Microseismic Monitoring Data Fusion Algorithm and Coal and Gas Outbursts Prediction

Vo. 1 No 4, Dec. 2010Journal of measurement science and InstrumentationSum No. 4Microseismic Monitoring Data Fusion Algorithmand Coal and Gas Outbursts PredictionZhi-gang ZHAO(赵志刚), Yun-liang TAN(谭云亮)Key Laboratory of Mine Disaster Prevertion and Control, Shandong University of science and Technology, @ingdao 266510, China)Abstract-The prediction study on coal and gas outbursts is carried with the microseismic information. In this paper, the mi-out by monitoring some indices which are sensitive to the initiation of coseismic monitoring data fusion algorithm and the prepal and gas outbursts. The values and changing rules of the indices diction method of coal and gas outbursts are studiedare the foundations of coal and gas outbursts prediction. But noonly the data of one key monitoring station is used in the coal and gas 2 Principle of microseismic monitoring lo-outbursts prediction practice, and the other data are ignored. In orderto overcome the human factor and make full use of the monitoring incationformation, the technique of multi-sensor target tracking is proposed toThe principle of microseismic monitoring location isseismic events, the activities of geological structure, fracture-depth of that: the sensors array is set up in the monitoring areastudies indicate that it is considerably possible to predict the coal and the signal can be pickup by the sensor and the signal isgas outbursts using microseismic monitoring with its inherent ability switched to voltage or electric charge; determine the ar-to remotely monitor the progressive failure caused by miningrival moment of signal, substitute the sensor coordinateKey words -aal and gns outbursts: microseismic monitoring: data and wave velocity into eqution groups; solve the equationand get the space- time parameters of hypocenterr:1674842(2010)040315Least squares method is a classic location algorithm,in which the equation group(1)is established according todio:10.399jisn.16748042.2010.04.03the signal arrival moment and the hypocenter location is1 Introduction(X1-X0)2+(Y-Y0)2+(Z-z0)2Coal and gas outburst is a dynamic phenomenon inV2×(T-T0)2coal exploitation, which causes great casualty and property Where X,, Yi, Z, is the number i sensor position; V,is thedamage. The damage caused by coal and gas outburst will wave velocity at number i sensor; T, is the signal arrivalbe more serious in deeper mining. It is very important to moment; Xo, Yo, Zo is the position of hypocenter; T; ispredict the occurance of coal and gas outbursts precisely the crack momentfor mine safety. There are many prediction methods forIf there are five sensors receive effective signal, thencoal and gasoutbursts, among them, method of drilling(x1-x)+(y1-y)2+(x1-z)2=v2x(t-t)2,bits, AE monitoring method and electromagnetic radiation(x2-x)2+(y2-y2+(x1-z)2=v2x(t;-t)2monitoring method are based on in-situ monitoring; and(x3-x)2+(y-y)2+(z1-z)2=v2×(t1-t)2,(2)the prediction is conducted through the analysis of data(x4-x)2+(y-y)2+(x1-z)2=v2x(t;-t)2and change rule for indices sensitive to coal and gas out(x3-x)2+(y-y)2+(x1-x)2=v2x(t-t)Eliminate the x.x, 2, t, then we can get the linTo hold the integrate situation about gas and coalear transcendental equationmass, multi-stations of seismic monitoring are set in genar+ by+a +d, t=eeral, and there are several groups of information available where a, b,, d,, e, are the coefficients.Letbout coal mass evolution. But only one key monitoringdata of the monitoring station instead of the others can bea, b ci dused to the prediction model at the same time in coal and2 b2 C2 da3 b3 c d,x=yBgas outbursts at present, so we have to select one repree3sentative key station to predict the occurance of coal andgas outbursts. In order to overcome the human factor andThen equation (3)is equal as AX= B, solve themake full use of the monitoring information, correspond- equation using least squares method and thening with the mobility of coal mass microseismic, the techBnique of multi-sensor target tracking is proposed to deal中国煤化工Ce 5 locations and ifCNMHGs Received: 2010-10-08Corresponding author: Zhi-gang ZHA316Jarmal of measurement Science and InstrumentationN.42010we have 6 sensors, we have 6 locations. Select the geo- the errors of every mesh point are calculated, themetric center of the all hypocenters coordinate and we get are mapped in a 3D space which is called error space. Thehe location resultsmallest error space is thought as the optimum result3 Error analysis of microseismic monitor-real events location theoreticallying algorithm4 analysis of events locationthe time difference as minmum, and the simplest method used in coal mine. The three dimensional images of roadis to make the absolute value of time difference of arrival way surrounding rock failure could be shown visuallymoment-between the wave detected by sensor and the calthrough the surrounding rock failure monitoring. throughculated result-as minmum. To that aim we should comthe monitoring of fracture development we can get the gaspare the calculated moment and detected moment and we migration law and we can analyse the potential room oftion is meet the demand 34 The compare methods in- coal and gas outburstsThe procedure of microseismic application is micro-clude:absolute value deviation estimate (5)and least seismic signal extraction and analysis; microseismic loca-squares estimate(6)tion; coal( rock)failure analysis and energy analysis; 3-diE‖To-T。(5) mension coal (rock )mass failure field determination; re-gional prevention of coal and gas outbursts. The primarywhich method is selected based on the minmum tim (6) demand of microseismic monitoring is the good accuracyE=N∑(T0-T)2of events location. As of May 5, 2010, the monitoringferent error. The second method emphsizes that the bigerThrough the events records, we can get the hypoerror should be eliminate and the first method diminish center parameter such as space location, static stress dropthe effect of biger error so its application is wider. After dynamic stress drop, seismicity scale and the error rangeTab 1 Microseismic location eventsStatic sterssMaximum ofXDynamic sterssdrop( Pa)displacement(m)Seismic14704.66678.8-52947703.60.00030431614839.56717.5541.38569984905.30.00020573-2.069757914834.36839.9-692336052276.704563822.72380714702.36676.725431.26710.20.000264221.6055433714834.96722.9-501.37963793199.50.0000689824-2046620714784.46687.4776502.252420914826,46753.4551.8651930.225538.5000488301.183436815219.56207.1580.2292193.6823780.0002576141.743076414703.96700.5-518.40.00008314352.212010714798.86892.8-564.32457633.625154.1000484841.23477741535996501.3552.6227562.15085.90.00007592732.28405685 Conclusionstion of high-precision microseismic monitoring technique towater inrush monitoring in coal mine. Chinese Joumal of rackMechanics and Engineering, 27(9): 1932-1938ake the inner field and outer field location effect factors [2] Hua Fu, Zhong-he Shen, Hong- ge Sun, 2005. Research ofinto account, it is significantly possible to realize the highprecision microseismic hypocenter locationystem Joumal of Liaoning Technical University, 24( 2)2)It is the effective technology means for the real [3] Qingli Wang, 2009. Study on coal and gas outburst based ontime monitoring and series monitoring to discribe the pro-microseismic monitoring technique. Dissertation. Mining En-cess of gestation, development and failure for gas changineering Northeastern University[4]Ke Guo,Ji-bing Peng Oiang Xu, et al, 2006. Application ofReferencesH滤Del au cail Mechanics, 27(3):479.[1] Fuxing Jiang, Genxi Ye, Cunwen Wang, et al, 2008. Applica中国煤化工CNMHG