened at the positions of the semi-ellipsoidal recess cavity 4 corresponding to the bolt holes. The front protection plate 6 is fixed on the panel 3 through bolts 8.

[0035] The working principle of the ground penetrating radar is to radiate electromagnetic waves outward through the transmitting antenna and receive the reflected electromagnetic waves through the receiving antenna. When the ground penetrating radar antenna is installed on the cutter head of the shield machine, by designing an ellipsoidal recess cavity on the panel 3 and using the panel 3 as a back cavity, it can protect the surrounding and rear of the antenna from the influence of soil and the cutter head and reduce the electromagnetic interference of the surrounding mechanical metals. The protection plate 6 made of ceramic composite material not only plays a role in protecting the safety of the ground penetrating radar antenna 5 but also does not affect the propagation of electromagnetic waves.

[0036] Particularly, in the present invention, the semi-ellipsoidal recess cavity 4 is used to place the ground penetrating radar antenna 5. Compared with a rectangular hole, the semi-ellipsoidal structure reduces the stress concentration phenomenon of the panel structure around the recess cavity and reduces the adverse impact on the strength of the panel structure.

[0037] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A shield cutterhead integrated ground penetrating radar antenna device, characterized in that: The invention comprises a shield cutter head (1), a ground penetrating radar antenna (5) and a front protection plate (6); the shield cutter head (1) is provided with a semi-ellipsoidal recessed cavity (4); the shield cutter head (1) and the semi-ellipsoidal recessed cavity (4) are processed as one piece; the ground penetrating radar antenna (5) is located in the semi-ellipsoidal recessed cavity (4) and is fixedly connected to the front protection plate (6); the front protection plate (6) is fixedly connected to the shield cutter head (1) and covers the semi-ellipsoidal recessed cavity (4).

2. The shield cutterhead integrated ground penetrating radar antenna device according to claim 1, characterized in that: The cavity wall of the semi-ellipsoidal concave cavity (4) is filled with wave absorbing material (9).

3. The shield cutterhead integrated ground penetrating radar antenna device according to claim 1, characterized in that: The shield cutter head (1) comprises spokes (2) and a panel (3), wherein the panel (3) is a fan-shaped plate, the number of the spokes (2) and the panel (3) is multiple, the spokes (2) are radially distributed from the center to the surroundings, and the panel (3) is staggeredly installed between two adjacent spokes (2).

4. The shield cutterhead integrated ground penetrating radar antenna device according to claim 3, characterized in that: The semi-ellipsoidal concave cavity (4) is located on the panel (3), and the short axis points to the center of the shield cutter head (1).

5. The shield cutterhead integrated ground penetrating radar antenna device according to claim 1, characterized in that: A sealing ring (7) is provided on the inner side where the front protection plate (6) contacts the panel (3).

6. The shield cutterhead integrated ground penetrating radar antenna device according to claim 1, characterized in that: It also includes a transmission cable (10) for signal and power transmission, one end of the transmission cable (10) is connected to the ground penetrating radar antenna (5) in the semi-ellipsoidal recessed cavity (4), and the other end passes through the shield cutter head (1) to be connected to external equipment.

7. The shield cutterhead integrated ground penetrating radar antenna device according to claim 1, characterized in that: The front protection plate (6) is made of a ceramic-based composite material.

8. The shield cutterhead integrated ground penetrating radar antenna device according to claim 1, characterized in that: The shape of the front protection plate (6) is the same as the outer edge of the recessed opening of the semi-ellipsoidal recessed cavity (4), and the area is larger than the outer edge of the recessed opening of the semi-ellipsoidal recessed cavity (4).

9. The shield cutterhead integrated ground penetrating radar antenna device according to claim 8, characterized in that: The edge of the front protection plate (6) is provided with a plurality of bolt holes, the semi-ellipsoidal recessed cavity (4) is provided with threaded holes at positions corresponding to the bolt holes, and the front protection plate (6) and the semi-ellipsoidal recessed cavity (4) are connected via bolts (8).

10. The shield cutterhead integrated ground penetrating radar antenna device according to claim 1, characterized in that: The number of the ground penetrating radar antennas (5) is one or more.

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