Study on Dynamic Mechanical Properties and Crack Evolution Characteristics of Ice Rock Combination
During the excavation of water-rich bedrock by artificial freezing method,the bonding surface between artificial underground ice and rock mass is often affected by dynamic impact,and its stability determines the safety of underground engi-neering construction.In order to study the dynamic mechanical properties of ice-rock composite structure,the loading system of SHPB was constructed by PFC-FLAC coupling method.The dynamic characteristics and failure characteristics of ice-rock com-posite were analyzed,and the evolution law of microcracks was studied.The results show that the dynamic elastic modulus of the composite specimen is less affected by the inclination angle θ of the ice-rock interface.Under the action of dynamic load,the crack in the rock of the composite specimen gradually expands from the incident end to the ice-rock interface,and finally forms a penetrating main crack parallel to the loading direction.The propagation of micro-cracks'guides'the damage process of the composite.The final failure mode of the composite specimen is tensile and shear composite failure,and the failure charac-teristics of the rock part are mainly affected by the dip angle of the interface.When the dip angle of the ice-rock interface θ is 0°～45°,the peak stress has little difference,while the peak stress increases with the increase of θ,in the value ranges from 45° to 90°.
ice rock combinationSHPBPFCinclination angle of interfacenumerical simulation
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