Geotechnical Planning Advances for TBM Projects in Glacial Geology

摘要

Over the past three decades, a dozen TBM-driven tunnels have been constructed in the Seattlernmetropolitan area with its unique geological setting of interlayered glacial, glaciomarine, and non-glacialrndeposits. Several new tunnels—among them the Alaskan Way Viaduct Replacement Tunnel utilizing the world’srnlargest-diameter TBM manufactured to date—are under design or construction. Experience gained from eachrnof these projects resulted in new and innovative approaches in planning, design, contractual description ofrnsubsoil conditions, and formulation of contractual requirements for future tunnel drives. This paper analyzesrnthe different approaches and outlines trends in dealing with the specific challenges of tunneling in complexrnglacial geology.