Analysis of chloride invasion process in undersea RC circular lined tunnel based on nonlinear ADE theory: Analytical solution, numerical verification and experimental prediction

Abstract

In this paper, a new nonlinear chloride transport model is proposed for the problem of undersea RC circular lined tunnel corrosion. The model takes into account the advection effect induced by seawater pressure, the time-depending surface chloride concentration, the time-depending concrete parameters, the scale effect of initial chloride concentration and the seepage velocity varies with the radial direction of the tunnel. The analytical solution of the proposed model is derived by function transformation, eigenvalue system and integral transformation, of which accuracy is verified by comparison with FEM via hypothetical case. Subsequently, influence of chloride concentration in seawater, seawater pressure, diffusion coefficient of concrete, permeability coefficient of concrete, time-dependent surface chloride concentration model and time-dependent concrete parameter model on chloride penetration in the reinforced concrete of tunnel is especially discussed. Finally, the practical use of the proposed model is demonstrated by two groups of tests based on circular lined tunnel. The paper provides an effective and concise analytical solution to evaluate the chloride invasion of cylindrical tunnel.