The weight of fully saturated soil in a prism having a 4.00 sq. ft. base (or a base of 4.00 ft*ft) is 4,000 lbs. Pore pressure at the base is 499 lbs/(ft*ft). True or False: The effective stress at the base is 501 lbs/(ft*ft).
To determine the effective stress at the base, we need to subtract the pore pressure from the total weight of the soil.
The formula for effective stress is:
Effective Stress = Total Stress - Pore Pressure
Given that the weight of the saturated soil is 4,000 lbs and the pore pressure is 499 lbs/(ft*ft), we can plug these values into the formula:
Effective Stress at the base = 4,000 lbs - 499 lbs/(ft*ft)
Using this calculation, we can find the effective stress at the base, which is:
Effective Stress at the base = 3,501 lbs/(ft*ft)
Since the effective stress at the base is 3,501 lbs/(ft*ft) and not 501 lbs/(ft*ft), the statement is False.