G2 Consulting provided geotechnical investigations, vibration monitoring, geotechnical instrumentation services, and pile dynamic analysis for the project which will reconstruct and widen a segment of I-75. In fact, the last segment between Flint and Saginaw to be expanded to four lanes in each direction. The project also replaces the aging M-46 interchange and renovates bridge structures in the area.
“Every project has its own unique characteristics,” said Christopher Nicol, P.E., G2’s Project Manager. “One interesting aspect of this project was the need to fill in a ‘dip’ in I-75 that previously allowed the highway to pass underneath a railroad bridge, a bridge that has long since been removed.”
“Highway dips and other low-points are natural gathering spots for storm water therefore require pump stations to keep the roads open to safe travel,” Nicol said. “Since the railroad overpass is no longer there, bringing I-75 back to grade was an important improvement to avoid impediments to travel and the costs associated with pumping.”
Under MDOT’s guidance, G2’s activities were managed by Grand Rapids-based Fishbeck and Commerce-based C.A. Hull in the design-build effort.
“The Michigan road industry has learned a lot of valuable lessons over the recent ‘lean’ years where underfunding was the norm. There has been constant innovation in road evaluation, construction processes and material technologies. Now that infrastructure needs are top of mind and meaningful funding is on the way, Michigan has both the public and private engineering and construction capabilities to get the jobs done efficiently and effectively,” Nicol said.
G2’s geotechnical work focused on analyzing and evaluating below-the-road factors — soil and pavement conditions, drainage, and the level of deterioration a road has experienced over a time period — to determine the best approach to reconstruction within the specific environment. This information is key to prudent decision making and often impacts final design. Considerations include the amount of traffic using the road and predictive models for future deterioration. With the huge amount of work that needs to be done across Michigan communities, construction partners need to work intelligently to get the most out of every dollar spent.
Although G2’s portion of the project is nearly complete, the overall project is expected to last into July 2022. The team has largely held to its schedule, despite the summer’s heavy rains which, at times, hampered progress. G2 lives by its mantra of “Smart. Results. Fast.”