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 to#229. The contractor has made progress in the preparation of the retaining wall foundation and the Lots #224 to #229.

Backfilling and compaction activities were performed within Lots #228 & #229. The contractor utilized a Kobelco 310LC excavator to place the fill material in designated areas. Following placement, the material was transported and distributed across the lots using a Bobcat 265 and Takeuchi TL12R2 compact track loaders. Once the fill was placed, compaction operations commenced using a Bomag BW211 sheepsfoot roller. The contractor redirected efforts toward completing grading of the green space slopes between Lots #224 to #229. Additionally, work commenced on the rear slopes adjacent to the retaining walls for all lots within this range. Excavation of soil was performed using a Kobelco 310LC excavator, and material was hauled using a CAT 725 articulated dump truck. The contractor also proceeded with placing additional lifts of the retaining wall near Lot #229 by an additional two layers of Diamond blocks.

Nuclear gauge density testing was conducted on the compacted layer near each individual lot and also near the retaining wall 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 dedicate additional time to compaction in areas with insufficient density. After re-compaction, general probing and proof-rolling tests were performed.  No severe deflections were noted.

Upon successful compaction of the 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 verified stability of surficial soils. Near the wall the compaction was carried out with a remote compactor BMP8500 for even compaction along the retaining wall.

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.