The test sample of cohesionless soil with a little cohesion is given in tabular form below.
(1) Soil density ρd = 1.62g/cm³
Data sheet for sample 1: (for sample 2, 3, and 4 similar data sheets are to be prepared)
Initial area = Ao = 6×6 = 36 cm².
Initial thickness = 2.4 cm.
seating pressure = 0.5 kg/cm²
| Horizontal dial gauge reading | Horizontal displacem ent (mm) | Corrected area(cm2) | Proving ring reading | Force (kg) | ζ (kg/ cm2) | Vertical Dial reading | Vertical Displace ment (mm) | Ht(cm) |
|---|---|---|---|---|---|---|---|---|
* Corrected area in cm2 is given by b (b-horizontal displacement)
b= width of shear box=6cm
From three samples the following results are obtained
| Test No | Normal stress σ(kg/cm2 ) | Shear stress at failure ζ(kg/cm2 ) |
|---|---|---|
| 1 | 0.5 | |
| 2 | 1.0 | |
| 3 | 1.5 |
From the results a graph of Horizontal displacement VS Shear stress is drawn Mohr’s circles are also plotted.
From Mohr’s circle the following details are obtained;
Major principal stress σ1=-----------kg/cm2
Minor principal stress σ2=----------kg/cm2
Inclination to major principal stress θ1=--------degrees
Inclination to minor principal stress θ2=--------degrees