Advances in Materials Science and Engineering

Research Article

Force and Deformation Characteristics during the Reconstruction and Expansion of Shallow Single-Tube Tunnels into Large-Span Multiarch Tunnels

Table 5

Compressive stresses at measurement points of the middle partition wall (MPa).
Measurement pointPY(A)PZ(B)B/A(%)
P-1−0.59043−1.11401188.68
P-2−0.53609−1.93816361.54
P-3−1.37772−2.43763176.93
P-4−0.65321−2.59516397.30
P-5−1.16796−1.90799163.36
P-6−1.10355−2.08942189.34
P-7−0.43117−1.10307255.83
Note. PY is the first principal stress at measurement point of the middle partition wall after completion of the right tunnel tube excavation. PZ is the first principal stress at measurement point of the middle partition wall after completion of the left tunnel tube excavation.