Soil type and liquefaction
The materials required for this science fair project:
- 1 pail of sand
- 1 pail of clay
- 1 pail of loam
- Tap water
- 1 measuring jug (able to measure 100ml)
- 3 bricks
- 1 black marker
- 1 ruler
- 1 stopwatch
1. For this science fair project, the independent variable is the type of soil used – sand, clay and loam. The dependent variable is the amount of water required for the brick to sink. This is determined by counting the number of times 100ml of water is poured into the pail containing the brick and soil. The constants (control variables) are the amount of soil in the pail, the weight of the brick and the sinking height of the brick.
2. Fill each pail to 90% of its height with a different type of sand. Stack the 3 bricks on top of the sand in one of the pails.
3. Draw a line 30mm from the bottom of the bricks using the marker and the ruler. This line will mark the sinking of the brick in the soil during liquefaction.
4. Pour 100ml of tap water into the sand using the measuring jug. Allow the sand to absorb the water for 2 minutes. Then, add another 100ml of water to the soil. Repeat this procedure until the bricks sink 30mm or collapse in the sand. Record the number of times water was added to the soil. Calculate the amount of water used and record it in the table given below.
5. Repeat steps 2 to 4 for the remaining pails.