CONSTRUCTION METHOD OF LARGE CROSS-SECTION UNDERGROUND SPACE, AND OUTER SHELL SHIELD STARTING BASE

摘要

PROBLEM TO BE SOLVED: To construct a widened underground part using a circumferential shield tunnel as an underground starting base, the circumferential shield tunnel having a structurally stable circular cross-section and being low in a cost.SOLUTION: A construction method of a large cross-section underground space provided includes the following steps of: constructing two circumferential shield tunnels 10A, 10B having a circular cross-section, next to each other and leaving an interval, in a circumferential direction E around a main line shield tunnel 11 and a ramp shield tunnel 12; constructing a plurality of connecting galleries 102 between the adjacent circumferential shield tunnels 10A, 10B, in the circumferential direction E and leaving an interval; and excavating a plurality of outer shell shield tunnels 13 using the plurality of circumferential shield tunnels 10A, 10B and the plurality of connecting galleries 102 as an underground starting base 15.SELECTED DRAWING: Figure 2