ELASTIC-PLASTIC ANALYTICAL SOLUTION OF DEEP BURIED CIRCLE TUNNEL CONSIDERING STRESS REDISTRIBUTION

In order to reflect the effects of stress redistribution, the stress adjustment coefficient is introduced in this paper to develop the elastic-plastic analytical solution of deep buried circle tunnel. The developed solution is compared with the elastic solution with and without the consideration of the seepage filed, and it is found considering stress redistribution is necessary. The stress redistribution will increase the circumferential stress and decrease the radial stress. If the seepage field is considered, the stress will be underestimated, and the radial stress will exceed the circumferential stress at some positions far from the tunnel center. When the inner head is small，considering the seepage field will underestimate the plastic radius, which decreases with the enlarging of inner head until the plastic zone disappears eventually.