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

Table 4

Displacements of the secondary lining (mm).

Measurement point	EYY(A)	EYZ(B)	EZZ(C)	B/A(%)	C/B (%)
EY/Z-1	−2.70	−3.59	−1.68	132.81	46.73
EY/Z-2	2.78	2.98	1.46	107.28	48.89
EY/Z-3	0.25	0.55	0.77	217.33	—
EY/Z-4	−0.74	−0.04	−0.30	5.11	—

Note. E_YY is the displacement of measurement points of secondary lining of the right tunnel tube after the completion of the right tunnel tube excavation. E_YZ is the displacement of measurement points of secondary lining of the right tunnel tube after the completion of the left tunnel tube excavation. E_ZZ is the displacement of measurement points of secondary lining of the left tunnel tube after the completion of the left tunnel tube excavation.