Temperature effect on shear behavior of ore-backfill coupling specimens at various shear directions

Understanding the temperature effect on shear behavior of the ore-backfill coupling structure is critical for the safety and stability of backfill stope under the condition of high horizontal stress in deep mining. Direct shear tests were carried out on the cemented rod-mill sand backfill (CRB) and ore-CRB (OCRB) coupling specimens at various temperatures (20, 40 and 60 degrees C). The shear behavior and AE characteristic parameters of OCRB at different shear directions were compared and analyzed. The results show that the temperature effect on the shear performance of CRB mainly depends on the characteristics of microstructures and main mineral phases; the performance of CRB at 40 degrees C is relatively good; the shear deformation of OCRB has one more peak fluctuation stage than CRB and has a good correlation with AE characteristic parameters. The temperature can positively or negatively impact the shear strength of OCRB, depending on the temperature and shear direction; the shear performance of OCRB along the axis direction (D1) is significantly better than that perpendicular to the axis direction (D2). The co-bearing capacity of the ore-backfill coupling structure (i.e., stopes) is closely related to the ambient temperature and principal stress orientation.

Automated summary

Understanding the temperature effect on the shear behavior of the ore-backfill coupling structure is crucial for the safety and stability of backfill stopes in deep mining with high horizontal stress. Temperature can influence the shear performance of CRB and OCRB, with CRB performing relatively well at 40 degrees Celsius. The shear behavior of OCRB is affected by temperature and shear direction, with its performance along the axis direction significantly better than perpendicular to it.