Table 1.
Summary of recent research outcomes performed on the excavation-tunneling complex.
| Reference | Research methodology | Type of soil | Number of the tunnel | Tunnel position relative to excavation | Salient research outcomes |
|---|---|---|---|---|---|
| Zhang et al.20 | Analytical solutions | Clay | Twin-lines tunnel | Beneath the excavation |
(1) Proposed a method to solve the excavation-soil-structure interaction problem (2) Some important parameters should be consider in the design and construction for decreasing excavation deformations |
| Liang et al.21 | Analytical solutions |
Three different layers: (1) A clay (2) A silty clay (3) A sandy silt |
One tunnel | Beneath the excavation |
(1) If the Young modulus of ground increases, the unfavorable influences in the tunnel-excavation problem reduce significantly (2) Heave of the tunnel is rarely sensitive to the increasing of the tunnel shear stiffness |
| Ng et al.22 | Experimental investigation (centrifuge tests) and numerical modeling (ABAQUS) | Sand | One tunnel | Beneath the excavation |
(1) The tunnel tend to move upward when positioned directly at the bottom of the basement (2) As compared to the tunnel positioned beneath the basement, the maximum values of strains in both tunnel directions are less, if the tunnel positioned at the besides of the basement |
| Huang et al.23 | Experimental investigation (centrifuge tests) |
Three different layers: (1) Sandy silt (2) Grey silty clay (3) Muddy clay |
One tunnel | Beneath the excavation |
(1) Heave of the tunnel reduces exponentially with the tunnel excavation deviation (2) Bigger tunnel could have a lower value of deformation, when spacing between tunnel axis and excavation bottom are equal |
| Zheng et al.24 |
Numerical modeling (PLAXIS 2D) |
Silty clay | One tunnel | Beside or close to the excavation |
(1) The retaining structure deformation type has a remarkable influence on the deformation of certain tunnels (2) The amplitude of deformation of the tunnel created by an excavation, the area surrounding the excavation could separate into a very intensive effective, an intensive effective, and moderate effective and slight effective zones |
| Dai et al.25 | Numerical modeling (PLAXIS 3D) |
Six different layers: (1) Fill (2) Silty clay (3) Gravelly sand (4) Round gravel (5) Coarse sand (6) Gravelly sand |
Twin tunnels | Beneath the excavation |
(1) The surface settlement outside of the excavation area is composed of tunnelling-induced settlement and additional settlement created by the retaining structure deformation (2) Bored piles located between twin tunnels were exposed to the repeated disturbances |