Question

Describe, briefly, the frost-heave phenomenon. How could you reduce the negative impacts of this phenomenon

Answer 1

It occurs in the places where the tempterature goes below the freezing temperature of the water and then rises back above the melting temperatures in cycles. Whenever a porous soil having its pores filled with water is present at such places, the water will feeeze out in winter, and thereby will increase the size of the pores. The increase jn size is due to the fact that ice of the same water has higher volume than the water. Whe the temperature goes up again, the ice melts but leaves behind the bigger pores and cracks.

Next time more water comes in filling up the bigger pores. When temperature goes down again, a new cycle starts and pores and cracks gets bigger. Generally this process take place underground, and this change in volume appears on the surface pf the ground we call upheaval of the surface.

Remedy:

1. Treat the soil with lime, cement or other soils to make jt well graded and compact, thus reducing its porosity, so that no water can enter the soil.

2. Prevent water from entering the soil by creating water drains around the area, creating sheet walls around the area etc. In pavements the top surface is paved with bitumen asphalt, and a camber is provided for the drainage.