The Tunnel Boring Machine (TBM) method is a common method for the construction of tunnels in soft soils in urban areas. This section presents the construction stages that are typically followed in this method, and how such tunnels can be simulated in our shoring design software DeepEX. TBM tunnels can be analyzed with the DeepEX Finite Element Analysis engine DeepFEM, which can be aquired as an additional module and works within the DeeEX software superior interactive interface, expanding the program capabilities. With the Finite Element Analysis add on, DeepEX can design and optimize any deep excavation model fast, considering full soil-structure interaction.
Figure: A TBM Tunnel Simulated in DeepEX Software
TBM Tunnels - Typical Construction Stages
The excavation and tunnel construction sequence corresponds to 5 individual stages as illustrated in the following Figure.
Figure: TBM Tunnel Stages - Side View
Stage 0: The green field conditions of the site prior to the tunnel construction initiation.
Stage 1: The cutterhead section passing from the studied tunnel section.
Stage 2: The combination of soil loss at the tunnel face and along the shield are directly prescribed as a percentage area loss through the contraction option.
Stage 3: Tthe grouting of the gaps left by the retraction of the shield tail. The grout pressure is simulated as a surface load applied in internal walls of the excavated soil area.
Stage 4: The state of the tunnel after the installation of the final lining.
Figure: TMB Tunnel - Typical Construction Stages as simulated in DeepEX Software
Video Example: A TBM Tunnel Simulated and Analyzed with DeepEX Software: