WMATA Silver Spring Transit Center, Silver Spring, MD
The Silver Spring Transit Center (SSTC) is a newly constructed multi-modal transportation facility located in Silver Spring, MD. The structure was designed as a cast-in-place concrete structure with bonded post-tensioning used in the beam and slab construction. The structure consists of two elevated levels and a slab-on-ground. The upper elevation was designed for vehicular (taxi and passenger drop-off), with the lower levels and the slab-on-ground designed for bus transit. The SSTC was intended to have a minimum design service life of 50 years.
The evaluation was motivated by the observation of concrete cracking and questions regarding the thickness of the concrete slabs in the elevated portions of the structure. The goal of the evaluation by WDP was to assess both the structural design and expected long-term durability of the structure prior to the acceptance of the structure into the Washington Metropolitan Area Transit Authority (WMATA) inventory.
The evaluation by WDP included a series of nondestructive tests to evaluate the as-built condition of the structure, a review of documents related to the design and construction, and structural analyses to examine the as-designed and as-built adequacy of the structure based on applicable codes and design load requirements. WDP also reviewed the repairs recommended by other parties.