Experimental Study on Characteristics of Seismic Damage and Damping Technology of Absorbing Joint of Tunnel Crossing Interface of Soft and Hard Rock

Table 4

Test results and mixture ratio of similar materials of surrounding rock.

Lithology	Mixture ratio of materials (%)				Test results
	Barite	Quartz sand	Gypsum	Water	Cohesion (kPa)	Friction angle (°)	Modulus of elasticity (MPa)
Soft rock	40	123	2.2	15	2.2	29.8	8
Hard rock	60	113	3.5	10	5.0	33.4	90

The prototype of soft rock is gravel layer, while the prototype of hard rock is sandstone.