An Investigation on the Effect of Closely Passing New Tunnel FEM Model
The increase of underground space applications as an economical and technical solution for congested urban areas makes it inevitable to cross closely spaced underground structures. The analysis of new TBM-bored tunnel under existing underground station was conducted by 3D finite element method. In this paper, a parametric study was conducted to study ground movements and lining moments. It is shown that moment increase is significant when the tunneling face is in the closest distance to existing underground station. The significant increase of circumferential moment was appeared in sides; therefore, more attention should be paid on side walls. The comparison of controlling parameters shows that the deeper structures intensify interaction effects on station crown deformation and side walls moments. The results showed that thicker final lining does not have notable influence on station deformations but it causes significant increase in side walls moment. The results show that the stress increase by traffic load should be considered.