| In the general mining,excavating caused by shear load instability and failure of coal and rock is one of the main damage form.And under natural conditions,coal and rock in the process of shear failure is a combination of a variety of factors.Therefore,in order to explore coal rock mass seepage coupling mechanism of shear-based on the type of coal and rocks(sandstone and shale)as the research object,and a variety of materials and the use of independent research and development of coal and rock seepage coupling shear-test apparatus,carried out under different test conditions of coal/rock cutting-seepage coupling experiment research,mainly discussed the different method to stress,the shear failure of coal and rock under different pressure conditions such as mechanical properties,the seepage characteristics,shear plane shape characteristic,etc.,and obtained the following results:(1)The use of independent research and development of coal and rock seepage coupling shear-test device,this paper discusses the normal stress of coal/rock seepage coupling test,the influence of shear-,with the increase of normal stress of coal/rock peak shear stress increases and their corresponding peak shear deformation,and coal/rock peak shear stress and normal stress approximate linear growth the tendency,and through to the coal and rock shear plane morphology characteristics of the analysis and comparison,normal stress can control the size of the shear crack propagation region,making normal stress,the greater the degree of shear plane ups and downs and roughness of coal or rock.(2)The use of independent research and development of coal and rock seepage coupling shear-test unit,probes into the pressure of coal/rock cutting-seepage coupling test,the influence of air pressure makes the rocks due to the internal high pore pressure,and the high pore pressure can make pore fissure between the tension,and the air pressure,the greater the tensioning force will lead to greater role.Tension effect to reduce the cohesive force between the rock mineral grains,shear damage the specimen are more likely to happen,when to cut rock peak shear stress decreases,and the corresponding peak shear deformation and failure of the method to decrease deformation.(3)Compared the different rock types on seepage coupling test,the influence of shear-found in coal/rock cutting-seepage coupling experiment,a type of coal and rock materials generally have many different,in terms of mechanical properties,shear failure type coal mainly plastic failure,as the shear deformation continues to increase,coal type and there are no big stress drop and curve integral is relatively stable,and the general,shale,sandstone rock material shear stress in the specimen cut slope break,shear stress curve will be falling sharply,a large stress drop;In terms of seepage characteristic,type coal permeability under normal stress,the type of coal specimen was cut,specimen remains relatively low permeability,and rock material is cut,the seepage channels open,seepage flow surge,basic is not affected by method to stress specimen permeability;In terms of shear plane shape characteristic,the same test conditions,the type of coal specimen shear plane roughness and fluctuation degree more like rock specimen is smaller.(4)Combining previous research results,using 3 d scanner to 3 d scan of coal and rock cut section,and introduces two dimensional parameters and the characteristics of three-dimensional morphology quantitative characterization parameters on the shear plane information,summarizes a kind of applicable to the new method of analyzing the characteristic of the shear plane morphology of coal or rock.Using this method,the implementation of the coal and rock shear plane by the transition to the naked eye now past 2 d and 3 d numerical value analysis. |
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