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-#229. The contractor has made progress in the preparation of the retaining wall foundation.

Focusing on backfilling and compaction operations behind the newly installing retaining wall sections along Lots #224–#229.  Following the drainage installation, the next layer of backfill was placed over the previously installed geogrid reinforcement sheet, in preparation for subsequent compaction. Excavation and placement of fill material was conducted using a Kobelco 310LC excavator and transported on site with a CAT 750 dump truck. 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. A new type of soil material was borrowed today, and a sample of this material was dropped by the ASEC laboratory for a Moisture-Density relationship (proctor).

Nuclear gauge density testing was performed on the compacted layer to evaluate moisture content and dry density. The results showed compaction levels exceeding 95% in some locations but falling short in others. Based on this data, the superintendent was advised to spend additional time to recompact in areas with insufficient density. After re-compaction, general probing and proof-rolling tests were performed.

Upon successful compaction of the first lift, the contractor advanced to the next layer of backfill. This subsequent layer underwent the same testing and quality control process. Both general probing and proof-rolling tests were performed. Near the wall the compaction was carried out with remote compactor BMP8500 for even compaction along the retaining wall.

Due to rainfall beginning at midday, work was halted for the remainder of the day. As a result, the contractor suspended operations the following day as well to allow site conditions to dry out.

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.