Flows of pore water in saturated soft soils would deviate from Darcy’s flow law under low hydraulic gradient, which is non Darcy seepage mode. Supposing that the velocity of flow is exponentially related to the hydraulic gradient, the analytical solutions of non-Darcy seepage field in shallow single-hole and double-hole circular tunnels are derived by using the principle of mirror method. The analytical solutions of non-Darcian seepage and Darcian seepage for shallow circular tunnels are compared and verified by case analysis. The influence of non-Darcy seepage index and the seepage coefficient ratio of soil to lining on tunnel seepage field is also discussed. The results show that the non-Darcy seepage index and the ratio of seepage coefficient have great influence on tunnel seepage and pore pressure of surrounding soil. With the increase of seepage index, the loss of water head in soil is accelerated, and the pore pressure and seepage flow around the tunnel are gradually reduced. With the increase of the ratio of seepage coefficient between soil and lining, the drainage capacity of lining is enhanced, the seepage flow of tunnel is gradually increased, and the pore pressure around the tunnel decreases more.
Rock and Soil Mechanics
analytical solution of seepage