Evaluate Drainage Backfill Material

What happens here

Carefully examine the material used for drainage backfill behind the retaining wall. The speaker demonstrates this by picking up and showing the material, identifying it as "pea gravel" instead of the recommended "3/4 inch limestone." Pea gravel, with its small, round particles, is unsuitable for drainage backfill as it can easily compact and allow fine soil to infiltrate and clog the drainage system. Proper drainage requires larger, angular aggregates like 3/4 inch crushed limestone to ensure efficient water flow and prevent hydrostatic pressure.

Goal: Determine if the correct type of material was used for drainage backfill.