Geotechnical Engineering Flashcards
Think of inverses for soil sizes
ie 40% larger than .45 mm so…
60% is smaller than .45 mm
D_60=.45 mm
Remaining unsettled in a hydrometer test is comprised of
Clay
To find unit weight given S, ω, G_s
Use saturated unit weight BUT use ( Se) in numerator
Shear stress on failure surface given
σ_1, σ_3, θ
τ = [(σ_1 + σ_3)/2] x sin(180 - 2θ)
σ_1 when given;
σ_3, φ, c
σ_1 = σ_3tan^2(45+φ/2) +2c*tan(45+φ/2)
φ given
Κ_Ρ - Rankine value
2arctan(sqrt(K_P))
q_gross = ΣW/A
vertical effective stress q
= γD_f
q_net =
q_u - q
FS with respect to q
= q_net / q_all
Strip footing used for
Supporting a row of columns or a wall
Criteria for loose footing
Length/width = 10
What foundation supports larger loads
End bearing cum friction piles
Type of settlement that causes problems for doors and windows
Differential
All types of settlement cause problems for the main entrance if the settler is large
True
H_A
H_total - (# of equipotential lines on one side)*(H/(all equipotential lines +1))
Weight per unit
W = A*γ
Multiply by radians if specific section
M_mob
W_Mxcos(β)
X is the x_c Eq from concurrent forces
Aspect of Portland cement that contributes to soil stabilization
Cement hydration
What aspect of asphalt in soil contributes to soil stabilization
Bonding effect of asphalt
Effective unit weight of a fully submerged soil sample will be
Less than saturated soil sample
Density of water in g/cm^3
1.0
Round down for effective stress
81.2 -> 80
Red block denotes A
NOT THE ARROW
REMEMBER
degree of saturation multiplies top e in saturated unit weight
If S not given, sub in Eq
Hydraulic gradient
(γ_sat - y_w)/y_w
Slope failure W_m
y_sat - y_w * area
