Log (p) Void Ratio (e) W.T. G.S. sand = 96 pcf clay = 110 pcf w c = 0.3 3 ft 4 ft 16 ft P o Sand Clay P o l sample was obtained from the clay layer duct consolidation test [9 load increments ] t e vs. log (p) (Figure 2) ermine Compression Index (C c ) & Swelling Index (C s ) Example: Figure 2 Figure 1 Soil Sample C c C s p p 7 p p 1 p 9 In the lab and after removing e soil sample from the ground, stresses on the soil sample = 0 In the lab the stresses are added to the soil sample p 1 p 9 ine P o = 3.(96) + 4.(96-62.4) + 8.(110-62.4) = 803.2 lb/ft 2 Stress Increments e o = 0.795 p 2 In the ground, the sample was subjected to geostatic stresses. In the lab and before the consolidation test the stresses on the sample = 0. During testing, the geostatic stress is gradually recovered C c = 0.72 C s = 0.1 Dr. Kamal Tawfiq - 201
Transcript
Log (p)
Void
Rati
o (e
)
W.T.
G.S.
sand = 96 pcf
clay = 110 pcf
wc = 0.3
3 ft
4 ft
16 ftPo
Sand
Clay
Po
1. Soil sample was obtained from the clay layer2. Conduct consolidation test [9 load increments ]3. Plot e vs. log (p) (Figure 2)4. Determine Compression Index (Cc ) & Swelling Index (Cs)
Example:
Figure 2
Figure 1
Soil Sample
Cc
Cs
pp7
pp1
p9
In the lab and after removing the soil sample from the ground,
the stresses on the soil sample = 0
In the lab the stresses areadded to the soil sample
