Live/dynamic load is considered well dispersed at what depth?

Study for the BICSI OSP Design Test. Prepare using multiple choice questions, with hints and explanations to enhance understanding. Succeed in your exam journey!

The idea here is how soil distributes a live or dynamic load as you go deeper. A load placed on the surface doesn’t stay concentrated at a single point once you go below the surface—the stress spreads laterally and downward through the soil. As depth increases, that load’s influence extends over a larger volume of earth and the peak pressure on any buried asset drops. When you reach about six feet, the load has dispersed enough that it won’t act as a sharp, concentrated force on the buried path; it becomes effectively well distributed, reducing the risk of localized movement or damage. That’s why six feet is considered the depth at which live/dynamic loads are regarded as well dispersed. Shallower depths (like two or four feet) don’t spread the load as much, so the force remains more concentrated, while deeper burial isn’t necessary for meeting this criterion.