Hollow cylindrical sandstone specimens filled with Al,Pb and polymethyl methacrylate(PMMA),as well as hollow and solid specimens were tested under monotonic unconfined compression.The discrepancies in the elastic modu...Hollow cylindrical sandstone specimens filled with Al,Pb and polymethyl methacrylate(PMMA),as well as hollow and solid specimens were tested under monotonic unconfined compression.The discrepancies in the elastic modulus,unconfined compressive strength and failure pattern of the specimens were studied and then illustrated.The interaction stress threshold and localized failure stress threshold were identified by the strain gauges on the rock and filling rod.The results indicated that unobvious changes in the strength and elastic modulus were found between the solid and hollow specimens,while for the hollow specimens with infillings,the strength decreases with increasing the stiffness of the infilling material.The filling material with a higher stiffness leads to a high hoop stress,and hence a stronger interfacial force.The specimens coupled with filling rod are mainly fractured with tensile cracks,while the solid and hollow specimens are typically split into blocky fragments with dominated shear fractures.Finally,the equivalent inner pressure in the opening was theoretically derived.The findings suggested in the experiments can be well explained using the theoretical thick-walled cylinder model.展开更多
基金Projects(51904101,51774131,52004143)supported by the National Natural Science Foundation of ChinaProject(MDPC201916)supported by the Key Laboratory of Mining Disaster Prevention and Control,China。
文摘Hollow cylindrical sandstone specimens filled with Al,Pb and polymethyl methacrylate(PMMA),as well as hollow and solid specimens were tested under monotonic unconfined compression.The discrepancies in the elastic modulus,unconfined compressive strength and failure pattern of the specimens were studied and then illustrated.The interaction stress threshold and localized failure stress threshold were identified by the strain gauges on the rock and filling rod.The results indicated that unobvious changes in the strength and elastic modulus were found between the solid and hollow specimens,while for the hollow specimens with infillings,the strength decreases with increasing the stiffness of the infilling material.The filling material with a higher stiffness leads to a high hoop stress,and hence a stronger interfacial force.The specimens coupled with filling rod are mainly fractured with tensile cracks,while the solid and hollow specimens are typically split into blocky fragments with dominated shear fractures.Finally,the equivalent inner pressure in the opening was theoretically derived.The findings suggested in the experiments can be well explained using the theoretical thick-walled cylinder model.
