Projects

NTL Engineering & Geoscience, A Terracon Company, performed the geotechnical investigation for the Kalispell Bypass. Our involvement began in 1995 with a preliminary soil survey and culminated in 2010 with construction of the southern half of the alignment. Along with providing pavement section design recommendations for the Bypass Mainline and 20 associated named roadways, geotechnical guidance was provided for noise walls, pedestrian tunnel, and 10 bridge structures for creek crossings and separated-grade intersections. Challenging subgrade conditions were present along much of the alignment and included very soft, compressible lakebed clays and areas of deep woodchip fill in the area of a former log pond. Recommendations were developed for deep ground improvement including stone columns and prefabricated vertical (PV) drains to accelerate settlement below bridge approaches and improve ground strength during the design seismic event.