HomeMy WebLinkAboutCT 02-18; THE BLUFFS; REPORT OF GEOTECHNICAL OBSERVATION AND TESTING OF ROUGH GRADING OPERATIONS; 2005-12-014
NorCal Engineering
Soils and Geotechnical Consultants
10641 Humbolt Street Los A1amitos,CA 90720
(562) 799-9469 Fax (5,62)'799-9459
December 1, 2005 Project Number 9482-01
Anastasi Construction
511 Torrance Boulevard
Redondo Beach California 90278
• Attn Mr. John Simmons -
- RE Report of Geotechnical Observation and Testing of Rough Grading
Operations - Proposed The Bluffs' Residential Development (Units 101
through 1405 and Recreation Building) - Located South of Chinquapin
Avenue Between Harrison Strëèt and Adam Street, in the City of
Carlsbad, California
4
• 4
-'---4 •. ,-'- -.•-•,
4
Dear Mr. Simmons: "
Pursuant to your request this firm has provided this getechnical report to summarize
the observation and testing performed during rough grading operations at the above
•
* referenáed projct. The geotechnical aspects of the grading were conducted in'
accordance with our report titled "Geotechnical Engineering Investigation', dated July
31 2001, Project Number 9482-01.,Our geotechnical services pertaining to the grading
of the project development are summarized in the subsequent sections of this report
Site Grading
The purpose of the grading operations was for the placement of fill to provide structural
support of the pro póséd development: All vegetation and demolition debris was stripped
and removed from the fill area prior to the placement of any fill soils The upper low
density, surface soils were removed to competent native material the exposed surface
scarified moisture conditioned and then recompacted to a minimum of 90% relative
-
compaction
:. .--:
•
t. 4 4' •.s • . •0 - •
.4
1
December 1 2005 Project Number 9482-01
Page
'In the opinion of this firm, the native soils are suitable to support the placement of fill
• material. Grading extended a minimum of five horizontal feet or to the depth of fill
placed, whichever is greater, beyond the edge of the proposed foundations.
• Fill soils placed were compacted to a minimum 90% of the laboratory standard in lifts
,
not in excess of eight inches in thickness. The maximum depth of fill soils placed was
approximately 6 feet. Conventional earthmoving equipment Was utilized for compaction
control. A water truck provided moisture control. OUr services. did not include any
• . surveying of excavation bottoms, building corners, or , s,ubgrade elevations during
grading .operations. . . . .
Laboratory/Field Testing
. . . The relative compaction was determined by Sand Cone Method (ASTM: D1556-00) and
by the Drive Tube Method (ATM: D2937-00). The maximum density of the fill soils was
obtained by the laboratory standard (ASTM: D1557-00) and results are shown on Table
I. Tests were performed a minimum of every 500-cubic yards placed and every two feet
in, depth of fill placed. .A summary of the compaction 'tests of the rough grading
operations are-described in Appendix B with locations shown onthe accompanying plan'.
Additional laboratory tests were performed on representative bulk bag samples of the'
'near surface soils at the completion of precise grading operations. The tests consisted
of the following: ,
A. Expansion index.-tests in accordance with the Uniform Building -Code Standard No.'
• 18-2 were performed on remolded samples of the upper soils to determine the
expansive characteristics and to provide any necessary recommendations for
reinforcement of the slabs-on-grade and the foundations. Results of these tests are
provided on Table II in Appendix A.
' ' . '. '
B. Soluble sulfate tests, in accordance, with California Test Method 417 were performed
on representative soils samples to estimate the potential for corrosion of concrete in
contact with the on-site soils. Results are provided 'on Table lii in Appendix A.
NorCal Engineering ' •.
. December 1, 2005 Project Number 9482-01
Page 3
Foundation Design .
. ,'
All foundations may be designd utilizing an allowable soil bearing capacity of 2,200 psf
- or an embedded depth of 18 Inches into approved compacted fill soilsor competent
native soils. The bearing value may be increase by 500 psf for each additional foot of
depth in excess of the 18-inch minimum depth, up to a maximum of 3,000, psf A one-
third increase may Be used when considering short term loading and seismicforces. A
representative of this firm shall observe all foundation excavations prior to pouring
- concrete: .-I
.
-•.
4
Slab Design
All concreteslabs shall be 'a minimun of four !nhe in thickness and placed on
approved subgrade soils. A vapor retarder sandwiched within four inches of select hand
I shall be -'utilized beneathfloor slabs which would be sensitive to the infiltration of
S . -
moisture. All concrete slab areas to receive floor coverings should be moisture tested-to
meet all manufacturer requirements prior.to placement.
. -: .
Corrosion Desiqn'Criteria
-. Representative samples of the surficial soils revealed negligible sulfate concentrations.
Therefore, all conôrete.in contact with on site soils shall be'deigned in accordahc with
1 , Table 19A-A-4 of the 1997 Uniform Building Code Sulfate test results may be found on
the attached Table Ill. - -.
- Expansive Soil
The on-site soils have very low expansion'.potential (El<20) On sites with expansive
sails special attention should be given to the project design and maintenance The
attached Expansive Soil Guidelines should be reviewed by the engineers, architects,
owner, maintenance personnel and other interested parties and considered during the -
9. . design of the project 'and future. property maintenance: : , •. .
. :.. -'S.- .
•
_4 .- • - - - S
NorCal Engineering
• December 1 2005 Project Number 9482-01
Pages
.
Expansive Soil Guidelines
• . .
The following expansive soil guidelines are provided for-your project. The intent of
these guidelines is to inform you, the client, of the importance of proper design and ;
• maintenance of project supported on expansive soils. You, as the owner or other -
interested party, should be warned that you have a duty to provide the
O information contained in the soi!report including these guidelines to your design
engineers, architects, landscapers and other design parties in order to enable
- them to provide a design that takes into consideration expansive soils.
'In addition, you should provide the soil report with these guidelines to any property
• manager, lessee, property purchaser or other, interested party that will have or assume
the responsibility of maintaining the development in the future.
Exp'ansive soils are fine-grained silts and clays which are subject to swelling and
contracting: The amount of this swelling and contracting is subject to the amount of
fine-grained clay materials present in the soils and the amount of moisture either
• introduced or extracted from the soils Expansive soils are divided into five categories
ranging from 'very low to "very high' Expansion indices are assigned to each
classification and are included in the laboratory testing section of this report. If the
expansion index of the soils on your site, as stated in this ,report, is 21 or higher, you
have expansive soils. The classifications of expansive soils are as follows:
•
Classification of Expansive Soil*
Expansion Index Potential Expansion
0-20 Very Low,
21-50. Low
51-90 Medium
91-130 . High
Above 130 Very High
*From Table 18A-1-B of California Building Code (1988)
When expansive soils are compacted during' site grading operations, care is takento
place the materials at or slightly above optimum moisture levels and perform proper
compaction operations. Any subsequent excessive wetting and/or drying of expansive
soils will cause the soil materials to expand and/or contact. These actions are likely to
cause distress of foundations, structures, slabs-on-grade, sidewalks and pavement over
the life of the structure. It is therefore impirativé that even after construction of
improvements, the moisture contents are maintained at relatively constant levels,
allowing neither excessive wetting or drying of soils. •.
N6rCa1 Engineering
December 1, 2005 - Project Number 9482-01
Page 6
Evidence of. excessive wetting of expansive soils may be seen in concrete slabs, both
interior, and exterior. Slabs may lift at constructionjoints producing a trip hazard or may
crack from the pressure of soil expansion. Wet clays in foundation areas may result in
lifting of the structure causing difficulty in the opening and closing of doors and windows,
as well as cracking in exterior and interior wall surfaces In extreme wetting of soils to
depth settlement of the structure may eventually result Excessive wetting of soils in
landscape areas adjacent to concrete or asphaltic pavement areas may also result in
expansion of soils beneath pavement and resultant distress to the pavement surface
Excessive drying of expansive soils is initially evidenced by cracking in the surface of
the soils due to contraction Settlement of structures and on-grade slabs may also
eventually result along with problems in the operation of doors and windows
Projects located in areas of expansive clay soils will be subject to more movement and
"hairline" cracking of walls and slabs than similar projects situated on non-expansive
sandy soils There are however, measures that developers and property owners may
take to reduce the amount of movement over the life the development. The following
guidelines are provided to assist you in both design and maintenance of projects on
expansive soils
, e Drainage away from structures and pavement is essential to prevent
excessive wetting of expansive soils Grades of at least 3% should be
designed and maintained to allow flow of irrigation and rain water to
approved drainage devices or to the street. Any "ponding" of water adjacent
to buildings, slabs and pavement after, rains is evidence of poor drainage the
installation of drainage devices or regrading of the 'area may be required to
assure proper drainage Installation of rain gutters is also recommended to
control the introduction of moisture' next to buildings.' 'Gutters should
discharge into a drainage device or onto pavement which drains to roadways
Irrigation should be strictly controlled around building foundations, slabs and
pavement and may need to be adjusted depending upon season This
control is essential to maintain a. relatively uniform moisture content in the
expansive soils and to prevent swelling and contracting Over-watering
adjacent to improvements may result in damage to those improvements.'
NorCal Engineering makes no specific recommendations regarding
landscape irrigation schedules
Planting schemes for landscaping around structures and pavement should
be analyzed carefully. Plants (including sod) requiring high amounts of water . may result in excessive wetting of soils. Trees and large shrubs may actually
extract moisture from the expansive soils, thus causing contraction of the
fine-grained soils
December 1, 2005 Project Number 9482-01
Page 7'
Thickened edges on exterior, slabs will assist in keeping excessive moisture
• "
from entering directly beneath 'the concrete. A six-inch thick or greater
'deepened edge on slabs may be considered. Underlying interior and exterior
slabs with 6 to 12 inches or more of non-expansive soils and providing
presaturation of the underlying clayey soils as' recommended in the soil
report will, improve the overall performance of on-grade slabs.
' o Increase the amount of steel reinforcing .in concrete slabs, foundations and
'
other structures to resist the forces of expansive soils. The precise amount
of reinforcing should be determined by the appropriate design engineers
and/or architects.
Recommendations of the: soil' report should always be .followed in the
development of the project. Any recommendations regarding presaturation
of the upper subgrade soils in slab areas should be performed in the field
and verified by the Soil Engineer.
S '• "• ' '.•
• ' ''
• ' ' ' ' .," ' ' • ' •2
• '" "'
' ''
'
'
•'• ' '
NorCal Engineering
- .December 1, 2005 . .. Project Number 9482-01
Page 8 1 . .. ... ,.
- .
TABLE
.
MAXIMUM DENSITY TESTS. -•
- :(ASTM: 01557-00) ..-. .
Optimum Maximum Dry
Sample Classification Moisture Density (lbs /cu if)
• I . ,. SAND fine to medium grained, - 9.0 125.5.
slightly silty - .. .
II SAND fine to medium grairied, 10.0 120.0
lightly silty
SAND fine to medium,grained, .95. -
.122.0
- slightly silty
- . .. .'
1._ .
TABLE 11
EXPANSION INDEX TESTS -. .
(U.B.C. STD. 18-2)
. . . Expansion
. - . Sample • .
Classification . Index
Pad Subgrade . SAND fine to medium grained, 04
• . slightly silty . • .
.
• Pad Subgrade . SAND fine to medium grained, 01
•
- slightly silty
., .'. . . . ..
- -
- . . • - . . . ,., TABLE III - -
SULFATE TESTS . . . .
(CA. TEST METHOD 417)
Sample. . . . Sulfate (% by Weight)
• . . Pd Subgrade •. .
0.021 , -•.
-. . . -.. Pad Subgrade .
-
0.010 •. -.
Pad Sübgrad& . - •- . 0.014
Pad Subgrade 0.007
Pad Subgrade . • .
.
•. .•t . - 0.009 . S. •
- • .. ., -. .:- . .
NorCal Engineering ,
December 1 2005 Project Number 9482-01
Page
SUMMARY OF COMPACTION TEST RESULTS
• Date of Test Percent Unit Wt. Relative Soil Test
Test No. Location Depth Moisture lbs./cu.ft. Compaction L S/D
10/24/05 101 Site Grading 2.0-2.5 8.6 119.4 95 I S
10/24/05 102 Site Grading 2.0-2.5 9.4 112.4 94 II . D
10/24/05 103 Site Grading 1.0-1.5 8.9 113.9 95 II D
• 10/25/05 104 Site Grading 1.5-2.0 9.0 110.1 92 II D
10/25/05 105 .Site Grading 1.0-1.5 9.3 114.6 91 I S.
10/25/05 106 Site Grading 0.5-1.0 8.8 116.7 93 I D
10/25/05 107 SiteGrading 2.0-2.5 9.1 115.5 92 I D
10/25/05 108 Site Grading 1.0-1.5 8.6 103.1 86 II D
•
. 5 5
10/25/05 108A** Site Grading .1.0-1.5 9.4 110.6 ,' 92 II D
10/25/05 109 Site Grading 1.0-1
'
.5 9.2 '113.6 91 I S .
10/25/05 110 Site Grading 3.0-3.5 8.7 114.9 92 I D
10/25/05 111 Site Grading 4.5-5.0 8.9 116.6 93 I D . 10/25/05 112 Site Grading 6.0-6.5 9.3 111.6 -1 93 .' II . D.
10/25/05 113 Site Grading 4.0-4.5 9.8 113.6 .: 91 I S
10/26/05 114 Site Grading 2.0-2.5 8.5 111.5 93 II D
10/26/05 115 Site Grading 0.5-1.0 9.6 114.1 91 I D
10/26/05 116 Site Grading 3.0-3.5 10.3 111.2 91 III
10/26/05 117 . Site Grading 2.0-25 8.8 118.3 ,' 94 I D
• 10/26/05 118 Site Grading 1.5-2.0 . 10.5 113.1 90 I . D
10/26/05 .119 . Site Grading 0.5-1.0 9.9 113.5 s93. 'Ill. D
10/26/05 120 Site Grading 2.0-2.5 10.2 113.4 90 I D
11/1/05 121 . Site Grading 0.0-0.5 8.5 116.7 93 I D
11/1/05 122 Site Grading 0.070.5 8.3 113.3 93 III S
• 11/1/05 123 Site Grading 0.0-0.5 8.6 116.2 . 95 ' III D
11/1/05 124 Site Grading 2.0-2.5 8.9 .' 119.4 95 I D
11/8/05 125 Site Grading 0.5-1.0 9.5 ,118.9 95 I S
11/8/05 126, Site Grading 0.51.0 9.7 112.1 . 93 II D
11/16/05 127 Site Grading 0.0-0.5 8.5 118.9 95 .1 . D
11/16/05 128 Site Grading 0.0-0.5 9.7 116.8 93 I D
11/16/05 129 Site Grading 0.0-0.5 9.6 112.0 93 II S
11/16/05 130 Site Grading 0.0-0.5 9.9 112.8 945 II D.
11/16/05 131 Site Grading 0.0-0.5 9:4 , 114.3 95 II D
**Rétest of failing tests after area reworked
S= Sand Cone Method . .
D=. Drive Tube Method
• S
,' 5
NorCal Engineering
.,
December 1, 2005 Project Number 9482-01
Page-10
SUMMARY OF COMPACTION TEST RESULTS
Date of Test Percent Unit Wt. Relative Soil Test
Test No Location Depth Moisture .Ibs./cu.ft. Compaction L SID
11116/05 :132 Site Grading 0.0-0.5 9.8 116.6 93 I D
11/16/05 133 Site Grading 1.0-1.5 9.1 114.6 91 I D
..11/16/05 134 Site Grading,-,1.0-1.5. 8.9 113.6 93 . III D
• 11/16/05 135 Site Grading 1.0-1.5 9.2 118.1 94 I
11/16/05 136 Site Grading 0.0-0.5 8.7 113.3 94 II . S
11/16/05 137 Site Grading:. 0.0-0.5 . 9.0 117:4 94 . I D
11/16/05 138 Site Grading .0.0-0.5 9.2 114.0 95 II D
• 11/16/05 139 Site Grading 1.04.5 8.9 114.1 91 I S
• 11/16/05 140 Site Grading 1.0-1.5 9.2 116.0 95 III D
11/16/05 141. Site Grading 1.0-1.5 9.5 116.9 93 I. D
11/16/05 142 Site Grading 0.0-0.5 9 112.9 94 II S
11/16/05 143 Site Grading 0.0-0.5. 9.7 111.2 93 I D
11/16/05 144 Site Grading 0.0-0.5 9.4 117.0 93 I D
11/21/05 145 Site Grading 0.0-0.5 .-. 9:6 115.5 95 Ill D
11/21105 146 Site Grading 0.0-0.5 9.1 113.8 93 III S
11128/05 147 Site Grading 0.0-0.5 9.8 121.1 96 I D
11/28/05 148 Site Grading 0.0-0.5 9.5 112.3 . 94 II •
11/28105 149 Site Grading 0.5-1.0 9.9 118.2 94 I D
• 11/28/05 150 Site Grading 0.0-0.5 9.4 118.8 95 I S
11/28/05 151 Site Grading 0.0-0.5 9.7 114.9 92 I D
11/28/05• 152 Site Grading 0.0-0.5 10.2 112.81 94 II D
11/28/05 153 Site Grading 0.0-0.5 9.8 115.7 92 • .1 . D
• •• •
**Retest of failing tests after area reworked .
• S= Sand Cone Method .
D= Drive Tube Method •
• :
••.
• .
NorCal Engineering
. ___ ___ _________ ______ ______
% 10' IN 77 MAN I I -' 11' I I
_____
__
MV? AM
16
1b -.00
Do.
7 10
100
00
___ ___
-
L_12-kOOk
-
-—_—' - [ ___ - 1 -
__ - i, ~/
-
___ ___ ___ ___ 2 - — ___
-----------------
Y,-,% __ — — — — — — —P-11 — — — — — — — ---
A-
:,: ~7 / // I M5 .5 I Berm
VACAM PD? SW
- - -- 7 , - ---
-IN /
7/ 1/ ,' .:
0 A-
f 'fl .ct ADAMS TREE i / I .' I ' ' . . . r - - -
71CV IV
/,'\ -
- / - / -
( —
- - / - I
77 wa
10
I I -
_-'- \ -,
- 0
--_- A- I
,- 2O5D8;00- 02O542O43OO ' k -
/
00
iN
- Ar ofl78 PIT
N. tj
Wall
11 Wall
2, C15 WYATAW
A_
LOr 46
AP2O5OO7Oo I/'_. (4 AMLLENT r / - / MAP 2f03 \\\ 7' // / -- - ----
APR 20,6-f20-09-00 "el
--
/
NN
ej 01 50 0
10'-
-- - -
\ /
I 7 -- , .( - -
- .' - - - ,
' :i_ I "
,i SCpIE.1E2o' 0 }
,-_ , /\ ( I l I k r /1
, . •.
2WC-
I L
' ER fl -
ffR,9')R C-J \ \ \
I
' \ - P R(17
I / / _j ' I __,iJ==I__ - — '
75370 1
ALL 74
_j \ AAM 115ALL r - 7450 F;
' - -- -i---1 - -
.5 /S.\,(\ Pa 52M
ZPPEYUJi7
' "i "
/ (" "APN/" %
I
I -
//
6O 14=74.52 39
(0 7557
I \I
131: -
1
--
1
ALrr PAR3.VVr
107 lj!ff 2V3 \1 06 I - i
BLOCJI'A Ar
L07 p,40_7574 •S
,'I\ I I -ri '---
- rr—cooj' 11!:
AAO
PA BLOCKA >
/
0_:7J 7 136 810 7AAZLL2' - •4I - - - - fP4W P40=7355 FF=d 07 151 '124' ".°'- \IT
74
=707 /T:5907
OF= 73 4j . SS i:i 1
- "
125 6.267 COlE VAT 71 15
voays Y0 00
A-
.42
T
V,95
qj
7.1 N • -
_
PA,0=72 88
f F=6534 130
- - - // "
-'
/
PAD=75JO PAD-77 07 F\J T40. I -A
t
OF-77671 02 CF=7725 GF=7701 OF= 76 78
PAD=77,00 PAD=& M PAD-Z. 34 PAD=76 11
rp GF=76.39 6F=75 97 GF=75.74 =875 FF=86.75 875 =85.75 . =85.47 8547 =847 ff47 -- - . — — — 4'ff=866 L. 828 7242 I . ....... '• ' . 5 '
. I'. r2 I .102
-----''-- J1 —.5---- / V 129 101 \
V
If) sI1 7W 4.6
ID' i44.r
L! f7ANIIV4U1
.
\,
ISTAU
&t =/O. GF=7502 CF=7482 CF=7460 'c._' - CF=7420 61=7399 - CF=7377 CF=7357 A7A7I 1 I FF=8366 V /T-8z18 CF=7224
FF=8424 FF=8424 FF=8424 \ FP=8424 FF-8328 P1=8328 FF-8328 FP=8328 PAD=7268 I -. FP=83OF= 7J J5 d 123
9J I 64ST1 I l
S.___ ' I - - H
-k- • NJ-' , .L V
___
• I_-- --
I 152 I -
- -)
- V:I II a
'OWN, 1
0? SMOM
4
- V • •.9I55 I ---
D-,o?1r II swam
17
IV IL
IJAL
R48
?AMI VAil V -
I
/V
l 1 I k • V \ / 1 V
-, - .z au / CF-69 23 , I -
I
I
"
1 (, ci AIAP2YOS MAP21os
PAD=7
V
- -- -------*= =---==s -
1 5< ,__/v_ I 056'
LOr
205-120-02-00 API? 205-120--02-D0 F { I 119 BOC BALL COVRT- 4 I I . -
'V\ V - - -
- 1 r VA7(R 4
I / I
(' p_i' 1 .1116 •
JJ T
10
1 14U
121
0-
-; I 7 I 14(427W I1 r('14j- 41
92 02 1007
I I 46
PAD 7174 PA 7163 PAD 7144 PAD 7121 I I PAD 7082 PAD 7059 -\-
14
Ar
PAD 7040 PAD 7017 PAD 6994
CF=7241 =7230 CF=7211 CF=l• CF-71.26 CF-71,07 OF= CF=70.61 7/88 =7
Ff '=80 57 FF=80 57 fF=80 57 1:11 I rsar CP
60
14
145 F13011 FiND31 F1407
B6 ILE
L072 7217i1 au
•
/ I I - &'7W I / r I $
API? 20%-12D-02-'00
LAW 7w
Ib
I I 4) 1 !. 72tVF
'_J At -','
air , slAw'y ,,c I' 11250\ S •' "
0 _,ffí / Pf=64.66
/
ioOii1 —i - - — - -, '. — — — --g'--- ..., W
- ff=5466 PA lar WAAP
wff 044, Az~
11---------- I ti tJ 11
t61S1/ZT L S.5 SSS _fl I
rF-6566 h 77 59
rr 66'
128 1 'II I
U7lJTYL4Y7 " .5
5. 1 '18 Aall
10
-149 / / /
//
B,w4!
R5d7g 55 [F 55 fF=
r/ 1071 V204 T_ V? A04 1201 1 .7 E1207 F7001
5763 /Z N
TO kXW
4&AV it 24 2M
~Mw 7w
s
'' *
/
I .- k
- -,
- TF__
-- _ - \_\ - - 11
V
- -- -
/ -- / - PA ' I - --
I\ I V .5 - • V C.) { V C')
• Q)V
_____1
1 1
-
--
- -
.-- PA;CWVr iv
A Berm k
12100 HARRI$ON SAItT PM DW 4X-8 ZZ,
00 A IMITS OF FILL
I
5.
1 co
I £ I •
- '*- - -
'\
- j__ - - I I Rrm ,/- \H\- J ___ - / — - - ___-
'-7
I'-
#1
-------------- &V
.................... Q11- PK V A;,FS
~T "7~_ NJ C
SIT ............
L. ..... .0 ......... . ............. -,v ......... N-f
. . ........... . . . . ...... ...
. .... . ......................... ........ .....
2
'N 00M
"tf/ " i I _j ~ / -\~ ; I PLA
'SHEET I OF I
e) DESIGNED BY: K.D..C.O.IJ.T.
DRAWN BY: J.S._C.F.
PROJECT MGR.:_C.OD.
N T S
DATE: NOV.2004
SCALE: 1* = 20
JOB NO.: 01-1022
CONSULT
2710 Laker Avenue West
Suite 100
Civil Engineering
Planning ENGINEER OF WORK:
Carlsbad. California 92008 Processing
760-931-7700
Fax: 760-931-8680
Surveying
DATE:
GEORGE 0'DAY RCE: 32014
: \ulluzz\wzzzzl.).awg uct ii, zuuz
Xrefs: 0122TP01; 0122mcp; 01227U11. 0122STR; 0122CRD; 0122UTL; 0122GTXT