Which type of support system is characterized as temporary during excavation adjacent to existing structures?

The correct answer is shoring, as it refers specifically to a support system used temporarily during excavation to provide stability to existing structures that are adjacent to the work site. This technique is vital for ensuring that the soil and the structure do not shift or settle in an uncontrolled manner during excavations. Shoring typically involves the use of props or supports that are placed against the walls or foundations of the existing structure to redistribute loads and prevent potential collapse or damage.

Shoring is critical in construction practices to maintain safety as well as to protect the integrity of existing structures while new work is being performed, essentially creating a safe working environment. By implementing shoring systems, contractors can effectively manage the risks associated with excavation work near existing buildings or infrastructures, ensuring both the new work and the existing structures remain secure and stable throughout the construction process.