HomeMy WebLinkAboutCT 72-20; LA COSTA VALE UNIT NO. 1 LOTS 1-10, 108-209, 232-246; INTERIM REPORT ON GEOTECHNICAL COMPACTED FILL; 1973-04-02BENTON ENGINEERING, INC.
Af•PLIEO SCIL MEc:HANIC"S · FOuNOATl\"1Nt-
5717 CONVOY COURr
SAN DIEGO, CALIFORNIA 92111
PHILIP HENKINti Bia."' roN
PRESIDENT ~ CIVH ENGINl:t!R April 2, 1973
la Costa land Canpony
Costa Del Mar Road
C'.arlsbod, California 92008
Subject:
Gentlemen:
Project No. 72-8-180
Grading Permit No. l.6392
T .M. 3036
fnterim Report on
C_gnpgcted Filled bround
Lots 1 to 10 inclusive
Lots 108 to ~09, inclusive, and
L~32 to 246, inclusive
La Costa Vole Unit No. 1
Carlsbad, California
7-~
RECEIVED
APR 4 1973
CITY OF CARLSBAD
Tt, J~~j!~t~s, ~rt,nent
This is to report the results of tests and observations mode in order to insfM,ct the compaction
of filled ground placed on certain areas of Lots 1 to 10, inclusive, 100 to 209, inclusive, and
232 to 246, inclusive, of La Costa Vale Unit No. 1 in Carlsbad, California, formerly a part
of the County of San Diego. Filled ground was placed on lots 17 to 22, inclusive, on February
16, 1970 and the major grading of the subdivislon 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
Morch 1, 1973.
The fiUed 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 suh;ect lots were induded in our previous report doted Morch 1,
1973. The results of field density test Nos. 1020 to 1109, inclusive, ore presented on pages
T-28 to T-30, inclusive, under the "Tobie of Test Results." The laboratory determinations of
the maximum dry densttles and optimum moisture contents of the major fill materials are presented
on page l-1, under the "Laboratory Test Resu~ts. 11 Some of the maximum dry densities shown in
the 11Toble of Test Results" were combinations of these. The tests were taken during the weekly
periods indicat~ on the following page.
Project No. 72-8 .. 18D
La Costa Vale Unit No. J
Test Number
1020 to 1035, inclusive
1036 to 1040, inclusive
1041 to 1072, Inclusive
1073 to 1105, inclusive
1106 to 1109, tnclusive
-2-
Week Ending
March 3, 1973
March 10, 1973
March 17, 1973
Morch 24, 1973
March 31, 1973
Aprll 2, 1973
Only nonexpanstve soils were placed in the upper three feet below finished grade in the fill
areas on the sub}ect lots. All expanslve soils e>efstlng in the upper three feet below finished
grade tn cut areas and areas of shallow flll were removed and were replaced with properly
compacted nonexpansfve fill solls. Therefore, special design fer expansive soil conditions will
not be required en the subject lots.
The flnol results of tests and observations indicate that the compacted filled ground has been
placed at 90 percent of the maximum dry density or greater. It has been detenntned 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 at a minimum depth
and placed five feet or more rnside the top of compocted filled ground slopes. 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 1/2 horizontal to 1 vertical line projected outward
ond downward from a paint 5 feet horizontally Inside the top of compacted ftlled ground slopes.
Tests indicate that the compa~ted 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
Vole Unrt No. 1.
Respectfully submitted,
BENTON ENGINEERING, INC. Dlstr:
By-,£({?~~
R. C. Remer
(4) Addressee
La Costa Land Company
(1) Attention: Mr. Burton L. Kramer
(1) Rick Engineering Company, Carlsbad
San Diego County Engineering
(1) Attention: Mr. H. M. Taylor
(l) Attention: Mr. Willard Robinson, Rm. 260
CHy of Carlsbad
(1)
(2)
Deparhnent of Building Inspection -
Deportment of Engineering
Reviewed ba w@~ :7~~
Pardee Construction Company, Los Angeles
Attention: Mr. Russell R. Ofria
Attention: Mr. Jack Wagner
Attenftom Mr. Bob Trede Phtllp H: Benton, Civil Engineer (1)
Pardee Construction Company, San Diego
(1) Attention: Mr. Art Scott
(1) Attention: Mr. Mike Capik
(1) Delivered to fob site by Bud Beattle
RCR/PHB/ew
Project No. 72-8-18D T-28 Apr II 2, 1973
la Costa Vale Unit No. 1
TABLE OF TEST RESULTS (CONT.)
Approx-Depth Maximum
imate of Fill Field Dry Dry
Test location at Test Moisture Density Density Percent
No. Lot No. In Feet % dry wt lb/cu ft lb/cu ft Compaction Remarks
1020 84 14.0 15. 1 107.5 115.2 93.2
1021 84 16.0 15.0 107.2 115.2 93.0
1022 84 18.0 15.3 109.4 115.2 94.9
1023 84 20.0 12.5 107.1 1.15.2 93.0
10'24 84 22.0 12.5 109.2 114.2 95.S
1025 84 24.0 11.7 109.0 115.2 94.5
1026 84 26.0 12.8 111. 9 115.2 97.0
1027 83 I .0 JO.O 107.4 112. 8 95.4
l<Y.28 84 30.0 11.4 110. 7 115.2 95.8
l<Y.29 83 5.0 10.2 112.6 115.2 97.5
1030 84 34.0 15.3 110. 7 111.0 99.6
1031 83 9.0 13.1 109.5 114.0 96.0
1032 84 38.0 15.8 101.8 109.3 92.9
1033 83 13.0 16.1 105.8 110. 9 95.4
1034 83 15.0 11.2 110. 7 113.6 97.4
1035 83 17.0 13.3 107.5 115.2 93.2
1036 44 5.0 17.2 108. J 116.0 93.3
1037 . 48 4.0 17.0 108.0 118.1 91.4
1038 47 14.0 14.6 108.0 115. 7 93.5
1039 83 19.0 15.9 107.9 115.4 93.3
1040 55 2.0 15.2 112. 1 118. 8 94.6
1041 109 6.0 * 20.4 101. 9 111.8 91.2 Ck on 1952
1042 123 15.0 * 12.9 101.8 111.8 90.9 C!:k on l983
1043 128 14.0 * 16.7 107.8 115.2 93.2 Ck on 1969
1044 136 1s.o• 11.2 105.0 111.8 94.0 Ck on #973
1045 137 10.0 * 16.1 105.2 115.2 91.4
1046 139 4.0 * 16.2 105.6 115.2 91.5
1047 140 3.0 * 16.8 109.0 115.2 94.4
1048 141 3.0 * 16. 1 111. 0 115.2 96.2
1049 142 3.0 * 14.5 110. 9 115.2 96.0
1050 143 22.0 * 13.2 J 14. 1 117.9 97.J
1051 144 3.0 * 14.8 108.3 115.2 94.0
1052 145 10. 0 • 15.5 105.4 115.2 91.5
1053 146 28.0 * 11. 7 111. 7 115.2 96.7
1054 147 40.5 * 13.9 102.2 115.2 88.7 Reworked
1055 148 43.0 * 12.5 104.0 115.2 90.2
1056 153 8.0 * 11.4 103.8 111.8 93.0
1057 149 29.0 * 17. 1 107.3 115.2 93.1 Ck on #977
1058 156 16.0 * 12.3 103.8 113.5 91.3 Ck on 1677
1059 159 3.0 * 14.2 105.1 115.2 91.2
* Finished Grode
~-,.-----q -~ -~-, .. ------.......... ----·· ----.--~---·. .
Proiect No. 72-8-lED T-29 April 2, J 973
La Costa Vale Unit No. 1
TAB1£ OF TEST RESULTS (CONT.)
Approx-Depth Maximum
lmate of Fi II Field Dry Dry
Tost location at test Mofsture Density Density Percent
No. Lot No. In Feet % dry wt lb/cu ft lb/cu ft Compaction Remarks
1060 160 3.0* 12.8 101. 7 111.8 91.0 Ck on. 1680
1061 162 14.S * 16.0 105.2 115.2 91.3 Ck on 1682.
1062 164 36.0 * 16.0 101. 7 115.2 88.2 Reworked
1063 166 34.0 * 16.9 105.8" 115.2 91.5
1064 167 14.b 17.2 108.0 115.2 93.6 Ck on #995
106.5 167 17.0 * 16.0 107.3 115.2 93. 1
1066 171 3.0 * 13.2 102.5 111.8 91.8 Ck on l743
1067 177 1.0 14.1 109.3 115.2 94.9 Ck on #925
1068 177 3.0 * 14.6 108.0 115.2 93.6
1069 178 3.0 * 16.1 104.3 115.2 90.5
1070 179 3.0 * 16.0 105. 1 115.2 91.1
1071 180 1.0 18.4 105. 1 115.2 91.1 .Ck on 1891
& #992
1072 180 3.0 * 16.5 106. 1 115.2 92.1
1013 181 2.0 17.3 101 .8 111.8 91.1 Ck on #990
1074 181 5.0 * 17. l 102.2 113.5 90.2
1075 201 1.0 8.6 107.0 111~8 95.8 Ck on 1851
1076 1(32. 6.0 12.4 107.1 115.2 92.9 Ckon 1889
1077 182 9.0 * 15.7 105. 9 115.2 91.7
1078 183 14.5 * 15.7 108.2 115.2 93.8
1079 184 24.5 * 14.9 112. 1 115.2 97.3
1080 208 3.0 * 13.4 107.1 115.2 93.0 Ck on l94a
1081 201 7.0-* 13.5 106.6 115.2 9'l.4 Ck on #885
1082 195 7.0 * 16.0 106. 1 115.2 9'l. 1
1083 194 10.0 * 19.4 100. 1 115.2 86.9 Reworked
1084 19'.3 16.0 * 13.6 107.2 115.2 93.0 Ck on #1002
1085 19'2 21.0 * 14.9 107.7 115.2 93.3
1086 191 22.5 * 12.3 105. 1 115.2 91.1 Ck on 11000
1087 187 5.0 * 11.0 102.7 J15.2 89.0 Reworked
1088 186 12.5 * 13.7 111.3 115.2 96.5
1089 185 22.5 * 15.4 112.0 115.2 97.1
1090 204 3.0 * 13. J 107.1 115.2 93.0 Ck on 1888
1091 242 8.0 * 13."7 103.8 113.5 91.4 Ck on 1582
1092 243 17.0 * 14.3 103.7 115.2 90.0 Ck on 1661
1093 244 20.5 * 17.0 106.4 115.2 92.4 Ck on 1660
1094 70 10.0 18.7 101. 9 111.2 91.3
1095 71 18.'0. 13.6 109. 1 115.2 94.6
1096 72 l 1 .. 0· 15.5 109.0 115.8 94.3
1097 46 16.0 22o2 102.8 110. 9 92.7
1098 45 14.0 15.6 110.0 118.5 93.0
1099 233 3.0 * 11.6 104.5 115.2 90.6
* Ftnlahed Grode
Project No. 72-8--lQ) T-30
La Costa Vale Unit No. 1
TABLE OF TEST RESULTS (CONT.)
Approx--Depth Maximum
lmote of Fill Fteld Dry Dry
Test Location at test Notsture Dendty Density Percent
No. Lot No. In Feet % dcy wt lb/cu ft lb/cu ft Compaction Remarks
1100 245 15.0 10.2 109.2 115.2 94.6
1101 245 17.0 * 16.4 · 109.5 115.2 94.9
1102 246 28.0 13.9 107.7 115.2 93.5
1103 246 30.0 * 18. 1 104.1 115.2 90.3
1104 247 37.5 * 20.7 103.9 115.2 90.0 Ck on 1659
1105 18 40.0 20.7 106.4 115.2 92.4
1106 147 40.5 * 15.8 111. 9 115.2 97.0 Ck on #)054
1107 164 36.0 • 17. I 106.7 115.2 92.7 Ck on #1062
&1697
1108 187 5.0 • 10.1 104.6 111. 8 93.6 Ck on IJ087
& #999
1109 194 10.0 * 15.3 103.3 113.5 91. 1 Ck on 11083
• Finished Grade
Profeet No. 72-8-100
La Costa Vale Unit No. 1
L-1 March 1, 197J
Revised• April 2, 1973
LABORATORY TEST RESULTS
The maximum dry denstttes and optimum mc,Jsture contents of the mafor ftl I materlal1 QI determined
by the A.S. T .M. 0 1557-661 method, that uses 25 blows of a 10 pound rarnmer falllng from a
height of 18 Inches on each of 5 layers In a 4 tnch diameter 1/30 cubic foot compaction cyllnder,
are presented as follows:
Maxtnl.lm Optimum Mofs-
Dry Density ture Content
Sol I Description lb/cu ft o/o dry wt
Light brown gray clayey silt 107.2 19.0
01 ive green sf lty clay 107.5 16.4
Brown gray silty c I ay 109.0 17.8
light yellow brown silty very fine to fine sand wtth 109.2 16.8
clay binder and chunks of silty clay
Yellow brown and gray very fine sondy slit 110.4 15.4
Yellow brown very fine to ftna sanely clay 110.4 15.5
Gray brown fine sandy clay 110. 9 14.3
Oltve green stlty clay 111.2 15.0
Ught brown sllty rtne sand 112.5 10.9
ltght gray-yellow clayey fine sand 114. 1 13.9
Light gray brown clayey very fine to fine sand 114.2 14.4
Gray with red brown and white stlty clay 114.7 15.3
Light gray brown clayey fine sand 115.2 14.7
Light gray sllty very fine to fine sand with slJght 115.2 13.7
clay blnder
Gray-black stlty clay 116.8 11.8
Brown clayey fine sand with some ftne sandy clay 117.8 13.3
Light brown sflty fine sand with clay binder 118.3 11. 9
Light brown and gray sllty clay 118.6 14.0
Light yellow brown fine sandy clay 121.6 11.5
Ltght yellow sllty fine sand 123.6 10.5
Greenish-brown fine sandy clay 118.8 12.2
Brown clayey fine to medfum sand 128.0 9.2
Groytsh=-brown 1Jlty flne sand 117.0 13. 1
Ught brown sflty fine to medium sand 118.5 12.0
Red-brown fine to medium sandy clay 111.3 15.0
light gray clayey silt with streaks of red brown 111.3 16.0
and yellow
light gray silty clay with yellow streaks 110.7 15.1
light gray sllty ff ne sand 111.8 12.5
ProJect No. 72-8-180
· La Costa Vole Unit No. 1
-2-
Test Number
1142 to 1178, inclusive
1179 to 1210, Inclusive
121 l to 1251, Inclusive
1252
1253 to 1255., Inclusive
1256
February 28, 1974
Week Ending
April 21, 1973
April 28, \ 973
May 5, 1973
May 19, 1973
June 9, 1973
February 6, 1974
Compacted filled 9round was placed on an area west of Lot 1 ouhlde the boundary of la Costa
Vole Unit No. 1 and ls designated on Drawing No. 1 as Area "A".
The final results of tests 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 squcre foot for one foot wide continuous footings founded at a depth of one
foofbelow 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 com-
-paeted 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 a 1 1/2 horizontal
to 1_ vertical line prof ected outwcrd and downward from a point 5 fe9t horizontally inside the top
of compacted filled ground slopes. Tests indicate that the compacted filled ground is adequate
to satisfactorily support the proposed one aid two $tory wood frcme dwellings withou: detrimental
settlements.
Only ~expansive soils were placed in the upper three feet below finished grade on the following
lots:
A.Lt. L 1 to 10, inclusive rlfGR
/108 to 209, inclusive =,HoM IXPlt.rlSIVli ~ .
. . 219 to 225, inclusive · '-'Re ·
232 to 246, inclusive #J( P/tN>lv/:
-. . ~ "'Pe'~, ,
All exponsive soils existing in the upper three feet below finished grade in cut areas atJ areas of
shallow fill were removed on the above lots and were replaced with properly compacted non-
--expansive fill soils. Therefore, special desi9n for expansive soil conditions will not be required
on these lots. ·
'-a ------------... ., -~) ~df~ ~n the subdivision were determined to havei;;'riticotl e. ~ive soils '1-n the upper
t ree eet e oW finishe~ grade. Therefore, in order to minimize poss, e etnmental effects
caused by these potentially expansive soils, the follow(n9 spec I al design and preca~tf ons ore
-recommended.
1. Avold the use of isolated interior piers where possible. Use continuous
footrn9s throughout, and place these at a minimum depth of ~o feet below
the lowest odJacent 9xtortor final ground surface.
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ProJcct No. 72-8 .. 18D
~Q Costa Vale Unit No. 1
Febru0ry 28, 197 4
2.
3.
4.
5.
Reinforce and interconnect continuously with steel bars all interior and
exterior footings with one 15 bar at 3 inches above the bottom of all
footings with one 15 bar placed 1 1/2 inches below the top of the stems
of the footings.
Raised wooden floors that span between continuous footings ore preferable.
Concrete slabs on grade should be reinforced with at least 6 x 6 .. 10/10
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 barrier 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 1/2 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 fef t over the full depth of the front thickened edge of the
garage slab. Cut off garage door stops at least 1/2 inch above the garage
slab.
Provide positive drainage away from all perimeter footings with a vertical
foll of at least 6 inches in a horizontal distance of 5 feet, to a distance of
at least 5 feet outside the house walls.
6. Exercise every effort to assure that the soil under the concrete slabs hos 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-£C~
R. C. Remer
G _r· J//J ~--
Reviewed .. :J X; (j~
. ]ip.nion, Civil Engineer
RCR/PHB/pk
Distr: (4) Addressee
(1) Addressee, Attention: Mr. Burton L. Kromer
San Diego County Engineering Department
(1) Attention: Mr. H. M. Taylor
(1) Attention: Mr. Willard Robinson, Room 206
(2.) City of Carlsbad 8ulldin9 Department
(1) Rick Engineering Company, Carlsbad
(2) Title Insurance and Trust Company
AttAnttnn• Ruth t ~",.f,., ....
J