Published: Tunneling Rules of Thumb: Sequential Excavation Method Tunnelling

January 17, 2019 Keivan Rafie

In this Tunnels and Tunneling magazine article, Keivan Rafie explains sequential excavation method tunneling: its basics, support requirements, and ground considerations


Sequential excavation method (SEM) is a type of tunnel design and construction that started to gain popularity in the 1960s and 1970s. The essential component of the SEM approach is to take advantage of the natural capacity and strength of surrounding geology to support the tunnel with minimum cost and time required.

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About the Author

Keivan Rafie

Keivan Rafie’s engineering expertise is in tunneling, mining, and ground-improvement projects. For the last 15 years, he’s worked across the globe in Asia, Australia, the Middle East, and North America. Keivan’s knowledge and experience go deep with tunneling methods, such as drill and blast, NATM, and TBM, and he is involved in all stages from design to manufacturing and construction.

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