Observations/Finding

On July 26, 2023, the assigned ASEC representative was present on-site at the Northfields Project to observe and evaluate the ongoing work for compliance with the project plans, specifications, and standards.

A proof-roll was performed on a 355-foot long section that extended from the newly constructed entrance over the creek and terminating adjacent to the retention pond south of the creek. The proof-roll was conducted using a loaded dump truck making parallel passes.

During the proof-roll, a notable deflection was observed in a 25 x 5-foot area adjacent to the fire hydrant. This indicates an area of potential instability or insufficient compaction, requiring remedial work. The contractor has been advised to excavate this area, removing approximately 12 inches of the existing material. The excavated area will then be backfilled with a graded aggregate base (GAB).

The entire section was subsequently backfilled according to the construction plans.

OBSERVATIONS AND RECOMMENDATIONS:

1. The proof-roll was an essential exercise to identify weak spots in the subgrade, and the deflection noted near the fire hydrant is a significant finding. Contractors should expedite the excavation and backfilling process to prevent any delays.
2. The backfilled area should be closely monitored for stability, especially in the 25 x 5-foot section that has been corrected.
3. Regular proof-rolls should be performed on all areas receiving fill to ensure compliance with the project specifications.
4. The contractor should continue to comply with the construction plans during the backfilling process.