Which lateral earth pressure coefficient is accounted for using Coulomb Theory?

Coulomb's earth pressure theory is utilized to calculate lateral earth pressures exerted on retaining structures, such as walls and foundations, due to soil. This theory incorporates several critical angles and coefficients in its derivation: the internal friction angle of the soil (Φ), the angle of wall friction (δ), and the angle of the backfill surface relative to the horizontal (β).

The internal friction angle (Φ) is significant because it represents the resistance of soil particles to sliding over each other, which directly impacts the earth pressure exerted against retaining structures. The wall friction angle (δ) contributes to the effective stress distribution acting along the surface of the wall, while the inclination of the backfill surface (β) modifies the calculation of lateral pressures based on the angle at which the soil is placed.

By considering all these angles and factors, Coulomb's theory provides a comprehensive approach to estimating the horizontal and vertical components of lateral earth pressure. Therefore, stating that all relevant coefficients, including Φ, δ, and β, are part of the Coulomb theory correctly addresses the lateral earth pressure computations based on this theoretical framework.