Analysis of a 1.8 km tunnel in East-West Algerian Corridor for stabilisation during construction

摘要

The East-West Algerian highway is a major infrastructure public road network which the Government of Algeria has planned and undertaken since the last five years. This intensive and complex road development, the largest in the country, once completed will link Algeria's East border with Tunisia to Moroccan border at the West with a distance of approximately 1200 km. This paper describes a major 1.8 km twin-tube tunnel built in the central part of the highway network, and presents the construction process of excavation that has been used. Moreover, to demonstrate the stabilisation process and to meet the strength requirements, the tunnel lining structure is modeled using the finite element method. The numerical model of the tunnel lining structure is analysed using different loading conditions. In the finite element model, the numerical approach to the hyperstatic reaction method is obtained by subdividing the tunnel lining into a finite number of linear bar elements connected to support springs. The effect of soil-structure interaction between the lining structure and the surrounding soil medium is simulated through the use of independent spring supports of the Winkler type. The values of the spring supports are based on the deformation modulus measured at different locations of the soil mass. The numerical results obtained from this analysis are used to check the concrete tunnel lining strength for stabilisation during construction process.