| Filling mining method is an important mining method of green mines.Complete tailings cemented filling slurry is coupled with surrounding rocks,forming an integrated two-medium composite rock mass under triaxial stress.Therefore,ensuring the overall stability of composite rock mass is of great significance for the safety of goaf.collecting experimental materials,making standard samples,using ANSYS to carry out the numerical simulation test of composite rock mass with different occurrence.The mechanical properties of the composite rock mass under triaxial stress environment are studied by means of indoor physical experiment,theoretical analysis and numerical simulation.Research indicates:1)The main failure mode of the composite rock mass of filling body and surrounding rock is shear failure.The composite rock mass with 0°and 15°is a tensionshear composite failure mode;the shear failure of filling element mainly occurs in the composite rock mass with 30°~60°.When confining pressure increases,the sliding phenomenon tends to be significant;The composite rock mass with 75°and 90°shows more obvious tension failure.2)The triaxial compressive strength of composite rock mass increases linearly with the increase of confining pressure,and decreases first and then increases with the increase of contact angle.When confining pressure is small,the contact angle has a great influence on the failure mode of composite rock mass.When confining pressure increases to a certain value,the influence of confining pressure is gradually obvious.3)Based on the interaction,three dimensional mechanical analysis of composite rock mass is carried out.,through two kinds of methods to obtain the shear strength parameters.According to the results of analysis and numerical simulation test,the failure mechanism of the composite rock mass of filling body and surrounding rock is revealed,which provides a theoretical basis for the strength design of filling body.Figure 74;Table 7;Reference 60... |
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