Mechanical property of thick-walled hollow cylinders of sandstone with filling

Based on uniaxial and pseudo-triaxial compression tests, the effect of support on the strength, deformation and failure characteristics of circular roadway is simulated by using solid specimens, thick-walled hollow cylinder specimens and thick wall cylinder specimens with aluminum rod. The tests indicate that: (1) The uniaxial compressive strength and elastic modulus of solid specimens and filled specimens are roughly the same, and those of the cylinder specimens are decreased by 31.8% and 22.4%; (2) When the thick-wall cylinder specimens have layered destruction along the circumference under triaxial compression, the shear area decreases with the increase of confining pressure, and collapse hole appears when the confining pressure is 40 MPa; (3) Filling have significant influence on mechanical properties of specimens when the filled specimens enter the plastic deformation, and it can change the rock stress state and make the two-dimensional stress state of inner wall back to the three-dimensional stress state; (4) Filling can cause inhibition of larger lateral displacement of inner wall and prevent the rock of free surface fall off; (5) Rock failure doesn't mean that the bearing capacity disappears, rock of filled specimens loses cohesive force, and the bearing capacity of filled specimens mainly depends on friction forces of filling and rock and rock fractures.