Abstract In order to study the influence of a new overlapped tunnel on the existing tunnel induced by shield con? struction with different crossing angles, the shield construction processes under the crossing angle of 0°, 30°, 60°,90° are simulated and the effects on the existing tunnel stability are analyzed by a model test, taking Fuzhou metro line 2 project as the background. The study results show that during the construction process, the soil layers along the longitudinal direction of the new tunnel are mostly affected by the construction disturbance, and the closer to the working face, the more significant the construction disturbance for the soil layer; the variation law of the additional internal force at each measuring point of the existing tunnel is consistent, and the change is most obvious at the working face of the new tunnel; when the overlapped angle changes from 0° to 90°, with increase of the angle, the soil layers in the longitudinal direction of the existing tunnel are less affected by the construction disturbance at the separated section of the two tunnels, and the longitudinal internal force is also reduced gradually. However, the influence of the construction disturbance on the soil layers at the overlapped section is consistent, and the longitudinal additional internal force is slightly reduced because of the integrity of the existing tunnel.
Abstract：
In order to study the influence of a new overlapped tunnel on the existing tunnel induced by shield con? struction with different crossing angles, the shield construction processes under the crossing angle of 0°, 30°, 60°,90° are simulated and the effects on the existing tunnel stability are analyzed by a model test, taking Fuzhou metro line 2 project as the background. The study results show that during the construction process, the soil layers along the longitudinal direction of the new tunnel are mostly affected by the construction disturbance, and the closer to the working face, the more significant the construction disturbance for the soil layer; the variation law of the additional internal force at each measuring point of the existing tunnel is consistent, and the change is most obvious at the working face of the new tunnel; when the overlapped angle changes from 0° to 90°, with increase of the angle, the soil layers in the longitudinal direction of the existing tunnel are less affected by the construction disturbance at the separated section of the two tunnels, and the longitudinal internal force is also reduced gradually. However, the influence of the construction disturbance on the soil layers at the overlapped section is consistent, and the longitudinal additional internal force is slightly reduced because of the integrity of the existing tunnel.
WANG Chaodong1 LAI Peng′an1 CAO Yang2 YANG Sheng2
.Model Test Study on the Influence of the Close Crossing Angles of Overlapped Shield Tunnels on Existing Tunnels in Coastal Soft Soils[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(1): 168-174
2021, Vol. 58 