The upper bound theorem and reliability method were utilized to investigate the stability of shallow tunnels excavated in nonhomogeneous and anisotropic soils.The result shows that the effect degree of soil nonhomogeneity and anisotropy is governed by the buried depth of tunnel.When the buried depth is less than 15 m,the self-stabilization capacity of the surrounding rock is poor.As a result,the influence of nonhomogeneity and anisotropy is not obvious,and the supporting pressure tends to increase with the increase of buried depth.However,when the tunnel is deeply buried,greater than 20 m,the self-stabilization capacity of the surround rock is strong.In this circumstance,the supporting pressure varies greatly as the parameters of nonhomogeneity and anisotropy increase.It is also found that the distribution of nonhomogeneity and anisotropy parameters and the variable coefficient have a great effect on the supporting pressure through reliability research,especially when the parameters obey the logarithmic normal distribution.It is suggested that more attention should be paid to the nonhomogeneity and anisotropy of soil mass in the design of shallow tunnel,which would prevent either the increase of construction costs or the collapse of tunnel.