Abstract:In order to cut down the complexity and workload of seismic analyses, three approximate analytical methods for seismic design of circular tunnels were discussed. The first one is based on the function of complex variable and improved by using shear stresses in strata gained by the vibration equation for stratification strata, the second one is founded on the Bessel function, and the third method is grounded on the theory of elasticity mechanics. Seismic analyses of a circular tunnel were carried out respectively using the three analytical methods and by numerical calculation based on the seismic deformation method. The results show that the first two analytical methods can obtain relatively close results, so it is feasible to carry out the seismic analysis by the worst combination of their calculation results, and the third analytical method can be only used at the preliminary stage of seismic design.