HomeMy WebLinkAbout; La Costa Greens Lots 5-8; Soils Report Final; 1972-06-27BENTON ENGINEERING. INC.
APPLIED 501L MECHANICS ~~~~ FOUNDATIONS
6741 EL CAJON BOULEVAFID SAN OIEGO. CALIFORNIA 92115
P”ILIP b4ENKING BENTON 5.N “ifG0~ 583.5654
PRESIDENT ClYlL ENGINEEI June 27, 1972 L* MESA, 469.5554
La Costa Land Company
Costa Dei Mar Road
Ran&a La Costa, California 92008
Subiect: Project No. 72-5-27D
Final Report on Compacted Filled Ground
Portions of Lok 5 6 7 and & .,,., r,~ ____ “_.“l,~ .,.,_,.-,., ,.,., I 1~. il ,_. ,.-.
Gentlemen: -
This is to report the resulk of tests and observations made in order to inspect the compaction
of filled ground placed on certain areas of Lots 5 to 8, inclusive, of La Costa Greens in San
Diego County, California. These fills were placed on May 26, 1972.
Reference is made to our report dated May 28, 1972 of this same project in which we reported
the results of tesk and observations mode to inspect the compaction of filled ground placed on
Lots 1 to 10, inclusive, of La Costa Greens. The approximate area and depths of the additional
- filled ground placed during the recent grading are shown on the attached Dravn’ng No. 1,
entitled “Location of Compacted Filled Ground,” and revised June 22, 1972. The limits of the
additional compacted filled ground were determined by field measuremenk made by our inspector.
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The final test results are presented on page 3 under the “Table of Test ibsuik.” The Iabomtoory
determinations of the maximum dry densities and optimum moisture contents of the major fill
- materials are also presented on page 3 under the “Laboratory Test Resuik.” Some of the maxi-
mum dry densities shown in the “Table of Test Results,” were combinations of these.
The final test resdk and observations indicate that the filled ground, placed under our inspection,
has been compacted to 90 percent of maximum dry density or greater.
- It should be noted that certain of the soils placed in the compacted filled ground area, as reported
herein, are of the “expansive” type. Also the fill - placed over compressible ground and it is
recommended that no structures be placed within the area represented by the diagonal cross-hatched
area added on the north side of Lots 5, 6, 7 and 8 on Drawing No. 1.
SlOlO
el7.74
=. I
- public worm figenw
wMm 0~. BUIIDING WECT’oN
Project No. 72-5-27D
La Costa Greens
-2- June 27, 1972
Recommendations were presented previously for special foundation design on pages 2 and 3
of our report dated Nay 28, 1970 under Project No. 69-10-240 for those areas of Lots 1, 2,
3, 4, 5, 6, 7 and 8 which are shown within the shaded (but not cross-hatched) areas of
Drawing No. 1, revised as of 6-22-72. The filled ground formerly existing on Lok 9 and 10
has now been removed so none of the recommendations pertain to these iok.
Respectfully submitted,
BENTON ENGINEERING, I NC.
< Q//-&S
BY
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Philip H. & nton, Civil Engineer -
Distr: (4) Addressee
(1) La Costa Land Company
Attention: Mr. Burton L. Kmmer
(1) Rick Engineering Company
(2) San Diego County Building inspection, Vista Office
(1) San Diego County Engineering Department
Attention: Mr. Joe Soveila
(also report of May 28, 1970, Project No. 69-lo-24D)
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DFL/PHB/ew
SENTON ENGINEERING. INC.
Project No. 72-5-271)
La Costa Greens
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Test
No.
Appmx - Depth
imate bf Fill
Location ot Test
Lot No. in Feet
8 2.0
8 4.0
8 6.0 *
6 1.5
7 3.0 l
5 1.5
5 3.0 *
* Finished Grade
TABLE OF TEST RESULTS
Field DW
Moisture Density
% dry wt Ib,‘cu R
15.4 107.2
11.4 99.5
14.4 104.5
13.0 108.0
13.6 111.3
13.4 106.3
14.2 104.2
June 27, 1972
Maximum
DV
Density Percent
Ib/cu ft Compaction
115.2 93.1
110.6 90.0
116.0 90.1
118.9 90.9
122.0 91.3
115.8 91.9
115.8 90.1
LABORATORY TEST RESULTS
The maximum dry densities and optimum moistuh contents of the major fill materials as
determined by the A.S.T.M. D 1557-66T method, that uses 25 blows of a 10 pound mmmer
foiling from a height of 18 inches on each of 5 layers in a 4 inch diameter l/30 cubic
foot compaction cylinder, are presented as follows:
Soil Description
Maximum Optimum Mois-
Dry Density ture Content
Ib/cu ft % dry wt
Gray very fine to fine sandy clay 1 Ii.8 9.8
Dark gray very fine sandy clay 119.9 12.2
Light greenish-grey clayey very fim to fine 124.2 11.2
sand with claystone chunks
Light greenish-gray slightly clayey fine sand
Olive-green silty cloy
Yellow-brawn silty fine sand
122.1 11.5
110.6 15.7
116.0 13.2