Abstract Based on conformal mapping of the complex variable function, the semi-infinite plane of a tunnel was
transformed into a concentric ring region. With the soil around the tunnel regarded as a homogeneous, continuous,isotropic, saturated medium, the boundary collocation method was applied to control the local leakage of shield tunnels. The analytic method and numerical method were combined to solve the basic differential equation of the twodimensional seepage of saturated soil masses under steady seepage, and a semi-numerical and semi-analytical solution of pore water pressure variations due to local water leakage of shield tunnels is obtained. The effects of the water leakage range, location, and total water head difference between the ground surface and the tunnel leakage boundary on the pore water pressure of the soil mass around the tunnel are discussed through this calculation method. The results show that there are great changes to the pore water pressure under a one time central buried depth of a tunnel in the horizontal direction when lateral water leakage occurs, and the larger the leakage range, the more significant the decay rate of the pore water pressure; the larger the total water head difference between the ground sur?
face and tunnel leakage boundary, the more obvious the influence is on the pore water pressure of the soil mass, and it is proportional to the total water head difference and volume of the pore water pressure reduction; and the lateral leakage volume of tunnels increases with an increase of the total water head difference, being characterized by a linear relationship.
Abstract：
Based on conformal mapping of the complex variable function, the semi-infinite plane of a tunnel was
transformed into a concentric ring region. With the soil around the tunnel regarded as a homogeneous, continuous,isotropic, saturated medium, the boundary collocation method was applied to control the local leakage of shield tunnels. The analytic method and numerical method were combined to solve the basic differential equation of the twodimensional seepage of saturated soil masses under steady seepage, and a semi-numerical and semi-analytical solution of pore water pressure variations due to local water leakage of shield tunnels is obtained. The effects of the water leakage range, location, and total water head difference between the ground surface and the tunnel leakage boundary on the pore water pressure of the soil mass around the tunnel are discussed through this calculation method. The results show that there are great changes to the pore water pressure under a one time central buried depth of a tunnel in the horizontal direction when lateral water leakage occurs, and the larger the leakage range, the more significant the decay rate of the pore water pressure; the larger the total water head difference between the ground sur?
face and tunnel leakage boundary, the more obvious the influence is on the pore water pressure of the soil mass, and it is proportional to the total water head difference and volume of the pore water pressure reduction; and the lateral leakage volume of tunnels increases with an increase of the total water head difference, being characterized by a linear relationship.
WANG Zhi-Liang- Shen-Lin-Fang- Wu- Zeng
.Influence of Local Water Leakage of Shield Tunnels on the Pore Water Pressure of Soil Masses[J] MODERN TUNNELLING TECHNOLOGY, 2017,V54(1): 89-95
2017, Vol. 54 