Numerical Simulation Study of Dynamic Characteristics of Cemented Backfill Based on RHT Model
As an artificial pillar,the cemented backfill is often subjected to impact loads during underground blasting mining,which seriously affects its stability.Based on the RHT(Riedel Heirmaier Thoma)damage constitutive model,ANSYS/LS-DYNA software was used to conduct SHPB dynamic impact numerical simulation experiments on the cemented backfill with different lime sand ratio(1∶4,1∶6,1∶8)at different impact rates(2,3,4,5 m/s).The relationship between dynamic com-pressive strength,strength growth factor,absorption energy,and impact rate of the cemented backfill is explored,and the dy-namic failure mode and process of the cemented backfill is analyzed.The study results show that:① The dynamic compressive strength and dynamic strength growth factor of the cemented backfill increase with impact rate,and the higher the lime sand ra-tio at the same impact rate,the greater the dynamic compressive strength of the cemented backfill,but the dynamic strength growth factor is actually smaller.② The absorption energy of the cemented backfill gradually increases with impact rate,show-ing a linear growth trend,and the higher the lime sand ratio,the faster the absorption energy growth.The failure process of the cemented backfill is manifested as the first occurrence of damage at the end of the specimen,followed by axial and transverse cracks that propagate until they penetrate and develop inward,ultimately leading to complete failure and loss of load-bearing capacity.③ The above conclusions also verify the accuracy of the RHT model parameter values,and the successful application of the RHT damage constitutive model provides a reference for subsequent conducting numerical research on the dynamic char-acteristics of the cemented backfill.
cemented backfilldynamic strengthincident energydestruction modeRHT model
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