Shallow SEM Tunneling with Limited Clearance to Existing Structures: Design, Construction and Observations

Synopsis: The excavation and initial lining has just been successfully completed for the Downtown Bellevue Tunnel using Sequential Excavation Methods … Read more »

SCMAGLEV – Fast and Innovative Mode of Transportation in the Northeast Corridor – Tunneling Challenges

Synopsis: The Northeast Corridor Superconducting Maglev Project (SCMAGLEV) entails con­struction of a high-speed train system between Washington, D.C. and New … Read more »

Risk Reduction, Management, and Mitigation from Experience‑Based Learning During Construction of Cross Passages, Seattle, Washington

Synopsis: Cross passages are critical elements in transit and highway tunnels, providing a means of safe emergency egress between adjacent … Read more »

Considerations for Very Shallow Conventional (SEM) Tunneling in Urban Settings

Synopsis: Construction of shallow mined tunnels is frequently undertaken by use of conventional tunneling known as the Sequential Excavation Method … Read more »

Bergen Tunnels Rehabilitation – A Success After All

Synopsis: 2001, the New Jersey Transit Authority commissioned the JV Merco-Obayashi with the rehabilitation contract of the approximately 130-year-old, 4,200 … Read more »

Monitoring Successful NATM in Singapore

Synopsis: The Fort Canning Tunnel, Singapore, is an approximately 50 feet (15m) wide vehicular tunnel under shallow ground cover that … Read more »

NATM Through Clean Sands – The Michigan Street Experience

Synopsis: A 100 ft long, 20 ft high and 18 ft wide NATM tunnel was excavated through grouted clean sands … Read more »

The Dulles Corridor Metrorail Project – Extension to Dulles International Airport and Its Tunneling Aspects

Synopsis: The Virginia Department of Rail and Public Transportation and the Metropolitan Washington Airports Authority are undertaking the extension of … Read more »