Rock damage acoustic monitoring system

Patent metadata

Field	Value
Publication number	US-10955574-B2
Application number	US-201816015235-A
Country	US
Kind code	B2
Filing date	Jun 22, 2018
Priority date	Jun 23, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

The invention discloses a rock damage acoustic monitoring system including an acoustic emission sensor installed in a borehole of a monitored rock mass and a ground workstation. The acoustic emission sensor is composed of an acoustic emission probe and a probe installation mechanism for installing the acoustic emission probe and a transmission mechanism for transmitting the probe installation mechanism. The probe installation mechanism includes a shell, a probe sleeve installed in the shell, an end cap fixed on the upper end surface of the probe sleeve, and a piston hydro-cylinder arranged between the top of the inner wall of the shell and the end cap. The present invention realizes the control of the moving direction of the shell and the probe sleeve by the piston hydro-cylinder component and the hydraulic pump.

First claim

The invention claimed is:

1. A rock damage acoustic monitoring system, comprising:
an acoustic emission sensor and a ground workstation, the acoustic emission sensor is installed in a borehole of a monitored rock mass, a received monitoring signal is transmitted to the ground workstation by the acoustic emission sensor through a cable, the received monitoring signal from the acoustic emission sensor is processed and displayed by a computer in the ground workstation, wherein
the acoustic emission sensor comprises at least one acoustic emission probe, a probe installation mechanism and a transmission mechanism transmitting the probe installation mechanism installed with the acoustic emission probe to a setting position in the borehole, a number of the probe installation mechanisms is the same as a number of the acoustic emission probes,
the ground workstation further comprises a hydraulic pump and an oil tank;
the probe installation mechanism comprises a shell, a probe sleeve, an end cap, a piston hydro-cylinder component and a connection component;
the shell is a cylindrical body with two open ends, an inner hole of the shell is provided with a guide cylinder used for combining with the probe sleeve, the guide cylinder is located at a bottom of an inner wall of the shell and an inner hole of the guide cylinder is a through hole penetrating a wall of the shell, a centerline of the guide cylinder is perpendicular to a centerline of the shell;
the probe sleeve is a cylinder with a closed lower end and an open upper end, an inner hole of the probe sleeve is in clearance fit with the acoustic emission probe, an outer shape of the probe sleeve is in clearance fit with the inner hole of the guide cylinder, a lower end surface of the probe sleeve is an arc surface matched with an arc of the borehole of the monitored rock mass, an upper end of a wall of the probe sleeve is provided with one or two notches for extending out a cable connector of the acoustic emission probe, if a number of the notches is two, the two notches are axial symmetrically distributed relative to a centerline of the probe sleeve;
the piston hydro-cylinder component comprises a piston, a piston rod and a hydro-cylinder arranged at a top of the inner wall of the shell, a centerline of the hydro-cylinder and the centerline of the guide cylinder are in a straight line;
a number of the sets of the connection component is two, the two sets of the connection component are respectively installed at both ends of the shell;
the acoustic emission probe is installed in the probe sleeve, and the cable connector of the acoustic emission probe extends from the notch provided in the wall of the probe sleeve; the end cap covers an upper end surface of the probe sleeve and is detachably connected to the probe sleeve; the probe sleeve installed with the acoustic emission probe is placed in the shell, a lower section of the probe sleeve is inserted into the guide cylinder provided on the shell and a lower end of the probe sleeve is located out of the shell, a placement position of the probe sleeve is supposed to make the cable connector of the acoustic emission probe face an end of the shell; the piston is installed in the hydro-cylinder, a first end of the piston rod is fixedly connected to the piston, and a second end is fixedly connected to a central portion of a top surface of the end cap, an oil inlet of the hydro-cylinder communicates the hydraulic pump through an oil pipeline, an oil return port of the hydro-cylinder communicates with the oil tank through the oil pipeline;
the transmission mechanism is connected to the connection component installed on the shell.

2. The rock damage acoustic monitoring system according to claim 1 , wherein
the connection component comprises;
a nut and at least two connection brackets, a first end of each of the connection brackets is evenly distributed around an outer wall of the nut and hinged with the outer wall of the nut, a second end of each of the connection brackets is fixedly connected to the shell.

3. The rock damage acoustic monitoring system according to claim 2 , wherein
the transmission mechanism is formed by a combination of a transmission rod, a connection rod and a roller component;
a central portion of one end of the transmission rod is provided with a connection screw hole, a central portion of the other end of is provided with a connection hole and a first fastening screw is arranged on a wall of the connection hole, a type and size of an internal thread of the connection screw hole are the same as a type and size of an internal thread of the nut in the connection component;
the connection rod comprises a thread section and a column section, the connection rod is used for a connection between the transmission rod and the connection component and a connection between the transmission rods, a type and size of an external thread of the thread section are matched with the type and size of the internal thread of the connection screw hole provided on the transmission rod, a shape and size of the column section are matched with a shape and size of the connection hole provided on the transmission rod, the column section of the connection rod is inserted into the connection hole of the transmission rod and then the connection rod is fixed by the first fastening screw;
the roller component comprises rollers, U-shaped installation plates, axles and a roller sleeve, a number of the rollers is two or three, a number of the U-shaped installation plates and a number of the axles are the same as the number of the rollers, each of the rollers is respectively installed on the corresponding axle, both ends of each axle are respectively installed on two side plates of a corresponding U-shaped installation plate, so that each of the rollers is respectively located between two side plates of the corresponding U-shaped installation plate, an outer diameter of an inner hole of the roller sleeve is larger than an outer diameter of the transmission rod and a second fastening screw is arranged on a wall of the roller sleeve, each of the U-shaped installation plates is respectively fixedly connected to an outer wall of the roller sleeve, when the number of the U-shaped installation plates is two, an included angle between centerlines of the two U-shaped installation plates is 120°-135°, when the number of the U-shaped installation plates is three, centerlines of two of the three U-shaped installation plates are in a straight, included angles between a centerline of a remaining U-shaped installation plate and the centerlines of the two U-shaped installation plates are both 90°;
at least one roller component is configured on each of the transmission rods, the roller sleeve of the roller component is sleeved on the transmission rod and the roller sleeve is fixed by the second fastening screw.

4. The rock damage acoustic monitoring system according to claim 1 , wherein
the notch arranged on the upper end of the wall of the probe sleeve for extending out the cable connector of the acoustic emission probe is a U-shaped notch.

5. The rock damage acoustic monitoring system according to claim 1 , wherein
the lower end surface of the acoustic emission probe in contact with the bottom of the probe sleeve is coated with a coupling agent.

6. The rock damage acoustic monitoring system according to claim 4 , wherein
the lower end surface of the acoustic emission probe in contact with the bottom of the probe sleeve is coated with a coupling agent.

7. The rock damage acoustic monitoring system according to claim 2 , wherein
the notch arranged on the upper end of the wall of the probe sleeve for extending out the cable connector of the acoustic emission probe is a U-shaped notch.

8. The

Assignees

• Univ Sichuan

Inventors

• Liu Jianfeng
• Wang Lu
• Xu Huining
• Pei Jianliang
• Zheng Jun
• Fu Wenxi
• Lei Xiaozhang
• Deng Jianhui

Classifications

• G01N29/227

  related to high pressure, tension or stress conditions · CPC title

• G01V1/00 Primary

  Seismology; Seismic or acoustic prospecting or detecting · CPC title

• G01V1/166 Primary

  Arrangements for coupling receivers to the ground · CPC title

• G01V2210/1429

  Subsurface, e.g. in borehole or below weathering layer or mud line · CPC title

• G01N29/223

  Supports, positioning or alignment in fixed situation (mounting transducers per se G10K11/004) · CPC title