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.

Following up on the progress from the previous day, work has continued behind Lots #224 through #229. The contractor has made progress in the preparation of the retaining wall foundation.

Following inclement weather conditions on Sunday and Monday, which left the site saturated, the contractor-initiated site drying procedures on Tuesday, April 8, 2025. These preparatory efforts allowed for work to resume on Wednesday, April 9, 2025, with a focus on backfilling and compaction operations behind the newly installed retaining wall structure along Lots #224–#229.

The contractor began with the placement of the first layer of backfill over the previously installed Geo Grid Reinforcement sheet. Excavation and movement of fill material were conducted using a Kobelco 310LC excavator and transported on site with a CAT 750 dump truck to place a 1-foot lift of backfill material. Subsequent to placement, two Takeuchi TL12R2 Bobcats were used to distribute the fill uniformly along Lots #224–#229. Once the fill was evenly spread, compaction was carried out using a Bomag BW211 sheep foot compactor in combination with a Bomag RR-106 roller.

Nuclear gauge density testing was performed on the recently placed backfill. The results showed compaction levels exceeding 95% in some locations but falling short in others. Based on this data, the superintendent was advised to dedicate additional time to compaction in areas with insufficient density. After re-compaction, general probing and a proof-roll test was performed.  Both probing and proof-rolling found the subgrade soils to be stable.

Upon compaction of the first lift, the contractor advanced to the next layer of backfill. Again, density testing was performed using a nuclear density gauge. Both general probing and proof-rolling were performed again on the second lift.  No severe pumping/rutting was observed.

Following backfill operations, preparations commenced for the next course of retaining wall construction, including Geo Grid reinforcement placement and layout for the upcoming lift.

We appreciate the opportunity to be of service to you on this project. If you have any questions regarding this report, please feel free to contact us. We will be more than happy to discuss it with you.