Abstract Facing the special "soil/rock" mixed ground condition in the Changchun area, the monitoring data of
ground surface settlement and the convergence deformation during cross-passage construction were analyzed, and the settlement and deformation laws were obtained during the construction process using the CRD method. Then, a numerical simulation was conducted using MIDAS/GTS finite-element software to study the settlement, deformation and mechanical behaviors of the support structure and buried pipelines during cross-passage excavation. After a comparison with the measured data, some results were determined: 1) ground surface subsidence induced by the excavation of pilot tunnels 1~4 accounts for 74% of the total settlement; 2) the influence scope caused by tunnel face excavation is around 15 m ahead of and behind the face; 3) the Mises stress in the vault and invert of the primary support structure is high, and the stress concentration emerges at the junction of the primary support structure; and 4) the maximum Mises stress is in the middle of the pipelines with the lowest stress point being about 10 m away from the axis of the pipeline.
Abstract：
Facing the special "soil/rock" mixed ground condition in the Changchun area, the monitoring data of
ground surface settlement and the convergence deformation during cross-passage construction were analyzed, and the settlement and deformation laws were obtained during the construction process using the CRD method. Then, a numerical simulation was conducted using MIDAS/GTS finite-element software to study the settlement, deformation and mechanical behaviors of the support structure and buried pipelines during cross-passage excavation. After a comparison with the measured data, some results were determined: 1) ground surface subsidence induced by the excavation of pilot tunnels 1~4 accounts for 74% of the total settlement; 2) the influence scope caused by tunnel face excavation is around 15 m ahead of and behind the face; 3) the Mises stress in the vault and invert of the primary support structure is high, and the stress concentration emerges at the junction of the primary support structure; and 4) the maximum Mises stress is in the middle of the pipelines with the lowest stress point being about 10 m away from the axis of the pipeline.
.Analysis of Mechanical Behaviors during Shield Launching Shaft Cross Passage Construction in Soil/Rock Mixed Ground[J] MODERN TUNNELLING TECHNOLOGY, 2017,V54(3): 82-89
2017, Vol. 54 