Introduced the coal and rock AE propagation rule,wave guide fixing technics onAE sensors,and AE forecasting coal and rock disaster on the scene and so on,The coaland rock AE propagation rule that follows the exponent ...Introduced the coal and rock AE propagation rule,wave guide fixing technics onAE sensors,and AE forecasting coal and rock disaster on the scene and so on,The coaland rock AE propagation rule that follows the exponent attenuation function on different AEfrequencies,different quality factors and different propagation distances were analyzedand deduced by theory,numerical simulation,and by actual experiment.Consequently,itwas deduced that the coal and rock AE propagation rule follows the exponent attenuationfunction.Based on the correlative theory of wave dynamics and AE sensor,the AE waveguide propagation mechanical model on the sensor fixing manner is found,and the relationsof displacement and speed and acceleration between the AE signal source and theAE signal receiving terminal are presented.The effect of the AE sensor fixing manners oncoal and rock surfaces,coal and rock bottoms and wave guides were studied by actualexperiment.For the results,the effect of the AE sensor fixing manner on wave guides isbetter than on coal and rock surfaces,and was equivalent to the fixing manner on coal androck bottoms.Based on the above study results,actual coal and rock dynamistic disasterswere successfully forecasted.展开更多
Under two rock strata combination conditions,over 10,000 microseismic eventswere received with microseismic location monitoring technology which possessed by theauthor's studying team,used in fully mechanized coal...Under two rock strata combination conditions,over 10,000 microseismic eventswere received with microseismic location monitoring technology which possessed by theauthor's studying team,used in fully mechanized coal face of Huafeng Mine of XinwenCoal Mining Group Co.,Shandong Province.On the basis of the achievement of the locationresults,the conclusions were drawn as follows:On the basis of the achievement of 3Dstrata fracturing situation and the section plane of microseimic events in different areas,the relationship between spatial structure of overlying strata and mining pressure field wasfound,and we might describe distribution range of dynamic pressure of advance pressureand lateral stress around long face,and range of structure ad-tivation.Quantitative guidanceto prevent dynamic disasters was provided.The practice in coal mine got a effectiveresults.According to the FLAC3D soft numerical simulation of diameter drilling hole (thediameter is 300 mm) to relieve pressure in specified geological condition in Huafeng Mine,the right distance of two dirlls is 2.5 m and the right depth is 12 m.The research pro-videdbasic guiding and practical experiences for the underground microseismic monitoring anddisaster prevention in side slopes or tunnels engineering.展开更多
Based on statistical damage mechanics,the constitutive model of a rock underthree-dimensional stress was established by the law that the statistical strength of rockmicro-element obeys Weibull distribution.The acousti...Based on statistical damage mechanics,the constitutive model of a rock underthree-dimensional stress was established by the law that the statistical strength of rockmicro-element obeys Weibull distribution.The acoustic emission (AE) evolution model ofrock failure was put forward according to the view that rock damage and AE were consistent.Moreover,in the failure process of rock under three-dimensional stress,the change inrelationship between stress condition parameter and the characteristic parameters of AE,such as the event number and its change rate,were studied.Also,the rock AE characteristicunder uniaxial compression was analyzed in theory and verified with examples.Theresults indicate that the cumulative event number and change rate of AE in rock failure aredetermined by stress state parameter F.Along with the gradual increase of F,first the cumulativeevent number increases gradually,then rapidly,and then slowly after the stresspeak.The form of change rate of an event by increasing F is consistent with the distributionform of rock micro-element strength.The model explained the phenomenon that a relativelyquiet period of AE appears before rock rupture that is observed by many researchersin experiments.Verification examples indicate that the AE evolution model is consistentwith the test results,so the model is reasonable and correct.展开更多
基金Supported by the Project of National Basic Research Program of China(973 Program)(2005CB221505)the Significant Project of National Natural Science Fund(50534080/E041503)the Project of Coal Mine Gas and Fire Hazard Prevention Major Lab in Henan Province(HKLGF200508)
文摘Introduced the coal and rock AE propagation rule,wave guide fixing technics onAE sensors,and AE forecasting coal and rock disaster on the scene and so on,The coaland rock AE propagation rule that follows the exponent attenuation function on different AEfrequencies,different quality factors and different propagation distances were analyzedand deduced by theory,numerical simulation,and by actual experiment.Consequently,itwas deduced that the coal and rock AE propagation rule follows the exponent attenuationfunction.Based on the correlative theory of wave dynamics and AE sensor,the AE waveguide propagation mechanical model on the sensor fixing manner is found,and the relationsof displacement and speed and acceleration between the AE signal source and theAE signal receiving terminal are presented.The effect of the AE sensor fixing manners oncoal and rock surfaces,coal and rock bottoms and wave guides were studied by actualexperiment.For the results,the effect of the AE sensor fixing manner on wave guides isbetter than on coal and rock surfaces,and was equivalent to the fixing manner on coal androck bottoms.Based on the above study results,actual coal and rock dynamistic disasterswere successfully forecasted.
基金Supported by the National Natural Science Foundation of China(40674017,50534080)the Open Fund of State Key Laboratory of Coal Resources and Safe Mining(2007-04)+1 种基金the Open Doctor Innovation Fund of Shandong Province(200703020)the Chinese Postdoctoral Science Fundation(20080440304)
文摘Under two rock strata combination conditions,over 10,000 microseismic eventswere received with microseismic location monitoring technology which possessed by theauthor's studying team,used in fully mechanized coal face of Huafeng Mine of XinwenCoal Mining Group Co.,Shandong Province.On the basis of the achievement of the locationresults,the conclusions were drawn as follows:On the basis of the achievement of 3Dstrata fracturing situation and the section plane of microseimic events in different areas,the relationship between spatial structure of overlying strata and mining pressure field wasfound,and we might describe distribution range of dynamic pressure of advance pressureand lateral stress around long face,and range of structure ad-tivation.Quantitative guidanceto prevent dynamic disasters was provided.The practice in coal mine got a effectiveresults.According to the FLAC3D soft numerical simulation of diameter drilling hole (thediameter is 300 mm) to relieve pressure in specified geological condition in Huafeng Mine,the right distance of two dirlls is 2.5 m and the right depth is 12 m.The research pro-videdbasic guiding and practical experiences for the underground microseismic monitoring anddisaster prevention in side slopes or tunnels engineering.
基金Supported by the Key Program of National Basic Research Program(973)of China(2005CB221505)the National Natural Science Foundation of China(2005E041503)
文摘Based on statistical damage mechanics,the constitutive model of a rock underthree-dimensional stress was established by the law that the statistical strength of rockmicro-element obeys Weibull distribution.The acoustic emission (AE) evolution model ofrock failure was put forward according to the view that rock damage and AE were consistent.Moreover,in the failure process of rock under three-dimensional stress,the change inrelationship between stress condition parameter and the characteristic parameters of AE,such as the event number and its change rate,were studied.Also,the rock AE characteristicunder uniaxial compression was analyzed in theory and verified with examples.Theresults indicate that the cumulative event number and change rate of AE in rock failure aredetermined by stress state parameter F.Along with the gradual increase of F,first the cumulativeevent number increases gradually,then rapidly,and then slowly after the stresspeak.The form of change rate of an event by increasing F is consistent with the distributionform of rock micro-element strength.The model explained the phenomenon that a relativelyquiet period of AE appears before rock rupture that is observed by many researchersin experiments.Verification examples indicate that the AE evolution model is consistentwith the test results,so the model is reasonable and correct.