Research Article
Characteristics of Unloading Creep of Tuffaceous Sandstone in East Tianshan Tunnel under Freeze-Thaw Cycles
Table 4
The variation of volume creep.
| Stepwise unloading | T0 specimen | T20 specimen | T40 specimen | T60 specimen | Differential stress (MPa) | (10−3) | Differential stress (MPa) | (10−3) | Differential stress (MPa) | (10−3) | Differential stress (MPa) | (10−3) |
| Initial state (20 MPa) | 158 | 1.49 | 134 | 1.31 | 114 | 1.27 | 100 | 1.16 | First step (17 MPa) | 161 | 0.72 | 137 | 0.42 | 117 | 0.24 | 103 | 0.02 | Second step (14 MPa) | 164 | −0.34 | 140 | −0.65 | 120 | −0.94 | 106 | −1.62 | Third step (11 MPa) | 167 | −1.52 | 143 | −2.05 | 123 | −2.42 | 109 | −3.39 | Fourth step (8 MPa) | 170 | −3.46 | 146 | −4.51 | 126 | −5.12 | 112 | −5.67 |
|
|