Settlement of Foundations Quiz

Void Ratio and Pressure

• The first step in analyzing the change in void ratio of a soil specimen under pressure involves determining the specimen's initial state.

• The initial height of voids, Ho, is calculated by subtracting the height of solids, Hs, from the total initial height of the specimen:

  Ho = Ht - Hs
  

### Calculating Void Ratio

• After the first incremental loading, the change in void ratio (Δe) is determined by comparing the initial void ratio (eo) and the void ratio after loading (e1), using the formula:

  Δe = e1 - eo
  

• The initial void ratio (eo) represents the initial volume of voids in the specimen relative to the volume of solids.

• The height of solids (Hs) is calculated by multiplying the total initial height of the specimen (Ht) by the ratio of the specific gravity of the soil particles (Gs) to the sum of Gs and the initial void ratio (eo):

  Hs = Ht * (Gs/(Gs + eo))
  

Consolidation Test Parameters

• In a consolidation test, σ1 represents the applied vertical stress or pressure.

• ΔH1 represents the settlement or change in height of the specimen after applying the first incremental loading.

• Equation (11.6) is used to calculate the void ratio (e1) using the measured settlement (ΔH1) after applying the first incremental load, initial void ratio (eo), initial height (Ht), and area of the specimen (A).

• A, representing the area of the specimen, is used in the calculation of the height of solids (Hs).

• ρw, the density of water, is utilized to convert the change in height (ΔH1) to the change in void ratio (Δe) during the consolidation test.

Test your knowledge on the settlement of foundations, including primary consolidation, secondary consolidation, and elastic settlement. Understand how different soil types affect settlement behavior.