A soil mass shifts load from its weaker components to its stronger components such that the load is distributed in proportion to the stiffness of the components. This characteristic often results in the shifting of load around weak zones or cavities in the soil. Such redistribution of stresses in a soil mass is called arching. Arching is usually thought of in regard to pipe and tunnels. However, arching is a consequence of a more general property of soil known as internal shearing resistance. Slope stability, the bearing capacity of shallow footings, and the pressure distribution on retaining walls depend on the internal shear resistance. This paper discusses internal shearing resistance, the movement required to mobilize it, its measurement, typical values for common trench soils, and how it relates to the load applied to a buried pipe.