Analysis of the double-tunnels interaction by using finite element method: Influence of tunnels position and excavation sequence

Abstract

The advancing of development requires the use of underground area for the construction of transportation infrastructure facilities. Construction of double-tunnel at the same time, with the position of tunnel which is adjacent to the others tunnel may be done horizontally manner. The excavation method which is used in soft soil tunnel construction is three-bench seven-step excavation method that can stabilize the tunnel face but it does not require any additional support, it has been widely used in tunnels with large cross-sections for highway. Since, both the tunnels spacing and the excavation sequence affect the displacement and stresses in the lining, it is major interest to study the influence of these factors on the tunnel design. Numerical simulations are conducted to reveal displacement characteristics and obtain optimal construction approach for tunnels in Indonesia. The method which is used for calculation is very suitable for estimating the stability level of tunnels with reliable result. This paper presents analysis of this issue with a particular interest for the optimization of both tunnels spacing of the double-tunnels and the excavation sequence. The analysis conduct in two dimensions of analysis.