3D numerical investigation on the interaction between mechanized twin tunnels in soft ground

• Published in: Environmental earth sciences Vol. 73; no. 5; pp. 2101 - 2113
• Main Authors: Do, Ngoc-Anh, Dias, Daniel, Oreste, Pierpaolo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.03.2015; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Biogeosciences; Construction; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Excavation; Geochemistry; Geology; Grounds; Hydrology/Water Resources; Mathematical analysis; Mathematical models; mechanization; Original Article; prediction; Settlements; Soft ground; Terrestrial Pollution; Three dimensional; Tunnels; Tunnels (transportation); Underground construction; Settlement; Lining response; Segmental lining; Numerical modelling; Tunnel distance; Twin tunnel
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-014-3561-6

During the construction of twin tunnels excavated in close proximity to each other, the prediction of the influence of a new tunnel construction on an already existing one plays an important role in the design and construction of the tunnels. The researches in the literature indicate that this influence depends to a great extent on the distance between the tunnels. However, most of the reported cases in the literature on the mechanized excavation of twin tunnels have focused on the effects of the relative position between the two tunnels on surface settlements. Some of them have dealt with the behaviour of the tunnel structure through the use of simplified numerical models. The numerical investigation performed in this study, using the FLAC³ᴰfinite difference code, has made it possible to predict the impact between tunnels using full three-dimensional simulations, in which most of the elements of a mechanized tunnel process have been modelled. The effects of tunnel distance on the structural forces induced in both tunnels, and the displacements in the surrounding ground have been highlighted. A modification has been made to the superposition method to predict the settlement surface trough over twin tunnels.