BLD-2024-1673_JobCard.pdf(10)LIII)ROMIG
ENGINEERS
Mr. Stefano Cei
21627 Rosario Avenue
Cupertino, California 95014
Dear Mr. Cei:
June 26, 2024
6584-1
RE: GEOTECHNICAL OBSERVATION
POOL REMOVAL AND BACKFILLING
21627 ROSARIO AVENUE
CUPERTINO, CALIFORNIA
As requested, we provided geotechnical observation and testing services during
demolition and backfilling of the former swimming pool on your property at 21627
Rosario Avenue in Cupertino, California_ Our geotechnical recommendations for
demolition and backfilling of the swimming pool were presented in our recommendations
letter dated March 15, 2024.
PROGRESS OF WORK
A member of our staff visited the property on June 6, 7, 10, and 11, 2024, during
demolition and backfilling of the former swimming pool. The entire pool shell was
demolished, and demolition, debris was removed from the site. The resulting excavation
was approximately 7 feet deep. The bottom of the excavation exposed stiff native soil.
Imported soil, which consisted of approved Silty Sandy was placed and compacted in lifts
to backfill the pool excavation.
A sheepsfoot compactor and jumping jack compactor were used to compact the pool
backfill_ Our field density tests indicated the backfill was generally compacted to at least
92 percent relative compaction below a depth of 4 feet below adjacent grade and to at least
90 percent relative compaction above a depth of 4 feet below adjacent grade, as
recommended. Approximately the upper foot of the pool backfill was composed of
compacted soil and/or non -expansive fill to be more compatible with the future hardscape.
The results of our field density tests are listed in Table 1, attached.
WARRANTY
We make no warranty, expressed or implied, for the services we performed for this
project. Our services are performed in accordance with the geotechnical engineering
principles generally accepted at this time and location.
OPINION
Based on our field observations and density test results, it is our opinion that demolition
and backfilling of the former swimming pool on your property at 21627 Rosario Avenue
in Cupertino were performed in general compliance with our recommendations and with
generally accepted geotechnical engineering practice in the area.
Please call if you have questions or comments about site conditions or the geotechnical
observation and testing services that we performed during demolition and backfilling of
your former swimming pool
1390 El Camino Real, Second Floor I San Carlos, CA 94070 I (650) 591-5224 I www.romigengineers.com
Mr. Stefano Cei Swimming Pool Backfill Page 3 of 3
Table 1. Summary of Field Density Test Results
Cei Swimming Pool Backfill
21627 Rosario Avenue
Cupertino, California
Test Depth Below Thickness Dry Water Relative
No. Date Finish Grade of Density Content Compaction
(feet) (feet) (pcf) (percent) (percent)
1 06/06/2024 5.0 2.0 114.1 12.1 93
2 06/06/2024 5.0 2.0 113.4 11.2 92
3 06/07/2024 4.5 2.5 113.7 16.4 92
4 06/07/2024 4.0 3.0 114.3 16.2 93
5 06/07/2024 4.0 3.0 115.3 14.4 94
6 06/07/2024 3.5 3.5 111.5 14.3 91
7 06/10/2024 2.0 5.0 116.0 12.6 94
8 06/10/2024 2.0 5.0 113.0 13.3 92
9 06/11/2024 1.0 6.0 114.0 13.7 93
10 06/11/2024 1.0 6.0 115.2 12.8 94
* Relative compaction for tests 1 through 10 based on a maximum dry density of 123 pounds per
cubic foot (at an optimum water content of 10 percent).
gr8)ROMIG
ENGINEERS