Dorsey Drive Interchange on State Route 49 – Grass Valley, CA

H&K provided geotechnical engineering, construction materials testing and inspection, and stormwater pollution prevention (SWPPP) services for this award-winning project. The project included construction of northbound and southbound on- and off-ramps from SR 49; re-alignment of an existing frontage road; construction of concrete masonry sound walls; cast-in-place concrete retaining walls; a cast-in-place pre-stressed box girder bridge supported by cast-in-place concrete piles; lane additions to the existing Dorsey Drive overpass; and extensive cuts and fills up to 65 feet in height. Approximately two miles of Highway 20/49 were repaved, in addition to nearly a mile of locally affected roadways.

The project required testing of 47,000 cubic yards of fill, 800 cubic yards of structural concrete, and 21,000 tons of hot mix asphalt. H&K developed a procedural specification for fill placement utilizing the onsite excavated weathered rock, thus eliminating the need to off haul the material and reducing the chance for project delay. H&K also designed a “rock socket” that received Caltrans approval and was used for the first time in the region, resulting in significant cost savings for installation of the overhead sign.

H&K was responsible for observing and confirming compaction of the mass fills containing high volumes of rock, which was being generated during on-site grading operations. Following grading, H&K provided quality assurance sampling and materials testing services, including density testing during construction of structural road sections; sampling and testing of aggregate baserock to confirm compliance with project specifications; and plant inspection, field sampling, and laboratory testing of concrete during construction of cast-in-drilled-hole (CIDH) piers, bridge girders, bridge deck, and bridge abutments.

This project earned the 2014 Construction Project of the Year Award from the Sacramento Chapter of the American Society of Civil Engineers (ASCE) and the 2014 Transportation (Interchange) Project of the Year Award from the Sacramento Chapter of the American Public Works Association (APWA).