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.

Our ASEC representative was on site for the observation/testing of the placement of fill/backfill. The contractor continued to place lifts of approximately 6 in to 8 in thick across Lots #1 through #4 and the roadway in front of these lots. ASEC performed density testing on the final grades of these lots and retested any failing tests after recompaction.

The contractor removed the temporary pond structure and began building up the slope and partial of Lot #4 in front of the detention pond. Structural fill was placed in this area and density testing was performed. There appears to be a mix of material being used in this area with a high mica content. Fill was undercut from the bottom of the detention pond to be used on the slope, and the contractor began placing topsoil back in the undercut. All test results were provided to the contractor. ASEC watched as loaded trucks rolled across the lifts to check for stability. There were no signs of severe pumping or rutting present, and the lifts appear to be stable.

The contractor finished an approximate 2-foot thickened lift across the commercial lot area located around the front detention pond. Once the thickened lift was completed, the contractor began placing approximately 8 in lifts across this area and compacted using an 815 sheep’s foot roller. Density testing was performed, and all test results were provided to the contractor. ASEC watched as loaded off road dump trucks rolled across the lifts to check for subgrade stability. There were no signs of severe pumping or rutting observed.

The contractor began backfilling structure BZ headwall structures and pipeline (leading into front of detention pond). Structural fill was used to backfill these structures and density testing was performed at approximately 2 foot over the pipeline. Test results were found to be satisfactory, and test results were provided to the contractor.

A proof-roll was performed on the approximate location of Lots #8 through #13 and #52 through #60 (and the roadway in between these lots). The proof-roll showed minimal pumping. The contractor undercut one area where severe pumping was present. The contractor plans to bench into the natural slopes in approximate 2-foot by 2-foot sections as they work up the slopes. This area contains a natural valley that deflected water to what appears to be a small creek outside of the property line. It was recommended to place an approximate 2-foot thickened lift through this valley prior to placing and compacting lifts. This is a deep fill area, exceeding 15 to 20 feet of fill. The contractor agreed and will begin fill placement in this area on the following workday.

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.

BZ2

BZ1

backfilling BZ headwall structure/pipeline

backfilling BZ headwall structure/pipeline

slope of detention pond and lot #4

commercial lot area around detention pond

commercial lot area around detention pond and lots #1 - #4

proof rolling lots #8 - #13 and #52 - #60