1.3. Recompression and Compression Curves

Try these first

1. 1.

   What does the void ratio represent in soils?

   Hint

   Think about how we differentiate solid and empty spaces in soil.

2. 2.

   What occurs when soil is unloaded?

   Hint

   Remember the CD path we discussed.

3. 3.

   What does the virgin compression curve indicate?

   • It shows the initial compression.
   • It indicates significant compression beyond a limit.
   • It represents the unloading path.

   Hint

   Where do we see heavy compression taking place on the graph?

4. 4.

   Hysteresis loops are formed during which processes?

   • True
   • False

   Hint

   Consider if these loops appear when there's a difference in stress paths.

5. 5.

   A load is applied to a soil sample which undergoes a certain amount of compression. If the load is then removed, calculate how much strain remains in the soil given a known elastic modulus and previous void ratio.

   Hint

   Break down the calculations into elastic and plastic components.

6. 6.

   You have two soil samples; one follows a distinct compression curve while the other has similar parameters but shows hysteresis. Discuss the implications of these differences on sub-grade performance when loaded.

   Hint

   Compare and contrast their compressibility behavior as structural foundations.