CN202216938U - Rock triaxial compression acoustic emission testing system - Google Patents
Rock triaxial compression acoustic emission testing system Download PDFInfo
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- CN202216938U CN202216938U CN2011202711692U CN201120271169U CN202216938U CN 202216938 U CN202216938 U CN 202216938U CN 2011202711692 U CN2011202711692 U CN 2011202711692U CN 201120271169 U CN201120271169 U CN 201120271169U CN 202216938 U CN202216938 U CN 202216938U
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Abstract
The utility model discloses a rock triaxial compression acoustic emission testing system, which comprises MTS815 rock servo testing system. An upper pressure head and a bottom pressure head are arranged in a triaxial chamber of the system, an acoustic emission detector is arranged in the bottom pressure head, a shielding signal line of the acoustic emission detector penetrates out of the triaxial chamber through a communication channel reserved in a system base, and then the shielding signal line is connected with a preamplifier arranged outside of the triaxial chamber so as to achieve outdoor transmission of detection signals of the acoustic emission detector. The rock triaxial compression acoustic emission testing system can monitor more comprehensive and real acoustic emission signals, and provide more reliable test results by utilizing rock triaxial compression acoustic emission information to forecast rock rupture and avoid mine accidents caused by the rock rupture.
Description
Technical field
The utility model relates to pilot system, relates in particular to be used for the contract pilot system of acoustic emission of rock three axial compressions.
Background technology
Disaster accidents such as the roof fall of down-hole, mine, roof and floor gushing water, rock burst happen occasionally, and cause very big harm for the country and people's lives and properties, and the generation of these disaster accidents is all closely related with the rock mass unstability of breaking.Rock material is when bearing load; Its inside will produce local elastic plastics characteristic concentration phenomenon, after energy accumulation arrives a certain critical value, cause the generation and the expansion of microfissure; Must follow snap-out release and the propagation in the rock mass around of elastic wave or stress wave, produce acoustic emission phenomenon.Through collection, processing, analysis and research to acoustic emission signal, can infer the metamorphosis that it is inner, its failure mechanism of inverting is predicted its unstability of breaking.The dispose procedure of elastic wave or stress wave, with respect to the rock mass than large scale, because high frequency attenuation gets soon, the frequency that detects signal is low, and still energy is big, usually at 20～200Hz, is called microearthquake; For the rock sample of small scale, it is very little greater than 200Hz and energy usually to detect wave frequency, is called acoustic emission.Though the yardstick of rock sample and rock mass and microseismic signals energy difference are very big, its principle is similar.Acoustic emission phenomenon is the important precursor information of rock compressive failure unstability; Rational rock compressive failure acoustic emission experiment method studies science; On experiment basis, inquire into the relation of acoustic emission information and rock interior damage evolutionary process; Draw the rock compressive failure acoustic emission Forecasting Methodology that tallies with the actual situation, for adopting the relevant disaster accident of acoustic emission (microearthquake) monitoring technology prevention to have most important theories and practical significance.
Rock mechanics testing system combines with acoustic emission monitoring system, can monitor the acoustic emission information that produces in the rock compressive failure process, and then utilizes acoustic emission information prediction rock damage evolutionary process.
More advanced rock mechanics testing system is the MTS815 electro-hydraulic servo rock test system that the U.S. introduces at present, and it is to have world-class large-scale precision rock mechanics instrument and equipment.Tests such as can carry out this equipment rock uniaxial compression, three axial compressions contract, pore water pressure and infiltration.The principal feature of system is: 1. omnidistance computer control, can realize automatic data acquisition and processing; 2. being equipped with three overlaps independently servo-drive system and controls axial compression, confined pressure and hole (infiltration) pressure respectively; Thereby the very little elastic energy that only stores 3. solid steel loading frame realizes the rigid pressure test; 4. servo-valve reaction quick (290HZ), test accuracy is high; 5. can in high temperature (200 ℃), high pressure (140MPa) oil, accurately work with the tens(i)ometer (American MTS house journal) that test specimen directly contacts, can the most accurately measure the ess-strain before and after the rock failure mechanism of rock; 6. test can be adopted any loading waveform and speed, can change automatically in three kinds of control mode tests; 7. the closed loop heating system that range of adjustment is broad can provide the even temperature field.The deficiency that exists is:
This rock test system is easy to carry out rock uniaxial compression acoustic emission test.Because there is not the confined pressure problem that applies in uniaxial compression, the acoustic emission wave detector is easy to rationally contact with rock sample, can also add layer butter etc. between acoustic emission wave detector and the rock sample and be coupled, so the reliable collection of acoustic emission signal realizes easily.But when carrying out rock three axial compressions and contracting acoustic emission experiment,, can only place triaxial chamber outer wall (rock sample is in triaxial chamber) owing to can't place the acoustic emission wave detector in the triaxial chamber of pilot system, as shown in Figure 1.In this case, the acoustic emission wave detector is difficult to detect all real acoustic emission signal, and detected acoustic emission signal signal to noise ratio (S/N ratio) is low.Main cause has the following aspects:
(1) in the rock sample compressive failure process, can produce polytype vibration wave usually, like wave of compression (compressional wave), shearing wave (shear wave) etc.Compressional wave is meant the direction of vibration ripple consistent with direction of wave travel of particle, and all media that can produce stretching or compression stress can both be propagated compressional wave, so compressional wave can be propagated in various media; Shear wave is meant the direction of vibration and the orthogonal ripple of direction of wave travel of particle; Particle in the medium receives alternating shear stress and the waveform that produces; Only can bear the medium of shear stress and can propagate shear wave, so shear wave can not pass liquids and gases and can only pass through the solid propagation.And the stronger composition of its energy of vibration wave that the rock sample compressive failure the produces rock sample internal crack shear wave that expansion produces that breaks often.According to the detection method that wave detector is placed on the triaxial chamber outer wall shown in Figure 1; There are the type and the travel path conversion of ripple; Though can receive the part acoustic emission signal; But can't receive acoustic emission direct wave signal, have the stronger shear pulse ripple conductively-closed of energy greatly and fall, and have only sub-fraction shear pulse wave energy to propagate along transduction pathway through last push-down head and triaxial chamber outer wall.
Can increase the propagation distance of vibration wave (acoustic emission signal) when (2) wave detector is placed in the triaxial chamber outer wall, cause the vibration wave energy attenuation.According to the spherical diffusion effect and the attenuation by absorption effect of ripple, the wave propagation distance is big more, and the absorption of its energy, decay, diffusion loss are big more.
The interference of the electromagnetic noise signal that receives when (3) wave detector places the triaxial chamber outer wall is relatively large, and the Signal-to-Noise that receives is lower.
Therefore, need improve MT reconnaissance S815 electro-hydraulic servo rock test system.
Summary of the invention
The purpose of the utility model is to solve the problem that existing rock servo test system can't carry out triaxial compression test to rock, and system improves to MTS815 rock servo test, and a kind of rock three axial compressions acoustic emission pilot system that contracts is provided.
The technical scheme that addresses the above problem is:
A kind of rock three axial compressions acoustic emission pilot system that contracts; It comprises MTS815 rock servo test system, is provided with seaming chuck and base pressure head in the triaxial chamber of system, it is characterized in that; In the base pressure head, be provided with the acoustic emission wave detector; The shielded signal wire of acoustic emission wave detector passes outside the triaxial chamber from the reservation communication channel of system's base, and shielded signal wire links to each other with the outside prime amplifier of triaxial chamber, to realize the outdoor transmission of acoustic emission wave detector detection signal.
Insert in the cavity for the ease of the acoustic emission wave detector, described base pressure head is the boss shape, and to the cavity of a side opening, cavity is on the last item line under the rock sample, through opening the acoustic emission wave detector is inserted in the cavity in the processing of the particle size position of base pressure head.
For the ease of above-mentioned base pressure head is fixed in the triaxial chamber, the bottom of base pressure head also is provided with flange, and a circle threaded hole evenly is set on the flange.
Shielded signal wire for the ease of making the acoustic emission wave detector passes from reserve communication channel; Be drilled with on the seating plane in being in triaxial chamber and reserve the boring that communication channel communicates; The shielded signal wire of acoustic emission wave detector pass boring back with epoxy resin with borehole sealing, in case hydraulic oil is revealed.
The preferable configuration of above-mentioned acoustic emission wave detector is, is provided with piezoelectric ceramic piece at the end face of a cylinder.Or being provided with piezoelectric ceramic piece at the end face of a cylinder body, the staving bottom is provided with the eyelet that communicates with triaxial chamber.Hydraulic oil gets in the acoustic emission detection body during test, makes inside and outside equipressure, guarantees its normal reception to acoustic emission wave under the confined pressure effect.
The beneficial effect of the utility model is:
The utility model is based on MTS815 rock servo test system; Through the acoustic emission wave detector is placed in the base pressure head; Realized that the acoustic emission wave detector can be built in the triaxial chamber; And rationally contact with rock sample, make that rock can monitor more comprehensively, real acoustic emission signal under condition is contracted in three axial compressions, break and then prevent and more reliable experiment method and experimental result are provided for utilizing the rock three axial compressions acoustic emission information prediction rock that contracts because of the break mine disaster accident of generation of rock mass.
Description of drawings
Fig. 1 is that the existing rock three axial compressions acoustic emission experiment that contracts is arranged synoptic diagram;
Fig. 2 is that rock three axial compressions of the utility model acoustic emission experiment that contracts is arranged synoptic diagram;
Fig. 3 is the vertical view of experiment pressure head;
Fig. 4 is a piezoelectric ceramics acoustic emission wave detector stereographic map.
Marginal data: 1-triaxial chamber; 2-base pressure head; 3-acoustic emission wave detector; The 4-shielded signal wire; The 5-base; 6-boring; 7-reserves communication channel; The 8-cavity; The 9-prime amplifier; The 10-threaded hole; The 11-cavity; The 12-piezo ceramic element; The 13-right cylinder; The 14-eyelet.
Embodiment
Below in conjunction with accompanying drawing the utility model embodiment is further specified.
Fig. 1 is that the existing rock three axial compressions acoustic emission experiment that contracts is arranged synoptic diagram, as can be seen from the figure, owing to can't place the acoustic emission wave detector on the base, and so the acoustic emission wave detector can only place the triaxial chamber outer wall.As shown in Figures 2 and 3; Rock three axial compressions of the utility model acoustic emission pilot system that contracts is the base pressure head 2 that in the triaxial chamber 1 of existing MTS815 rock servo test system, is provided with seaming chuck (not drawing among the figure) and boss shape; Process cavity 8 at the particle size position of base pressure head 2 to a side opening; Cavity 8 is on the last item line under the rock sample; The bottom of base pressure head 2 also is provided with flange, and a circle threaded hole 10 evenly is set on the flange, through threaded hole 10 usefulness bolts base pressure head 2 is fixed in the triaxial chamber 1.Be provided with acoustic emission wave detector 3 in the cavity 8.For the shielded signal wire 4 that makes acoustic emission wave detector 3 passes from reserve communication channel 7; In base 5, drill through a boring 6 that communicates with reservation communication channel 7 on the seating plane in being in triaxial chamber 1; And pass the back in the shielded signal wire 4 of acoustic emission wave detector 3 and hole 6 with epoxy sealing, in case hydraulic oil is revealed.Shielded signal wire 4 passes the back and links to each other with the outside prime amplifier 9 of triaxial chamber from the reservation communication channel 7 of system's base, thereby realizes the outdoor transmission of acoustic emission wave detector detection signal in the triaxial chamber.
As shown in Figure 4, acoustic emission wave detector 3 is to be provided with piezo ceramic element 12 in the upper surface of right cylinder 13, in order to realize the inside and outside equipressure of acoustic emission wave detector, is provided with cavity 11 in the right cylinder 13, and cavity 11 communicates with triaxial chamber 1 through bottom eyelet 14.Hydraulic oil gets in the acoustic emission wave detector cavity 11 through eyelet 14 in the test, realizes that the acoustic emission wave detector is inside and outside isobaric, guarantees its normal reception to acoustic emission information under the confined pressure effect.The diameter 18.9mm of acoustic emission wave detector 3, height 14.8mm, interior is cavity, bottom eye diameter 3mm.
Claims (6)
1. rock three axial compressions acoustic emission pilot system that contracts; It comprises MTS815 rock servo test system; Be provided with seaming chuck and base pressure head in the triaxial chamber of system, it is characterized in that, in the base pressure head, be provided with the acoustic emission wave detector; The shielded signal wire of acoustic emission wave detector passes outside the triaxial chamber from the reservation communication channel of system's base, and shielded signal wire links to each other with the outside prime amplifier of triaxial chamber.
2. the rock three axial compressions as claimed in claim 1 acoustic emission pilot system that contracts; It is characterized in that; Described base pressure head is the boss shape; To the cavity of a side opening, cavity is on the last item line under the rock sample, through opening the acoustic emission wave detector is inserted in the cavity in the processing of the particle size position of base pressure head.
3. the rock three axial compressions as claimed in claim 1 acoustic emission pilot system that contracts is characterized in that the bottom of base pressure head is provided with flange, and a circle threaded hole evenly is set on the flange.
4. the rock three axial compressions as claimed in claim 1 acoustic emission pilot system that contracts; It is characterized in that; Be drilled with on the seating plane in being in triaxial chamber and reserve the boring that communication channel communicates, the shielded signal wire of acoustic emission wave detector pass the boring back with epoxy resin with borehole sealing.
5. arbitrary described rock three axial compressions acoustic emission pilot system that contracts like claim 1-4 is characterized in that, described acoustic emission wave detector is that the end face at a cylinder is provided with piezoelectric ceramic piece.
6. arbitrary described rock three axial compressions acoustic emission pilot system that contracts like claim 1-4 is characterized in that, described acoustic emission wave detector is that the end face at a cylinder body is provided with piezoelectric ceramic piece, and the staving bottom is provided with the eyelet that communicates with triaxial chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202711692U CN202216938U (en) | 2011-07-19 | 2011-07-19 | Rock triaxial compression acoustic emission testing system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202711692U CN202216938U (en) | 2011-07-19 | 2011-07-19 | Rock triaxial compression acoustic emission testing system |
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| Publication Number | Publication Date |
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| CN202216938U true CN202216938U (en) | 2012-05-09 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2011202711692U Expired - Fee Related CN202216938U (en) | 2011-07-19 | 2011-07-19 | Rock triaxial compression acoustic emission testing system |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102305829A (en) * | 2011-07-19 | 2012-01-04 | 山东科技大学 | Rock triaxial compression acoustic emission test system |
| CN102879468A (en) * | 2012-09-18 | 2013-01-16 | 东北大学 | Double-bending-element ultrasonic sensing test device and method for evaluating rock damage |
| CN104913976A (en) * | 2015-06-03 | 2015-09-16 | 北京科技大学 | Temperature-controllable rock uniaxial compression sound emission test device and temperature-controllable rock uniaxial compression sound emission test method |
| CN106644739A (en) * | 2017-02-21 | 2017-05-10 | 湖北工业大学 | Real-time ultrasonic scanning device used during rock triaxial compression |
| CN114216970A (en) * | 2021-12-16 | 2022-03-22 | 广西大学 | Acoustic emission/microseismic sensor installation mechanism in rock indoor test and installation method |
-
2011
- 2011-07-19 CN CN2011202711692U patent/CN202216938U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102305829A (en) * | 2011-07-19 | 2012-01-04 | 山东科技大学 | Rock triaxial compression acoustic emission test system |
| CN102879468A (en) * | 2012-09-18 | 2013-01-16 | 东北大学 | Double-bending-element ultrasonic sensing test device and method for evaluating rock damage |
| CN102879468B (en) * | 2012-09-18 | 2014-09-03 | 东北大学 | Double-bending-element ultrasonic sensing test device and method for evaluating rock damage |
| CN104913976A (en) * | 2015-06-03 | 2015-09-16 | 北京科技大学 | Temperature-controllable rock uniaxial compression sound emission test device and temperature-controllable rock uniaxial compression sound emission test method |
| CN106644739A (en) * | 2017-02-21 | 2017-05-10 | 湖北工业大学 | Real-time ultrasonic scanning device used during rock triaxial compression |
| CN114216970A (en) * | 2021-12-16 | 2022-03-22 | 广西大学 | Acoustic emission/microseismic sensor installation mechanism in rock indoor test and installation method |
| CN114216970B (en) * | 2021-12-16 | 2023-12-22 | 广西大学 | Acoustic emission/microseism sensor installation mechanism and installation method in rock indoor test |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120509 Termination date: 20120719 |