Abstract Based on seepage theory, water pressure formulas for tunnel linings under the conditions of axial symmetry were deduced. Then, through numerical analysis, the applicability of an axisymmetric solution for non-circular cross section tunnels-including circular section, square section, passenger-dedicated railway tunnel section and horseshoe section tunnels-and shallow tunnels was analyzed. The research results are presented as follows: Firstly, the cross section shape of a tunnel has little influence on the water pressure exerted upon the lining and can be ignored. Secondly, the main factor determining the reduction factor of water pressure on linings is the relative permeability of the lining to the rock mass. Thirdly, for shallow tunnels with low water heads, the non-lining water inflow calculated using the axisymmetric solution has a large margin of error compared to the real value of water inflow, with a maximum error of 36.5%. It is, however, consistent with numerical solutions, and the maximum error is only 6.3% for the calculations of the lining water inflow and the water pressure exerted on the lining.
Abstract：
Based on seepage theory, water pressure formulas for tunnel linings under the conditions of axial symmetry were deduced. Then, through numerical analysis, the applicability of an axisymmetric solution for non-circular cross section tunnels-including circular section, square section, passenger-dedicated railway tunnel section and horseshoe section tunnels-and shallow tunnels was analyzed. The research results are presented as follows: Firstly, the cross section shape of a tunnel has little influence on the water pressure exerted upon the lining and can be ignored. Secondly, the main factor determining the reduction factor of water pressure on linings is the relative permeability of the lining to the rock mass. Thirdly, for shallow tunnels with low water heads, the non-lining water inflow calculated using the axisymmetric solution has a large margin of error compared to the real value of water inflow, with a maximum error of 36.5%. It is, however, consistent with numerical solutions, and the maximum error is only 6.3% for the calculations of the lining water inflow and the water pressure exerted on the lining.
ZHENG Bo,
WANG Jian-Yu,
WU Jian
.A Study of the Applicability of an Axisymmetric Solution for Calculating the Water Pressure on a Tunnel Lining[J] MODERN TUNNELLING TECHNOLOGY, 2012,V49(1): 60-65
2012, Vol. 49 