|
US$209.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB/T 25217.8-2021: Methods for test, monitoring and prevention of rock burst - Part 8: Monitoring method of electromagnetic radiation
Status: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| GB/T 25217.8-2021 | English | 209 |
Add to Cart
|
3 days [Need to translate]
|
Methods for test, monitoring and prevention of rock burst - Part 8: Monitoring method of electromagnetic radiation
| Valid |
GB/T 25217.8-2021
|
PDF similar to GB/T 25217.8-2021
Basic data | Standard ID | GB/T 25217.8-2021 (GB/T25217.8-2021) | | Description (Translated English) | Methods for test, monitoring and prevention of rock burst - Part 8: Monitoring method of electromagnetic radiation | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | D20 | | Word Count Estimation | 11,127 | | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | GB/T 25217.8-2021: Methods for test, monitoring and prevention of rock burst - Part 8: Monitoring method of electromagnetic radiation
---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Methods for test, monitoring and prevention of rock burst-Part 8.Monitoring method of electromagnetic radiation
ICS 73.040
D 20
National Standards of People's Republic of China
Rockburst measurement, monitoring and prevention methods
Part 8.Electromagnetic radiation monitoring methods
Released on 2021-04-30
2021-11-01 implementation
State Administration of Market Supervision and Administration
Issued by the National Standardization Management Committee
Foreword
GB/T 25217 "Measurement, Monitoring and Prevention Method of Rock Burst" is divided into 14 parts.
---Part 1.The method of measuring the impact tendency of roof rock formation and index;
---Part 2.Classification of impact tendency of coal and measurement method of index;
---Part 3.The method of measuring the impact tendency and index of coal-rock composite specimens;
---Part 4.Microseismic monitoring method;
---Part 5.Ground sound monitoring method;
---Part 6.Drill cuttings method monitoring method;
---Part 7.Mining stress monitoring method;
---Part 8.Electromagnetic radiation monitoring methods;
---Part 9.Coal seam water injection prevention methods;
---Part 10.Coal seam borehole pressure relief prevention method;
---Part 11.Coal seam pressure relief blasting prevention method;
---Part 12.Prevention and Control Methods of Mining Protective Layer;
---Part 13.Prevention and Control Methods of Roof Deep Hole Blasting;
---Part 14.Prevention and treatment methods of roof hydraulic fracturing.
This part is Part 8 of GB/T 25217.
This section was drafted in accordance with the rules given in GB/T 1.1-2009.
This part is proposed and managed by the China Coal Industry Association.
Drafting organizations of this section. China University of Mining and Technology, Liaoning University of Engineering and Technology, Xuzhou Fuan Technology Co., Ltd., Henan Dayou Energy Co., Ltd.
Co., Ltd., Fushun Mining Group Co., Ltd.
The main drafters of this section. Wang Enyuan, He Xueqiu, Dou Linming, Wang Aiwen, Liu Xiaofei, Wang Xiyuan, Liu Jun, Sheng Jiquan, Wei Xiangzhi, Jiang Hongbing.
Rockburst measurement, monitoring and prevention methods
Part 8.Electromagnetic radiation monitoring methods
1 Scope
This part of GB/T 25217 specifies the monitoring instruments, monitoring requirements, and monitoring requirements involved in the monitoring method of coal mine rock burst electromagnetic radiation.
Measurement methods, monitoring data recording and processing, and early warning of electromagnetic radiation of impact hazards.
This part is applicable to the monitoring of electromagnetic radiation of rock burst in coal mines.
2 Normative references
The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article
Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.
GB 3836.1-2010 Explosive Atmosphere Part 1.General Requirements for Equipment
GB 3836.4-2010 Explosive atmosphere Part 4.Equipment protected by intrinsically safe "i"
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
Electromagnetic radiationofcoalandrock
The process or phenomenon of radiating energy in the form of electromagnetic waves or electromagnetic pulses accompanying the process of coal and rock mass being loaded or deformed and ruptured.
Note. Coal and rock electromagnetic radiation is referred to as electromagnetic radiation.
3.2
Electromagnetic radiation intensity
The magnitude of the electromagnetic radiation signal generated by the deformation and fracture of coal and rock mass.
Note. Electromagnetic radiation intensity is abbreviated as electromagnetic intensity, and the unit is millivolt (mV).
3.3
Electromagnetic radiation pulse number
The number of electromagnetic radiation signal pulses generated by coal and rock mass deformation and fracture per unit time.
Note. The number of electromagnetic radiation pulses is referred to as electromagnetic pulse.
3.4
Portable electromagnetic radiation monitor
It is composed of a directional receiving electromagnetic antenna, a host, and an electromagnetic radiation test and analysis early warning software. It has a mobile test of coal and rock electromagnetic radiation,
Portable instrument with result display and hazard alarm function.
3.5
Electromagnetic radiation monitoring system
It consists of electromagnetic radiation sensor, monitoring sub-station, intrinsically safe uninterrupted power supply, transmission network, monitoring center machine, server, terminal computer and electromagnetic
Radiation monitoring and analysis and early warning software, etc., with real-time collection and transmission of electromagnetic radiation signals from multiple regions and multiple points, as well as data storage and processing,
Online monitoring system with functions such as result display and danger alarm.
3.6
Early-warningvalueofthreshold
The critical value of the electromagnetic radiation monitoring index used to determine whether the monitoring area has impact hazard. When the monitoring index value exceeds this value, the table
Obviously there is a danger of rock impact.
3.7
Change rate of trend changerateoftrend
The electromagnetic radiation in the monitoring area has a continuous or fluctuating growth (or decline) trend, and the electromagnetic radiation monitoring index value and the initial value of the trend are
The percentage of the ratio of the difference to the initial value of the trend.
3.8
Early-warningvalueoftrend
The critical value of the trend change rate of the electromagnetic radiation monitoring index used to determine whether there is impact risk in the monitoring area.
The potential change rate exceeds this value, indicating the danger of rock burst.
3.9
Duration
The time of continuous or fluctuating increase (or decrease) of electromagnetic radiation in the monitoring area.
3.10
Electromagnetic interference
Signals or phenomena that cause abnormal electromagnetic radiation monitoring indicators by electromechanical equipment.
3.11
Gain
The logarithmic value of the ratio of the intensity of the antenna's strongest radiation direction to the intensity of the reference antenna.
Note. The gain unit is decibel (dB).
4 Monitoring equipment and monitoring requirements
4.1 Portable electromagnetic radiation monitor
4.1.1 Directional receiving electromagnetic antenna.
a) The antenna has directional test (monitoring) and noise filtering functions;
b) The effective direction of the antenna monitoring. the main direction is the axial 60° cone area, and the side direction is the slot facing the triangle area;
c) Antenna monitoring frequency range. 1kHz~500kHz, 30Hz~1kHz;
d) The effective range of antenna monitoring. 1kHz~500kHz, 7m~50m; 30Hz~1kHz, 100m~300m;
e) Antenna gain. not less than 60dB.
4.1.2 Host.
a) Dynamic range of electromagnetic radiation intensity. 0~500mV, resolution not less than 1mV;
b) The dynamic range of the number of electromagnetic radiation pulses. 0~5000, and the resolution is not less than 1.
4.1.3 Electromagnetic radiation test and analysis early warning software.
a) It has the functions of instrument parameter setting, data communication and chart display;
b) It has the functions of data processing, regional analysis and trend analysis;
c) Combining critical value method and trend method for early warning of rock burst danger.
4.2 Electromagnetic radiation monitoring system
4.2.1 Electromagnetic radiation sensor.
a) It has electromagnetic radiation signal directional testing (monitoring), noise filtering, real-time acquisition, storage, processing and analysis, display, early warning and communication functions;
b) Monitoring effective direction. the main direction is the axial 60° cone area, and the side direction is the slot facing the triangle area;
c) Monitoring frequency range. 1kHz~500kHz, 30Hz~1kHz;
d) Monitoring effective range. 1kHz~500kHz, 7m~50m; 30Hz~1kHz, 100m~300m;
e) Gain. not less than 60dB;
f) Output mode. RS485,.200Hz~1000Hz, 4mA~20mA.
4.2.2 Electromagnetic radiation monitoring sub-station.
a) It has the functions of multi-channel data acquisition, storage, processing and analysis, communication, disconnected transmission, sensor and substation working status display;
b) Input mode. RS485,.200Hz~1000Hz, 4mA~20mA;
c) Output mode. RS485 and Ethernet, etc.
4.2.3 Electromagnetic radiation monitoring and analysis early warning software.
a) With system parameter setting, real-time communication and chart display functions;
b) With electromagnetic interference signal analysis and automatic filtering function;
c) It has functions such as data processing, regional analysis, trend analysis and automatic danger alarm;
d) Using the combination of critical value method and trend method to carry out automatic early warning of the danger of rock burst;
e) It has system fault identification and prompt function.
4.3 Electromagnetic radiation monitoring requirements
The use of electromagnetic radiation equipment for monitoring must meet the following requirements.
a) The electromagnetic radiation monitoring instrument meets the requirements of GB 3836.1-2010 and GB 3836.4-2010, and has an explosion-proof certificate and mine
Use product safety mark certificate;
b) Portable electromagnetic radiation monitors and electromagnetic radiation monitoring systems should be calibrated regularly;
c) When electromagnetic radiation is used to monitor and pre-warn the danger of rock shock, a reasonable selection of portable electromagnetic radiation should be based on the monitoring range and the degree of danger.
Radiation monitor or electromagnetic radiation monitoring system;
d) The electromagnetic radiation monitoring system should be installed as a priority for real-time monitoring of electromagnetic radiation in multiple areas and points.
5 Monitoring method
5.1 Mobile monitoring
5.1.1 Layout of measuring points in tunneling face
5.1.1.1 When monitoring the impact hazard of the tunneling face, it is necessary to arrange the layout on the left side, left front, front right, right front and right side of the tunneling face.
Set five measuring points, and the antenna faces the left side, left front, right front, right front and right side of the tunneling face respectively (see Figure 1).
5.1.1.2 Arrange measuring points on one or two sides of the area where the tunneling roadway needs to be monitored. The distance between the measuring points is 5m~20m, which can be determined according to the monitoring area.
The thickness of the coal seam where the domain is located is determined, the general thin coal seam is 5m, the medium thick coal seam is 10m, and the thick and extra-thick coal seam is 20m; there are structures or structures in the roadway.
When the area affected by coal pillars, etc., it is necessary to add measurement points in the corresponding area according to the actual situation.
Fig.1 Layout of electromagnetic radiation mobile measuring points in tunneling face
5.1.2 Layout of measuring points in the working face
5.1.2.1 Taking the open cut or stop mining line as the reference point, the mining stress concentration influence area or other possible dangerous areas in the roadway of the mining face,
Arrange multiple measuring points and test in order, as shown in Figure 2.
5.1.2.2 When testing the hazard of rock burst in the working face, arrange the measuring points in order from the upper end or the lower end, and proceed in order.
test.
5.1.2.3 The distance between measuring points is 5m-20m, generally 5m for thin coal seams, 10m for medium-thick coal seams, and 20m for thick and extra-thick coal seams;
When there are areas affected by structures or coal pillars, additional measurement points should be added in the corresponding areas according to the actual situation.
Figure 2 Electromagnetic radiation mobile measuring point layout of roadway or mining face
5.2 Online monitoring
5.2.1 Arrangement of electromagnetic radiation sensor in tunneling face
5.2.1.1 When monitoring the impact hazard of the tunneling face, an electromagnetic radiation sensor needs to be arranged on the tunneling face, and the sensor is 5
m~15m (see Figure 3), should be moved forward regularly with the tunneling length, so that the sensor is always within the first 5m~15m range from the tunneling face
Inside; the main direction of the antenna faces the coal body in front of the work.
5.2.1.2 Deploy sensors in the areas that need to be monitored in the excavation roadway, and the sensor spacing is 40m~60m; there are structures or coal pillars in the roadway.
When waiting for the affected area, it is necessary to increase the sensor or reduce the distance between the sensors in the corresponding area according to the actual situation; the antenna is inclined to the roadway wall.
The included angle is 30°, the opening is toward the center of the monitored coal body area, and the slot is toward the coal wall or the roof and floor to avoid interference from cables.
Figure 3 Layout of the electromagnetic radiation monitoring system for the tunneling face
5.2.2 Arrangement of electromagnetic radiation sensors at the working face
5.2.2.1 Arrange electromagnetic radiation sensors and sensors in the area affected by mining stress concentration or other possible dangerous areas in the roadway of the mining face
The spacing is 40m~60m (see Figure 4); when there are areas affected by structures or coal pillars in the roadway, it should be in the corresponding area according to the actual situation
Increase the sensor or reduce the distance between the sensors.
5.2.2.2 With the advancement of the working face, when the electromagnetic radiation sensor is less than 5m away from the coal wall of the working face, it should be moved back once and moved to a distance from the working face.
20m~30m from the coal wall.
5.2.2.3 The antenna and the roadway wall are inclined at an angle of 30°, the opening faces the center of the monitored coal body area, and the slot faces the coal wall or roof and floor to avoid electricity.
Cable and other interference.
6 Monitoring data recording and processing
6.1 Data acquisition and recording
6.1.1 Mobile monitoring data acquisition and recording
The mobile electromagnetic radiation monitoring data is obtained through manual testing and computer communication, and its daily monitoring needs to fill in the monitoring record form (see appendix
Table A.1) in A, and indicate the interference situation.
6.1.2 Online monitoring data acquisition and recording
The online electromagnetic radiation monitoring data is automatically collected, stored and analyzed by the electromagnetic radiation monitoring system, and the daily monitoring needs to fill in the monitoring records
Table (see Table A.2), and indicate the interference situation.
6.2 Analysis Index
Dangerous electromagnetic radiation monitoring of rock burst uses electromagnetic intensity as the main analysis indicator, and electromagnetic pulse as an auxiliary analysis indicator.
When the intensity change is not obvious and the overall value is high, the electromagnetic pulse should be analyzed.
6.3 Data processing
Technicians should make periodic electromagnetic radiation change diagrams and electromagnetic radiation distribution diagrams every day, and the data analysis period is at least 7 days.
It should be determined according to the duration of abnormal electromagnetic radiation of the mine's rock burst risk.
6.4 Electromagnetic interference treatment
The software automatically filters out electromagnetic interference signals through feature analysis and trend analysis.
6.5 Daily report
Mobile and online electromagnetic radiation monitoring should fill in daily reports every day (see Table A.3).
7 Early warning of shock hazard electromagnetic radiation
7.1 Early warning methods
Early warning methods for electromagnetic radiation of rock burst danger include critical value method and trend method.
7.2 Critical value method
7.2.1 Critical value analysis
All mines should determine the critical warning value of electromagnetic radiation according to the level of electromagnetic radiation of coal and rock, specific geology and mining conditions.
7.2.2 Determination of critical warning value
7.2.2.1 When the critical warning value of electromagnetic intensity is not determined, the critical warning value of electromagnetic intensity can be determined by referring to formula (1).
7.3 Trend method
7.3.1 Trend analysis
7.3.1.1 By analyzing the change law of electromagnetic radiation monitoring indicators at the same measurement point or in the same area over time, and determine whether there is continuous
Or fluctuating growth (or declining) trend; the data analysis cycle is at least 7 days, and the specific data should be based on the electromagnetic radiation of the mine's rock burst hazard.
The constant duration is determined.
7.3.1.2 When the electromagnetic intensity or electromagnetic pulse has a continuous or fluctuating increase (or decrease), it is judged as having a ΔT=t2-t1 time.
There is a monotonous and continuous trend.
7.3.1.3 When the computer software automatically determines that the electromagnetic intensity has a continuous or fluctuating increase (or decrease), calculate the electromagnetic intensity according to formula (3).
Trend change rate ηE.
7.3.2 Determination of trend warning value
7.3.2.1 Each mine shall determine the electromagnetic intensity or electromagnetic pulse corresponding to the specific geological and mining conditions, rock pressure and electromagnetic radiation changes.
The trend warning value of the trend change rate ηC and the minimum duration scale TC.
7.3.2.2 When the trend warning value is not determined, refer to. ηC≥35%, TC≥2h.
7.4 Regional analysis
By analyzing the regional distribution law of electromagnetic radiation monitoring indicators at different measuring points in the same time period, the abnormal area of electromagnetic radiation is determined.
7.5 Impact risk determination and early warning
7.5.1 Risk determination
When the monitoring area has one of the following conditions, it is determined that the area has the risk of rock shock, and an early warning or reminder of the shock risk is required.
a) The average value of electromagnetic intensity or electromagnetic pulse of two or more consecutive measuring points in the same area exceeds the critical value, E≥EC
Or N≥NC;
b) The electromagnetic intensity or electromagnetic pulse has an obvious continuous increasing trend, which is close to the critical warning value, and its trend change rate exceeds the trend
Warning value, the duration is greater than the minimum duration scale, |η|≥ηC and T≥TC;
c) When the electromagnetic intensity or electromagnetic pulse in a certain area obviously increases to the maximum value in the near term and then decreases, |η|≥ηC and T≥TC,
In particular, it is the most dangerous situation when it clearly continues to increase to the maximum value in the near term and then drops to the minimum value in the near term;
d) After confirming that there is no interference, little interference or no fault, the electromagnetic intensity or electromagnetic pulse changes strongly, and the amplitude of the change exceeds
Trend warning value.
7.5.2 Risk warning
The software issues early warning prompts, and technicians should check and analyze the distribution law and change trend of monitoring data, and further combine geology and mining
For the appearance of mining data and pressure, consider other monitoring methods and monitoring data for comprehensive analysis, and when it is confirmed that there is a danger, the danger of rock burst will be issued
Sexual warning.
Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 25217.8-2021_English be delivered?Answer: Upon your order, we will start to translate GB/T 25217.8-2021_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time. Question 2: Can I share the purchased PDF of GB/T 25217.8-2021_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 25217.8-2021_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet. Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. If you need your currency to be printed on the invoice, please write an email to [email protected]. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.
|