HomeMy WebLinkAboutPD 2018-0027; GEE RESIDENCE; FINAL SOILS REPORT; 2022-08-16
EDG Project No. 226750-4
Date: August 16, 2022
To: Hacienda Development Solutions LLC
Attn: Sergio Vazquez
106 5th Avenue
Chula Vista, California 91910
Re: Proposed Drainage and Stormwater Improvements, to be Located at 3800 Alder
Avenue, Carlsbad, California.
Subject: Compaction and Construction Observation Report – Rough Grading for the
Construction of New Fill Slopes, Detention Basins, and Drainage Systems.
Ref:
1. “Limited Geotechnical Investigation and Recommendations for the Additions and
Remodel to the Residence Located at 3800 Alder Avenue, Carlsbad, California,” dated
July 22, 2014, prepared by Engineering Design group.
2. Grading Plan, Drawing No. 520-3A, prepared by Engineering Design Group.
3. Updated Geotechnical Recommendations, dated October 2, 2020, prepared by
Engineering Design Group.
INTRODUCTION
In accordance with your request and authorization we have provided limited earthwork
observation and compaction testing services during the construction of fill slopes at detention
basins, and backfilling of trenches associated with drainage systems, at the above referenced
site. The results of our limited quality control and compaction testing operations are summarized
below.
GRADING OPERATIONS
Grading observed and tested for this project consisted of creating a new fill slope at Detention
Basin 1A, limited reestablishment of fill slope at Detention Basin 1B, and backfilling of trench
excavations for drainage lines. Rough grading at the subject site was conducted during May 2022.
ENGINEERING
DESIGN GROUP
www.designgroupca.com
2121 Montiel Road, San Marcos, CA 92069
760.839.7302
EDG Project No. 226750-4
In areas of new fill slopes at Detention Basin 1A, existing weathered and fill materials were
removed, keyways were extended into competent material at the toe of the proposed slope.
Keyways were excavated to a depth of 4 feet below adjacent grade and canted into the slope.
Keyway subgrade was scarified to a depth of 12 inches, moisture conditioned and fill soils
recompacted. As part of the creation of fill slopes, competent material was benched, soils
placed and recompacted utilizing earth moving equipment. As part of construction of
Detention Basin 1B, a portion of the existing slope was removed to allow access for equipment.
As part of a localized reestablishment, a keyway was extended into competent material to a
depth of 2 feet below adjacent grade, competent material was benched, soils placed and
recompacted utilizing earth moving equipment.
Onsite soil materials were utilized as graded fill. Prior to re-compaction, soils were generally
cleaned of vegetative and other debris and cobbles greater than 6 inches and moisture
conditioned. Onsite soil consisted of Light grey to brown, silty sands/sandy silts to sandy clays.
Based upon observation, onsite soils possess a low to medium potential for expansion. Soil was
moisture conditioned with a fire hose and placed and re-compacted utilizing a Bobcat, mini
excavator, and mechanized whacker.
FIELD AND LABORATORY TESTING
Limited field density tests were performed in accordance with D2922 (Nuclear Gauge Method).
Our test results indicate that, in the locations tested, soils have been compacted to at least 90%
relative compaction, as determined by ASTM D1557, (Procedure A). The reported test results are
representative of the soil conditions at the locations tested. Our observation and field density
testing methods are in accordance with normally accepted procedures. The accuracy of the
relative compaction values is subject to the precision limitations of the ASTM test methods. The
accuracy of the maximum dry density determination (ASTM D1557) is discussed in the Annual
Book of ASTM Standards, Section 4, Volume 04.08, entitled, Soil and Rock; Building Stones.
Variations of relative compaction values should be expected, laterally and vertically, from actual
test locations.
TESTING SUMMARY
In general, it is our opinion, based on the placement procedure and the test data collected, the
fill soils tested, at the locations tested, were compacted to a minimum of 90% relative
EDG Project No. 226750-4
compaction (based on ASTM D1557, Procedure A).
If you have any questions regarding this report, or if we can be of further service, please do not
hesitate to contact us. We hope the report provides you with the necessary information to
continue with the development of the project.
Sincerely,
ENGINEERING DESIGN GROUP
Erin Rist Steven B. Norris
California RCE# 65122 California GE# 2590
Attachments:
1) Table 1 & 2: “Laboratory and Field Test Results”
2) Figure 1: “Approximate Location of Compaction Tests”
EDG Project No. 226750-4
LABORATORY AND FIELD TEST RESULTS
TABLE NO. 1
Laboratory Test Results
SOIL
TYPE
(#)
SOIL TYPE
MAXIMUM DENSITY
(PCF)
OPTIMUM
MOISTURE
(%)
U.S.C.S.
CLASSIFICATION
1
Moderate Brown,
Sandy Clay/Clayey
Sand
122.4 12.5 SM - SC
TABLE NO. 2
Field Test Results
TEST
NO.
DATE ELEVATION
(FT)
SOIL
TYPE
(#)
DRY
DENSITY
(PCF)
FIELD
MOISTURE
(%)
RELATIVE
COMPACTION
(%)
COMMENT
1 5/10/2022 273 1 112.0 13.3 92
2 5/10/2022 273 1 105.4 12.5 84 RETEST 3
3 5/10/2022 273 1 112.1 12.6 92
4 5/12/2022 275 1 116.2 11.2 95
5 5/12/2022 275 1 110.0 11.3 90
6 5/12/2022 275 1 110.2 13.8 90
7 5/12/2022 272 1 120.6 12.4 99
8 5/13/2022 277 1 113.0 13.1 92
9 5/13/2022 277 1 115.8 11.6 95
10 5/13/2022 277 1 112.5 11.3 92
11 5/17/2022 279 1 107.9 9.4 88 RETEST 12
12 5/17/2022 279 1 117.4 8.6 96
13 5/17/2022 279 1 111.0 10.8 91
14 5/17/2022 274 1 111.8 11.1 91
15 5/19/2022 281 1 118.1 9.7 97
16 5/19/2022 281 1 119.0 9.3 97
TEST
NO.
DATE ELEVATION
(FT)
SOIL
TYPE
(#)
DRY
DENSITY
(PCF)
FIELD
MOISTURE
(%)
RELATIVE
COMPACTION
(%)
COMMENT
17 5/19/2022 276 1 110.6 8.5 90
18 5/25/2022 284 1 112.4 11.7 92
19 5/25/2022 284 1 116.8 11.7 95
20 5/25/2022 278 1 118.0 9.0 96
21 5/25/2022 278 1 113.2 9.4 93
FIGURE 1
Approximate Location of Compaction Test
Project: Hacienda Development Solutions
Address: 3800 Alder Avenue, Carlsbad, California
EDG Project No:226750-4
●1
●3
●2
●4
●5
●6
●8
Not to Scale
●9
●10
●11
●12
●13
●15
●16
●18
●19
●7●14
●17●20
●21
Wall Not a Part
Previously Done Grading-Not
Part of Earthwork
Observation/Inspection Per
This Report
Basin 1A
Basin 1B
ENGINEERING
DESIGN GROUP
www.designgroupca.com
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