Research Article
Calculation Model and Influencing Factors of Surrounding Rock Loosening Pressure for Tunnel in Fold Zone
Table 1
Relationship between
and
values.
| | Equivalent inner friction angle (°) | | Equivalent inner friction angle (°) | |
| | <20 | (0∼0.1) | 45∼50 | (0.5∼0.6) | | 20∼30 | (0.1∼0.2) | 50∼55 | (0.6∼0.7) | | 30∼35 | (0.2∼0.3) | 55∼60 | (0.7∼0.8) | | 35∼40 | (0.3∼0.4) | 60∼65 | (0.8∼0.9) | | 40∼45 | (0.4∼0.5) | >65 | 0.9 |
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