1. Soil Strength (CH13)

2. Strength Greatest stress a material can sustain Concrete strength?

3. Soil Strength Soil fails in shear SHEAR Earth slopes Foundations Retaining Walls Tunnels Pavements

4. Shear Strength Failure definition Loose (or NC) vs. Dense (or OC)…  –  curves depend on the soil and the testing conditions. We must simulate field loading in the lab.

5. Shear Strength Mohr – Coulomb Failure Criterion Concrete strength?

6. Hydrostatic Pore Pressure, u h z Ground surface Soil,  “hydrostatic pore water pressure at A” hphp

7. Excess Pore Pressure, u e Pore pressure generated in excess of hydrostatic due to an applied load. u e is temporary

8. Loading Conditions shear LOOSE DENSE Soil densifies due to the change in structure (e ) (water squeezes out of the voids)

9. shear LR: Loading rate? DR: Drainage rate? = fn (k) Water drains out, volume change, e Water carries load, no volume change, e = ct. DRAINED UNDRAINED Loading Conditions