J. David Rogers, Ph.D., P.E., P.G.J. David Rogers, Ph.D., P.E., P.G.Karl F. Hasselmann Chair in Geological Engineering Karl F. Hasselmann Chair in Geological Engineering

Missouri University of Science & TechnologyMissouri University of Science & Technologyfor the course for the course

GE 441 Geotechnical Construction PracticeGE 441 Geotechnical Construction Practice

Lecture 5SUBSURFACE

DRAINAGE

Part 1Part 1

FUNDAMENTAL FUNDAMENTAL CONCEPTS OF CONCEPTS OF

SHALLOW SHALLOW SUBSURFACE SUBSURFACE

FLOWFLOW

Groundwater TerminologyGroundwater Terminology

Theoretical movement of groundwater through Theoretical movement of groundwater through uniformly permeable materialuniformly permeable material

Gainingand

losing streams

Hydraulic gradient linear approximationHydraulic gradient linear approximation

Darcys Law is useful for providing Darcys Law is useful for providing approximations of groundwater flowapproximations of groundwater flow

Where Where hh11 h h22 LLis the is the hydraulic gradienthydraulic gradient

InterflowInterflow SpringsSprings

Springs occur where the ground water Springs occur where the ground water table intersects the Earths surfacetable intersects the Earths surface

Natural outflow of groundwaterNatural outflow of groundwater Can be caused by an aquitard, creating Can be caused by an aquitard, creating

a localized zone of saturation, which is a localized zone of saturation, which is called a called a perched water tableperched water table

Ephemeral springs present the greatest Ephemeral springs present the greatest engineering challenge, because they engineering challenge, because they can be very difficult to detectcan be very difficult to detect

Springs resulting from Springs resulting from a perched water tablea perched water table

Perched water tables are common to the Ozarks, much of the Perched water tables are common to the Ozarks, much of the Midwest, and the Appalachian Mountains/Piedmont areasMidwest, and the Appalachian Mountains/Piedmont areas

Development

of karsttopography

The slope of the groundwater table in karst is typically about degree!

Slide 1Slide 2Groundwater TerminologySlide 4Slide 5Hydraulic gradient linear approximationDarcys Law is useful for providing approximations of groundwater flowInterflow Springs resulting from a perched water table