Abstract:

The strength of prestressed concrete lining of Yellow-River-crossing tunnel was analyzed and verified by using 3-D non-linear finite element model. According to the features and action mode of the double composite lining structure, the prestress loss caused by the friction between steel strand and duct, the anchorage device deformation and the inward shrink of steel was taken into account. The distribution of effective prestress in prestressed steel strand was obtained. The distribution of hoop stress in the inner and exterior surface of the lining, as well as the average hoop stress respectively under the stretched steel strand condition and the design waterhead condition was also acquired. The calculation results indicate that the loss of prestress is severe when the steel strands are stretched. The tension stress and other factors affecting the loss of prestress should be controlled strictly so that the effective prestress could meet the strength requirement. Under the above two conditions, the whole section of the concrete lining is totally pressed and its stress distribution is also feasible enough to assure the tunnel’s long-term running. The basic variation and key parameters such as the stress parameters of the numerical calculation results are consistent with those of the full-scaled simulation model test.

Key words: Yellow-River-Crossing tunnel, prestressed lining, 3-D nonlinear finite element, strength analysis