Lateral Earth Pressure Flashcards
Vertical or near-vertical slopes of soil are supported by ____________, ________, ______, ______, and other similar structures
retaining walls, cantilever
sheetpile walls, sheet-pile bulkheads, braced cuts
The proper design of those structures requires an estimation of lateral earth
pressure, which is a function of several factors, such as ____________–, ______________-, ________, _________
(a) the type and amount
of wall movement, (b) the shear strength parameters of the soil, (c) the unit
weight of the soil, and (d) the drainage conditions in the backfill
____________ such as retaining walls, basement walls, and bulkheads
commonly are encountered in foundation engineering as they support slopes
of earth masses
Retaining structures
Proper design and construction of these structures require
a thorough knowledge of the _________ that act between the retaining
structures and the soil masses being retained
lateral forces
The resulting horizontal stress from the soil on the
wall is called__________
Lateral Earth Pressure.
basic soil parameters
unit weight γ ,
angle of friction φ , and cohesion c
The lateral earth
pressure on the wall at any depth is called the __________-
at-rest earth pressure
With
sufficient wall tilt, a triangular soil wedge behind the wall will fail. The lateral
pressure for this condition is referred to as ____________
active earth pressure
The wall may be pushed into the soil that is retained (Figure 12.1c). With
sufficient wall movement, a soil wedge will fail. The lateral pressure for this
condition is referred to as ____________
passive earth pressure
Level Ground
At-Rest Condition
No soil movement
System is in equilibrium
Retaining Walls
Active Condition
Soil in extension
The wall moves away from
the soil
Anchors
Passive Condition
Soil is in compression
The wall moves toward
the soil
The rotation, and the lateral strains, required to produce slip planes in
front of the wall (Passive) is much larger than that required for the back
of the wall (Active). T or F
T
often necessary to
prevent lateral soil movements
Lateral Support
Lateral Support
Cantilever retaining wall
Braced excavation
Anchored sheet pile
_________ have been used in Queensland.
Good drainage & allow plant growth
Crib walls
Horizontal Earth Pressure Coefficient
K
It takes less strain to develop Active condition than to develop a
Passive condition. T or F
T
- Passive pressure much larger than active pressure
- Kp requires more movement to develop than Ka
- Ka and Kp represent failure conditions ( in extension and
compression, respectively)
FACT
The vertical stress will not change, but the lateral effective stress on
Active state will be ________, while that for Passive state will be
_____________.
reduced, increased
Ko increases when soil is ______________ because the horizontal
stresses tend to get locked in more than vertical stresses do
overconsolidated
Active and passive forces frequently coexist in geotechnical
engineering designs. We traditionally rely on __________ to
counteract the active driving forces
passive forces
The _______ in the soil resists
the increase in lateral earth
pressure therefore it must be
accounted
cohesion
The depth Zc is usually referred to
as the____________,
because the tensile stress in the soil
will eventually cause a crack along
the soil–wall interface
depth of tensile crack
