Construction of urban expressway tunnel with special large cross section by NATM -Metropolitan Inter-City Highway (Ken-O-Do) Ome Tunnel-

摘要

Ome tunnel is a two-story highway tunnel with large cross section excavated at a shallow depth in unconsolidated ground right under urban residential area. The tunnel is excavated by so-called NATM and long span forepiling with injection is adopted to ensure face stability. Monitoring and evaluating ground behavior during construction, jetting piles (footpiles) and temporary support piles are employed to restrain excessive surface subsidence.