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Salgado 16.1 ‐16.3○Ch. 16 Lecture Notes○
Reading Assignment
Develop a spreadsheet for the design of an embedded gravity wall (see example in class notes.) Turn in your solution for the case given in the lecture notes
1.
Determine the factor of safety against overturning and sliding for the following case:
2.
Wall Dimensions Fill Properties
Top 4 ft β backfill deg 20 0.349 radians
Bottom 4 ft β toe deg 0 0.000 radians
γconcrete 150 pcf φ deg 40 0.698 radians
H 15 ft δ deg 20 0.349 radians
D 3 ft Qbackwall deg 0 0.000 radians
Qfrontwall deg 0 0.000 radians
γ backfill 120 pcf
Partial AnswerFactors of Safety
FSsliding 2.813
FSoturn 1.462
Determine the factor of safety against overturning and sliding for the following case:
3.
Wall Dimensions Fill Properties
Top 3 ft β backfill deg 0 0.000 radians
Bottom 3 ft β toe deg 0 0.000 radians
γconcrete 150 pcf φ deg 40 0.698 radians
H 10 ft δ deg 20 0.349 radians
D 0 ft Qbackwall deg 0 0.000 radians
Qfrontwall deg 0 0.000 radians
γ backfill 120 pcf
Homework Assignment
Ch. 16 Retaining StructuresMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 1
Failure modes(a) bearing capacity failure of base or footing(b) sliding(c) overturning(d) global instability
Introduction to Retaining StructuresMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 2
(a) bearing capacity failure
http://www.fhwa.dot.gov/publications/research/infrastructure/structures/11030/005.cfm
This failure was due to liquefaction of the foundation soils ‐ 2010 Chilean earthquake
Introduction to Retaining Structures (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 3
(b) sliding
http://www.michael‐roberts.co.uk/photo/pmisc0.jpg
Introduction to Retaining Structures (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 4
(c) overturning
http://designandbuildllc.com/design‐and‐build‐gallery/
Introduction to Retaining Structures (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 5
(d) global instability
Introduction to Retaining Structures (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 6
Remediation of MSE wall failure ‐ Woodlands Building C, Philippines
Introduction to Retaining Structures (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 7
Remediation of MSE wall failure ‐ Woodlands Building C, Philippines
Final configuration without EPS Geofoam
Introduction to Retaining Structures (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 8
K = 'h / 'v
Earth Pressure Theory ‐ Which Theory?Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 9
'
'
Earth Pressure Theory, Ko ConditionsMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 10
Earth Pressure Theory, Ko Conditions (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 11
Earth Pressure Theory, Ko Conditions (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 12
Earth Pressure Theory, Ko Conditions (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 13
Earth Pressure Theory, Ko Conditions (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 14
Earth Pressure Theory, Active StateMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 15
Earth Pressure Theory, Active State (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 16
Earth Pressure Theory, Active State (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 17
Earth Pressure Theory, Active State (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 18
For sliding
For toppling
Earth pressure diagram for the active case(for case without water in backfill).
Earth pressure diagram
Active Failure State Pressure DiagramsMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 19
For sliding
For toppling
Earth pressure diagram for the active case(for case with water)
Earth pressure diagram Hydrostatic water pressure diagram
Active Failure State Pressure Diagrams (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 20
Force diagram
EA is unknown. Maximize EA by solving
for dEA / d = 0
For more information, see Coulomb Theory
Active Failure State ‐ Sloped BackfillMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 21
Earth Pressure Theory, Passive StateMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 22
Earth Pressure Theory, Passive State (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 23
Earth Pressure Theory, Passive State (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 24
Earth Pressure Theory ‐ More Pressure DiagramsMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 25
Earth Pressure Theory ‐ More Pressure Diagrams (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 26
Earth Pressure Theory ‐ More Pressure Diagrams (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 27
Earth Pressure Theory ‐ More Pressure Diagrams (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 28
Earth Pressure Theory ‐ More Pressure Diagrams (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 29
Earth Pressure Theory, Coulomb Theory ‐ Active StateMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 30
Earth Pressure Theory, Coulomb Theory ‐ Active State (cont.)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 31
Kp equation from Das, Principles of Geotechnical Engineering4th Edition. I have corrected the error in this equation.
Earth Pressure Theory, Coulomb Theory ‐ Active and Passive StateMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 32
The notation in this table is different from that used in the free body diagrams in
the previous pages. For this table, ALPHA) is the inclination of the backwall measured from the horizontal (i.e., is 90 for a vertical backwall); BETA) is the inclination of the slope behind the wall, (phi) is the internal angle of friction of
the backfill soil, and (delta) is the interface friction between the backfill soil and the wall (i.e., concrete).
The values in this table can be used to check your functions entered in the homework spreadsheet.
Earth Pressure Theory, Coulomb Theory ‐ Active and Passive StateMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 33
Earth Pressure Theory, Rankine Approximation for Sloped BackfillMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 34
Note that the amount of lateral displacement wlat is much larger for the passive state e when compare with that of active state. This means that full active earth pressure is mobilized after only small displacements; whereas full passive earth pressure requires more displacement. Hence, especially for passive earth pressure, one must consider the amount of displacement that is expected in order to estimate the passive earth pressure.
Active and Passive Pressure ‐ Movement of WallMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 35
Active and Passive Pressure ‐ Application in Wall DesignMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 36
Retaining Wall Design (Free Body Diagrams ‐ Gravity Wall)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 37
Retaining Wall Design (Gravity Wall ‐ Spreadsheet)Tuesday, December 5, 2017 10:49 AM
Ch. 16 - Retaining Structures Page 38
For more information on the design of cantilevered wall systems, see handout on course website
Retaining Wall Design ( FBD ‐ Cantilevered Wall)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 39
Retaining Wall Design ( FBD ‐ Cantilevered Wall with Tieback)Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 40
Retaining Wall Design (Mechanically Stabilized Earth Walls ( MSE))Monday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 41
Soil NailingMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 42
Remediation of a MSE wall using soil nailing
Soil nailing ‐ Provo CanyonTo stabilize a potential landslide, which could be triggered by a cut for the new roadway alignment, Schnabel Foundation Company installed 208 encapsulated 14‐strand anchors in the sidehill cut. The anchors have a design load of 400 kips and an average installed length of 160 feet in order to make capacity behind the failure plain
From <http://www.schnabel.com/projects/view/75>
Soil NailingMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 43
BlankMonday, November 9, 2015 11:43 AM
Ch. 16 - Retaining Structures Page 44
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