Shaft Construction Methods

Abstract

The San Francisco Bay Area has historically been a center for tunneling and shaft construction. Shafts are often vital access for construction, operation, and maintenance of tunnels and underground structures. No one-size-fits-all approach exists for shaft design and construction and because of this, the method used for the construction of a shaft must be carefully selected in order for specific project requirements to be met. This paper will examine several common considerations for shaft design and construction including: controlling geologic conditions, constructability concerns, as well as non-technical issues. Common shaft construction methods and the use of a series of Bay Area case studies demonstrate how the design considerations relate to the use of several construction techniques. After discussing strategic design methods, we will examine several case studies of shafts constructed since 2007 and how each of these shafts addresses the various design concerns/considerations.