SCDOT I-26 / Volvo Interchange

Bringing thousands of auto industry jobs to Ridgeville, South Carolina, Volvo Cars broke ground on its first American factory in 2015. Its opening was the catalyst for the construction of a new $44 million three-leg directional interchange along Interstate 26. Formed of both at-grade and flyover ramps, it provides access from I-26 to Volvo Boulevard and the 2.3 million sf plant that manufactures mid-sized sedans.

The interchange’s flared superstructures are composed of pre-stressed concrete girders supported by multi-column pier bents on a pile-supported foundation and integral end bents. Mechanically stabilized earth walls reinforce the embankments. Schnabel’s preliminary geotechnical input during the project pursuit laid the groundwork for continuation of services on Johnson, Mirmiran & Thompson’s project team. During design, we were responsible for reviewing data contained in the South Carolina Department of Transportation’s “Geotechnical Base Line Report” and conducting supplementary subsurface exploration, soil laboratory testing, and engineering analyses.

We documented our findings in separate preliminary and final geotechnical engineering reports for each bridge structure and associated roadways. The preliminary bridge reports described subsurface data at each structure and addressed foundation elements, types, and sizes; anticipated construction challenges; corrosion potential; and requirement for vibration monitoring assessment. The final bridge reports provided the geotechnical basis for design. The preliminary and final roadway reports addressed embankment design, slope stability and settlement analyses, ground improvement, and drainage.

Construction phase quality control services required pile hammer evaluation by wave equation analyses; dynamic pile load testing with a pile driving analyzer; and signal matching analysis with a case pile wave analysis program. We also provided construction oversight during the wick drain installation, settlement plate data evaluation, and earthwork including subgrade evaluation for the ramps.

^{Photo: © SCDOT}