scope:

Description of Driving Event:

DFRC had a dozen large diameter (20"+/-) fire water sectional valves located in large vaults around the flight line. The requirement was to backfill these vaults with earthen materials, and remove the top of the vaults, and pave flush around them for minimal impact to the flight line area. The problems of doing this with "dirt" included working down in deep confined spaces, substandard compaction, hazards and probabilities of using power compactors around critical facility pressurized piping, and possible pipe damage resulting in flooding and drowning hazards.

The simple solution arrived at was to "pour" in pea gravel, that flowed in like water and achieved near-100% compaction.