ANS:C -

The total pressure on the vertical face of a retaining wall per unit run exerted by the retained earth can be calculated using Coulomb's theory of earth pressure. According to Coulomb's theory, the total pressure P on the vertical face of the retaining wall per unit run is given by: P=1/2​⋅γ⋅h^2 Where:

• γ is the unit weight of the retained earth (weight per unit volume)
• ℎh is the height of the retaining wall

So, the total pressure on the vertical face of a retaining wall per unit run exerted by the retained earth is directly proportional to the unit weight of the retained earth (γ) and the square of the height of the retaining wall (ℎ2). Therefore, the formula for the total pressure P can be written as: P=1/2​⋅unit weight of retained earth⋅height of wall^2 This equation provides an approximation of the total pressure exerted by the retained earth on the vertical face of the retaining wall per unit run.