National Kaohsiung University of Applied Sciences (KUAS), Taiwan
Y. Y. Tsai
CECI Engineering Consultants, Taiwan
C. C. Tsai
In this paper, design and construction of cross passage of urban metro are discussed using a case history from a contract at south end of Qutab Minar Line of the Delhi metro project. In order to start to build permanent structural works in TBM driven shafts as early as possible, construction activities of cross passages should be isolated from TBM shafts. Vertical shafts for cross passages were thus installed between the two main running tunnels from ground surface level to increase workable areas as well as to transport excavated spoil. Details of design and construction of the cross passage will be reported in this paper. Analyses using 3- dimensional FEM program MIDAS GTS were undertaken in order to evaluate ground deformations induced by the construction of the cross passage. It is concluded that the ground deformation induced is very small (up to 5mm) and this might be connected with high soil stiffness as well as arch influence generated by a circular excavation. Finally, engineering properties of soils were explored and it was found that the silt and silty clay on site are over-consolidated so parameters used for design might not fit the real situation."