Bishop's effective stress theory

Bishop's effective stress theory is a way engineers understand how soil or rock holds together under pressure, especially when it contains water. When water is present, some of the applied stress is "carried" by the water pressure rather than the solid particles. The theory adjusts for this by calculating an "effective stress," which is the actual stress that influences the soil's strength and stability. This helps predict how soils will behave, such as during construction or slope stability, by accounting for both the physical pressure and the effects of pore water within the material.