HomeMy WebLinkAbout; Library; Soils Investigation; 1966-03-24-
SOILS INVESTIGATION
-
-
Proposed Library Building
Elm Avenue and Elmwood Street
Carl&ad, California
-
-
For The
City of Car l&ad
-
-
ENGlNEERlNG DEPT. LfBRARY City of Carl&d 2075 Las Palmas Drive
Carlsbad CA92009-4859
Project No. 66-2- IbA
March 24, 1966
-
BENTON ENGINEERING. INC.
BENTON ENGINEERING, INC.
APPLIED SOIL MECHANICS - FOUNDATIONS
6741 EL CAJON BOULEVARD
SAN DIEGO. CALIFORNIA 92115
-
-
-
-
-
-
PHILIP HENKING BENTON PRESIDENT - CIVIL ENGINEER SAN DIEGO: 583.5654 LA MESA: 469.8684
SOILS INVESTIGATION
Introduction
This is to present the findings and conclusions of a soils investigation conducted at the
site of a proposed Library Building to be located west of Elmwood Street, between Elm Avenue
and Laguna Drive, in Carlsbad, California. Two borings were also drilled in future proposed
building areas southwest of the library site. The objectives of the investigation were to
determine the existing soil conditions and physical properties of the soils in order that
engineering recommendations could be made for the design of foundations for the proposed
Library Building and also to determine if the soil conditions in the area to the southwest were
similar to those encountered on the library site. In order to accomplish these obiectives, five
boringi were drilled, both undisturbed and loose bag samples were obtained, and laboratory
tests were performed on these samples.
It is understood that the proposed building will be of steel frame construction with a
concrete floor slab on grade. A portion of the building will have a mezzanine and maximum
column loads in this area are estimated to be on the order of 140 kips. It is planned to grade
the site to approximately Elevation 123.5 feet which will require placing fill to a maximum
depth of 5.5 feet on the southwest portion of the building area.
Fie Id lnves tigation
Five borings were drilled with a truck-mounted rotary bucket-type dri I I rig at the
approximate locations shown on the attached Drawing No. 1, entitled “Loca tion of Test
Borings . ” The borings were drilled to depths of 11 to 20 feet below the existing ground
-
4 -
surface. A continuous log of the soils encountered in the borings was recorded at the time
of drilling and is shown in detail on Drawing Nos. 2 to 6, inclusive, each entitled, “Summary
Sheet ,‘I
The soils were visually classified by field identification procedures in accordance with
the Unified Soil Classification Chart. A simplified description of this classification system
is presented in the attached Appendix A at the end of this report.
Undisturbed samples were obtained at frequent intervals in the soils ahead of the drilling.
The drop weight used for driving the sampling tube into the soils was the “Kelly” bar of the
drill rig which weighs 1100 pounds, and the average drop was 12 inches. The general proce-
dures used in field sampling are described under “Sampling” in Appendix B.
Laboratory Tests
Laboratory tests were performed on all undisturbed samples of the soils in order to deter-
-
mine the dry density, moisture content, and shearing strength. The results of these tests are
- presented on Drawing Nos. 2 to 6, inclusive. Direct shear tests were also performed on
saturated and drained samples to determine the minimum angle of internal friction and apparent
-
cohesion of the soils. Consolidation tests were performed on representative samples in order
- to determine the load-settlement characteristics of the soils. The results of these tests are
presented on Drawing Nos. 7 and 8, each entitled, “Consolidation Curves .”
-
In addition to the above laboratory tests, expansion tests were performed on some of
the silty sands with clay binder to determine their volumetric change characteristics with
change in moisture content. The recorded expansions of the samples are presented on the
-
following page.
BENTON ENGINEERING, INC.
-3-
-
t -
-
-
Boring
Number
Percent Expansion Under
Depth of Unit Load of 500 Pounds
Sample Sample, per Square Foot from
No. in Feet Soi I Description Air Dry to Saturation
2 1 1.5-2 .O Si Ity sand with some clay binder 0
3 1 1.5-2 .O Si I ty sand with some clay binder 0
The general procedures used for the preceding laboratory tests are described briefly
in Appendix B .
Compaction tests were performed on a representative sample of the soil to be excavated
and used in the compacted fill area. The soi I was tested according to a modified A .S . T .M .
D698-58T method of compaction which uses 26 blows of a 10 pound hammer dropping 18 inches
on each of 3 layers in a 4 inch diameter 1/3Oth cubic foot meld. The results of the tests are
presented as fol lows :
Boring
Number
Maximum Optimum Mois-
Bag Depth Dry Density ture Content
Sample in Feet Soi I Description Ib/cu ft 5% dry wt
1 1 2.5-3.5 Slightly silty fine to 129.8 9.4
medium sand with some
clay binder
DISCUSSION AND RECOMMENDATIONS
Soil Strata -
Firm silty fine to medium sand was found below the asphalt pavement and to a depth of
- 1.5 feet in Borings 1 and 2. The soils below 1.5 and those encountered below the surface in
Boring 3 consisted generally of firm to very firm silty sands containing small amounts of clay -
binder. Pockets and layers of fine to medium sand were also found embedded in the silty sands
- at various depths.
BENTON ENGINEERING, INC.
-
-
-
-
-
-
-4-
A silty sand topsoil was encountered to depths of 1 .O foot in Boring 4 and to 1 .9 feet
in Boring 5. M d e ium firm silty fine to medium sand was found below the topsoil at Boring 4
and was underlain by firm to very firm silty sand with clay binder and pockets of fine to
medium sand. A clayey fine to medium sand was found between 17.8 and 18.0 feet, the
depth of exploration at Boring 4. A clayey fine to medium sand was encountered below a
depth of 1 .9 feet in Boring 5 and merged to a very firm silty fine to medium sand containing
clay binder below a depth of 3.3 feet. Small pockets of fine to medium sand were found
embedded in the si Ity sand below 6 feet. Very firm slightly silty fine to medium sand was
found below 11 feet and contained approximately 30 percent gravel between 17.3 and 18 .O
feet, the limit of exploration at Boring 5.
Ground water was not encountered in the exploration borings. However, very moist
soil conditions were observed in the gravelly slightly silty sand at the bottom of Boring 5.
Site Preparation
It is proposed to grade the site to an elevation of approximately 123.5 feet and support
the footings partially on natural ground and partially on compacted filled ground. Visual
observations and laboratory tests indicate that the soils in the proposed cut area are suitable
for use as compacted fill in the proposed building area. During the demolition of the structures 7
existing on the site, all concrete footings, slabs, and any other portions of structures embedded
below the existing surface should be removed. Open pits or depressions should be cleaned of
debris and loose soi Is prior to placing compacted fill. Loose fi I I and/or topsoi Is should be
removed and the compacted filled ground should be placed on the underlying firm to very firm
natural soils. It is recommended that all fill to a distance of 10 feet horizontally outside the
building be uniformly compacted to at least 95 percent of maximum dry density in accordance
with the attached “Standard Specifications for Placement of Compacted Filled Ground,”
BENl-ON ENGINEERING, INC.
-
-5
Appendix AA. Fill placed outside the designated building area should be compacted to at
least 90 percent of maximum dry density .
Footing Recommendations -
It is concluded that the proposed building may be supported on either the firm and very
firm natura I soi Is or on fi I I soi Is uniformly compacted to at least 95 percent of maximum dry
density. It is recommended that footings should be founded at a minimum depth of one foot
into the firm and very firm undisturbed natural soils and at least one foot below the lowest
adjacent final compacted fi I led ground surface. Continuous footings placed at these depths
may be designed for a safe bearing value of 1900 pounds per square foot with an allowable
increase of 900 pounds per square foot for each additional foot of depth below the minimum
depth required. The bearing value may also be increased at the rate of 200 pounds per square
foot for each additional foot of width over one foot to a maximum of 3000 pounds per square
foot.
Square footings, one foot wide and placed at the minimum required depths, may be
designed using a bearing value of 2200 pounds per square foot. This value may be increased
at the rate of 500 pounds per square foot for each additional foot of depth below the minimum
and at a further rate of 170 pounds per square foot for each additional foot of width, to a
maximum of 3600 pounds per square foot.
These recommended bearing values are for dead plus live loads and may be increased
one-third for combined dead, live and seismic loads.
It is concluded from calculations based on the results of the load-consolidation tests
on representative samples that the total settlement of a one foot wide continuous footing
supporting a load of 1900 pounds per lineal foot is estimated to be less than l/8 inch. The
BENTON ENGINEERING. INC.
-
-6-
settlement of a square footing, 6.3 feet wide, placed’either 2 .O feet into firm natural ground
or two feet into filled ground, uniformly compacted to at least 95 percent of maximum dry
density, and supporting a column load of 140 kips is estimated to be on the order of l/4 inch.
-
Future Building Sites (Borings 4 and 5)
-
-
-
Visual observations of the soil conditions encountered in Borings 4 and 5 and the results
of laboratory tests indicate that the soils in these areas are generally similar to those found at
the proposed library site . However, the shear strengths of the soi Is in Borings 4 and 5 are
slightly lower in certain zones than those in Borings 1, 2 and 3. Also, a clayey sand was
found between 1.9 and 3.3 feet in Boring 5 that may have greater potential expansion than
any of the upper soils encountered in the other four borings. It is recommended that other
additional borings be drilled in this area in order to provide data for final recommendations
for the design of foundations for other proposed buildings,
Respectfully submitted,
BENTON ENGINEERING, INC.
BY&?~&/w=
R. C. Remer
Reviewed by
-
BENTON ENGINEERING, INC.
.-
-
La
-
P
s
-
-
-
-
-
-
-
-
-
SUMMARY SHEET
BORING NO. 1
ELEVATION 127.6’*
Red Brown, Moist, Firm
Very Firm, Slight Clay Binder
--
6-
-
8-
In terbedded Layers and Pot ke ts
of Gray Brown Fine to Medium
Sand Below 5.5’
Partia I ly Cemented Be low 9 .O’
16
18
ASPHALT
SILTY FINE TO
MEDIUM SAND
FINE TO MEDIUM
SAND
SLIGHTLY SILTY
FINE TO MEDIUM
SAND I
5.5
7.7
9.9
14.3
8.8
9.0 115. 1029
8.6
8.8 108, 2.32
8.2 108. 3.49
7.5 106. 2.85
* The approximate elevations presented herein were determined by
interpolation of the contour lines as shown on the “Topographic Map”
prepared by the City of Carlsbad, dated January 27, 1966.
0 - Indicates undisturbed drive sample
Cl - lndica tes loose, representative bag sample
PROJECT NO. DRAWING NO.
66-2-16A BENTON ENGINEERING, INC. 2
-
if
-L
-
-
-
-
-
-
-
-
SUMMARY SHEET
BORING NO.2
ELEVATION 126.9’
-0
.
2 2a ‘.J : Moist, Firm
rown and Gray, Moist,
4 Clay Binder Below 1.5’, Few
.
-P
Small Lenses With No Clay
a
6
8
16
18
Red Brown and Gray, Moist,
Very Firm, Few Fine to Medium Very Firm, Few Fir& to Medium
ASPHALT
SILTY FINE TO
MEDIUM SAND
SLIGHTLY SILTY
FINE TO MEDIUM
SAND
SILTY FINE TO
MEDIUM SAND
4.4 803 117.i 1.12
4.4 10.3
7.7
7.5
115.: 1.2c
5.5 108.: 1.46
6.6 106 .: 2.82
2.3E
3.51
PROJECT NO.
66-2-16A BENTON ENGINEERING, INC. I DRAWING NO.
3
-
4
-
-
-
-
-
-
-
-
SUMMARY SHEET
BORING NO. 3
ELEVATION 12 1.8’
,.,I
Red Brown, A
Binder
Few Small Fii
Pot kets
Aoist, Firm, Clay
ne to Medium Sand
6
8
Very Firm
More Clay Binder ,&low 8’
SILTY FINE TO
MEDIUM SAND
2.8 9.4
4.4
9.9
12.1
8.4
8.5
7.8
09.
09.
104.
109.
w
.
9
5
9
5
0.61
0.84
1.22
3.24
PROJECT NO.
66-2-16A BENTON ENGINEERING, INC. DRAWING NO.
4
-
-
I
i
-
-
-
-
-
-
-
-
-
~ SUMMARY SHEET
BORING NO. 4
ELEVATION 708.3 I
$$A Brown, Moist, Medium Firm
isj, Medium Firm
Firm, Clay Binder
\ Light Brown, Moist, Very Firm,
Few Coarse Grains -
SILTY FINE TO
MEDIUM SAND
{TOPS01 L) /
SILTY FINE TO
MEDIUM SAND
CLAYEY FINE TO
MEDIUM SAND ,
2.2
4.4
7.7
7.1
9.0
10.0
5.5 8.9
13.2 7.4
9.9 8.5
110.
115.
09.
09.
110.
110.
0.36
0.91
0.97
1.6C
3.59
3.25
PROJECT NO.
66-2-16A I BENTON ENGINEERING, INC. DRAWING NO.
5
9
-
-
L
-
#j -
-
-
wa t I{ -
-
-
-
-
-
-
-
-
-
z I I ulp: SUMMARY SHEET Aul
BORING NO. 5
ELEVATION 103.1’
Brown, Moist, Medium Compact
2
Brown. MDist. Firm
Very Firm
Brown to Red Brown, Moist,
Very Firm, Clay Binder,
Partially CementedAbove6.0’,
Few Small Fine to Medium
Sand Pockets
Brown to Red Brown, Moist,
Very Compact .‘;yr 14 .,;2,:i’ ‘, 5j.q -0
16 .+’ ” 1’ 7:
18
IL ;.;x.::<
f . . .,: fl Brown to Red Brown, Very .-
\
Moist, Very Compact, 30%
Gravel to 2”, Micaceous
SLIGHTLY SILTY
FINE TO MEDIUM
SAND
lTOPSOl L) I
CLAYEY FINE TO
MEDIUM SAND 1
SILTY FINE TO
MEDIUM SAND
SLIGHTLY SILTY
FINE TO MEDIUM
SAND
GRAVELLY
SLIGHTLY SILTY
FINE TO MEDIUM
SAND
15.8 8.9
112.
114.
7.7 8.2 108.
8.8 5.3 104.
13.2 14.4 99.
119.
117.
0.73
1.06
1 .69
0.94
1.95
PROJECT NO.
I BENTON I
DRAWING NO.
66-2-16A ENGINEERING, INC. 6
.,
CONSOLIDATION CURVES
LOAD IN KIPS PER SOUARE FOOT
1.4 0.6 0.8
-
S
i
ai 1
f
+
t .
I
-
2 e - 9 .- w.d w 2 - 22 6 u
-- --
-
o Indicates percent consol idation at field moisture
l Indicates percent consolidation after saturation
PROJECT NO.
66-2-16A
DRAWINQ NO. BENTON ENGINEERING, INC. ’ 7
1 L
-
-
-
0'
1
2
3
4
2
s
5 F t-
!Y
$
$0
&
1
5 w
2
E2
I
i: F
2
f
0
0
1
2
CONSOLIDATION CURVES
LOAD IN KlPS PER SQUARE FOOT
0.4 0.6 0.8 1 n 3 4 6 A In I
. Boring 2
IO Sample 4
D 11 .o I
16
PROJECT NO.
66-2-16A
o Indicates percent consolidation at field moisture
l Indicates percent consol idotion after saturation
DRAWINS NO. BENTON ENGINEERING, INC. 8
- BENTON ENGINEERING, INC.
-
PHILIP HENKING BENTON SAN DIEGO: 553-5654 PRESIDENT - CIVIL ENGlNEER LA MESA: 469-5654
-
APPLIED SOIL MECHANICS - FOUNDATIONS
6741 EL CAJON BOULEVARD
SAN DIEGO. CALIFORNIA 92115
APPENDIX AA
STANDARD SPECIFICATIONS FOR PLACEMENT
OF COMPACTED FILLED GROUND -
-
1. General Description. The objective is to obtain uniformity and adequate internal strength
in filled ground by proven engineering procedures and tests so that the proposed structures
may be safely supported. The procedures include the clearing and grubbing, removal of
existing structures, preparation of land to be filled, filling of the land, the spreading,
and compaction of the filled areas io conform with the lines, grades and slopes as shown
on the accepted plans.
The owner shall employ a qualified soils engineer to inspect and test the filled ground as
placed to verify the uniformity of compaction of filled ground to the specified 90 percent
of maximum dry density. The soils engineer shall advise the owner and grading contractor
immediately if any unsatisfactory conditions are observed to exist and shall have the
authority to reject the compacted filled ground until such time that corrective measures
are taken necessary to comply with the specifications. It shall be the sole responsibility
of the grading contractor to achieve the specified degree of compaction.
Clearing, Grubbing, and Preparing Areas to be Filled.
-.
-
2. -
.-
(4
04
(4
All brush, vegetation and any rubbish shall be removed, piled and burned or otherwise
disposed of so as to leave the areas to be filled free of vegetation and debris. Any
soft, swampy or otherwise unsuitable areas shall be corrected by draining or removal,
or both.
The natural ground which is determined to be satisfactory for the support of the filled
ground shall then be plowed or scarified to a depth of at least six inches (6’1, and
until the surface is free from ruts, hummocks, or other uneven features which would
tend to prevent uniform compaction by the equipment to be used.
Where fills are made on hillsides or exposed slope areas, greater than 10 percent,
horizontal benches shall be cut into firm undisturbed natural ground in order to pro-
vide both lateral and vertical stability. This is to provide a horizontal base so that
each layer is placed and compacted on a horizontal plane. The initial bench at the
toe of the fill shall be at least 10 feet in width on firm undisturbed natural ground
at the elevation of the toe stake placed at the natural angle of repose or design
slope. The soils engineer shall determine the width and frequency of all succeeding
benches which will vary with the soil conditions and the steepness of slope.
APPENDIX AA
-2-
.-
-
3.
-
-
- _.
-
(d) After the natural ground has been prepared, it shall then be brought to the proper mois-
ture content and compacted to not less than ninety percent (90%) of maximum density
in accordance with A.S.T.M. D-698 method modified to use 26 blows of a IO-pound
hammer falling from 18 inches on each of 3 layers in n 4” diameter cylindrical mold
of a 1/30th cubic foot volume.
Materials and Special Requirements. The fill soils shall consist of select materials so graded
that at least 40 percent of the material passes a No. 4 sieve. This may be obtained from
the excavation of banks, borrow pits of any other approved sources and by mixing soils from
one or more sources. The material used shall be free from vegetable matter, and other de-
leterious substances, and shall not contain rocks or lumps of greater than 6 inches in
diameter. If excessive vegetation, rocks, or soils with inadequate strengthor other unac-
ceptable physical characteristics are encountered, these shall be disposed of in waste areas
as shown on the plans or as directed by the soils engineer. If during grading operations,
soils not encountered and tested in the prcli,minary investigation are found, tests on these
soils shall be performed to determine their physical characteristics. Any special treatment
recommended in the preliminary or subsequent soil reports not covered herein shall become
an addendum to these specifications.
The testing and specifications for the compaction of subgrade, subbase, and base materials
for roads, streets, highways, or other pub1 ic property or rights-of-way shall be in accordance
with those of the governmental agency having jurisdiction.
4. Placing, Spreading, and Compacting Fill ti\aterials
(a) The suitable fill material shall be placed in layers which, when compacted, shall not
exceed six inches (6”). Each layer shall be spread evenly and shall be thoroughly
mixed during the spreading to insure uniformity of material and moisture in each layer.
(b) When the moisture content of the fill material is below that specified by the soils engin-
eer, water shall be added until the moisture content is near optimum as specified by
the soils engineer to assure thorough bonding during the compacting process. -
-
-
(c) When the moisture content of the fill material is above that specified by the soils
engineer, the fil I material shal I be aerated by blading and scarifying or other satis-
factory methods until the moisture content is near optimum as specified by the soils
engineer.
(d) After each layer has been placed, mixed and spread evenly, it shall be thoroughly
compacted to not less than ninety percent (9B!) f o maximum density in accordance
with A.S.T.M. D-698 modified as described in 2(d) above. Compaction shall be
accomplished with sheepsfoot rollers, multiple-wheel pneumatic-tired rollers, or other
approved types of compaction equipment, such as vibratory equipment that is specially
designed for certain soil types. Rollers shall be of such design that they will be able
--
APPENDIX AA
-3-
-
-
-
to compact the fi II material to the specified density. Rolling shall be accomplished
while the fill material is at the specified moisture content. Rolling of each layer shall
be continuous over its entire area and the roller shall make sufficient trips to insure
that the desired density has been obtained. The entire areas to be filled shall be
compacted.
(0
-
(e) Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equip-
ment. Compacting operations shall be continued until the slopes are stable but not too
dense for planting and until there is no appreciable amount of loose soil on the slopes.
Compacting of the slopes shall be accomplished by backrolling the slopes in increments
of 3 to 5 feet in elevation gain or by other methods producing satisfactory results.
-
Field density tests shall be made by the soils engineer for approximately each foot in
elevation gain after compaction, but not to exceed two feet in vertical height between
tests. Field density tests may be taken at intervals of 6 inches in elevation gain if
required by the soi Is engineer. The location of the tests in plan shall be so spaced to
give the best possible coverage and shall be taken no farther apart than 100 feet. Tests
shall be taken on corner and terrace lots for each two feet in elevation gain. The soils
engineer may take additional tests as considered necessary to check on the uniformity
of compaction . Where sheepsfoot rollers are used, the tests shall be taken in the com-
pacted material below the disturbed surface. No additional layers of fil I shal I be spread
until the field density tests indicate that the specified density has been obtained.
(g) The fill p t o era ion shall be continued in six inch (6”) compacted layers, as specified
above, until the fill has been brought to the finished slopes and grades as shown on
the accepted plans.
-
5. Supervision. Sufficient inspection by the soils engineer shall be maintained during the
filling and compacting operations so that he can certify that the fill was constructed in
accordance with the accepted specifications .
-_
-
-
6. Seasonal Limits. No fill material shall be placed, spread, or rolled if weather conditions
increase the moisture content above permissible limits. When the work is interrupted by
rain, fill operations shall not be resumed until field tests by the soils engineer indicate that
the moisture content and density of the fill are as previously specified.
7. Limiting Values of Nonexpansive Soils. Those soi Is that expand 2.5 percent or less from
air dry to saturation under a unit load of 500 pounds per square foot are considered to be
nonexpansive.
8. All recommendations presented in the “Conclusions” section of the attached report are a
part of these specifications.
BENTON ENGINEERING, INC.
APPLIED SOIL MECHANICS - FOUNDATIONS
6741 EL CAJON BOULEVARD
SAN DIEGO. CALIFORNIA 92115
PHILIP HENKING BENTON P”E*lDeNT - C,“lL ENGINEER APPENDIX A
Unified Soil Classification Chart*
SOIL DESCRIPTION GROUP
SYMBOL
I. COARSE GRAINED. More than half of .
material is larger t%‘an No. 200 sieve
size.**
GRAVELS CLEAN GRAVELS
m half of
coarse fraction is
larger than No. 4
sieve size but SmallerGRAVELS WITH FINES
than 3 inches (Apprec iabl e amount
of fines)
SANDS CLEAN SANDS
man half of
coarse fraction is
smaller than No.
4 sieve size SANDS WITH FINES
(Appreciable amount
of fines)
II. FINE GRAINED, More than half of
material is smaller than No. 200
sieve size .** SILTS AND CLAYS
Liquid Limit
Less than 50
SILTS AND CLAYS
Liquid Limit
Greater than 50
Ill. HIGHLY ORGANIC SOILS
GW
GP
GM
GC
SW
SP
SM
SC
Wel I graded gravels, gravel -sand mixtures,
little ar no fines.
Poorly graded gravels, gravel-sand
mixtures, little or no fines.
Silty gravels, poorly graded gravel-
sand-silt mixtures.
Clayey gravels, poorly graded gravel-
sand-clay mixtures.
Well graded sand, gravelly sands, little
or no fines.
Poorly graded sands, gravelly sands,
little or no fines.
Silty sands, poorly graded sand-silt
mixtures.
Clayey sands, poorly graded sand-clay
mixtures.
ML
CL
OL
MH
CH
OH
Inorganic silts and very fine sands, rock
flour, sandy silt or clayey-silt-sand
mixtures with slight plasticity.
Inorganic clays of low to medium plas-
ticity, gravelly clays, sandy clays,
silty clays, lean clays.
Organic silts and organic silty-clays of
low plasticity.
Inorganic silts, micaceous or diatoma-
ceous fine sandy or silty soils, elastic
silts.
Inorganic clays of high plasticity, fat
clays.
Organic clays of medium to high
plasticity.
PT Peat and other highly organic soils.
TYPICAL
NAMES
SAN DIEGO: 583-5654 LA MESA: 469.5654
* Adopted by the Corps of Engineers and Bureau of Reclamation in January, 1952.
** All sieve sizes on this chart are U.S. Standard.
-
- BENTON ENGINEERING, INC.
APPLIED SOIL MECHANICS - FOUNDATIONS
6741 EL CAJON BOULEVARD
SAN DIEGO. CALIFORNIA 92115 -
-
-
PHILIP HENKING BENTON CIILSIDCNT - CIVIL ENGINEER SAN DIE~XO: SOS-56SA LA MESA: 46S-S6SA
APPENDIX B
Sampl ing
-
-
-
The undisturbed soil samples are obtained by forcing a special sampling tube into the
undisturbed soils at the bottom of the boring, at frequent intervals below the ground surface.
The sampling tube consists of a steel barrel 3.0 inches artside diameter, with a special cut-
ting tip on one end and a double ball valve on the other, and with a lining of twelve thin
brass rings, each one inch long by 2.42 inches inside diameter. The sampler, connected to a
twelve inch long waste barrel, is either pushed or driven approximately 18 inches into the soil
and a six inch section of the center portion of the sample is taken for laboratory tests, the soil
being still confined in the brass rings, after extraction from the sampler tube. The samples are
taken to the laboratory in close fitting waterproof containers in order to retain the field mois-
ture until completion of the tests. The driving energy is calculated as the average energy in
foot-kips required to force the sampling tube through one foot of soil at the depth at which the
sample is obtained.
Shear Tests
-
-
--
-
The shear tests are run using a direct shear machine of the strain control type in which
the rate of deformation is approximately 0.05 inch per minute. The machine is so designed that
the tests are made without removing the samples from the brass liner rings in which they are se-
cured. Each sample is sheared under a normal load equivalent to the weight of the soil above the
point of sampling . In some instances, samples are sheared under various normal loads in order to
obtain the internal angle of friction and cohesion. Where considered necessary, samples are
saturated and drained before shearing in order to simulate extreme field moisture conditions.
Consolidation Tests
The apparatus used for the consolidation tests is designed to receive one of the one inch
high rings of soil as it tames from the field. Loads are applied in several increments to the upper
surface of the test specimen and the resulting deformations are recorded at selected time intervals
for each increment. Generally, each increment of load is maintained on the sample until the
rate of deformation is equal to or less than l/10000 inch per hour. Porous stones are placed in
contact with the tap and bottom of each specimen to permit the ready addition or release of water.
Expansion Tests
One inch high samples confined in the brass rings are permitted to air dry at 105°F for
at least 48 hours prior to placing into the expansion apparatus. A unit load of 500 pounds per
square foot is then applied to the upper porous stone in contact with the top of each sample.
Water is permitted to contact both the tap and bottom of each sample through porous stones.
Continuous observations are made until downward movement stops. The dial reading is recorded
and expansion is recorded until the rate of upward movement is less than l/10000 inch per hour.
I
I
I
I
1
I
1
I
I
I
I
I
PHILIP HENKING SENTON CRLSiDEHT - ClVll. ENGlNELR
City of Carlsbad
2960 Pio Pica Drive
BENTON ENGINEERING. INC.
APPLIED SOIL MECHANICS - FOUNDATIONS
6741 EL CAJON BOULEVARD
SAN DIEGO. CALIFORNIA 92115
SAN DIEGO: 563-9654 LA fdrsr: A69-S654
,--
Carlsbad, California I
Attention: Mr. Wayne Lill,
City Engineer
, 1.
.
Gentlemen:
Enclosed are four copies of our report entitled, “Soils Investigation, Proposed Library Building,
Elm Avenue and Elmwood Street, Carlsbad, California,” dated March 24, 1966.
We are also sending one copy to Mr. Robert E. Melvin, Architect, and one copy to Mr. Tom
Atkinson, Structural Engineer-
If any question should arise concerning the interpretation of any of the data presented in this
report, please contact use
Very tru ly yours,
BENTON ENGINEERING, INC.
Enclosures Jy.!T ,, , ‘,:,,,I
cc: (1) Mr. Robert E. Melvin, Architect Cl-p/ i,‘!,. :;“‘;I ,- ‘- - \
(1) Mr. Tom Atkinson, Structural Engineer p-lgin~- “_I ..
RECEIVED
‘\ r. :
5 -
\
‘!li
..’
.MAR 25 1966
‘CITY OF CARLSWJ
Engineering Depa c:: _ . . c
P. H, Lw8ti ttlammw- 03.
B, 0. Btw#E?
mbee B, I+@dl&, AJA.
t
AL. d. MURRAY & ASSOCIATES
CONWJLTINO CNOINLLRS ‘
1557 SLVRNTH AVENUE
SAN DlLOO. CAUCORNlA 08101 ’
PNONC ¶84-OSS@
Jao\uary 3, 1967
Mr. Robert E. ?&lvin, A.I.A. 2210-Avenida De La Playa La Jollo, Califemia
Dear Sir:
Subject: Electrical Fixture5 "A" T -*'Bee for City Of Carlsbad Libfary
We received a sumple of light fixture t1A*9 and the other information we requested on there fixtures. We cannot j approve
1.
2.
3.
b.
5.
tte fixtuGe5 for the following reaoons:
Fixture *‘At9 rhowo on the photolPctric that we would require approximately one third more fixture8 to get tk sime amount of light.
The wttmd of holding the lens while re- lam&g ir.very poor, and wcruld make it very awkward to work on the fixture.
To inrtall a new ballast it would entail rcsoving a great numkr of wire nuts.
The fixture hu 5 projrcticm on the top which mould hold it too far from the ceiling.
We are dirapproving fixtwe "B** because fixture5 *'A@* and trBtr are in the rame room5 and all fixture5 rhould be of 5ame manufacture and configuration.
AI.. J. MURRAY & ASSOCIATES
LONSULTING ENGINEERS
1357 SEVENTH AVENUE
SAN DIEGO. C.~LIFORNIA 92101 ..-_ -
PHONE 234-0320
January 3, 1967
Mr. Robert E. Melvin, A.I.A. 2LLO.Avenida De La Playa :,a 301La. California
Subject: Electrical Service forsitjl of Carlshad L,ibrarl
We are in receipt of a change of location of the power pole serving this project. We suggest that a change of "ost be requested from the Electrical Contractor to cover the additional material and labor to make this change, as
in the following manner:
Please submit amount of contract sum increase due to change of location of serving pole from that indicated on Drawing U-l on Elm Street to a loca- tion at intersection of Elmwood Street and Lagund Drive. This will increase length of run of two 3" conduits and concrete envelope from approxi- mately 45’ to approximately 175'.
Very- truly youFs, I i ' // I I
i I. .+ ,.‘i j ).I , ,
AL!+ i
;-- _ ,i
Murray Consulting Engineer li
AJM:js
Mr. Robert E. *lvin Page 2 January 3, 1967
..’ ._ _: - . _ . . . ;.-: : ._
ke therefore recti&d’~~bt the; Electrical- Contractor use t'nt fixtures originally specified.
I .: . ,.-
.-. -- ; . .A : Am: j$. -'. _ - -.--..I.: :'..z:..*.-'i: . . 1. y; I r,;,' -. ;. __ .. ;:.- -?-‘; .T. :-.z .. .; _. -, F -T.s:'-I- '.. -: --: -- __ ;- :
.I
W4 USARDt CDOJSf. CO,
.-
i S”& ,*++* 8 is ,k \. . .’ -5% ‘-3 ??.- ,; L
*^ .$ . S,) 2
i
,‘i . . ,F-. ,., ” -:. *.-SF >a e..,.:i ‘.$ :z.-.‘-,$ “<i &;‘& p : ‘3, ”
s :p 5
P. P. llox 882
704 Wa*EANttLe
Vi)lTA. UALWPRNW 9PBB3
CHBNlP 7hb*OltPO .i
- 15 lBmGabsr 9* 1966
re ur’ 4
R, f. MefYirrt, Armtect *b“ I i 2210 Ara De br Plet$8
La Jaila, Gwak3rof8 ) ‘
Strwturti Gtdl Cluib&art$uer. , . i
2 i '.f ji g:r;;i’ +- .’ . ‘P ,p F: i-h+ ,,.L’ 5 I c-
I r: @‘ p--” r ,.j Ij, s : ., : "
i&8& It, X+88. floor
.
,. Ilcnr &u the lb 022 011 line 3 be&wean Zlnem iB& %WitmeS ?a the cumrets block v8llT J. .I_ : *.
1 A/82 rhouo A #6 rebar field velded tb &y. &A’B+ Mig m3S
:f
8beet 61, dbensicm8 between lfnes C&P(! lioe 3 bsrrrgme~ with
, di8. e the smc luc8tfoD on sht. sz.
4 ,.+ L. @et&i1 K/S8
L i Huv da88 the 6 J0, k.h rul~lon comect to the iloor?
tN$>j Detail A/12-D
:L.i PGW @es tiw half-tube fraee that holds the au% mreen
v8l.J uorme~t to the floort
/;-
J=-
6, )Detail A/102 B, connection on top?
Le’e7f &et*ir rrj&d, rut eA9tat:ou ,, I‘, ..--/..’ Kaw doesthe 8&i tubes comect to tne coacr&e COI’+. d
P
liau D&E?
8. I’ Petri&i a/a8 _ _.. i-x KOV gr t&e I/2$3 banger rod comaected to met&L at&r thread?
j
$2. )Sb*et 0x
,.( bW& at line 2 bctveen liaes D 4 Ir IL h&trB be&t&on c?f door / .% .* qesipg required so that we ca& de%emains #a auct hm@& a&
an&~ bolt location of the 14 B 17.2 r;bowg 011 Skeet 82,
a .‘i,., * p
. .i
..I >‘ “, ,
* L L.
;r ,-I
.”
; _,
.:
-- ” . .
.;; -*‘_ * 1-..
.: ~
_-
_
:
I :, >
.
--
.
j
i - .I
.,:- --i
.::. ~.
.1: .- * .a+, , i %’ ‘* + -F +. -*.::
.;TZ te ..;.. ,
*~ -., -. .,
I?. E. Xelvfn Arcnitcct Wovesber 9, 1966
Page 2
/:: 20 1 *
i .I? - , Detail Ul2l 0; B&i? ueaf tlevatfon;- IMat is tie l itratim
II-, ,,,,' :L
bf the.&4 tube outrigger? ; .
: -.,
; _ . z - : r * r . -.. j?, ;L,( “)I y:‘;t;&& - -
wcwnlb ‘_ . .
: -’ ; fyq, . u* ‘Ci Luea c _
-Ciyfl Eogb& .. 1.. _ -, - ‘\
:- ,
,.p
‘. .
. . . .
i.
. b. -‘.’ :!
‘& ’
; ; _. 1 : : ,‘L. ‘. ’ ; z 3’ ?“a ._ :.
I 2 . : :“h. - : ;..
.
Jam NAU~ c.0 WnmAN. Amnson b ASSOCIATES SW?. / or ---- --
f D4rc e? --
CONSuLTIwo ICNOINLSRS -- ----
. eY.-Al Jom No
w
i
.
0 2 @k - #I+ ~aGfG97L-+?&-s- ,p;;Ly, l
; .
Ia shcc/ s- 2 /s wf-ec./: ~,/7%%7JdO/) /s #@&v d:
@J
.- ----- - - -.-- --- -._ ---- -.-. .-___ ________. ._-_ ___ _ _ _ ._ __
I Jo8 NAME &-/&<.+H& ..-I- - I L// -7 WHITMAN. A SW - C-IF &. cp & I ,J;. a/; q’ ._ . . emTKtN!SON & ASSOCIATES - DATE I z ,
!?LvAL CONSULTING ENGINEERS ./ -’
-- Joe No .
:j$ sip f ;j
G’ECP, d>,& r I - - ..--r ._ - *-I- +&&.. - -m :
I rt : l4B I 4 v i CO0-v~. zqp >k’ i ;ro 7L‘P &d?4$0
/g g&n l i S/M m*
.4
//z”h
i
I v -7
r-I .J
m
-. 1 I 1 ‘+
Tl \ .
I .f
0 /
I ._ BO773H C0MwD f/uL&vi9 .‘ ” CP&W 6.43 &ONr
Jam WAW~ b- sm. ’ Of
~7ffg--p.- e--m &Da
WHITMAN. AWNSON & Assmms --- .- T---- --
CONClULnNG ENGINEERS
DATC /mr/‘,&-L
hEJ Jom No
.
5’. I! ,
Gecember S, 1966
.
P. H. Llsardi
. P. 0. Box 832
-. Viste, Cclifomia
P~,QJEcT: Cgmsncdm Test Footings OA Czrlsbad Library Pm&ct
.
Geiltleizlcnl .
Please be advised that the compxtion tests indicated n faiiure to
meet grad&g s;kciflcations and you are hereby instructed to reixove
the fill milterial zt the footing lines both on the ,perimeter and Interior
concentrated ,Aers and to recompact to sS(“,. Rciative density on such
recomnpaction d footing area shall be done under the supervision of a
soils engineer from Benton Engineers Zompwy and notification to
the City of when to have the services of said soils engineer shall be
given four (4) hours idor to starting x-Tork.
In Ileu of recompiction the Contractor zwy, at his option, place the
bottom Df all foottip 1*-O” into natural UM.turbed soil.
I trust that this work will kgin as soon as i*ossible in order that
trenching or-erations can begin dutig the week of lkember 12 to
Lecenlber 16.
Sfncereiy,
riobcrt E. :&Ml, A .I..\ .
Rbll/kjc
CC: City of CilrlSbad
l \ ! . .r. I:ick %bxw
-
-
-
,L -
+” ‘. -
p ‘; -
-
-
-
-
-
-
-
-
-
PHlLlP HENKING BENTON PRESlDENT - ClYlL ENGINEER
City of Carl&ad
2960 Pio Pica Drive
Carlsbad, California 92008
Attention : Mr. R. S . Osburn
BENTON ENGINEERING, INC.
APPLIED SOIL MECHANICS - FOUNDATIONS
6741 EL CAJON BOULEVARD
SAN DIEGO. CALIFORNIA 92115
December 2, 1966aE CE ~~~~~~~~:~~~~
DR 5 1966
CITY OF CARL&#)’ Enghleering D@@&&@
Subject: Project No. 66-1 l-29D
Results of Field Density Tests
Site for Proposed Library Building
Elm Avenue and Elmwood Street
Carlsbad, California
Gentlemen:
This is to report the results of field density tests taken at the subject site on November 30,
1966. The approximate locations at which the tests were taken and the final results of
both field and laboratory tests are presented as follows:
TABLE OF TEST RESULTS
Test
No.
1
Approx-
ima te
Loco tion
Southeast
Portion, Inside
Bui Iding
Northwest
Portion, Inside
Building
Northeast
Corner, 3’
Outside
Building
Depth
of Test
Below
Existing
Grade
in Feet
o-o .5
1.0-1.5
o-o.5
Field Dry
Moisture Density
% dry wt Ib/cu ft
6.3 123.2
7.2 119.5
5.4 108.3
Maximum
Dry
Density Percent
Ib/‘cu ft Compaction Remarks
129.3 95.4 Fill Area
129.3 92.4 Fi I I Area
129.3 83.8 Cut Area
Test
No.
4
5
6
Approx-
ima te
Loco tion
Southwest
Corner, 7’
Outside
Building
Northwest
Corner
Outside
Building
Southwest
Corner, 6’
Outside
Building
-2-
TABLE OF TEST RESULTS (CONT.)
Depth
of Test
Below
Existing
Grade
in Feet
Field
Moisture
% dry wt
o-o.5 5.5
o-o .5 7.2
o-o.5 4.2
Dry
Density
Ib/cu ft
120.6
Maximum
bY
Density Percent
Ib/cu ft Compaction Remarks
131.4 91.7 fill Area
118.1 128.1 92.3 Fi I I Area
110.5 129.3 85.4 Cut Area
LABORATORY TEST RESULTS
The maximum dry densities and optimum moisture contents of the fill materials as determined by
the A.S .T.M, D 698-58T method, modified to use 26 blows of a 10 pound hammer falling
from a height of 18 inches on each of 3 layers in a 4 inch diameter l/30 cubic foot compaction
cylinder, are presented as follows:
Soil Type
Maximum Optimum Mois-
Dry Density ture Con tent
Ib/cu ft % dry wt
Brown si Ity fine to medium sand with some clay binder 129.3 9.6
Brown silty fine to medium sand 131.4 a.4
Brown silty fine to medium sand with some clay binder 128.1 9.8
It is concluded from these test results and the final results of tests taken by Tanner, Marquardt
8, Assoc., Inc., reported November 30, 1966, that the filled ground in the building area was
not uniformly compacted to a minimum of 95% of maximum dry density as required by the job
specifications. It is also understood that the fill in the building area was not placed under the
inspection of any soils engineer in that only spot tests were taken and therefore no certification
was made for the approval of the fi II for structural support.
BENTON ENGINEERING. INC.
-3-
-
-
In view of these circumstances, it is our opinion that either the contractor be Irequired to
remove and recompact the fill to the required relative density under engineering supervis
or the footings should be deepened through the fill and founded at least one foot into
approved firm natural ground.
Respectfully submitted,
- BENTON ENGINEERING, INC.
BY A?~~ $ - R. C. Remer
Reviewed b
-
-
-
Dist: (3) Addressee
(1) Mr. Robert E. Melvin, Architect
(1) Mr. Tom Atkinson, Structural Engineer
(1) P. H. Lusardi Construction Company
ion,
-
-
-
-
-
-
-
-
BENTON ENGINEERING. INC.
ENGINEERING
PLANNING
SURVEYING
SOIL MECHANICS
JOHN F. TANNER
R. C. E.
JEAN K. MARQUARDT R. C. E.
TANNER, MARQUARDT AND ASSOCIATES, INC.
230 West Third Avenue . Escondido. California 92025 . (714) 745-7720
November 30, 1966
Job #7515
City of Carlsbad
296 0 Pio Pica Drive
Carlsbad, California 92008
Gentlemen:
At the request of Mr. Osborne, we have checked the density of the
fill placed at the site of the new Carlsbad Library. The results of
our laboratory and field tests are as follows:
Laboratory Compaction Tests: ASTM D1557-58T
Soil:
Maximum Density:
Optimum Moisture :
Light -brown, silty
sand topsoil
129.7
9.9
Tan, silty sand
133.6
8.2
Field Densities :
Test Depth Below Field Dry Max. R.elative R.equired
No. Fimsh Grade Moisture Density Density Compaction Compaction
1. 3.3’ 1.8% 105.5pcf 133.6pcf
2. 2.3 8.6 101.4 129.7
3. 1.3 10.2 124.1 133.6
4. 3.6 8.4 127.2 129.7
5. 2.6 10.5 126.4 129.7
6. 1.5 8.7 129.3 133.6
7. 0.5 10.5 128.0 133.6
8.(RT#2) 2.1 12.8 116.1 133.6
9. 1.6 10.7 126.2 133.6
10. 1.3 7.2 113.6 133.6
11. 1.4 7.7 115.2 133.6
12. (RT#~) 2.1 10.0 126.1 133.6
13.( “#lo) 1.0 7.4 120.0 133.6
14. (” fJl1) 1.4 7.4 114.3 133.6
15. 1.0 8.3 117.5 133.6
16. 0.6 9.2 125.9 133.6
17. 0.7 8.3 128.3 129.7
18. (“#14) 1.0 6.7 122.7 133.6
79. o%* -- % 78.2 90
92.9 90
98.1 90
97.5 90
96.8 90
95.8 90
86.9,. 90
94.5 90
85.0 95
88.8/ 95
94.4 90
90.0 95
85.6 95
87.9 ** --
94.2 90
98.9 90
91.8 95
-
City of Carlsbad
November 30, 1966
Page 2.
Job #7515
-
-
-
-
-
(“1 Natural ground
(:k*) Outside the present limits of grading as shown on grading plan,
There was a surplus of soil
The approximate locations of the field tests are shown on the attached
sheet.
As indicated above, the soil within the building area was not compacted
to the required 95% compaction. The prime contractor, Lusardi
Construction Company, and the City of Carlsbad were notified by
telephone of this situation on Tuesday morning, November 22, 1966.
The pad area within building was surface worked in an attempt to increase
the density. Three additional field tests and a laboratory check on the
maximum density were then made. The results are as follows:
Test Depth Below Field Dry Max, R,elative Required
No. Finish Grade Moisture Density Density Compaction Compaction
19. 0’ 5.4% 122.5pcf 133.6pcf 91.7% 95%
20. 1’ 7.3 119.8 133.6 89.7 95
21. 0’ 6.1 111.6 133.6 83.5* --
(:g) In natural cut ground at the northeasterly corner of the building.
Laboratory Check: Moisture content 8.1%
Density 135.2pcf
These results were conveyed to Mr. Kelly, the grading contractor; the
City of Carlsbad; and Lusardi Construction Company by telephone on
November 29, 1966.
The compaction within the building area, including the prism extending
downward and outward from the outside of the exterior footings, is not
to specifications.
Very truly yours,
TANNER., MARQUARDT & ASSOC., INC.
James A. Smith
Soils & Foundation Engineer
JAS:mc
cc: Lusardi Construction Company