Investigations on the effect of natural structural surfaces containing
calcite fillers on the mechanical properties of limestone
Abstract
The damage mode and strength characteristics of rock masses containing
natural structural surfaces are important factors affecting the
stability and safety of underground cavern excavation and slope
engineering. The damage behavior of tuff rock masses containing calcite
mineral filling under uniaxial compression experimental conditions is
unclear, and the fracture mechanism of the rock masses needs to be
further explored. In this study, uniaxial compression tests were
conducted on tuff rock specimens containing natural calcite filled
structural surfaces by combining acoustic emission (AE) and digital
image correlation (DIC) techniques. The effects of these structural
surfaces on the generation and development of cracks on the surface of
the specimens until the formation of macroscopic penetration, the
overall state of the macroscopic cracks formed, the final damage state
of the specimens, and the strength properties of the rock mass were
analyzed. The results showed that (1) the transversely distributed
structural planes caused significant stress concentrations in the rock
specimens (2) the longitudinally distributed structural planes caused
cracks in the specimens or influenced the expansion path of the
longitudinal principal cracks. (3) The final damage pattern of the
specimens did not differ significantly from that of conventional rock
masses due to the presence of structural planes. (4) The presence of the
structural face had a significant effect on the uniaxial compressive
capacity of the rock, but the load variation process of the specimen
with time still conformed to the load variation pattern during the
uniaxial compressive test of conventional rocks.