Study on the Mechanical State of Concrete Lining of Deep Buried Tunnel Under Different Corrosion Degrees

Based on the Drucker-Prager criterion, the analytical formula of the concrete lining support force of deep-buried circular tunnels under different corrosion degrees was derived under plane strain conditions. Taking the deep-buried tunnel of Xianglu Mountain as the research background, the stress state of the concrete lining under five different corrosion degrees was obtained by analytical methods and numerical simulation methods. This engineering instance is introduced to compare the calculated load with numerical simulated value. The result show that: Under deep burial conditions, stress concentration is likely to occur on the inside of the apex of lining. During construction and durability evaluation, it is necessary to strengthen monitoring of this location. As the degree of corrosion increases, the stress on the lining gradually decreases. When corrosion rate reaches 30%, the rock pressure on the lining of the hard rock section and the fracture rock section decreases by 7.32% and 5.03%, respectively. The difference between the analytical method and the numerical simulation results is small, so the derived analytical formula are credible, which can provide some reference value for the durability design of similar projects.