Question

Consider the following statements regarding Coulomb's theory of earth pressure:

Which of these statements are correct?

• A. 1, 2 and 3
• B. 1 and 2 only
• C. 2 and 3 only
• D. 1 and 3 only

Answer 1

The correct option is A 1, 2 and 3

The Coulomb theory provides a method of analysis that gives the resultant horizontal force on a retaining system for any slope of wall, wall friction, and slope of backfill provided. This theory is based on the assumption that soil shear resistance develops along the wall and failure plane. Since wall friction requires a curved surface of sliding to satisfy equilibrium, the Coulomb formula will give only approximate results as it assumes planar failure surfaces. The accuracy for Coulomb will diminish with increased depth. For passive pressures the Coulomb formula can also give inaccurate results when there is a large back slope or wall friction angle.