单轴压缩胶结充填体裂纹扩展及汇集模式

Crack propagation and convergence mode of cemented backfill under uniaxial compression

采用WAW-300型伺服万能试验机及裂纹观测系统,对灰砂质量比为1∶4的胶结充填体进行了单轴压缩试验,获取了单轴压缩下胶结充填体裂纹演化全过程,探讨了胶结充填体裂纹扩展及汇集模式,结合灰砂质量比为1∶6的胶结充填体单轴压缩试验和颗粒流数值模型从宏细观角度进行了验证.结果表明:胶结充填体裂纹扩展模式以单一裂纹单向扩展与单一裂纹双向扩展为主;其汇集模式分为单一裂纹向轻度破损区汇集、单一裂纹向重度破损区汇集、两条短裂纹沿起裂区汇集和两条短裂纹沿轻度破损区汇集;胶结充填体试样各表面贯穿裂纹之间具有对称性和邻近性.

Based on WAW-300MEMS servo universal test and crack observation system,the uniaxial compression tests were carried out on cemented backfill with a cement-sand mass ratio of 1∶4.The whole process of crack evolution of cemented backfill under uniaxial compression was obtained.The crack propagation and convergence mode of cemented backfill were discussed,which was verified by uniaxial compression test and particle flow numerical model on cemented backfill with a cement-sand mass ratio of 1∶6from a macro and meso perspective.The results show that the crack propagation mode of cemented backfill is mainly single crack unidirectional propagation and single crack bidirectional propagation.The crack convergence mode of cemented backfill is divided into single crack converging to mild damage zone,single crack to severe damage zone,two short cracks to crack initiation zone and two short cracks to slightly damaged zone.The through cracks on the surface of cemented backfill samples have symmetry and proximity.