HomeMy WebLinkAbout6024-1; La Costa Avenue Slope Repair; Report of Compaction Testing; 2016-04-12April 12, 2016
Project No. 107544010
Ms. Sherri Howard, PE
City of Carlsbad
1635 Faraday Avenue
Carlsbad, California 92008
Subject: Report of Compaction Testing
La Costa Avenue Slope Repair (60241)
Carlsbad, California
References: City of Carlsbad, 2015, Improvement Plans for La Costa Avenue Slope Repair:
dated April 30.
Ninyo & Moore, 2008, Geotechnical Evaluation, La Costa Avenue Slope Failure,
Carlsbad, California, Project No. 106270001: dated February 25.
Dear Ms. Howard:
In accordance with your request, we are providing this letter summarizing our observations and
testing that was performed during the grading operations associated with the subject project. The
purpose of our services was to observe the placement of fill and to document and test soil mate-
rials used during the earthwork operations for the project.
The site is located along the south side of La Costa Avenue between Gibraltar and Romeria Streets in
Carlsbad, California (Figure 1). The site includes an approximately 50-foot side section of the north
facing slope that had previously slumped down toward the road. The project included the reconstruc-
tion of this portion of the slope to match the pre-existing grades and configurations.
La Costa Avenue Slope Repair (60241) April 12, 2016
Carlsbad, California Project No. 107544010
107544010 L La Costa.doc 2
SUMMARY OF EARTHWORK OPERATIONS
Earthwork operations observed and tested by our field representative generally included the
slope reconstruction. The earthwork operations took place from March 16 through March 24,
2016. To perform the earthwork operations, the contractor utilized an excavator equipped with
a bucket and sheepsfoot roller attachment and a haul truck. The excavator was used for exca-
vation, mixing, and compaction, using a sheepsfoot roller attachment. The haul truck was used
to import and export the soil.
The reconstruction of the subject slope began with excavation of a keyway near the base of the
slope. This keyway was constructed in accordance with the recommendations of the project ge-
otechnical report. Elevations at the bottom of the keyway excavation are presented on Figure 2.
After the keyway was constructed, a back drain consisting of a 4-inch diameter non-perforated pipe
surrounded by gravel wrapped in filter fabric was installed along the back edge of the excavation.
The back drain was daylighted to the nearby curb and gutter for the adjacent roadway. Also, during
reconstruction, zones of seepage were observed in the temporary backcut. To mitigate seepage, var-
ious panels of drain board were placed along the backcut and connected to the backdrain.
After construction and filling of the keyway, along with the installation of the backdrain, the con-
tractor removed loose material and reconstructed the remainder of the slope with import soils and
geogrid. As the contractor progressed, filling from the bottom to the top of the slope, near-
horizontal benches were cut into competent soils within the slope. The layers of geogrid were
placed horizontally between lifts at approximate 2-foot intervals within the fill, in accordance with
the recommendations of the geotechnical report (Ninyo & Moore, 2008).
LABORATORY AND FIELD TESTING
Laboratory testing was performed on a representative sample of the import soils to evaluate the
modified Proctor dry density and moisture content. The modified Proctor dry density and mois-
ture content were evaluated in general accordance with American Society for Testing and
Materials (ASTM) Test Method D 1557, and the results are presented in Table 1.
La Costa Avenue Slope Repair (60241) April 12, 2016
Carlsbad, California Project No. 107544010
107544010 L La Costa.doc 3
Our field representative was generally on-site full-time for observation and testing services dur-
ing construction of the keyway, installation of the backdrain, and reconstruction of the slope. In-
place density and moisture content testing was performed by our field representative in accord-
ance with ASTM D 6938 (Nuclear Gauge Method). During the earthwork operations, when a
field density test was performed that resulted in less than specified allowable relative compac-
tion, the area was generally reworked, and a retest was taken. The specified relative compaction
for fill materials was 90 percent. A summary of the results of field density tests are presented in
Attachment A and the approximate locations of the tests are indicated on Figure 2.
CONCLUSIONS
The field density tests performed during these operations indicated the specified relative com-
paction, after retesting the reworked areas. Based on our observations and the results of our field
and laboratory tests, it is our opinion that the earthwork operations associated with the project
were performed in general accordance with the referenced project plans, the project geotechnical
report, and Ninyo & Moore’s field recommendations. The geologic conditions observed in the
backcut and keyway were generally similar to the conditions described in our referenced report
(Ninyo & Moore, 2008).
The geotechnical services outlined in this report have been conducted in accordance with current
practice and the standard of care exercised by geotechnical consultants performing similar tasks in
this area. No warranty, expressed or implied, is made regarding the observations and conclusions
expressed in this report. The reported test results represent the relative compaction and moisture
content at the locations tested. It is important to note that the precision of field density tests and the
modified Proctor dry density tests are not exact and variations should be expected. The reported
locations and elevations of the density tests are estimated based on correlations with the site staking
and the referenced plans (City of Carlsbad, 2015). Further accuracy is not implied.
NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE
1_107544010_SL_93.mxd AOB88
55
15
805805
215215
SITE
MAP INDEX
San DiegoCounty
0 1,500 3,000750
SCALE IN FEET
SITE LOCATION FIGURE
1PROJECT NO.DATE
107544010 4/16
SOURCE: USGS, FAO, NPS, EPA, ESRI, DELORME, TANA, OTHER SUPPLIERS
LA COSTA AVENUE SLOPE REPAIR (60241)
CARLSBAD, CALIFORNIA
FIGURE2LA COSTA AVENUE SLOPE REPAIR (60241)CARLSBAD, CALIFORNIAPROJECT NO.107544010DATE4/1602040SCALE IN FEET2 107544010 fdt la costa.dwg
FIELD DENSITY TEST LOCATIONSNOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATELEGENDF-28FILL FIELD DENSITY TESTSOURCE: RICK ENGINEERING COMPANY, DATED APRIL 8, 2015.F-19F-13,14F-10,11F-7F-17F-12F-8,9F-4,5F-15,16F-6F-18F-20F-22F-23,24F-21F-25F-26,27F-28F-1F-3F-2LOCATION OF KEYWAY, WITH ELEVATIONSLOCATION OF BACK DRAIN136136135134136
La Costa Avenue Slope Repair (60241) April 12, 2016
Carlsbad, California Project No. 107544010
107544010 L La Costa.doc 1 of 1
Table 1 – Modified Proctor Density Test Results
Soil
Type No. Description
Proctor
Density
(pcf)
Optimum
Moisture
Content (%)
1 Silty SAND (Import) 123.0 10.5
Note:
pcf – pounds per cubic foot.
La Costa Avenue Slope Repair (60241) April 12, 2016
Carlsbad, California Project No. 107544010
107544010 L La Costa.doc
ATTACHMENT A
SUMMARY OF FIELD DENSITY TESTS
Tested material does does NOT meet the requirements of the approved project documents.
The material was was NOT sampled and tested as required by the approved project documents.
NOTE: Tests results shown bold italicized have been corrected per ASTM D 4718 Section 4.2 for oversize rock content.
91
123.0
10.5
1
104.9 111.4 106.3111.2 107.6
8790
90
110.5
123.0
10.5
11
90
114.6
93
123.0
CF CF CF
NG
1507
Sand + Bottle Before (lbs) / (DS)
Test Of CF CF CF
Test Type (SC/SC(SR) = Sand Cone, NG = Nuclear Gauge)NGNG
LFV
1
141.0
CF
CF
CF
GSW
GSW
LFV
LFV
LFV
LFV
LFV
LFV
Test
Of
Block
No.
CF
CF
CF
CF
90
10.5
1
Initials Test Location
STA 77+45 SLOPE REPAIR (KEYWAY)
STA 77+51 SLOPE REPAIR (KEYWAY)
Elev. or
Depth (ft)
136.5
138.0
GSW
90
91
11
5
Relative Compaction (%)
Corrected Maximum Density (pcf)
12.8
TEST RESULTS1
123.0
90
90
Soil Type Number
Dry Density (pcf)
1373
PASS
MOISTURE
91
123.0
111.4
3/17/16
3/17/16 139.0
3/18/16
STANDARD& TEST COUNTS200
Sand in Cone + Hole (lbs) / (DC)
2158
CF
125.7
Sand + Bottle After (lbs) / (MS)
Coarse Fraction (lbs)
10.5 10.5
11.8 12.8
123.0
90 9090 90
1
119
1
90
1
86
10.5 10.5 10.5
91 85
10.5 10.5
123.0 123.0123.0 123.0
11.3 10.6 11.2 11.011.2 10.9
111.9 111.8
119.6 127.1 124.5 116.9123.6123.6 116.7
155146 154 160 156
CF CF
NG
2088
NGNG
2088
492370 402 491
645
6
2072
10
NG
2088
645
5
1489 453
NG
645
2158
NG
703
365
196
124.6
Percent Moisture
138.0
2158
703
Wet Density (pcf)
703
124.3
183
STA 77+74 SLOPE REPAIR (KEYWAY)
2088
23
10
4
CF
3/18/16 142.0
CF
CF
Test No.
Plan File No.:
La Costa Avenue (~2912 La Costa), Carlsbad, CA
60241
8
STA 77+50 SLOPE REPAIR
137.0CF
La Costa Avenue Slope Repair Project No:107544010
137.0
Project Name:
3/18/16
Permit No.:
Project Street Address:
Jurisdiction:City of Carlsbad
4
Test Date
3/16/16
3/16/16
SUMMARY OF FIELD DENSITY TESTS
9
STA 77+51 SLOPE REPAIR (KEYWAY)
STA 77+74 SLOPE REPAIR (KEYWAY)
2072
78
642645
144
Optimum Moisture (%)
FAILPASSPass/Fail PASS
Specified Relative Compaction (%)
Coarse/Finer Fraction in Max (%)
10.0
FAIL PASS PASS PASS FAIL
Laboratory Maximum Density (pcf)
PASS
Retest on (if applicable)
642
NG
2072
642
364
131
3/16/16
Test
No.
1
2
STA 77+69 SLOPE REPAIR
5
9
6
7
139.0
Soil + Rock + Tare (lbs)
Coarse Fraction (%)
Finer Fraction (%)
3
STA 77+82 SLOPE REPAIR (KEYWAY)
141.0
STA 77+55 SLOPE REPAIR (KEYWAY)
STA 77+69 SLOPE REPAIR
WET DENSITY & ROCK CONTENTTest Type:
3/17/16
Fill
Tare (lbs)
Sand in Cone (lbs) / (MC)
3/17/16
5710 Ruffin Road, San Diego, CA 92123
107544010_FDT_ CF#1 (Slope).xls Field Density Test Sheet 2013 v 3.0
Tested material does does NOT meet the requirements of the approved project documents.
The material was was NOT sampled and tested as required by the approved project documents.
Fill
STA 77+83 SLOPE REPAIR
STA 77+83 SLOPE REPAIR
CF
Finer Fraction (%)
146.0
STA 77+55 SLOPE REPAIR
STA 77+75 SLOPE REPAIR
STA 77+45 SLOPE REPAIR
18
13
WET DENSITY & ROCK CONTENTTare (lbs)
Sand in Cone (lbs) / (MC)
3/21/16
3/21/16
144.0
Coarse Fraction (%)
172
15
19
16
17
650
2069
NG
17
2047
650
350365
647647647
Retest on (if applicable)
170
Optimum Moisture (%)
PASS
Specified Relative Compaction (%)
Coarse/Finer Fraction in Max (%)
Wet Density (pcf)
14
CF
15 16
CF
178 165 172 165
PASS FAIL PASS PASS PASS PASSPASS PASSPass/Fail
Corrected Maximum Density (pcf)
Relative Compaction (%)
90
1
90
NG
Dry Density (pcf)
Percent Moisture
Soil + Rock + Tare (lbs)
2047
20
NG
2069
NG
19
376
12 13
2069
CF
14
Test Date
3/18/16
142.0
Initials Elev. or
Depth (ft)
142.0
142.0
3/18/16
Test
No.
11
12
2072
642
LFV
Test
Of
STA 77+48 SLOPE REPAIR
STA 77+48 SLOPE REPAIR
CF
STA 77+80 SLOPE REPAIR
Project Name:La Costa Avenue Slope Repair Project No:107544010
142.0
146.018
LFV
LFV
LFV
SUMMARY OF FIELD DENSITY TESTS
5710 Ruffin Road, San Diego, CA 92123 Test Type:
3/21/16
Permit No.:
Project Street Address:
Jurisdiction:City of Carlsbad Plan File No.:
La Costa Avenue (~2912 La Costa), Carlsbad, CA
60241
20
647
CF
Sand + Bottle Before (lbs) / (DS)
Sand + Bottle After (lbs) / (MS)
3/22/16
NG
642 647
Laboratory Maximum Density (pcf)
127.7 121.7
10.8 11.5
124.6
CF CF CF
NG
2069
421 381
NG
450
2069
NG
335 320 355
2069
150
123.8 122.3 126.3122.7123.8 119.8 122.9
11.0 10.9 10.810.8 10.7
111.2
11.210.5
110.7
11
10.5 10.5
1111
90 90
10.5 10.5
92
10.5
90
90 90
10.5 10.5
FAIL
1614
89
144.0
144.0
148.0
171 160
11.0
3/21/16
3/21/16
CF
CF
CF
CF
Test No.
LFV
2072
156
Sand in Cone + Hole (lbs) / (DC)
11
3/22/16
STANDARD& TEST COUNTSTest Type (SC/SC(SR) = Sand Cone, NG = Nuclear Gauge)NG
3/21/16 CF
LFV
93
MOISTURE
91
123.0
112.5
10.5
TEST RESULTS1
123.0
Soil Type Number
90 90
108.2
88
123.0
90
91
11
123.0
111.5 110.3
Test Location
STA 77+50 SLOPE REPAIR
STA 77+65 SLOPE REPAIR
CF CF
352
90
10.5
90
10.5
Test Of CF
LFV
Block
No.
CF
CF
CF
LFV
LFV
LFV
Coarse Fraction (lbs)
NG
647
123.0
91
123.0 123.0
90
123.0
114.5 111.7109.6
123.0123.0
NOTE: Tests results shown bold italicized have been corrected per ASTM D 4718 Section 4.2 for oversize rock content.
113.6
107544010_FDT_ CF#1 (Slope).xls Field Density Test Sheet 2013 v 2.9
Tested material does does NOT meet the requirements of the approved project documents.
The material was was NOT sampled and tested as required by the approved project documents.
110.7 112.0108.3
123.0123.0
NOTE: Tests results shown bold italicized have been corrected per ASTM D 4718 Section 4.2 for oversize rock content.
91 93
123.0
110.4113.8 113.1
123.0
109.3
NG
123.0
2047
369
160
Test Of CF CF CF
NG NG NGTest Type (SC/SC(SR) = Sand Cone, NG = Nuclear Gauge)
LFV
LFV
LFV
CF
CF
LLB
LLB
LLB
LFV
CF
CF
CF
CF
Initials Test Location
STA 77+50 SLOPE REPAIR
STA 77+65 SLOPE REPAIR
Elev. or
Depth (ft)
148.0
150.0
Test
Of
Block
No.
PASS
LFV
Soil Type Number
10.6
90 90
92
11
123.0
Corrected Maximum Density (pcf)
10.7
Relative Compaction (%)
Specified Relative Compaction (%)
Coarse/Finer Fraction in Max (%)
90
Optimum Moisture (%)
1
10.5
90
1STANDARD& TEST COUNTSSoil + Rock + Tare (lbs)
Sand in Cone + Hole (lbs) / (DC)
92
123.0
113.7
TEST RESULTSDry Density (pcf)
MOISTURE
CF
Sand + Bottle Before (lbs) / (DS)
Sand + Bottle After (lbs) / (MS)
156.0
Test No.
3/24/16
25
29
154.0
155.0
CF
125.8 124.3
11
90
11.0
FAIL
10.5
123.0
10.5 10.5
10.9 11.7
27
90
88
90
10.5
90
10.5 10.5 10.5
89 90
11
90
10.1 11.1 13.0
126.0 120.3 125.6 124.7
662 1584
671
172 160 782
148 165 169
2062
671671
2062
397
2047
643650
467
2062
22 23
30
3029
NG
CF
NG
5710 Ruffin Road, San Diego, CA 92123 Test Type:
3/24/16
Permit No.:
Project Street Address:
Jurisdiction:City of Carlsbad
152.0
3/23/16
SUMMARY OF FIELD DENSITY TESTS
Fill
NG
CF
21
3/24/16 155.0
28
STA 77+65 SLOPE REPAIR
27 2824
STA 77+47 SLOPE REPAIR
26
STA 77+45 SLOPE REPAIR
STA 77+45 SLOPE REPAIR
STA 77+45 SLOPE REPAIR
Project Name:La Costa Avenue Slope Repair Project No:107544010
STA 77+65 SLOPE REPAIR
Plan File No.:
La Costa Avenue (~2912 La Costa), Carlsbad, CA
60241
152.0
24
Test Date
3/22/16
3/23/16
3/23/16
3/22/16
Test
No.
21
22
23
650
171 174
121.0Wet Density (pcf)122.8
Laboratory Maximum Density (pcf)
Percent Moisture
Retest on (if applicable)
Pass/Fail PASS
24
PASS
2006 2006 2006
PASS PASS FAIL PASS
CF
369
25
NG
CF
643
367
643
CF
Tare (lbs)
Sand in Cone (lbs) / (MC)
26
27
Coarse Fraction (%)
Finer Fraction (%)
Coarse Fraction (lbs)WET DENSITY & ROCK CONTENT107544010_FDT_ CF#1 (Slope).xls Field Density Test Sheet 2013 v 2.9