Experimental Study on Deformation and Acoustic Emission Characteristics of Arch Roadway under Different Unloading Rates

Table 1

Mechanical parameters of cement mortar specimens and the parameter range of sandstone.

Material types	Cohesion (MPa)	Friction angle (°)	Poisson ratio	Elastic modulus (GPa)	Compression strength (MPa)
Cement mortar	10.02	28.7	0.17	12.8	26.4
Sandstone	8–40	20–50	0.02–0.2	4.9–78.5	20–170