Monopole directional receiving system and monopole directional receiving method for tunnel drilling sound wave detection

Abstract

The invention provides a monopole directional receiving system and method for tunnel drilling sound wave detection, and the system comprises a drilling sound wave receiving housing, a synchronous excitation encoder, a clock synchronization system, a sound wave receiving transducer system, and an in-hole walking device, and the drilling sound wave receiving housing is cylindrical; a sound wave transducer system is arranged on the surface circumference of the drilling sound wave receiving shell, the sound wave transducer system comprises four groups of strip type monopole receivers, and each group of strip type monopole receivers comprises a plurality of receiving transducers which are arranged at intervals; the clock synchronization system is used for controlling the receiving transducers to work synchronously; the synchronous excitation encoder is used for exciting each receiving transducer, so that the receiving transducers receive sound wave signals according to a set time interval and transmit the received signals to an external control system; the in-hole walking device is used for driving the whole system to move along a drill hole, signals from four symmetrical directions can be received, and the geologic body orientation result can be achieved through the difference between the signals.

Description

Technical Field

[0001] The invention belongs to the field of borehole acoustic wave detection, and in particular relates to a monopole directional receiving system and method for tunnel borehole acoustic wave detection. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] As construction gradually shifts to areas with complex terrain and geology or blocked by water, a large number of dangerous mountain tunnels and cross-river and cross-sea tunnels have emerged. The geological disasters they face tend to be highly complex and diversified, posing a serious threat to tunnel construction safety.

[0004] However, the current mainstream tunnel advance prediction detection methods are mostly at the meter level. Therefore, there is an urgent need to develop sub-meter-level guided structure identification instruments and methods suitable for tunnel environments. The borehole acoustic wave instrument utilizes the characteristics of sound waves propagating in underground media. It obtains geological data by emitting sound wave pulses and recording their propagation and reflection in underground structures. With the change of the propagation speed of sound waves in different media and the interaction between sound waves and underground structures, the instrument can accurately identify different rock layers, cracks and other geological features. At the same time, modern borehole acoustic wave instruments are also combined with advanced data processing and analysis technologies, which can convert the collected data into visual geological images in real time, providing engineers with intuitive and comprehensive geological information, which can meet the needs of high resolution.

[0005] However, the current drilling sonic wave instrument weighs hundreds of kilograms, is tens of meters long, and has a diameter of hundreds of millimeters, which brings great inconvenience to construction. It is too large to pass through narrow tunnel boreholes or other underground engineering spaces. Existing drilling sonic wave detection instruments cannot be applied to tunnels and underground engineering fields. The receiving acoustic system structure is the key structure of the azimuth drilling sonic wave instrument. The traditional receiving acoustic system structure design usually faces problems such as being too long, too heavy, and complex to install, which is not conducive to rapid operation in narrow spaces such as tunnels. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a monopole directional receiving system and method for tunnel drilling acoustic wave detection.

[0007] According to some embodiments, the present invention adopts the following technical solutions:

[0008] A monopole directional receiving system for tunnel drilling acoustic wave detection comprises a drilling acoustic wave receiving housing, a synchronous excitation encoder, a clock synchronization system, an acoustic wave receiving transducer system and an in-hole walking device, wherein:

[0009] The drilling sound wave receiving shell is cylindrical;

[0010] The surface circumference of the drilling sound wave receiving shell is provided with a sound wave transducer system, the sound wave transducer system comprises four groups of strip-type monopole receivers, each group of strip-type monopole receivers comprises a plurality of receiving transducers arranged at intervals;

[0011] The clock synchronization system is used to connect to the transmitting source and trigger the signal when the transmitting source is excited to control the synchronous operation of each receiving transducer;

[0012] The synchronous excitation encoder is used to excite each receiving transducer of the sound wave transducer system so that it receives the sound wave signal at a set time interval and transmits the received signal to an external control system;

[0013] The in-hole walking device comprises a plurality of walking wheels and a driving mechanism arranged on the outer surface of the drilling sound wave receiving shell. The driving mechanism drives the walking wheels to drive the entire system to move along the drilling hole.

[0014] As an optional implementation, the four groups of strip-type monopole receivers are evenly arranged along the surface circumference of the drilling sound wave receiving shell, and the strip-type monopole receivers of each group are spaced 90 degrees apart.

[0015] As an optional implementation, the drilling sound wave receiving shell is made of glass fiber and is frosted to prevent the propagation of sound waves on the surface of the drilling sound wave receiving shell.

[0016] As an optional embodiment, the surface of the drilling sound wave receiving shell has four axially arranged grooves in the circumferential orthogonal direction for placing strip-type monopole receivers. The front and rear ends of the drilling sound wave receiving shell are designed with openings, the through hole at the front end is used to connect the transmitting source, and the through hole at the rear end is used to connect the external control system.

[0017] As an optional implementation, each receiving transducer is configured with a control circuit, and the control circuit is connected to the synchronous excitation encoder and the clock synchronization system.

[0018] As an optional implementation, the control circuit is arranged between adjacent receiving transducers, and a signal amplification circuit is also arranged in this area for amplifying the received sound wave signal of the corresponding receiving transducer.

[0019] As an optional implementation, receiving transducers in the same group are arranged with equal intervals.

[0020] As an optional embodiment, the synchronous excitation encoder includes a host, a cable and an excitation device, wherein the excitation device is used to simultaneously turn on four groups of strip-type monopole receivers to receive sound wave signals at set time intervals within a set time period, and the received sound wave signals are transmitted to the host via the cable, and then transmitted by the host to an external control system.

[0021] As an optional embodiment, the in-hole walking device further includes an encoder, which is used to record the number of rotations of the walking wheel or the driving mechanism to calculate the moving distance of the system in the borehole.

[0022] The working method based on the above system includes the following steps:

[0023] Controlling the in-hole walking device to drive the entire system to move at a uniform speed in the borehole, and determining the position of the system in the borehole;

[0024] The clock synchronization system receives the sound wave signal radiated outward at a fixed period by the transmitting source, and the trigger signal is used to control the synchronous operation of each receiving transducer of the sound wave receiving transducer system;

[0025] Each receiving transducer receives the reflected sound wave signal at a fixed period;

[0026] According to the position of the system in the borehole, the intensity of the periodic signal emitted by the transmitting source and the received acoustic wave signal, the relationship between position-time-wave field intensity is constructed to determine the orientation of the abnormal body.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The receiving acoustic system structure for drilling acoustic wave detection provided by the present invention is designed for the purpose of adapting to the horizontal drilling environment of the tunnel. The receiving system adopts an integrated vulcanization packaging method. Compared with the traditional silicone oil filling method, there is a cavity inside it, which is more suitable for the horizontal drilling environment where water is difficult to fill. It is simple, convenient, and more conducive to storage, which greatly reduces the overall length and weight of the instrument.

[0029] The present invention abandons the traditional form of separating the circuit and the receiving transducer, integrates the receiving transducer with the circuit, and places them on a circuit board. The circuit has a signal acquisition function, uses a transmission line to lead out the current signal, and collects and processes it on a host computer, thereby shortening the length of the instrument in the hole and reducing the weight.

[0030] The present invention utilizes the design of a strip-type monopole receiver, which can receive signals from four symmetrical directions. The differences between the signals can be used to achieve the orientation results of the geological body. Through the cooperation of the in-hole walking device, the clock synchronization device, and the synchronous excitation device, the four-directional receiver receives the reflection signals of the abnormal bodies at different directions around the hole and at different depths in the hole. Through post-processing, the position and azimuth information of the abnormal body can be obtained.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 A diagram showing a directional receiving sound system structure according to an embodiment of the present invention;

[0034] Figure 2 A cross-sectional view of a directional receiving sound system according to an embodiment;

[0035] Figure 3 A schematic diagram of an orientation method according to an embodiment;

[0036] Figure 4 A flow chart of a directional method according to an embodiment;

[0037] Figure 5 This is a simulation diagram of receiving sensitivity at 1-10KHz of an embodiment.

[0038] Among them, 1. the central axis support structure of the receiving sound system; 2. the outer shell of the drilling sound wave receiving; 3. the walking device in the hole; 4. the strip receiver; 5. the receiving transducer; 6. the control circuit, and 7. the abnormal body. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] In the absence of conflict, the embodiments in this application and the features in the embodiments may be combined with each other.

[0043] A receiving acoustic system for tunnel boring acoustic wave detection, such as Figure 1 As shown, it includes a drilling sound wave receiving housing 2, a clock synchronization system structure, a synchronous excitation encoder, a sound wave receiving transducer 5 system and an in-hole walking device 3, wherein:

[0044] The acoustic wave transducer system comprises four groups of integrated strip-type receivers 4, each group of strip-type receivers 4 is provided with eight acoustic wave receivers and a control circuit 6 corresponding to each receiver;

[0045] The drilling sound wave receiving shell 2 adopts an open design and utilizes the water body existing in the tunnel advance drilling for coupling. The receiving sound system shell is made of lightweight materials to protect the internal structure of the entire system (hereinafter referred to as the instrument) from wear and tear. The lightweight design is more adaptable to the horizontal advance drilling of the tunnel.

[0046] A receiving sound system central axis support structure 1 is arranged at the center of the drilling sound wave receiving shell 2 .

[0047] In this embodiment, the drilling sound wave receiving shell 2 is made of glass fiber, which has the advantages of good insulation, good heat resistance, good corrosion resistance and high mechanical strength. The shell is designed to be frosted to block the propagation of sound waves on the surface of the instrument. Its density is 2.5g / cm 3 Compared with steel materials of the same volume, the weight can be reduced by two-thirds, and its insulation performance, sound absorption performance and compressive strength are stronger than stainless steel materials.

[0048] The entire receiving sound system can be vulcanized in one piece, has a high degree of integration, and can be used at any time without oil filling. It is shorter in length and lighter in weight, and can be better coupled when used in horizontal drilling in tunnels.

[0049] In this embodiment, the drilling sound wave receiving shell 2 is slotted in design, with four long axial slots in the circumferential orthogonal direction for placing the strip receiver 4. The receiving shell is designed with holes at the front and rear ends, the opening at the front end is used to connect the transmitting transducer, and the opening at the rear end is used to connect the control host.

[0050] The strip-type receiver 4 integrates a receiving transducer 5 and a control circuit 6. In this embodiment, each strip-type receiver 4 integrates 8 transducers, and the spacing between the transducers is consistent and is set to 0.15 m.

[0051] The function of the clock synchronization system structure is to connect the transmitting source instrument, work with the transmitting short section, work with the transmitting source, trigger the signal while the transmitting short section is excited, control the receiving transducer 5 to work synchronously, and record synchronously when the transmitting source transmits the signal until the set time period ends.

[0052] The synchronous excitation encoder includes a host, a cable and an excitation device. Its function is to simultaneously turn on the excitation devices of four groups of strip receivers 4 through the control function of the host, and start receiving sound wave signals at specified time intervals within a time period. The received signals are transmitted to the host through the cable, and then transmitted to the external control system by the host.

[0053] The in-hole walking device 3 includes a multifunctional universal wheel arranged on the sound wave receiving housing to assist the instrument to move in the hole, including a driving motor and an encoder to drive the multifunctional universal wheel and record the number of universal wheel circles, thereby calculating the distance of the instrument inside the borehole.

[0054] When the above-mentioned receiving acoustic system is working, it can receive sound wave signals from four orthogonal directions, and convert the displacement signal of the sound wave transducer into an electrical signal and store it in the memory at the tail end of the receiving short section for use in subsequent data processing.

[0055] In other embodiments, a threaded hole is reserved at the front end of the receiving acoustic system for connecting to a dipole acoustic wave transducer transmitting acoustic system structure or a monopole acoustic wave transducer transmitting acoustic system structure for common use.

[0056] The detection method of the above-mentioned receiving sound system is as follows:

[0057] 1. During detection, according to the clock synchronization system structure, when the connected transmitting end sends an excitation signal, each strip receiver 4 receives the reflected sound wave of the geological body, starts to collect signals and records the time;

[0058] 2. When the receiving sound system works with the transmitting source, Figure 3 As shown, first read the number of universal wheel circles recorded by the traveling device in the hole, calculate the specific position of the instrument in the hole, determine the relationship between position-time-wave field intensity, and then determine the distribution of geological bodies within a certain range around the borehole;

[0059] 3. According to the different received signal strengths when the instrument is located in the four directions of positive x, negative x, positive y, and negative y, the position of the abnormal body can be determined by the size of the four components and the relative amplitude.

[0060] The directional receiving sound system receives sound wave signals from four directions: X+, X-, Y+, and Y-. It is composed of four groups of strip-type receiving transducers 5. Each receiving transducer 5 has 8 receivers evenly distributed. The receiving transducer 5 circuit and the signal amplification circuit are placed between the receiving transducers 5.

[0061] The overall instrument structure and detection principle of the directional receiving acoustic system in the borehole are shown as follows: Figure 2 As shown in the figure, the four-directional directional receiving system and the omnidirectional transmitting monopole sound source are fixed in the instrument housing and move at a uniform speed deep into the borehole for directional detection. The monopole sound source excites the sound source at a fixed time during the detection process, and the clock synchronization system transmits the signal to control the receiving sound system to start receiving the signal at the same time, and stop receiving the signal after the set time. Through the cooperation of the in-hole walking device, the clock synchronization device, and the synchronous excitation device, the four-directional receiver receives the reflection signals of the abnormal bodies at different directions around the hole and at different depths in the hole. Through post-processing, the position and azimuth information of the abnormal body can be obtained.

[0062] Embodiment 2

[0063] When the system provided in the first embodiment cooperates with the omnidirectional transmitting monopole sound source for sequential detection, the working principle flow chart is as follows: Figure 4 As shown, when the instrument moves at a uniform speed in the hole, the encoder connected to the walking device in the hole records the number of turns of the universal wheel at present, and the host reads and calculates the position of the instrument in the hole. The monopole sound source radiates the sound wave signal outward at a fixed period, and the four-directional directional receiving system receives the reflected sound wave signal at a fixed period, and transmits the position of the instrument outside the hole, the periodic signal emitted by the monopole sound source and the sound wave signal received by the four-directional receiving system to the host system outside the hole for processing in real time.

[0064] The position of the abnormal body relative to the instrument is determined by utilizing the differences in the intensity of sound waves received in different directions by the four-directional receiving acoustic system.

[0065] Assuming that the angle between the anomaly and the received signal in the instrument's positive x direction is θ, the angle with the positive y direction is 90°-θ. Assuming that the reflected signal is S'(t), the signals in the X+ and Y+ directions are as follows:

[0066] X+ received signal:

[0067] R X+ $(t)=S′(t)*cosθ

[0068] The signal received by Y+ is as follows:

[0069] R Y+ $(t)=S′(t)*sinθ

[0070] Therefore, the following formula is obtained:

[0071] tanθ= R Y+

[0072] R X+

[0073] The angle θ between the anomaly and the instrument can be solved by this formula:

[0074] θ=arctan R Y+

[0075] R X+

[0076] In contrast, due to the existence of the instrument itself, the signals received by the receivers in the X- and Y- directions are much lower than the signals received in the X+ and Y+ directions. Therefore, by judging the intensity in the four directions, the quadrant position of the abnormal body can be preliminarily determined.

[0077] like Figure 5 As shown, after simulation, the system provided by this embodiment has good sensitivity.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention without creative labor shall be included in the protection scope of the present invention.

Claims

1. A monopole directional receiving system for tunnel drilling acoustic wave detection, characterized in that: It includes a drilling sound wave receiving housing, a synchronous excitation encoder, a clock synchronization system, a sound wave receiving transducer system and an in-hole walking device, wherein: The drilling sound wave receiving shell is cylindrical; The surface circumference of the drilling sound wave receiving shell is provided with a sound wave transducer system, the sound wave transducer system comprises four groups of strip-type monopole receivers, each group of strip-type monopole receivers comprises a plurality of receiving transducers arranged at intervals; The clock synchronization system is used to connect to the transmitting source and trigger the signal when the transmitting source is excited to control the synchronous operation of each receiving transducer; The synchronous excitation encoder is used to excite each receiving transducer of the sound wave transducer system so that it receives the sound wave signal at a set time interval and transmits the received signal to an external control system; The in-hole walking device comprises a plurality of walking wheels and a driving mechanism arranged on the outer surface of the drilling sound wave receiving shell. The driving mechanism drives the walking wheels to drive the entire system to move along the drilling hole.

2. A monopole directional receiving system for tunnel drilling acoustic wave detection as claimed in claim 1, characterized in that: The four groups of strip-type monopole receivers are evenly arranged along the surface circumference of the drilling sound wave receiving shell, and the intervals between each group of strip-type monopole receivers are 90 degrees.

3. A monopole directional receiving system for tunnel drilling acoustic wave detection as claimed in claim 1, characterized in that: The drilling sound wave receiving shell is made of glass fiber and is frosted to prevent the propagation of sound waves on the surface of the drilling sound wave receiving shell.

4. A monopole directional receiving system for tunnel drilling acoustic wave detection as claimed in claim 1, characterized in that: The surface of the drilling sound wave receiving shell has four axially arranged grooves in the circumferential orthogonal direction for placing strip-type monopole receivers. The front and rear ends of the drilling sound wave receiving shell are designed with openings. The through hole at the front end is used to connect the transmitting source, and the through hole at the rear end is used to connect the external control system.

5. A monopole directional receiving system for tunnel boring acoustic wave detection as claimed in claim 1, characterized in that: Each receiving transducer is equipped with a control circuit, and the control circuit is connected to the synchronous excitation encoder and the clock synchronization system.

6. A monopole directional receiving system for tunnel boring acoustic wave detection as claimed in claim 5, characterized in that: The control circuit is arranged between adjacent receiving transducers, and a signal amplifying circuit is also arranged in this area for amplifying the received sound wave signals of the corresponding receiving transducers.

7. A monopole directional receiving system for tunnel boring acoustic wave detection as claimed in claim 1, characterized in that: The receiving transducers in the same group are arranged with equal spacing.

8. A monopole directional receiving system for tunnel boring acoustic wave detection as claimed in claim 1, characterized in that: The synchronous excitation encoder includes a host, a cable and an excitation device. The excitation device is used to simultaneously turn on four groups of strip-type monopole receivers to receive sound wave signals at set time intervals within a set time period. The received sound wave signals are transmitted to the host via the cable and then transmitted to the external control system by the host.

9. A monopole directional receiving system for tunnel boring acoustic wave detection as claimed in claim 1, characterized in that: The in-hole walking device also includes an encoder, which is used to record the number of rotations of the walking wheel or the driving mechanism to calculate the moving distance of the system in the borehole.

10. A working method based on the system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Controlling the in-hole walking device to drive the entire system to move at a uniform speed in the borehole, and determining the position of the system in the borehole; The clock synchronization system receives the sound wave signal radiated outward at a fixed period by the transmitting source, and the trigger signal is used to control the synchronous operation of each receiving transducer of the sound wave receiving transducer system; Each receiving transducer receives the reflected sound wave signal at a fixed period; According to the position of the system in the borehole, the intensity of the periodic signal emitted by the transmitting source and the received acoustic wave signal, the relationship between position-time-wave field intensity is constructed to determine the orientation of the abnormal body.

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