Refined Simulation Analysis of Water Pressure of Tunnel Lining Based on Temperature Analogy Method

In this study, the distribution of a lining's water pressure is calculated under different construction states including excavation, lining construction, and grouting to verify the accuracy and feasibility of the temperature analogy method in water pressure calculations. The results were compared with those of the theoretical analytical method and fluid-structure coupled method. Subsequently, the distribution of the lining's water pressure on transverse and longitudinal section was numerically explored through a refined model that includes a drainage system of a double lane highway tunnel. The results indicate that the water pressure of the lining significantly increases after lining construction and that a grouting circle can effectively reduce water pressure. The longitudinal distribution presents the characters of periodic variation above the longitudinal drain pipe, maximum water pressure occurs in the centre of two annular drain pipes, and minimum water pressure occurs in annular drain pipes. The transverse distribution presents an inverted gourd shape, minimum water pressure occurs in the arch foot, and maximum water pressure occurs in the vault and invert. Under the given computational assumptions, the maximum error between the temperature analogy method and theoretical analytical method is 0.3%, and the maximum error between the temperature analogy method and fluid-structure coupled method is 14.8%. Hence, the calculation precision satisfies the required engineering accuracy.