Considering steel sheet piles for semi-permanent or permanent subsurface water control for below-grade building spaces
Steel sheet piles have more than a century-long history of being used to support excavations for buried structures. During the construction process, the sheet piles traditionally provide earth retention and, in conjunction with a dewatering system, control of subsurface water into the construction site (both for leakage through the sheet pile system and for seepage below the sheet pile system).
In contemporary building development projects and in the context of subsurface water control, the role of the sheet pile system is typically temporary, until a dedicated waterproofing layer is applied to the building’s foundation wall.
However, for projects that do not include moisture-sensitive below-grade spaces, project teams sometimes elect to forego foundation wall waterproofing and rely instead on sheet piles alone for semi-permanent or permanent reduction of subsurface water. One example project application is a wall demarcating adjacent portions of a multi-phased below-grade garage (where subsequent phases of the below-grade structure will be constructed several years after the initial phase).
To implement this sheet pile “water management wall” approach successfully, multidisciplinary teams must closely coordinate to set appropriate expectations, assign and execute design and construction roles, and incorporate technical considerations that are not otherwise a focus of traditional sheet pile support of excavation (SOE) design. In this article, we explore aspects of sheet pile subsurface water control systems for buildings organized by the project’s primary stakeholders and considerations within their purview.
Building Design + Construction