Consider the following statements:
Ranking’s theory and Coulomb’s theory give the same value of coefficients of active and passive earth pressures when
1. the retaining wall has a vertical back.
2. the backfill is cohesionless.
3. angle of slope of backfill is equal to the angle of friction.
4. angle of slope of backfill is 0°.
5. angle of wall friction is 0°.
6. angle of wall friction is equal to the angle of internal friction of soil.
Of these statements
1
1, 2, 3 and 5 are correct
2
1, 2, 4 and 5 are correct
3
2, 3 and 6 are correct
4
1, 4 and 6 are correct