The Effect of Intersection Angle on the Failure Mechanism of Utility Tunnel
Table 3
The findings of the comparison between prior research and this paper.
Research model
Conditions of intersection with ground fissures
The characteristics of failure mechanism
Horseshoe-shaped tunnel model
Orthogonal intersection
Bending and tensile failure. Near the ground fissure, the upper and lower surfaces of the tunnel were under tension and compression, respectively. The deformation of the tunnel was symmetrical. [15].
Horseshoe-shaped tunnel mode
Oblique intersection
Bending-torsional shearing failure under oblique intersection conditions. The deformation of the tunnel was asymmetrical [15].
Open-cut box tunnel model
Orthogonal intersection
Bending and tensile failure. The deformation of the tunnel was symmetrical [15].
Open-cut box tunnel model
Oblique intersection
Tensile-torsional shear failure mode, which is caused by the coupling of longitudinal bending, torsion shearing deformation, and transverse bending deformation. The deformation of the tunnel was asymmetrical [15].
U-shaped tunnel mode
Oblique intersection
Tensile-torsional shear failure mode. The range in failure of the tunnel was up to 3.5 times the tunnel diameter on the hanging wall side and up to 4.5 times the tunnel diameter on the foot wall. The deformation of the tunnel was asymmetrical [24].
The model in this paper
Orthogonal intersection
Bending and tensile failure. Near the ground fissure, the upper and lower surfaces of the utility tunnel were under tension and compression, respectively. The deformation of the tunnel was symmetrical. The range in failure of the utility tunnel was up to 10 times the utility tunnel height on the hanging wall side and up to 10 times the utility tunnel height on the foot wall.
The model in this paper
Oblique intersection
Tensile-torsional shear failure mode. The tension stress in horizontal direction and shear stress vertical direction were increased with intersection angle, but shear stress and displacement in horizontal direction were decreased with intersection angle. The deformation of the tunnel was asymmetrical.
