Sub-rectangular Tunnel Behaviour under Static Loading
16/05/23 09:32AM
Pham, Van Vi; Do, Ngoc Anh; Dias, Daniel; Nguyen, Chi Thanh; Dang, Van Kien.  Transportation Infrastructure Geotechnology; New York Vol. 10, Iss. 3, (Jun 2023): 488-503. DOI:10.1007/s40515-022-00230-w


Circular- and rectangular-shaped tunnels are usually utilized when excavating at shallow depths in urban areas. Nevertheless, special-shaped tunnels such as sub-rectangular tunnels were recently considered to be used for overcoming some drawbacks of circular and rectangular tunnels in terms of low utilization space ratio and stress concentration at the corners, respectively. Using numerical analyses, this paper focuses on indicating the different behaviour of sub-rectangular tunnels under static loading in comparison with circular and rectangular ones having the same utilization space. It allows designers to decide the appropriate tunnel shape solution that should be used. The influence of parameters, including soil deformability, lateral earth pressure coefficient, and lining thickness, on the behaviour of different tunnel shapes under static loadings is also investigated. The results indicated a significant difference in the behaviour of sub-rectangular tunnels in comparison with the circular and rectangular ones when considering no-slip and full-slip conditions for the soil–lining interaction.