Observations/Finding

As requested, the site was visited by our AS Engineering and Consulting (ASEC) representative for the purpose of providing quality control inspection and testing services.  Visual observation techniques were employed to verify compliance with project drawing/specifications, applicable codes, and materials submittals. The following observations were observed on site this day.

This report documents the assessment and actions taken regarding subgrade preparation and proof-rolling evaluation at the project site. The evaluation covered two distinct areas, detailing the procedures conducted, observations made, and recommendations provided for further action.

Site Assessment: Upon arrival, it was noted that the site foreman was absent. Consequently, a proof-roll assessment was initiated to evaluate the subgrade conditions.

Area #1 Assessment:

• Area: Approximately 150 feet x 100 feet, located on the northeast side of the project.
• Scope: Included future Mallard Point Road from STA 4+00 to 5+00, partially Lots #33 to 41, and the back parking lot.
• Assessment: The initial proof-roll conducted with a loaded tandem off-road dump truck (refer to attached photo) displayed severe pumping and/or rutting.
• Action Taken:
  • The area was scarified and aerated for three hours and turned with a Komatsu dozer.
  • This area was re-compacted using a Caterpillar CP54B ride-on vibratory sheep’s foot.
• Follow-up: Another proof roll was conducted, with marginal improvement observed.
• Recommendation: Based on discussion with our ASEC engineer, it was advised to add several 8-inch compacted lifts and conduct additional proof-rolls to assess improvements.

Area #2 Assessment:

• Area: Approximately 115 feet x 100 feet, located on the west side of the project adjacent to the detention pond.
• Assessment: The initial proof roll was deemed unacceptable.
• Action Taken: The area was scarified; however, no further work was observed in this area.

Recommendations:

1. For Area #1:
   • Continue with the implementation of several 8-inch lifts and conduct additional proof-rolls to monitor progress.
   • Slope and seal the area in anticipation of upcoming rain events to mitigate potential damage.
2. For Area #2:
   • Implement appropriate measures to address subgrade concerns based on further evaluation.

Conclusion: The assessment revealed varying degrees of subgrade inadequacy, particularly in Area #1. Continued monitoring and implementation of recommended actions.

Attachments:

• Photos: Proof-roll assessment, scarification & aeration process.

area 1 being scarified

proof roll loaded tandem off road dump truck

area 2

area 2