Broken Arrow South Loop

Geotechnical Services (1998 – 2001)

In preparation for the Oklahoma Transportation Authority’s extension of the Creek Turnpike through Tulsa County, Oklahoma, MACTEC conducted the geotechnical exploration for a portion of the project approximately six miles long from U.S. Highway 169 to the Tulsa County-Wagoner County line. The project included one bridge widening, ramp improvements, a mile-long viaduct, 12 bridges, 17 culverts, four retaining walls, a utility relocation, and several embankments and cut sections.

Field exploration included mobilization of multiple drill rigs to complete over 150 soil test borings, some of which were located in areas difficult to access including heavy-forested areas and soft ground. Design recommendations included bridge abutments supported on piles driven into shale and bridge piers supported on drilled shafts founded in shale. Embankments for the project are as much as 60 feet in height, and cut sections as much as 30 feet in depth. Settlement and stability analyses were performed for the embankments based on consolidation and shear strength test results. The cut sections were evaluated for potential borrow for turnpike embankments. The project also included value engineering on a retaining wall planned to be constructed under an existing overpass in an area with soft foundation supporting soils and multiple existing utilities. The value engineering resulted in savings to the Oklahoma Transportation Authority of $400,000. MACTEC also performed pavement design for the project, including comparative analyses between concrete and asphalt and life cycle cost analysis. The pavement design analyses included laboratory testing for resilient modulus of soils constructed to grade and recommendations for subgrade modification inlcuded treatment with lime, fly ash, and cement kiln dust. Quality assurance testing for the Oklahoma Transportation Authority included soil, aggregate and concrete testing, compaction testing and engineering consultation for construction problems, including wet weather construction and erosion adjacent to a reinforced concrete box culvert. We also performed field cone penetrometer testing and laboratory shear strength analyses to evaluate potential soft subgrade areas in the embankments during construction.

MACTEC Services:
Geotechnical exploration, pavement design and quality assurance testing; soil/rock testing; material testing; construction QA testing; drilling and sampling; foundation design; embankment design; borrow investigation; and pavement design.