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).
A drained triaxial test was conducted on a saturated sand specimen using a stress-path triaxial testing system. The specimen failed when the axial stress reached a value of 100 kN/m2 from an initial confining pressure of 300 kN/m2.
The angle of shearing plane (in degrees) with respect to horizontal is ______________ (rounded off to the nearest integer).
A vertical smooth rigid retaining wall is supporting horizontal ground with dry cohesionless backfill having a friction angle of 30°. The inclinations of failure planes with respect to the major principal plane for Rankine’s active and passive earth pressure conditions, respectively, are