An initial proof roll was requested for the entire project site at Town Center Retail in Covington. The purpose of the proof-roll was to evaluate the initial subgrade’s stability prior to further grading activities and identify any areas requiring remediation.

Proof-roll Assessment

Upon arrival, a tandem-axled dump truck loaded with soil was provided for the proof-roll. The truck was used to traverse the entire site, except for areas obstructed by a rock pile and a work trailer.

During the assessment, the majority of the site was found to be not suitable for continued grading activities (fill placement) as significant movement and deflection were observed under the trucks load. The subgrade conditions failed to meet the required stability criteria.

Investigation & Findings

Following the failed proof-roll, a meeting was conducted with the ASEC engineer, Mr. Ram Mogulla, the site superintendent, and the grading foreman to discuss the observed issues. To further investigate, five test pits were randomly excavated across the site to examine subsurface conditions.

Findings from the test pits revealed:

• Excessive moisture content in the soil, located 1 to 2 feet below the current elevation.
• Poor subgrade stability due to the high moisture levels, contributing to surface deflections.

Recommendations

To address the identified issues, the following corrective action was recommended:

• Scarification of the site to a depth sufficient to reduce excessive moisture and improve soil stability.  We estimate that up to two feet of upper wet soils will require discing and scarification followed by aeration to bring these soils within operable moisture contents.

Conclusion

The site surficial soil conditions were deemed not suitable for fill placement based on the proof-roll assessment. A follow-up proof-roll should be scheduled after corrective actions are completed to verify improvements in soil stability.

Attachments: Photos of proof roll assessment.