Failure Behaviour of Sandstone with a Preexisting Joint under Stepped Excavation

Table 1

Physical and mechanical properties of sandstone and PLA material.

Material	Density (kg/m^3)	Uniaxial compressive strength (MPa)	Tensile strength (MPa)	Elastic modulus (GPa)
Sandstone	2185	25.96	2.29	1.96
PLA	1235	27.87	8.65	1.52