Mohr's theory, also known as the Mohr-Coulomb theory, states that the shear strength of a material is determined by two parameters: cohesion (C) and angle of internal friction (φ). According to this theory, the shear strength of a material can be calculated using the formula τ = C + σ' tan(φ), where τ is the shear stress, σ' is the normal stress on the failure plane, C is the cohesion, and φ is the angle of internal friction. This theory is widely used in geotechnical engineering to analyze stability and failure of soils and rocks.«Failure of rammed earth walls: from observations to quantifications »