FEM analysis the boundary value of high water pressure upon lining in deep-lying one track railway tunnel

Abstract

Mountain tunnels particularly the long and deep buried tunnels, are usually under groundwater level that forms higher water head. How much of water pressure value upon lining may be considered as high water pressure? There isn't clear boundary value in the field of tunnel engineering at present. The boundary value of high water pressure was researched by calculation and analysis the safety factor of lining whether achieving the railway tunnel design code requirement or not, using plane FEM, based on standard design drawings of one track railway tunnel, needn't change the shape of standard design cross-section as principle. The results show that in single-track railway tunnel, Whe first boundary value of high water pressure upon curved wall lining is 0.20 MPa and the second boundary value is 0.40 MPa. Water pressure is the main load upon lining when the value is higher. The boundary value of high water pressure is rarely related to the surrounding rock classification. The capacity supporting water pressure of standard design section in Single-track railway tunnel is limited. Other optimized sections should be used when static head upon lining is higher than 40 meters. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.