HomeMy WebLinkAboutCT 03-06; BLACKRAIL 16; AS GRADED GEOTECHNICAL REPORT; 2014-05-29C1o3—01(
SOUTHERN CALIFORNIA
(J SOIL & TESTING, INC.
'"- SBE I SLBE I DVBE I SDVOSB
May 29, 2014
Mr. Marty McComas
Davidson Communities
1302 Camino Del Mar
Del Mar, California 92014
Corporate Headquarters
6280 Riverdale Street
San Diego, CA 92120
Toll Free: 877.215.4321
www.scst.com
SCS&T No. 1311204
Report No. 5
Subject: AS-GRADED GEOTECHNICAL REPORT
BLACK RAIL ROAD - 16— SUBDIVISION
CARLSBAD, CALIFORNIA
Dear Mr. McComas:
PROJECT DESCRIPTION
Southern California Soil and Testing, Inc. (SCS&T) prepared this report to present the results of field
observations and compaction testing performed during earthwork for the subject project. This report
presents a summary of SCS&T's observations and testing between May 7, 2014 and May 27, 2014.
To assist in locating our field density tests, we were provided the referenced precise grading plan
prepared by Fuscoe Engineering, dated January 18, 201.4.
SITE PREPARATION
Site preparation began with the clearing and grubbing of the existing vegetation and debris. These
materials were exported from the site. The mass grading consisted of excavating about 2 feet
below the planned finish pad grade elevation. The surface exposed at the bottom of the
excavations was scarified to a depth of 6 inches; moisture conditioned, and compacted until field
density tests indicated a minimum of 90% relative compaction. Figure 1 presents the excavation
bottom elevations. Excavated material free of organics and deleterious material was placed as
compacted fill. The material was moisture conditioned and compacted until field density tests
indicated a minimum of 90% relative compaction. Fill was placed until planned pad elevations were
I
achieved. All references to optimum moisture and relative compaction in this report are based on
the ASTM D 1557 laboratory test method. Figure 1 presents the approximate density test locations.
AS-BUILT GEOLOGY
In our opinion the geological conditions exposed at the site were found to be similar to those
described in the referenced geotechnical report and generally as anticipated. Additionally it is our
opinion that the site is suitable for the planned construction.
San Diego I Los Angeles I Inland Empire Central Valley
I
Davidson Communities May 29, 2014
I
Black Rail Road 16 SCS&TNo. 1311204-05
Carlsbad, California Page 2
I FIELD OBSERVATIONS AND TESTING
Field density tests were performed in accordance to ASTM D6938 (nuclear gauge) procedures.
Figures 2 through 3 present the test results. The accuracy of the in situ density test locations and
elevations is a function of the accuracy of the survey control provided by others than SCS&T
representatives. Unless otherwise noted, their locations and elevations were determined by pacing
I and hand level methods and should be considered accurate only to the degree implied by the
method used.
I As used herein, the term "observation" implies only that we observed the progress of work for which
we were involved. We performed field density tests, which in conjunction with our observations,
were the base for our opinion as to whether the work performed was in substantial conformance with
I the geotechnical recommendations and the requirements of the applicable agencies.
A maximum dry density test was performed on two representative samples of the soil used in the
I compacted fill according to ASTM 01557. The results of these tests, presented on Figure 3, were
used in conjunction with the field density tests to determine the degree of relative compaction of the
I
compacted fill. The soluble sulfate content was determined in accordance with California Test 417.
The soluble chloride content was determined in accordance with California Test 422. Expansion
index results were determined in accordance with ASTM D4829. Figure 3 presents the test results.
I CONCLUSIONS
Based on our fieki observations and the in-place density test results, it is the opinion of SCS&T that
I the geotechnical engineering aspects of the grading are in compliance with the referenced
geotechnical report, the City of Carlsbad Grading Ordinance, and the California Building Code. In
I our professional opinion and to the best of our knowledge, the site appears to be suitable for the
planned construction.
I LIMITATIONS
This report covers only the services performed between May 7, 2014 and May 27, 2014. Our
opinions are based on our observations and the relative compaction test results and are limited by
I the scope of the work that we agreed to perform. Our work was performed in accordance with the
currently accepted standard of practice and in such a manner as to provide a reasonable measure
I of the compliance of the grading and backfill operations with the project requirements. No warranty,
express or implied, is made or intended with respect to the work that we have performed,
I
and neither the performance of this work nor the submittal of this report should be construed as
relieving the contractor of its responsibility to conform with the project requirements. Our work was
generally performed on an "on-call" basis. Therefore, the in-place density tests performed by our
I field representative can only be construed as representative of the areas tested as shown on the
attached figures.
!? IIIm O No. 2472
Exp. 8-31-14 II ui!l CERTIFIED
ENGINEERING ilIA ll
GEOLOGIST Ji */
Andrew K. Neuhaus, CEG 2591
Senior Engineering Geologist
I
Davidson Communities May 29, 2014
Black Rail Road 16 SCS&TNo. 1311204-05
I Carlsbad, California Page 3
I Should you have any questions regarding this document or if we may be of further service, please
contact our office at your convenience.
I Respectfully Submitted,
SOUTHERN CALIFORNIA ND TESTING, INC.
CD
LU NO. 2752 M
Principal Geotechnical
GBF:AKN:EAK:aw
I ATTACHMENTS
-Figures
I Figure 1 - In-Place Density Test Location Map
Figure 2 through 3 - In-Place Density and Laboratory Test Results
I (1) Cheryl Landes via e-mail at: cIandestdavidsoncomm unities. com
(1) Marty McComas via e-mail at: MMCComas(davidsoncommunities.com
(1) George Sturgeon via e-mail at: gsturgeon(davidsoncommunities.com
iOFES,0
K.
CERTIØ
I
Davidson Communities May 29, 2014
Black Rail Road 16 SCS&TNo. 1311204-05 I Carlsbad, California Page 4
REFERENCES
"Preliminary Geotechnical Investigation, Proposed 17-Lot Subdivision, Black Rail Road,
Carlsbad, APN 215-080-20,21,28"; prepared by Vinje and Middleton, Inc., dated May 22,
2003. Project Number 03-236-P
"Interim Report of Geotechnical Testing and Observation During Earthwork Construction,
Lots I through 16, Black Rail TM No. 2-026"; prepared by GeoTek, Inc., dated July 25,
2007, Project Number 3103SD3.
"Geotechnical Exploration and Review of Precise Grading Plan for Carlsbad 16 Project, Lots
I through 16 of Map 15521, Carlsbad, California- DRAFT'; prepared by NMG Geotechnical,
Inc., dated November 30, 2012, Project Number 12115-01.
"Update Geotechnical Report, Black Rail Road - 16 Subdivision, Carlsbad, California",
prepared by Southern California Soil and Testing, Inc., dated December 31, 2013.
Precise Grading Plans, Carlsbad 16, Lots 1-16 of Map 15521, Sheets 1 through 4, prepared
by Fuscoe Engineering, January 18, 2014.
JOB NAME: BLACK RAIL ROAD -16 - SUBDIVISION JOB NUMBER: 1311204-05
IN-PLACE DENSITY TESTS
TEST
NO. DATE LOCATION
ELEVATION
(feet,MSL)
MOISTURE
(percent)
DRY DENSITY
(p.c.f.)
SOIL
TYPE
REL.COMP.
(percent)
GRADING
1 5/7/14 Lot# 15-North PAD 374.0 11.7 115.9 1 92.1
2 5/7/14 Lot# 15- North PAD 374.0 12.2 113.8 1 90.4
3 5/7/14 Lot# 14- North PAD 374.0 12.0 115.1 1 91.4
4 5/7/14 Lot# 14- North PAD 374.0 11.3 113.7 1 90.3
5 5/7/14 Lot# 13- North PAD 372.0 13.0 114.6 1 91.0
6 5/7/14 Lot# 13- North PAD 372.0 12.0 114.4 1 90.9
7 5/8/14 Lot# 15- South PAD 374.0 13.2 113.5 1 90.2
8 5/8/14 Lot# 14-South PAD 374.0 10.1 117.8 1 93.6
9 5/8/14 Lot# 12- North PAD 366.5 10.9 115.6 1 91.8
10 5/8/14 Lot# 12- North PAD 366.5 11.1 117.7 1 93.5
11 5/9/14 Lot# 11- North PAD 362.0 9.7 113.8 1 90.4
12 5/9/14 Lot# 11- North PAD 362.0 10.6 118.1 1 93.8
13 5/9/14 Lot# 13- South PAD 372.0 14.2 114.9 1 91.3
14 5/9/14 Lot# 9-North PAD 355.0 9.7 113.9 1 90.5
15 5/9/14 Lot# 9-North PAD 355.0 9.9 114.5 1 90.9
16 5/9/14 Lot# 10- North PAD 357.0 8.6 116.4 1 92.5
17 5/9/14 Lot# 10- North PAD 357.0 10.4 113.7 1 90.3
18 5/12/14 Lot# 1 - South PAD 373.5 13.0 114.0 1 90.5
19 5/12/14 Lot# 1 - Middle PAD 373.5 12.5 113.4 1 90.1
20 5/12/14 Lot#1-North PAD 373.5 13.2 115.6 1 91.8
21 5/12/14 Lot #4-South PAD 371.0 11.3 114.3 1 90.8
22 5/12/14 Lot #4- Middle PAD 371.0 10.7 113.5 1 90.2
23 5/12/14 Lot #4-North PAD 371.0 12.2 117.1 1 93.0
24 5/13/14 Lot# 11-South PAD 362.0 11.4 114.7 1 91.1
25 5/13/14 Lot# 8- South PAD 356.0 11.0 116.5 1 92.5
26 5/13/14 Lot #4 FG 373.0 12.3 117.1 1 93.0
27 5/13/14 Lot# 2-South PAD 374.0 11.3 116.4 1 92.5
28 5/14/14 Lot# 10- South PAD 355.0 12.4 114.4 1 90.9
29 5/14/14 Lot# 9-South PAD 355.0 11.6 113.5 1 90.2
30 5/14/14 Lot# 12- South PAD 366.5 11.4 115.8 1 92.0
31 5/14/14 Lot# 3-South PAD 373.5 13.2 114.6 1 91.0
32 5/14/14 Lot# 3-North PAD 373.5 11.8 113.9 1 90.5
33 5/14/14 Lot# 7-South PAD 358.5 12.4 119.3 1 94.8
34 5/14/14 Lot # 7 - South PAD 358.5 14.3 116.5 1 92.5
35 5/14/14 Lot # 6 - South PAD 364.5 9.9 114.3 1 90.8
36 5/14/14 Lot# 6-South PAD 364.5 12.2 115.6 1 91.8
37 5/14/14 Lot# 5-South PAD 367.5 13.1 110.4 1 87.7
38 5/14/14 Lot# 5-South PAD 367.5 12.3 115.8 1 92.0
39 5/14/14 Retest #37 367.5 12.5 117.2 1 93.1
40 5/14/14 Lot# 16- North PAD 370.0 10.3 115.0 1 91.3
41 5/14/14 Lot# 16- North PAD 370.0 11.1 113.7 1 90.3
42 5/16/14 Lot# 16- South PAD 369.5 5.5 117.1 1 93.0
43 5/17/14 Lot# 5 - North PAD 367.5 12.3 117.8 1 93.6
44 5/17/14 Lot #6 - North PAD 364.5 10.2 121.4 1 96.4
45 5/17/14 Lot# 7-North PAD 358.5 11.6 119.5 1 94.9
46 5/17/14 Lot# 8- North PAD 356.0 10.9 115.0 1 91.3
47 5/27/14 Lot 9 FG 357.0 8.4 122.6 2 95.9
48 5/27/14 Lot 10 FG 359.0 7.0 125.4 2 98.0
49 5/27/14 Lot 11 FG 364.0 5.5 123.5 2 96.6
Figure No. 2
I
JOB NAME: BLACK RAIL ROAD -16 - SUBDIVISION JOB NUMBER: 1311204-05
I 1 IN-PLACE DENSITY TESTS
TEST ELEVATION MOISTURE DRY DENSITY SOIL REL.COMP.
NO. DATE LOCATION (feet,MSL) (percent) (p.c.f.) TYPE (percent)
50 5/27/14 Lot 12 FG 368.5 6.7 126.3 2 98.7
51 5/27/14 Lot 13 FG 374.0 6.5 113.8 1 90.4
52 5/27/14 Lot 14 FG 376.0 6.5 118.9 1 94.4
53 5/27/14 Lot 15 FG 376.0 5.4 115.9 1 92.1
54 5/27/14 Lot 16 FG 372.0 7.1 122.9 2 96.1
55 5/27/14 Lot FG 375.5 6.2 114.7 1 91.1
56 5/27/14 Lot FG 376.0 7.9 117.2 1 93.1
57 5/27/14 Lot FG 375.5 7.4 115.9 1 92.1
58 5/27/14 Lot FG 375.0 8.0 122.3 2 95.6
59 5/27/14 Lot FG 369.5 6.2 114.7 1 91.1
60 5/27/17 Lot FG 366.5 7.8 122.1 2 95.5
61 5/27/14 Lot FG 360.5 6.4 120.3 2 94.1
62 5/27/14 Lot 8 FG 358.0 8.1 119.4 2 93.4
FG = Final Grade
MAXIMUM DENSITY AND OPTIMUM MOISTURE SUMMARY (ASTM D1557)
Soil Maximum Optimum
Type Soil Description Density, pcf Moisture, %
1 Reddish Brown Silty Sand 125.9 11.0
2 Brown Silty Sand 127.9 9.1
EXPANSION INDEX RESULTS
EXPANSION SAMPLE REPRESENT EXPANSION EXPANSION
TEST SAMPLE LOCATION LOTS INDEX POTENTIAL
El 1 0 feet to 5 feet Lot # 9 19 Very Low
El 2 0 feet to 5 feet Lot # 6 28 Low
E13 0 feet to5feet Lot#8 23 Low
E14 0 feet to 5 feet Lot # 13 8 Very Low
SULFATE TEST RESULTS, % BY WEIGHT
SOLUBLE
SULFATE SAMPLE REPRESENT SULFATE SULFATE
TEST SAMPLE LOCATION LOTS CONTENT (%) EXPOSURE
SS1 0 feet to5feet Lot#9 0.048 Negligible
SS2 0 feet to5feet Lot #6 0.001 Negligible
SS3 0 feet to5feet Lot#8 0.012 Negligible
SS 4 0 feet to 5 feet Lot # 13 0.009 Negligible
CHLORIDE TEST RESULTS, % BY WEIGHT I SOLUBLE
CHLORIDE SAMPLE REPRESENT CHLORIDE CHLORIDE
TEST SAMPLE LOCATION LOTS CONTENT (%) EXPOSURE
SS 1 0 feet to 5 feet Lot # 9 0.01 Non-corrosive
SS 2 0 feet to 5 feet Lot # 6 0.01 Non-corrosive
SS 3 0 feet to 5 feet Lot # 8 0.015 Non-corrosive
SS 4 0 feet to 5 feet Lot # 13 0.015 Non-corrosive
Figure No. 3