A large pipeline company planned to use horizontal directional drilling (HDD) to install three pipelines beneath the Mississippi River and its levees near Empire, Louisiana. The US Army Corps of Engineers (USACE) has become more restrictive in its regulation of construction around Louisiana’s levee system in recent years, especially with images of Hurricanes Katrina and Rita fresh in the nation’s memory.
GeoEngineers worked with the pipeline company to create HDD engineering designs to specifically evaluate hydraulic fracture and inadvertent returns and their effects on the levees. GeoEngineers also provided HDD construction consulting services for the project. Hydraulic fracture occurs when the pressure required to keep drilling fluid flowing through the hole underground causes the surrounding soil to expand and eventually fracture, allowing drilling fluid to escape the HDD hole. When these drilling fluid leaks reach the ground surface, they are known as inadvertent returns.
GeoEngineers’ engineering recommendations and construction mitigation techniques demonstrated that even the most difficult HDD installations beneath levees are possible—without reducing the levees’ ability to protect coastal environments, economies and the general public.
ACEC-Missouri 2011 Engineering Excellence Awards, Grand Award, Energy Category