Effects of Rise of Water Table on Pore Water Pressure and Total Stress

Rise of water table above the ground surface can have significant effects on soil properties. The following points explain the effects of rise of water table on pore water pressure and total stress:

- Increase in Pore Water Pressure: As the water table rises, the soil pores become filled with water, which exerts hydrostatic pressure on the soil particles. This increase in pore water pressure can affect the stability and strength of the soil mass.
- Increase in Total Stress: The weight of the water above the water table adds to the total stress acting on the soil mass. Therefore, the total stress increases with the rise of water table.
- Equal Increase in Pore Water Pressure and Total Stress: The increase in pore water pressure and total stress due to rise of water table occurs simultaneously and in equal amounts. This is because the water in the soil pores and above the water table exerts equal pressure on the soil particles.

Significance of Equal Increase in Pore Water Pressure and Total Stress

The equal increase in pore water pressure and total stress due to rise of water table has important implications for soil behavior and engineering practice:

- Stability and Strength: The stability and strength of the soil mass can be significantly affected by changes in pore water pressure and total stress. Therefore, it is important to consider the effects of water table on soil properties in design and construction.
- Drainage and Seepage: Drainage and seepage control measures are often required to prevent or mitigate the effects of rise of water table on soil properties. These measures may include installation of drainage systems, use of impermeable liners, or application of soil stabilization techniques.
- Soil Classification: The classification of soils based on their water content and behavior can be affected by the presence or absence of a water table. For example, a soil that is normally classified as sandy may behave like a clayey soil when the water table is high.

Conclusion

In conclusion, the rise of water table above the ground surface can have significant effects on pore water pressure and total stress in soil. The increase in pore water pressure and total stress occurs simultaneously and in equal amounts. Therefore, it is important to consider the effects of water table on soil properties in design and construction, and to implement appropriate drainage and seepage control measures.

Option A is correct. that is the reason behind constant effective stress for this particular case. hope u get it.