Question

The unit weight of a soil is 14.9kN/m3. The moisture content of the soil is17% when the degree of saturation is 60%. Determine:

a. Saturated unit weight
b. Void ratio
c. Specific gravity of soil solids

Answer 1

a) 2622.903 N/m^3

b) 1.38233

c)4.878811765

Step-by-step explanation:

Find the void ratio using the formula:

`y = (G_(s)*y_(w) + w*G_(s)*y_(w) )/(1+e) ....... Eq1`

Here;

`G_(s)` is specific gravity of soil solids

`y_(w)` is unit weight of water = 998 kg/m^3

`w` is the moisture content = 0.17

`e` is the void ratio

`y` is the unit weight of soil = 14.9KN/m^3

Saturation Ratio Formula:

`w*G_(s) = S*e ..... Eq2`

S is saturation rate

Substitute Eq 2 into Eq 1

`y = (((S*e)/(w)) * y_(w) + S*e*y_(w) )/(1+e)`

`14900 = (3522.352941*e + 598.8*e )/(1+e) = (4121.152941*e)/(1+e)\\\\ e= 1.38233`

Specific gravity of soil solids

`G_(s) = (S*e)/(w) = (0.6*1.38233)/(0.17) = 4.878811765`

Saturated Unit Weight

`y_(s) = ((G_(s) + e)*y_(w) )/(1+e) \\=((4.878811765 + 1.38233)*998 )/(1+1.38233)\\\\= 2622.902571 N/m^3`