Approximate evaluation of stresses in degraded tunnel linings

Abstract

This paper uses numerical and analytical methods to examine the static and seismic response of tunnels with intact and degraded segmental concrete tunnel liners. Concrete degradation is simulated using a non-linear finite element (FE) model that accounts for soil-structure interaction and the non-linear stress–strain response of the soil and concrete. The non-linear FE model is used to calculate radial stresses in tunnel linings with local concrete delaminations and that are subject to both static and seismic loads. Then, the FE results are compared with an analytical solution for jointed tunnel linings in order to assess the accuracy of the solution for predicting stresses in degraded liners. The analyses and results presented in this paper illustrate a simple method for estimating and evaluating the effect of concrete degradation on the distribution of thrust and moment in segmental tunnel linings subject to either static or seismic loads.