Tunnel Face Reinforcement by Bolting – Numerical Modelling of Centrifuge Tests
J.P. Janin, D. Dias
Soils and Rocks, São Paulo, 37(1): 39-50, January-March, 2014 | PDF
This paper presents the results of numerical investigations on the deformation behaviour of a tunnel face reinforced by longitudinal pipes. The three dimensional finite difference calculations are based on series of reduced-scale centrifuge model tests (Al Hallak, 1999). Numerical analyses are developed and carried out with particular emphasis on the validation of the excavation method. Geomechanical parameters of two constitutive models are calibrated on triaxial and oedometric tests. The numerical models are then compared with the centrifuge model results. This comparison concerns especially the tunnel face extrusion, the ground surface settlements and the minimum pressure that guarantees the face equilibrium before failure. Bolting influence on these parameters is studied.
Submitted on February 19, 2013; Final Acceptance on September 24, 2013; Discussion open until July 31, 2014.