Experimental Study On The Charge Induction Law Of Water-containing Coal And Rock During Deformation And Failure

Water has an important influence on the physical mechanical properties and deformation and failure characteristics of coal and rock, with the increasing of mining depth, types of mine water disasters like mine water bursting, the unstability of coal pillar affected by actions of seepage action,the impact of water, corrosion and weakening on coal and rock are gradually increasing, which brings great harm to the life of workers and safe production in mines. Large amounts information including charge induction signal about coal and rock deformation and failure were released accompanying the occurrences of coalmine water disaster, charge induction signal reflects the coal and rock states in deformation and failure process and precursor information characteristics of coalmine water disaster, and which can be used as the basis for monitoring and forecasting the coalmine water disaster.With the method of experiment research in laboratory, loading ways, moisture content, water pressure and axial compression were studied to find the influence on the charge induction signal in deformation and failure process of coal and rock, which will provide the basis of reference data for the field application of charge monitoring technology. The main work and innovation points in this papet are as follows:(1) Based on the monitoring results of the physical and mechanical properties, the deformation and movement of rock and electrical parameters of coal and rock was studied and the charge induction signals under different loading conditions (uniaxial compression, triaxial and multistage cyclic loading) in the deformation and failure process of coal and rock was compared and the conclusion was obtained that confining pressure has the enhancing effect on the charge induction signal. Under the same condition, confining pressure makes the charge signal richer. Cyclic loading decreased the intensity of coal and rock and the charge induction signal is richer in the loading process.(2) The influence of moisture on the charge induction signal in the deformation and failure process of coal and rock was studied. By comparing the charge induction signal of coal and rock with different moisture content and different water quality in the deformation and failure process, it was found that the moisture content is higher, the lower the strength of coal and rock, when the water reached a certain value, the distribution of the charge induction signal in time will be up to average relatively, the experimental results of different moisture content of rock show that the moisture content is higher, the charge induction signal of rock richer in the micro crack steady increasing stage with the increasing of moisture content. With the increasing of moisture content, the induced charge quantity increased.(3) The charge induction signal in hydraulic fracturing test was researched. Through the analysis of the charge induction signal under the same axial compression and different axial compressions, the conclusions are drawn that with the increasing of axial compression, the hydraulic peak gradually reduced, the duration of the hydraulic peak gradually reduced, on the condition of the same axial compression, with the reduction of the peak hydraulic, the richness of the charge induction signal gradually reduce, the duration of the pressure peak value is very close.