Study On Infrared Radiation Characteristics Of Silty Sandstone In Deep Mining Under High Temperature And Water Immersion Conditions

Aiming at the stability of surrounding rock under high temperature and multi water conditions in deep mining of underground mines,this paper takes the natural drying treatment,50 ? water temperature treatment and 100 ? water temperature treatment of the powder sandstone specimen as the research object,carries out the infrared radiation experiment under the uniaxial compression condition,respectively from the discrete parameter,Shape parameters and image smoothness of the three aspects of the system analysis,at the same time the different water temperature conditions after the same parameters of the same parameter analysis,using the correlation coefficient method to discuss the characteristics of the parameters of the performance of the temperature field,the evolution of time and space and the IR precursor information.The main findings are as follows:(1)The stress-strain curves of specimens under different water temperature conditions are similar in overall performance,in order of compaction,elasticity,plasticity and four stages after the peak,the peak stress decreases with the increase of water temperature,and the maximum strain increases and then decreases after the whole specimen is loaded.(2)The characteristic parameters of IR radiation field are different in the light of the IR precursor of the post-peak failure stage of the loaded specimen.It is embodied as follows: Entropy value,fractal dimension,Euclidean distance performance is very good,all specimens have significant anomalies,maximum infrared temperature,minimum infrared temperature,extreme difference,variance,skewness,peak performance is slightly worse,Some of the specimens produced significant anomalies,the average IR temperature was the worst,and no significant anomalies were produced.With the increase of water temperature,the precursory anomaly amplitude of fractal dimension decreases gradually,which indicates that water temperature can inhibit its abnormal performance,and the temperature has little effect on the IR precursor characterization of other characteristic parameters.(3)The comparative analysis of the same parameters under different water temperature conditions shows that: the minimum infrared temperature,average IR temperature and maximum infrared temperature curve of 100 ? water temperature treatment specimens are smaller than natural drying specimens and 50 ? water temperature treatment specimens,and the curve variation amplitude is higher than that of natural drying specimens and 50 ? water temperature treatment specimens,Easyto distinguish,while the natural drying specimens and 50 ? water temperature treatment specimens are difficult to distinguish;In the variance aspect,the variance value increases first and then decreases with the increase of the water temperature condition,and the peak value of the water temperature decreases first and then rises;in the fractal dimension,the fractal dimension decreases with the increase of the water temperature,the other characteristic parameters are very poor,Skewness,entropy and Euclidean distance do not show significant boundary.(4)The stress-strain curve can fully reflect the change of the internal structure of the rock specimen during the loading period.Therefore,the correlation coefficient between the characteristic parameters and the stress of the infrared radiation field of the rock specimen is obtained,and the characteristics of the infrared radiation field in the rock under loading can be derived,and the optimal parameters are obtained.The results show that the correlation coefficient of natural drying specimen fluctuates greatly,and most of the characteristic parameters are less correlated.With instability,the correlation coefficients of extreme difference,skewness,kurtosis,entropy and fractal dimension are higher for 50 ? water temperature treatment specimens,and the performance is better,and the results are very good,and for 100 ? water temperature conditions,extreme difference,variance,skewness,The correlation coefficients of kurtosis,entropy and fractal dimension are all relatively large,and the performance is better,and the Euclidean distance is not satisfactory for the characterization of all specimens.