Consider the statements P and Q related to the analysis/design of retaining walls.
P: When a rough retaining wall moves toward the backfill, the wall friction force/resistance mobilizes in upward direction along the wall.
Q: Most of the earth pressure theories calculate the earth pressure due to surcharge by neglecting the actual distribution of stresses due to surcharge.
Which one of the following options is CORRECT?
Consider the statements P, Q, and R.
P: Compacted fine-grained soils with flocculated structure have isotropic permeability.
Q: Phreatic surface/line is the line along which the pore water pressure is always maximum.
R: The piping phenomenon occurring below the dam foundation is typically known as blowout piping.
Which of the following option(s) is/are CORRECT?
A homogeneous earth dam has a maximum water head difference of 15 m between the upstream and downstream sides. A flownet was drawn with the number of potential drops as 10 and the average length of the element as 3 m. Specific gravity of the soil is 2.65. For a factor of safety of 2.0 against piping failure, void ratio of the soil is __________ (rounded off to 2 decimal places).
The in-situ percentage of voids of a sand deposit is 50%. The maximum and minimum densities of sand determined from the laboratory tests are 1.8 g/cm3 and 1.3 g/cm3, respectively. Assume the specific gravity of sand as 2.7.
The relative density index of the in-situ sand is ______________ (rounded off to 2 decimal places).