A University of Arkansas geotechnical engineer is collaborating with the Arkansas Department of Transportation (ARDOT) to map subsurface conditions before road construction begins to identify issues early and help keep highway construction projects on track and on budget.
Clint Wood, a civil engineering associate professor and geotechnical engineer, creates profiles of subsurface conditions and soil composition by sending stress waves into the ground and measuring their response at the surface.
The technology provides important information for highway designers and construction contractors, who have had to rely on imperfect methods for determining subsurface conditions, such as exploratory drilling, a strategy that can miss changes between limited drilling locations, according to the University of Arkansas. Wood compares designing based on limited exploratory drilling to navigating with an incomplete map.
The research is conducted for and in conjunction with ARDOT. With an additional $115,318 grant, the transportation department has provided a total of $561,427 in funding. The work focuses on estimating the depth and stiffness of bedrock for new highway alignments and understanding subsurface conditions that cause slope instability. Unexpected changes in bedrock depth near slopes can also create pockets where water collects, which can cause the soil in the slope to become saturated, leading to instability, the University says.
Projects that encounter these issues can face substantial extra costs and delays while designers and contractors adapt the original plan or have to attempt another repair. Those problems can be avoided, or at least minimized, by better understanding the subsurface conditions through non-invasive testing, the University says.
SOURCE: University of Arkansas