The existing hospital was built with spread footings supporting it, but piles support the annex. Plans for the new stairwell show it extending all four levels of the building and therefore there were tight tolerances for differential settlement. McMahon & Mann recommended drilled shafts bearing in the underlying shale to support the new stairwell. We provided estimated capacities, bearing elevations and settlement estimates. We also estimated the seismic site class for design.
The Bath VA Medical Center engaged Iyer Environmental Group, PLLC, LLP and Watts Architecture & Engineering, P.C. to redesign a section of its Building 76 located in Bath, New York. Part of the redesign includes a new stairwell abutting the Building 76 Annex.
Subsurface information shows that the site is underlain by a complex stratigraphy of clay, silt, sand and glacial till covering shale. The existing hospital was built with spread footings supporting it, but piles support the annex. Plans for the new stairwell show it extending all four levels of the building and therefore there were tight tolerances for differential settlement.
The test boring results showed that spread footings could support the new stairwell, but estimated settlements would exceed allowable amounts. Piles were considered but rejected for excessive noise considerations. Therefore, McMahon & Mann recommended drilled shafts bearing in the underlying shale to support the new stairwell. We provided estimated capacities, bearing elevations and settlement estimates. We also estimated the seismic site class for design.
