عنوان مقاله [English]
In this research, the influence of tunnel construction of the 2nd line of Mashhad metro in the vicinity of Sadaf hotel has been chosen as a case study. It was aimed to investigate the ground displacements and surface settlement which has been induced by tunneling with Earth Pressure Balance-Shield Tunnel Boring Machine (EPB-TBM). FLAC-3D, as a finite difference software, has been used for numerical modelling.
Construction of underground tunnels plays an important role in development of modern cities. One of the most important problems caused by the construction of tunnels is that underground excavations can cause large settlement of surface ground. Transportation developments in cities often involve tunneling, which inevitably leads to ground movements and Tunnel construction in urban areas may inevitably require crossing close to adjacent surface structures.
Methodology and Approaches
In this paper, influence of effective parameters are assessed. These factors are geometrical parameters such as tunnel overburden, depth of foundation of building and lateral distance between tunnel and building. Numerical method in this study was performed with FLAC-3D code. Moreover, 4 scenarios are analyzed: green field analysis with close form solution, green field analysis with numerical method, tunnel foundation interaction and tunnel interaction with weight of structure.
Results and Conclusions
In conclusion, the line graph in various analyses illustrates that the green field analysis even numerical or not are evaluated underestimated results especially on settlement with respect of real condition. Then it is better to consider at least weight of structure for initial settlement analysis. The results indicate that, variation of tunnel overburden is more effective than building depth and lateral distance on surface settlements.