Lesson 08 - Shallow Foundations

Effect of Variation of Soil Properties
and Footing Dimensions (Table 8-2) 8
Properties and Dimensions
γ = γ a
= effective unit weight
γ b
= submerged unit weight
D f
= embedment depth
B f
= footing width (assume strip footing)
A. Initial situation: γ = 120 pcf, D f
= 0',
B f
= 5', deep water table
B. Effect of embedment: D f
= 5', γ=120
pcf, B f
= 5', deep water table
C. Effect of width: B f
= 10' γ = 120 pcf,
D f
= 0', deep water table
D. Effect of water table at surface:
γ = 57.6 pcf, D f
= 0', B f
= 5'
Cohesive
Soil
φ = 0
c = 1000 psf
q ult
(psf)
Cohesionless
Soil
φ = 30 o
c = 0
q ult
(psf)
5140 6720