Abstract:

Regarding the construction of the mined tunnel sections in Xi'an Metro, comparison and contrast are made on the option of "shield boring before the mined tunnel section is constructed" and the option of "the mined tunnel is constructed before shield advancing" (including shield advancing by transfer car, shield advancing by arcshaped cradle with steel plate and shield advancing by arcshaped cradle with steel rail). Finally, the option of shield advancing by arcshaped cradle with steel rail is adopted. The technology and control points of shield arrival control, nonexcavation shield advancing and secondary launching are presented. This paper can be served as reference for similar projects in the future.

Key words: shield, mined tunnel, arc shaped cradle with steel rail, arrival control, non excavation advancing, secondary launching