S440 – South 200th Link Extension, Sound Transit
The S440 South Link Project is for construction of a 1.6 mile extension of light rail infrastructure from the existing SeaTac airport station to a new light rail station at South 200th Street. CivilTech is a subconsultant to both the Designer and the Contractor on this Design Build Project. CivilTech’s work for the design team includes the complete design of the guideway superstructure from Bents B32 to D3, including the design of ten simple-span guideways, one 5-continuous span guideway, an dassociated structural elements such as corbels, dapped guideway seats, OCS connections, bearing pads and girder stops. CivilTech’s work for the contractor includes design excavation support structures at Bents A07, A09, A18 and A19 to facilitate the construction of guideway foundations, as well as the development of a settlement monitoring plan for the entire alignment from Bents A01 through D03, defining the zone of influence during certain elements of work and defining locations for monitoring points on adjacent structures and utilities. Additionally, CivilTech has also been retained to provide on-going review of settlement monitoring data and other engineering support during the construction phase.