HomeMy WebLinkAboutCT 72-20; La Costa Vale Unit 1; Soils Report; 1973-04-02.-
.- Gentlemen:
BENTON ENGINEERING. INC.
AI.PL,EO SC,,. MFc:H*NltS F<~rin,>*,~,iil”*
6717 CONVOl COUR7 SAN DIEGO. C*l.IFORNIA 92I,!
PHIL.IP”EN~:lNc; LlLIVI”N Pr)ESlDEM(l ‘:I”,, Ee+GINELR
La Cost0 land Cunpany
Costa Del Mar Road
Cartsbad, California 92008
April 2, 1973
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RECEIVED
APR 4 1973
CITY OF CARLSBAD ,?, ,!!!!4!?s, PmxPent
Subiect: Project No. 72-8-18D
Grading Permit No. t-6392
T.M. 3036
Interim Report on
C-acted Filled Ground
Lots 1 to 10, inclusive
Lots 108 to 209, inclusive. and
Lomto 246, inclusive
La mle Unit No. 1
Carl&ad, California
CT 7z?-aiQ of-us KJQ 1
This is to report the results of tests and observations made in order to inspect the compaction
of filled ground placed on certain areas of Lots 1 to 10, inclusive, 108 to 209, inclusive, and
232 to 246, inclusive, of La Costa Vale Unit No. 1 in Carlsbod, California, formerly a part
of the County of Son Diego. Filled ground was placed on Lots 17 to 22, inclusive, on February
16, 1970 and the major grading of the subdivision commenced on September 21, 1972. The
results of field density test Nos. 1 to 1019, inclusive, taken during the period between February
16, 1970 and February 27,1973, were presented in our interim report on this project dated
March 1, 1973.
The filled ground was placed under our inspection in accordance with the approved specifications.
The grading plan used for the placement of filled ground was prepared by Rick Engineering
Company and approved August 23, 1972.
Some of the tests taken on the subject Iok were included in our previws report dated March 1,
1973. The results of field density test Nos. 1020 to 1109, inclusive, are presented on pages
T-28 to T-30, inclusive, under the “Table of Test Results.” The laboratory determinations of
the maximum dry densities and optimum moisture contents of the maior fill materials are presented
on page L-l, under the “Laboratory Test Resu1.k.” Some of the maximum dry densities shown in
the “Table of Test Resulk” were combinations of these. The tests were taken during the weekly
periods indicated on the following page,
Project No. 72-B-1BD
La Costa Vale Unit No. 1
-2- April 2, 1973
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Test Number Week Ending
1020 to 1035, inclusive March 3, 1973
1036 to 1040, inclusive March 10, 1973
1041 to 1072, inclusive March 17, 1973
1073 to 1105, inclusive March 24, 1973
1106 to 1109, inclusive March 31, 1973
Only nonexpansive soils were placed in the upper three feet below finished grade in the fill
areas on the subject lots. All expansive soils existing in the upper three feet below finished
grade in cut areas and areas of shallow fill were removed and were replaced with properly
ccmpacted nonexpansive fill soils. Therefore, special design for expansive soil conditions will
not be required on the subject lots.
The final resulk of tesk and observations indicate that the compacted filled ground has been
placed at 90 percent of the maximum dry density or greater. It has been determined that the
fill materials, compacted to 90 percent of the maximum dry density, have a safe bearing value
of 1650 pounds per square foot for one foot wide continuous footings founded ot a minimum depth
and placed five feet or more inside the top of campocted filled ground slcpes. If footings are
placed closer to the exposed slopes than 5 feet inside the top of compacted filled ground slopes,
these should be deepened one foot below a 1 l/2 horizontal to 1 vertical lfne projected outward
and downward from a point 5 feet horizontally inside the top of compacted filled ground slopes.
Tests indicate that the compacted filled ground is adequate to satisfactorily support the proposed
one and two story wood frame dwellings without detrimental settlements.
A plan showing the approximate areas and depths of filled ground placed under our inspection in
accordance with the approved specifications will be submitted with our final report on La Costa
Vale Unit No. 1.
Respectfully submitted,
BENTON ENGINEERING, INC.
BY d?d? -&we
R. C. Remer
Distr: (4) Addressee
La Costa Land Canpany
(1) Attention: Mr. Burton L. Kramer
(1) Rick Engineering Company, Carlsbad
San Diego County Engineering
(1) Attention: Mr. H. M. Taylor
(1) Attention: Mr. Willard Robinson, Rm. 260
Cf ty of Corlrbad
(1) Department of Building Inspection.
(2) Department of Engineering
Pardee Construction Company, Los Angeles
- ~42) Attention: Mr. Russell R. Ofria
(4) Attention: Mr. Jack Wagner
Philip Hi Benton, Civil Engineer (1) Attention: Mr. Bob Trede
Pardee Construction Company, San Diego
(1) Attention: Mr. Art Scott
(1) Attention: Mr. Mike Copik
(1) Delivered to lob site by Bud Beattfe
RCR/f’HB/ew
CIENTON ENGINEERING. INC.
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Project Wo. 72-8-18D
Lo Costa Vale Unit No. 1
T-28 April 2, 1973
Test
No.
1020
1021
1022
1023
la?4
1025
1026
1027
W.28
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
Approx-
imate
Location
Lot No.
84
84
84
84
84
84
84
83
2
84
83
a4
83
83
2
4%
47
a3
55
109
123
128
136
137
139
140
141
142
143
144
145
146
147
148
153
149
156
159
TABLE OF TEST RESULTS(CONT.)
Depth
of Fill Field
ot Test Moisture
in Feet % dry wt
14.0 15.1
16.0 15.0
18.0 . 15.3
20.0 12.5
22.0 12.5
24.0 11.7
26.0 12.8
1.0 10.0
30.0 11.4
5.0 10.2
34.0 15.3
9.0 13.1
38.0 15.8
13.0 16.1
15.0 11.2
17.0 13.3
5.0 17.2
4.0 17.0
14.0 14.6
19.0 15.9
2.0 15.2
6.0 l 20.4
15.0' 12.9
14.0 * 16.7
15.0* 11.2
10.0 l 16.1
4.0 * 16.2
3.0 * 16.8
3.0. 16.1
3.0 l 14.5
22.0 l 13.2
3.0 l 14.8
10.0 * 15.5
28.0* 11.7
40.5 * 13.9
43.0 * 12.5
8.0 * 11.4
29.0 + 17.1
16.0' 12.3
3.0' 14.2
l Finished Grate
DW
Density
lb/cu ft
Maximum
Dry
Density
Ib/cu ft
107.5 115.2
107.2 115.2
109.4 115.2
107.1 115.2
109.2 114.2
109.0 115.2
111.9 115.2
107.4 112.8
110.7 115.2
112.6 115.2
110.7 111,o
109.5 114.0
101.e 109.3
105.8 110.9
110.7 113.6
107.5 115.2
108.1 116.0
108.0 118.1
108.0 115.7
107.9 115.4
112.1 118.8
101.9 111.8
101.8 111.8
107.8 115.2
105.0 111.8
105.2 115.2
105.6 115.2
109.0 115.2
111.0 115.2
110.9 115.2
114.1 117.9
108.3 115.2
105.4 115.2
111.7 115.2
102.2 115.2
104.0 115.2
103.8 111.8
107.3 115.2
103.8 113.5
105.1 115.2
Percent
Compaction Remarks
93.2
93.0
94.9
93.0
95.5
94.5
97.0
95.4
95.8
97.5
99.6
96.0
92.9
95.4
97.4
2:
91.4
93.5
93.3
94.6
91.2
90.9
93.2
94.0
91.4
91.5
94.4
96.2
96.0
97.1
94.0
91.5
96.7
88.7
90.2
93.0
93.1
91.3
91.2
Ck on 1952
Ckon&3
Ckon #969
Ck on 1973
Reworked
Ckon #977
Ckon 1677
FIENTON ENGINEERING. INC
Project No. R-8-18D
LaCosto Vale Unit No. 1
T-29 Apri12, 1973
Test bcation
No. Lot No.
1060
1061
1062
Ei
1065
1066 - 1067
1068
1069 - 1070
1071
160 3.0*
162 14.5 l
164 36.0.
166
167
34-P.
14.0
167 17.0*
171 3.0.
177 1.0
177 3.0'
178 3.0 l
179 3.0.
180 1.0
- 1,072
1073
1074 - 1075
1076
I077
1078
1079
1080 - 1081
1002
1083 - 1084
1085
1086 - 1087
1088
1089 - 1090
1091
1092 -
1093
1094
1095
1096
1097
1098 -
1099
180 3.0 l
181 2.0
18i 5.0 l
201 1.0
182. 6.0
182 9.0 *
183 14.5 l
184 24.5 *
208 3.0 *
201 7.0~.
195 7.0 l
194 10.0 l
193 16.0 *
192 21.0.
191 22.5 l
187 5.0 l
186 12.5 l
185 22.5 l
204 3.0 l
242 8.0'
243 17.0'
244 20.5 l
70 10.0
71 18.:0,
R 11.0
46 16.0
45 14.0
233 3.0 l
- * Finished Grade
Depth
of Fill
attest
In Feel
TABtE OF TEST RESULTS (CONT.)
Field b
Moisture DWlsity
% dry wt Ib/cu fi
Maximum
DV
Density
Ib/cu ft
Percent
Compaction Remarks
12.8 101.7 111.8 91.0
16.0 105.2 115.2 91.3
16.0 101.7 115.2 88.2
16.9 105.8 115.2 91.5
17.2 108.0 115.2 93.6
16.0 107.3 115.2 93.1
13.2 102.5 111.8 91.8
14.1 109.3 115.2 94.9
14.6 108.0 115.2 93.6
16.1 104.3 115.2 90.5
16.0 105.1 115.2 91.1
18.4 105.1 115.2 91.1
16.5
17.3
17.1
8.6
12.4
15.7
15.7
14.9
13.4
13.5
16.0
19.4
13.6
14.9
12.3
11.0
13.7
15.4
13.1
K
17:o
18.7
13.6
15.5
22.2
15.6
11.6
106.1 115.2 92.1
101.8 111.8 91.1
102.2 113.5 90.2
107.0 111.8 95.8
107.1 115.2 92.9
105.9 115.2 91.7
108.2 115.2 93.8
112.1 115.2 97.3
107.1 115.2 93.0
106.6 115.2 92.4
106.1 115.2 92.1
100.1 115.2 86.9
107.2 115.2 93.0
107.7 115.2 93.3
105.1 115.2 91.1
102.7 115.2 89.0
111.3 115.2 96.5
112.0 115.2 97.1
107.1 115.2 93.0
103.8 113.5 91.4
103.7 115.2 90.0
106.4 115.2 92.4
101.9 111.2 91.3
109.1 115.2 94-6
109.0 115.8 94.3
102.8 110.9 92.7
110.0 118.5 93.0
104.5 11502 90.6
Ck on.8680
Ck on 1682
Reworked
Ckon #895
Ck on 11743
Ckon#925
Ck on #89l
8, t892
Ckon #890
Ckon 8851
Ckon 1889
Ckont948
Ckon #885
Reworked
Ckon x1002
Ckon WlOOO
Reworked
Ckon 1888
Ck on 1582
Ckonf661
Ckon%O
sENTON ENGINEERINO. INC.
Project No. R-8-l3D
La Costa Vale Unlt No. 1
T-30
TABLE OFTESTRESULTS (CONT.)
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Test
NO.
1100
1101
1102
1103
1104
1105
1106
1107
- 1108
1109 -
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Approx-
imate
Location
Lot No.
245
245
246
246
247
18
147
164
187
194
Depth
of Fill Field
at test Moisture
In Feet %dryti
15.0 10.2
17.0* 16.4
28.0 13.9
30.0' 18.1
37.5 + 20.7
40.0 20.7
40.5 * 15.8
36.0 * 17.1
5.0 l 10.1
10.0 l 15.3
Dry
De&y
lb/w ft
M&mum
DV
Density
Ib/cu ft
109.2 115.2
109.5 115.2
107.7 115.2
104.1 115.2
103.9 115.2
106.4 115.2
111.9 115.2
106.7 115.2
104.6 111.8
103.3 113.5
Percent
Compactlon Remarks
94.6
94.9
93.5
90.3
90.0 Ckonj659
92.4
97.0 Ck on #lo54
92.7 Ckon 11062
ʹ
93.6 Ckon 51087
ϧ
91.1 Ckon #I083
- l Flnlrhed Grade
BENTON ENGINEERING. INC.
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Project No. R-8-180
La Costa Vale Unit No. 1
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LABORATORY TEST RESULTS
March 1, 1973
Revised - April 2, 1973
The maximum dry densities and optimum moisture contents of the maior fill materials o determined
by the A.S.T.M. D 1557-66T method, that uses 25 blows of a 10 pound rammer falling from o
height of 18 inches on each of 5 loyen in o 4 inch diameter i/30 cubic foot compactlon cylinder,
are presented as follows:
Soil Description
Maximum
Dry Density
lb/cu ft
Optimum Mois-
ture Content
% dry wt
Light brown groy clayey silt 107.2 19.0
Olive green rllty clay 107.5 16.4
Brown gray silty clay 109.0 17.8
Light yellow brown silty very fine to fine sand with 109.2 16.8
cloy binder ond chunks of silty clay
Yellow brown and gray very fine sandy silt
Yellow brown very fine to fine sandy cloy
Gray brown fine sandy clay
Olive green silty clay
Light brown silty fine sand
Light grayyellow clayey fine sand
Light gray brown clayey very fine to fine sand
Gray with red brown and white silty clay
Light grey brown clayey ffne sand
Light gray silty very fine to fine sand with slight
110.4 15.4
110.4 15.5
110.9 14.3
iii.2 15.0
112.5 10.9
114.1 13.9
114.2 14.4
114.7 15.3
115.2 14.7
115.2 13.7
clay binder
Grey-block silty cloy 116.8 ii.8
Brown clayey fine sand with some fine randy clay 117.8 13.3
Light brown silty fine sand with clay binder 118.3 il.9
Light brown and grey silty clay 118.6 14.0
Light yellow brown fine sandy clay 121.6 ii.5
Light yellow silty fine sand 123.6 10.5
Greenish-brown fine sandy clay 118.8 12.2
Brown clayey fine to medium sand 128.0 9.2
Graylsh&own silty fine sand 117.0 13.1
Light brown silty fine to medium sand 118.5 12.0
Red-brown fine to medium sandy cloy 111.3 15-o
Light groy clayey silt with streaks of red brown iii.3 16.0
and yellow
Light grey silty cloy with yellow streaks 110.7 15.1
Light groy silty fine sond 111.8 12.5
BENTON ENGINEERING. INC.
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Prolect No. 72-8-181)
La Costa Vole Unit No. 1
-2- February 28, 1974
Test Number Week Ending .-
1142 to 1178, inclusive April 21, 1973
ii79 to 1210, inclusive April 28, 1973
1211 to 1251, inclusive May5, 1973
1252 May 19, 1973
1253 to 1255, inclusive June 9, 1973
1256 February 6, 1974
Compacted filled ground was placed on an oreo west of Lot 1 outslde the boundory of La Costa
Vale Unit No. 1 and is designated on Drawing No. 1 as Area “A”.
The finol results oi tests ond observations indicate that the compacted filled ground hos been
placed at 90 percent of the maximum dry density ,or greater. It has been determined that the
fill moterials, compacted to 90 percent of the maximum dry density, have a safe bearing value
of 1650 pounds per square foot for one foot wide continuous footings founded at a depth of one
foof below the lowest adjacent compacted ground surface. This value may be increased to 1950
pounds per square foot for 16 inch wide footings placed 1.5 feet below the lowest adjacent corn-
patted ground surface. if footings are placed closer to the exposed slopes than 5 feet inside the
top of compacted filled ground slopes, these should be deepened one foot below o 1 i/2 horizontal
to 1~ vertical line projected outward and downward from a point 5 feet horizontally inside the top
of compacted filled ground slopes. Tests indicate thot the compacted filled ground is adequate
to satisfactorily support the proposed one and two story wood frame dwellings withou: detrimental
settlements.
Only nonexpansive soils were placed in the upper three feet below finished grode on ihe following IL.- -
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All expansive soils existing in the upper three feet
shallow fill were removed on the above lots ond were replaced with properly compacted non-
~_ expansive fill soils. Therefore, special design for exponsive soil conditions will not be required
on these lots. c’ .,
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the subdivision were determined to have&iticallv expansive soils In the upper
finished grade. Therefore, in order to n%imize’ posr;iEi[e detrimental effects
caused by these potentially expansive soils, the follow$z special design and preca%ons ore
- recommended.
1. Avoid the use of isolated interior piers where possible. Use continuous - footings throughout, and place these ot a minimum depth of ho feet below
the lowest adjacent oxtcrior finol ground surface.
BENTON LNGIN~ERINO, INC.
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Prclec, NO. 72-8-18D
!.p Costa Vale Unit No. 1
-3- February 28, 1974
2.
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5.
6.
Reinforce and interconnect continuously with steel bars all interior and
exterior footings with one #5 bar at 3 inches above the bottom of all
footings with one u5 bar placed 1 l/2 inches below the top of the stems
of the footingi.
Raised wooden floors that span between continuous footings are preferable.
Concrete slabs on grade should be reinforced with at least 6 x 6 - lO/lO
welded wire fabric. Provide a minimum of 4 inches of crushed rock 3/4
to 1 inch in size beneath all concrete slabs. A moisture borrier should
also be provided over the crushed rock and then 2 inches of sand should be
placed over the moisture barrier and below the bottom of the slab.
Separate garage slabs from perimeter footings by l/2 inch thickness of
construction felt or equivalent, to allow independent movement of garage
slabs relative to perimeter footings. Assure complete separation by extending
the construction felt over the full depth of the front thickened edge of the
garage slab. Cut off garage door stops at least l/2 inch above the garage
slab.
Provide positive drainage away from all perimetei footings with a vertical
fall of at least 6 inches in a horizontal distance of 5 feet, to a distance of
at least 5 feet outside the house walls.
Exercise every effort to assure that the soil under the concrete slabs has a
uniform moisture content at least 1 to 3 percent,greater than optimum
throughout the top 1.5 feet below’ finished grade at the time of placing the
foundations and slabs.
Respectfully submitted,
BENTON ENGINEERING, .INC.
BY
R<RGr& . .
&i&l> &i$5~ Reviewed b
PFiitrij H. tinton, Civil Engineer
RC R/PHB/pk
Distr: (4) Addressee
(1) Addressee, Attention: Mr. Burton L. Kramer
San Diego County Engineering Department
Attention: Mr. H. M. Taylor
Attention: Mr. Willard Robinson, Room 206
City of Carlsbad Building Department
Rick Engineering Company, Carlsbad
Title Insurance and Trust Company
Attention: Ruth J. RodgeL ENTON LNatNEER,NG. INC.
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