Simulation of 2D ground movement due to tunnel excavation using Finite Element Method (FEM)

Sustainability in construction of tunnel is very important to reduce environmental impact and also minimal use of earth resources. Therefore, numerical modelling is proposing at design stage to achieved this objective. To evaluate the changes in soil settlements during tunnel excavation, empirical, analytical, and numerical methods have been frequently applied movement research and the numerical method is effective in anticipating possible underground excavation scenarios. This paper describes the project on prediction of 2D ground movement due to the tunnel excavation by using Finite Element Method via ADONIS with the soil properties data from certain soil section of Goose Creek Tunnel project. The tunnel is in horse-shoe shape and typically be 1.8 m wide by 2.2 m tall. However, in this paper, the tunnel is assumed as a circular tunnel with diameter 2.2 m. This paper is focus on the effects of the constitutive soil models. The influence of type of soil model to the ground settlement is investigated and discussed. The simulation is confirmed by comparing the output of the settlement with manual calculation. The findings prove the Plastic Hardening (PH) model is more suitable in modelling ground movement due to tunnel excavation. By designing a tunnelling structure with a low prediction error, the engineers can build the most efficient tunnel.