Research Article
A Study on Excavation Characteristics of Tunnel with Upper-Soft Lower-Hard Stratum
Table 3
Material characteristic parameters.
| | Material | Unit weight (kN/m3) | Elasticity modulus (GPa) | Poisson’s ratio | Internal friction angle (°) | Cohesion
(kN/m2) |
| | C20 spray concrete | 22.0 | 21.00 | 0.2 | / | / | | Rock bolt | 78.0 | 200.00 | 0.3 | / | / |
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