Figure below shows a smooth vertical gravity retaining wall

Figure below shows a smooth vertical gravity retaining wall with cohesion less soil back fill having an angle of internal friction Φ. In the graphical representation of Rankine’s active earth pressure for the retaining wall shown in figure, length OP represents

1. vertical stress at the base
2. vertical stress at a height H/3 from the base
3. lateral earth pressure at the base
4. lateral earth pressure at a height H/3 from the base

OP doesn’t cut Mohr’s circle tangentially
∴ OP is the live represented vertical stand base.