Abstract:

In this paper,the stability coefficient and the supporting force of shallow bias tunnels are calculatedbased on the principle of virtual power from the viewpoint of energy,and the calculated results are compared.Theresults show that,based on the linear failure criterion,the calculated results of the stability coefficient are consistentwith the existing results with a maximum error of less than 10%,which demonstrates the validity of the calculationmethod; and based on the nonlinear failure criterion,the supporting force is greatly influenced by some negativefactors such as the nonlinear failure criterion of soil materials,the burial depth and the ground slope angle oftunnels,the ground load and the pore water.Besides,the failure surface positions corresponding to different parametervalues are put forward,which provides a theoretical basis for the supporting design of shallow bias tunnels.

Key words: nonlinear failure criterion, shallow bias tunnel, upper bound theorem, stability coefficient, supporting force, ground slope angle, failure modes