9/23/ S. Kenny, Ph.D., P.Eng. Lecture Goals. Reading List. Students will be able to: Lecture 09 Soil Retaining Structures

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ca Lecture Goals Students will be able to: identify civil engineering structures subject to lateral soil pressures, determine at-rest, active, and

1 Lecture 09 Soil Retaining Structures Shawn Kenny, Ph.D., P.Eng. Assistant Professor Faculty of Engineering and Applied Science Memorial University of Newfoundland Lecture Goals Students will be able to: identify civil engineering structures subject to lateral soil pressures, determine at-rest, active, and passive lateral soil pressure, and calculate effects of groundwater. 2 Reading List Das (2006). Principles of Geotechnical Engineering. 6 th Edition Section Title 12.1 At-rest, Active and Passive Pressures 12.2 Earth Pressure At-rest 12.3 Earth Pressure At-Rest for Partially Submerged Soil 3 1

Reinforcement Nails, dowels Reinforced Geotextile, metallic, glassfiber, polymer, anchors, geocells Hybrid Gabion/reinforcement

2 Soil Retaining Structures Classification Externally Stabilized In-situ Wall Timber, sheet pile, cast, bored non-contiguous pile Braced Struts, rakes Tied Augered, driven, injected Gravity Concrete, masonry, gabion, crib, cellular Internally Stabilized In-situ Reinforcement Nails, dowels Reinforced Geotextile, metallic, glassfiber, polymer, anchors, geocells Hybrid Gabion/reinforcement Special Low density fill Rowe (2001) 4 Soil Retaining Structures Examples Rowe (2001) 5 Soil Retaining Structures Examples Rowe (2001) 6 2

3 Soil Retaining Structures Examples Handy and Spangler (2007) 7 Other Potential Failure Mechanisms Handy and Spangler (2007) 8 Civil Engineering Applications McCarthy (2007) 9 3

Concept slide What is the common engineering function or load condition these structures must consider? What are the key parameters defining the magnitude of soil loads?

4 Concept slide What is the common engineering function or load condition these structures must consider? What are the key parameters defining the magnitude of soil loads? 10 At-Rest Pressure Engineering Considerations Isotropic, homogeneous soil mass Infinite boundary Level surface Normally consolidated 11 At-Rest Pressure Submergence Key Effects Effective stress Reduced soil pressure Increased hydrostatic pressure 12 4

5 Ex.9-01 Soil Pressure For the soil profile shown, draw the vertical and horizontal pressure distribution. Is there any significant characteristic? What is the K value for water? 13 At-Rest, Normally consolidated soil Overconsolidated soil Dense sand = ( 1 sin φ )OCR sin φ ( ) γ d 1 γ d min What does at rest imply? 14 McCarthy (2007) 15 5

6 At-Rest, Normally consolidated soil Overconsolidated soil Dense sand What does at rest imply? = ( 1 sin φ )OCR sin φ ( ) γ d 1 γ d min Das (2006); McCarthy (2007) 16 At-Rest McCarthy (2007) 17 Active Pressure Structure moves away from soil Lateral soil expansion Lateral pressure distribution for cohesive and cohesionless soil are different 18 6

7 Passive Pressure Structure moves away from soil Lateral soil compression Lateral pressure distribution for cohesive and cohesionless soil are different 19 Lateral Soil Pressures 20 References Das, B.M. (2006). Principles of Geotechnical Engineering, 6 th Edition. ISBN Handy, R.L. and Spangler, M.G. (2007). Geotechnical Engineering: Soil Foundation Principles and Practice, 5 th Edition, ISBN McCarthy, D.F. (2007). Essentials of Soil Mechanics and Foundations, 7 th Edition. ISBN Rowe, R.K. (2001). Geotechnical and Geoenvironmental Engineering Handbook. ISBN

GEOTECHNICAL ENGINEERING ECG 503 LECTURE NOTE ANALYSIS AND DESIGN OF RETAINING STRUCTURES

GEOTECHNICAL ENGINEERING ECG 503 LECTURE NOTE 07 3.0 ANALYSIS AND DESIGN OF RETAINING STRUCTURES LEARNING OUTCOMES Learning outcomes: At the end of this lecture/week the students would be able to: Understand