HomeMy WebLinkAboutCT 01-09; LA COSTA TOWN SQUARE COMMERCIAL; PRELIMINARY GEOTECHNICAL EVALUATION; 1990-06-06tt . •
. . Geotechñical • Geologic Environmental
5741 Palmer Way • Carlsbad, California 92008 • (760) 438-3155 • FAX(760)01-0915-
June 6, 1990
W.O. 1047-SD
N.A.G PROPERTIES
5057 Federal Avenue .
San Diego, California 92102
Attention: Mr. Gordon F. Hartley
Subject: Preliminary Geotechnical Study.Update
Parcels S.E. 13, and 25 Acres. Easterly of
La Costa Avenue and Mission Estancia,
La Costa, City of Carlsbad, California
Dear Mr. Hartley: .
In accordance with your request GeoSoils Inc. has performed a
preliminary geotechnical study and update for the above subject
property, The purpose of our study, was to evaluate the nature of
materials underlying the area and to provide recommendations for
project design, grading and construction based on -our findings.
SITE DESCRIPTION
The subject site is approximately 75 acres in area located north
of La Costa Avenue and east of Rancho Santa Fe Road in the
community of La Costa, City of Carlsbad, California (Figure 1).
A section. of Rancho Santa Fe Road and a truck by pass route
traverse the western and northern portion of the property. An
I
•.•'
J14
SAN
1
1!.
RC
.15
t 32
16
[-4 AD
:. 3
taken from " The Thomas Guide,.'1989- Edition"
LOCATION HAP
)
GeoSoils, Inc. DATE 5/90 IWO. NO.'1047-SD IBYIi
Soil Mechanics • Geology • Foundation Engineering
M.A.G. PROPERTIES . . JUNE 6, 1990
W.O. 1047-Sp
I
.' PAGE *2'
existing water line (Olivenhain Municipal Water. District), is
located along the northern edge of the truck route as well as
along the eastern and southern property boundaries. Minor fill
areas exist onsite and are predominantly, associated with existing
roadways which traverse and border the site (see Plate 1).
The western portion appears to have been used as a borrow site
and then as a site for dump fill and trash. Relatively flat
areas in the central portion have also been used for dump fill.
Topographically,. the site consists of several south to
southwesterly draining 'small canyons, gullies and swales with
intervening rounded southerly trending ridges. Natural slopes
vary from 8:1 to 2:1 in gradient along the canyon side slopes and
ridge lines varying from 12:1 to 4:1 in gradient. Total relief
across the site is approximately 175 feet.
Vegetation onsite consists of typical brush and cereal grasses.
Various imported vegetation exist within the dump fill areas.
PROPOSED DEVELOPMENT
Based on a schematic land parcel map prepared by. Rick Engineering
Company, proposed development will utilize cut/fill grading to
construct large level building .pads, street access and parking
areas for the proposed La Costa Town Center. A l'=lOO' scale
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1.990
W. 0. 1047-SD PAGE 3
topographic map, also prepared by Rick Engineering Company, is
utilized as the base map for the enclosed geotéchnical' map, (Plate
1). Schematic plans :indite the 'proposed development will
include abandonment of an'. existing portion of Rancho Santa Fe
Road with realignment. approximately along the- existing truck
'bypass route.
Fill slopes are proposed up to "approximately 70. feet in height,
at' 2:1 gradients. Cut slopes are proposed up to approximately 35
feet in heights at, gradients of 2:1. .:Maximum depth of fill
proposed is on the order of 40 (±) feet on -Lot 1. Maximum depth
of cut is approximately 30(±) feet on Lot 7.
In the event that any significant changes in the design (as
indicated above) , are., planned, ,conclusions, and, recommendations
contained in this report shall not be considered valid unless
changes are reviewed and the conclusions of thisreport verified
or modified in writing by this office. '
FIELD EXPLORATION
Subsurface conditions were explored during this study by
' excavating 15 expioratory test pits with a 'rubber tire' backhoe
and' 38 test pits with a track mounted hydraulic excavator.' Test
pits ranged from 1.5 feet to 10 feet in depth. Test pit-logs-of,
this study, as well as an earlier study by GeoSoils, Inc.
GeoSoils, Inc.
M.A.G'. 'PROPEIES ' . ' I JUNE' 6, 1990 '
WO. '1047-SD' ' " ", ' ' PAGE 4
(GeoSoils, Inc., 1982) are included'with this report as App
e
n
d
i
x
Recent field, exploration was perfored ,on May 1, 2, and
4
j 1990
by a staff geologist who logged the' test pits and obtained
samples of representative earth'materials for laboratory t
e
s
t
i
n
g
.
The approximate location of exploratory test pits from this st
u
d
y
and the location of test pits and seismic lines from-our ori
g
i
n
a
l
study are indicated on the enclosed Geotechnical Nap (Plate' 1).
Earth 'materials encountered onsite consist of - dump fill,
artificial fill, slopewash, topsoil, ' alluvium, sedimentary
bedrock belonging to the Delmar and Lusardi Formations,
a
n
d
volcanic bedrock of the Santiago, Peak Volcanics.
0
The original study bf this' property' (Geosoils, 1982) describe
d
sandstones as Torrey ' Sandstones and claystonès as Delmar
Formation. SUbsequently, regional geologic mapping by other's
(Eisenberg, 83; Tan,87; Weber,82) has described sedimentary
bedrock onsite as undifferentiated Eocene age Friars/Delmar
Formation. This designation is supported by the fine grain size,
molluscan fossil bed and claystone interbeds observed within the
sandstone bedrock. These traits, as well as the location of the
Mr'oSoils. Inc.
M.A.G. PROPERTIES " ..
JUNE 6, 1990
W. 0.. 104-7-SD • . . - PAGE 5
site on the eastern, edge of the Eocene sedimentary embaymnt, are
not characteristic of the Torrey Sandstone. .
Undifferentiated ,no2uenólature Friars/Deiar Formation: (Eisenb
e
r
g
,
83, 85) is used to describe bedrock of this approximate age and
. depositional environment, when, the transgressive or regressive
nature of sedimentation is unknown (i.eo transgressive=Del
m
a
r
Formatibn, regressive=Friars Formation). For ease, formational
sandstone and claystone.onsIte will be, ref erred to'as members of
the Delmar Formation.
Dump Fill '
Dump 'fills onsite occur in the west and central portions of the.
site as scattered.pi1esdf imported soil, trash and plant debris
dumped over existing.nátive soils. Dump 'fill' in .its present
condition is not suitable "for structural support. 'Dump fill may
be used as compacted fill provided it is cleaned. of plant debr
i
s
and trash. Scattered ,.oversize rock may be disposed of in de
e
p
e
r
fills onsite in accordance' with methods' specified in 'the gradi
n
g
guidelines 'section of this report (Appendix II).
Artificial Fill: map symbol (af
Artificial fills onsite are' associated with existing roadways
that border and traersé'the site. A fill 'thickness of five feet'
was encountered in Boi-'ing B-1, and included an abundance of
oversize volcanic rock fragments. This fill overlies topsoil and
GeoSoils, Inc.
M.A.G. PROPERTIES J1JNE.6, 1990
W lfl&1-Sfl PAGE .6
probably thickens toward: the present Rancho Santa Fe Road. An
existing fill slope, 15 (±) foot high, occurs along the westerly
portion of the truck bypass route.
A fill was placed on site during grading for La Costa Avenue in
approximately: 1985.
Topsoil
Much of the site is blanketed with a residual topsoil layer
varying up to three. feet thick. Topsoils onsite are of two
general types. ,
Where developed within sedimentary bedrock, they, consist of red.
brown to 'brown; dry, loose and porous silty sand that grades to
brown, gray brown and olive brown, moist, slightly porous sandy
' lean clays and clayey sand.. Carbonate ]nottlings 'are common along
the base.
Where developed on volcanic bedrock they consist of brown,
crumbly, porous silty' clay with common rock fragments. Topsoils
within areas of volcanic' bedrock typically grade downward into'
colluv'ial material consisting of red brown, stiff, brittle and
porous gravelly clay. Theuppèr portion of exposures observed in
the western half of the property contained rounded pebbles of
volcanic rock. These pebbles are possibly remnants of terrace
deposits that once blanketed the area, but have since eroded
away. Presence of these pebbles within 'topsoil • and the
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990
W.O. 1047-SD ' ' ' ' : PAGE 7
occurrence of topsoil over colluviuin/slOpewash indicate that' some
topsoils are at least in part colluvial 'in origin.
Alluvium: map symbol (gal)
Alluvium is. present within larger canyon bottoms onsite and was
encountered; 'up to' 6:,. (±I'. feet thick. Thicker deposits may be
found locally. Alluvium' consists of light brown, loose, dry to
slightly moist, porous silty sand. Where alluvium overlies
claystone, it consIsts of a dark greenish brown, moist, silty
'clay and sand-clay mixture. Alluvium is not considered suitable
for structural support unless it is removed,: moisture conditioned
and placed as properly compacted fill.
ammEo'atO
Sandstone member: map symbol 14,Tdsoa :
The sandstone member of the Delmar Formation consists of yellow
brown, orange brown and' gray, moist, dense,
Laminate iron oxide staining and
carbonate mottlings are common. Diagenetic intergrowths of
gypsum were. also observed in a few test pits. Near the base the
is a resistant fossiliferous limey sandstone bed approximately
one foot thick. An olive' brown claystone bed or' lens, 4' to 6
feet thick, was encountered within the upper portion of the
sandstone member (TP4] :,T46 and TP-47). Other beds or lenses
could be encountered.
GeoSol is, Inc.
M.A.G. PROPERTIES
W.O. 1047-SD
Claystone member: map symbài (Tdcs)
The claystone member of the Delmar Formation consists of dark
olive brown, olive brown and brown, moist, firmto stiff, dense,
thinly laminated to massive silty to sandy claystone and clayey .
siltstone. This member is occasionally fractured with
randomly oriented slickensides. The top of the claystone varies
from about elevation 270 feet in the west to .310 feet in the
northeast.
Bedrock - Lusardi Formation: map symbol (Ki)
onsite, the Cretaceous age Lusardi Formation consists of brown to
red brown, moist, medium. dense,. gravelly claystone. Our study
noted this formation to locally .exists along the southern
property line near Test Pits TP16 and TP-17 only. Typically,
the Lusardi Formation represents eroded material from the
surrounding volcanic. .rock mass that was deposited on ancient
lower slopes in. the region. Due to the anticipated orientation
of the basal contact on. , the. underlying volcanic rock, fill keys
should penetrate Lusardi and extend .at least two. feet into
underlying volcanic rock.. Where exposed in cut slopes, this
material should be stabilized.
Bedrock Santiago Peak Volcanics: map. symbo,1104105791
Jurassic. age Santiago Peak Volcanics are situated on the eastern
portion of the property. This formation consists of gray to
brown to orange, dense and yry hard metavoIcanic and volcanic
-
. G:eoSoils, Inc.
M.A.G. PROPERTIES
" ( JUNE-6,1j90.-
W.O. 1047-SD
'0
H PAGE 9
rock in various stages of. decomposition. Density typically
increases with depth. Hardness andrippability are related both
to the density and degree of fracturing. In low lying areas,
where 'it is overlain by deposits of alluvium, the volcanics are
highly decomposed, consisting of predominantly gravel sized
friable rock fragments in a clayey matrix. In the higher
elevations, volcanic rock is very hard and dense at. shallow
depths. General excavation characteristics are noted on the test,
pit logs and may be -used as a guide to rippability.
GEOLOGIC STRUCTURE
Bedding attitudes within the sandstone member are locally random
due to the cross-bedded, nature of this material. In general,
sedimentary bedrock dips approximately 2 to 5' degrees to the.west
and southwest. Fractures observed within some claystone exposures
in test pits are randomly oriented and of variable dip. As
such, 'prediction. of the 'effects of structure. relative to cut
slopes' in the sedimentary bedrock, is difficult. Generally,
stabilization of west and south facing cut slopes (i.e. below.'the
.western half of Lot', I) should 'be anticipated. This may be
modified based upon actual field conditions.
Within 'volcanic bed'ick shallow discontinuous joint sets are
generally oriented in a utherly to westerly direction and are
GeoSoils, Inc.
'M.A.G. PROPERTIES JUNE 6, 1990
W.O. 1047-SD PAGE 10
not anticipated to adversely effect cut slopes unless joint
patterns become continuous' with depth.
Due to the depositional environment of sedimentary bedrock on the
volcanic mass, westerly dipping contacts may exist.
Stabilization of these contacts should be anticipated, and may
Lest be discussed during 40 scale plan review.
Groundwater was not éncóuitered in 'any of our test 'pits • during
the 'most recent study. Or initial study (GeoSoils, 82) noted.
seeps in Boring B-3 at a depth of 17 feet and surface water was
observed within a canyon in the vicinity of T-9. These
observations reflect site conditions at the time of the
respective studies and do not preclude changes in local
groundwater conditions in the future from heavy irrigation or
precipitation. 'S
Field observations suggest there is a potential for creation of
perched groundwater conditions above the claystone members of the
Delmar Formation and on subsurface sedimentary/volcanic contacts.
After development, heavy rainfall and/or irrigation water may
reasonably be expected to migrate in through permeable sandstones
and pond on top of claystone and/or highly weathered volcanic
bedrock. Water can then cause unsightly 'seepage, reduce shear
GeoSoils, Inc.
strength or build, excessive hydrostatic pressure. These
conditions could lead to slope instability. When speáific grading
plans are available, comments can, b made on various cut, slopes
regarding possible stabilization. . .
. , .. FAULTING AND REGIONAL SEISMICITY
No known active 'or 'potentially , active faults are shown . on
published maps in the vicinity of thesité (Jennings, 1975). No
evidence, for faulting was encountered in any of our explbratory
excavations.
There' are' a number of faults in the Southern California area
which are considered active and which would have an effect on. the'
site in. the'. form 'of ground shaking, should 'they he the source of
an earthquake. These include the San Andreas Fault, the San
Jacinto Fault, the,,, Elsinore Fault and the .Coronado Bank Fault
Zone. Recent 'studies (by others), in the vicinity of Rose' Creek
indicate that the Rose Canyon Fault is also active.
The possibility of ground acceleration (Greensfelder, 1974), or
shaking, at the site may be considered as approximately similar
to the Southern California region as a whole. The relationship of
the site location to major mapped faults within Southern'
California is indicated 'on the Fault Map of Southern California
(Figure 2). Reeatablehiigh ground acceleration (Ploessel and
GeoSoils, Inc.
. _
•
one P-ft
' it
Turn', I 10
'
• 1.
S... •
36
• • •
bobeft
. CP .e PCK AL
Somrsheld
Tall racho
Bob;
' r :
DIG P:N( La"cos'e'
NTA r4ff. a'c<
Santo Bobo: . Venture San Be, -N'6- T.Pnl-lne VMS
- - + + 4<p '
34'
Sc'JQ ROSG SQnt3C-ru b - -
• p.,
cl er
• I aNq (1011 _
Søtl•m Ccda L c 40
c3r
do 5-
AL , .ITE , + 33•
• 12 20 (I Cr-"o
Vo(',.Do t lice .1
, t ••• -L I Cwa
50 too Gulf
-:
of
lie* 16-
Modified after Fiedmanáñd
Others, 1976 .-•
FAULT MAP
.•-'•..;- OF SOUTHERN CALIFORNIA
:.)
GeoSoil %s In" 5/90 Iwo 1047-SDBY GSI ç. DATE NO
Soil Mechanics- Geology • Foundation Engineering
--___________________ • S • FIGURE 2 •
M.A.G. PROPERTIES. .' ( " JUNE' 6, 1990
W.O. 1047-SD ' PAGE 12
Slosson, 1974) on the property will, likely not exceed O. 18g
assuming a magnitude 7.0 earthquake on the Elsinore Fault, 24
miles northeast of the site or 0.23g.assuming aInagnitudé 6.5 on
the Rose Canyon Fault 'located 8 miles to the west.,
Other Hazards Considered: The following listing includes other
eismic 'related hazards that have been 'considered for our
evaluation of the site. These hazards' are considered negligible
and/or completely mitigated as a result of typical " site
development procedures:
* 'Surface Fault' Rupture ' * Ground Lurching or Shallow Ground Rupture
* Liquefaction
* Seismic settlement or consolidation
* Potential 'for tsunamis '
* Seiche
LABORATORY TESTING
General
Laboratory tests were preformed on selected samples to evaluate
physical characteristics of representative on site 'materials.
This section is a compilation of laboratory testing performed
during this study and our initial study. Some data was derived
from nearby sites For ease of review, all laboratory data is
included herein.
GeoSouls, Inc.
M.A.G. PROPERTIES JUNE 6, 1990
W.O. 1047-SD PAGE 13
Field Moisture and Density '
Field moisture content and drr unit weight were determined for
"!undisturbed" 'samples of native materials. Dry unit weight was
determined in pounds per 'cubic foot and the field moisture,
content was determined as, a percentage of the dry unit weight.
Iesults of these tests are presented within the boring logs in
Appendix I.
Laboratory Standard
To determine the compaction' character of representative .samples
of onsite earth material laboratory testing was' performed in
accordance with ASTM Test Method D-1557-78. Maximum density and
optimum moisture content from these tests are sunmarized. 'below:
Location Description '
Maximum Density'
' Density (pcf) '
Optimum'
Moisture %
B-2 @ 31 , fine:sand ' ' 110.0 , 17.0
B-2 @ 24' silty clay 109.0 ' ' ' 18.0
B-3 @ 9' clayey silt 116.0 , 16.0
Parcel ' clay ' 109.0 , 20.0
S.E. 15 ,
Parcel Sandy silt , ' 109.0 , 17.5
S.E.' 15
Parcel ' Silty sand ' ' 115.0 ' 11.9
S.E. 15'
TP-16 @ 1' silty sand 124.0 , 12.5
w/gravel
TP-43 @ 5' silty fine sand ' 110.0 ' ' 17.5
'Expansion Tests
Swell tests were perormed', on remolded samples of near surface
soils. Samples were prepared at 80 percent of the optimum
GeoSoils, Inc.
N.A.G. PROPERTIES " I JUNE 61 1990 W.O. 1047-SD •.',. ' PAGE 14'
moisture and at 90 percent of the. maximum dry density, placed
under a• 60 pound per square' foo€,' surcharge, and submerged in
water for 24 •hours. The percent swell was then recorded- as the
amount of vertical :rise compared to the original one inch sample
height.
Expansion' index test were also performed.Testing was performed in
accordance with Standard 29-2 of Uniform Building Code.
Test results are summarized below:
Location , ' Swell % Expansion Index Expansion Potential
B-i @ 3' ' 2.4 - , low
B-3, @ 9' 11.6 - ' ' high
Parcel S.E'. 15 19.8 198 ' very high
clay
Parcel S.E. 15 .11.2 ' ' '61. medium
sandy silt
Parcel S.E. .15 5.2 22 . , low
silty sand
TP-16 @ 1' 5.5,' ' ' -' ' ' ' low
TP-43 @ 5" '13.5
, - 'high
Shear' Test
Shear tests were performed on undisturbed soil samples 'in a
strain control-type direct shear machine. Rate of deformation
was approximately 0.05, inches per minute. Samples were sheared
and 'resheared under varying confining loads in order to determine
the Coulomb' shear strength parameters, cohesion, and angle of
internal • friction. Samples were tested in an artificially
saturated condition.. .Results are plotted on the enclosed Shear
Test Diagrams, Plates SH-1,, SH-2 and SFI-3.
GeoSoils Inc.
M.A.G. PROPERTIES ' " , JUNE 6, 1990
W.O. 1047-SD ' S ' 'PAGE 15
Sulfates '
Samples of the site materials were analyzed for sulfate content.
Test results are as follows:
Parcel S.E. 15 clay. - 0.80%
Parcel S.E. 15 sandy silt - 0.02% '
Based on these, test results, Type II and Type V'-cement may' be
required for construction of the site. The actual cement type'
should, be determined upon 'completion of grading with specific 'pad
grade testing.
CONCLUSIONS
Based on our field exploration, laboratory testing, engineering
and geological analysis, it is our opinion that the project' site
is suited for the proposed development from a soils engineering
and geologic viewpoint, provided the recommendations presented
below are incorporated into the, final design, grading and
construction phase of development.
EARTHWORK RECOMMENDATIONS
The. most 'significant geotechnical factors affecting site
development are as follows:
GeoSoils, Inc.
'M.A.G. 'PROPERTIES I JUNE 6, 1990
W.O. 1047-SD '• . PAGE '16
Presence of hard volcanic rock requiring blasting to
excavate,' and subsequent placement of this material as' fill.
'Presence of claystones, both ,interbedded in the sandstones
and the massive unit in lower elevations.
Suitability of fill materials for slope construction and lot
capping.
Other considerations are the removal, of surfici'al soils, probable
need far extensive subdrains, expansive soil and stability of
graded, slopes.
Rock Hardness
'
Volcanic rock 'underlies the eastern or northeastern portion of
the site. Based on available data, significant 'portionsof the
proposed': cut areas would require blasting to excavate. While
b'oth recent trenching and previous seismic refraction studies
show variation 'of depths' at which blasting is likely to be
necessary, we anticipath' the upper 8 to 10(±) feet could
reasonable to ripped and excavated using a D9L or equivalent
ripper Cat. It may not be' bneficial to do this, , however.
Blasting procedures utilizing a certain "overburden" tend to be
more effective producing-'smaller (more fractured) rock pieces.
These are generally more readily placed as fill. Rock hardness
is further discussed in Appendix III.
Claystones '
Rather extensive cláystone are present. These 'are problematic
with respect to -slope, stability both in cuts and when utilize for
GeoSouls, Inc.
M.A.G. PROPERTIES . . JUNE 6,. 1990
W.O. 1047-SD .. PAGE 17
fill slopes. Claystones,..aré presents both in the Lusardi and
Delmar Formations.
The existing cut slope , south. of Boring •B-5 (Lot 4) will need to
be stabilized where it exposes claystone. While ultimate design
will .depend on" speOif Ic grading, we tentatively anticipate a 20
to 30.foot wide key, 5 to 7 feet.deep, below toe grade. 'A similar
key would extend easterly to the volcanic contact (near B-3)'.
A key should penetrate the Lusardi Formation and extend a, minimum
of two feet into volcanic .roOk near TP-16 below Lot 6.
Slopes near the claystoneinterbed in the sandstone section would
also need to be stabilized (i.e. the western area of Lot 1).
Fill Suitability . .... . . . .
While it Is possible to use any of the materials on site as-fill,
the majority of materials have some limitations which should be
discussed.
The majority of surficial soils are expansive clays and.are best
suited for placement in deeper fills and away from slope faces.
Claystones also are best placed in deeper fills and should not be
placed within 15(±) .feet of slope faces.
Sandstones on site should produce good quality fill and be
suitable both for slope construction and for placement near
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 61 1990
W.-O. 1047-SD. PAGE 18
finish grades on pads. 'While fill materials derived from
sandstone is. considered somewhat erqsive, this can typically be
controlled by mixIng and/or protective measures on finish slopes.
Our testing and observation indicate that the expansive potential
of these sediments varies from low to high, with low to medium
dominating.
Volcanic rock should produces highly variable fill materials.
The upper weathered. portion which, 'can excavated by ripping,
should produce reasonably good fill material with some oversized
rock. . Materials that display seismic velocities less than 9,000
to 10,000 'feet .per second (fps), but necessitate blasting should
produce ':materials well suited forplacement as structural rock
fill (see Fill Placement section page.24). Harder material will
likely' generate poor, quality fill containing minimal fines.
Placement in non-structural areas, mixing with crushed or mined
on-site materials, mixing with imported granular material or
export of this material should be anticipated.
Natural-Slopes -
Generally, existing natural slopes appear stable in the gross and
surficial sense. Conceptual development plans indicate that.' all
natural slopes onsite are to be graded.
GeoSoils, Inc.
M.A.G. PROPERTIES
W.O. 1047-SD
JUNE 6, 1990
PAGE ' 19
Cut Slopes-
Proposed cut slopes are projected in height to. about 30(±) feet
at 2:]. gradients. The majority of cut slopes are expected to
expose volcanic bedrock with a thin soil mantle. Smaller cut
slopes, 'on the order of seven feet or: less, are expected to
'expose sandstone 'bedrock of the Delmar Formation. 'Stabilization
of any west and southwest facing cut slopes exposing the Delmar
Formation may be recommended. These slopes 'will •be evaluated
during grading operations. Stabilization fills should be provided
with backdrainage.
Cut slopes in the volcanic bedrock are not anticipated to require
stabilization unless continuous fractures or shears are
encountered. Also, overblasting can weaken the rock 'material,
necessitating stabilization.
Field observations 'suggest there is a potential for perched water
conditions to form ,on the claystone members of the Delmar.
Formation and on subsurface sedimentary/volcanic contacts. 'After
development,, heavy rainfall and/or irrigation water may be
expected to migrate through permeable sandstones and' pond On top
of claystone and/or' hig1i1y' decomposed, clayey volcanic bedrock:.
Water can then cause unsightly seepage, reduce shear strength or
build excessive hydrostatic pressure. These conditions could lead
to' slope instability. As such, cut slopes exhibiting claystone
beds' sandwiched , between, sandstone beds should be stabilized and
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 61 1990'
W.O. 1047-SD I . PAGE 20
backdrains provided. When specific .gradiiig plans are available,
comments can, be made on various ut slopes regarding possible
stabilization.
All cut slopes should be mapped by a geologist from this office
during grading to allow for amendments to recommendations, 'should
exposed conditions warrant altètation of the design for
stabilization.
Fill Slopes'
Fill slopes are proposed to 70 (±) feet in height at gradients of
2:1. 'Fill 'material derived purely from the claystone member of
the DelLar. Formation should not be placed on fill slopes or
within 15 feet of a .fill'slope surface. Bench' drains should be
constructed on graded' sippes using the Uniform Building Code as a
minimum standard. ' Fill slopes are considered stable assuming
proper construction.
Existing Fills
Existing fills. within the property are associated with dirt
roadways crossing canyons in the eastern portion,
stockpiled/dumped on the western portion of the site or
associated with the truck bypass route and Rancho Santa Fe Road
in the northern portion.' In addition, engineered fill is-
situated in the western" canyon on the north side of La Costa
Avenue (see Plate 1). 'Research at the City of Carlsbad
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990 W.O. 1047-SD . PAGE 21
Engineering Department noted that grading along La Costa Avenue
was conducted with observations and testing of Southern
California Soils and Testing (SCST). However, a final soils
report was not available- at the City and is being requested from
SCST. We anticipate existing fills associated with La Costa
Avenue to be adequate for structural support in their present
condition.
Existing fill soils along the bypass route and Rancho Santa Fe
Road appears to. be limited and should be reworked in. areas of
proposed grading.
Stockpiled/dumped: fills, situated on the western portion of the
site, are considered loose and compressible in their present
condition and should be removed. These materials may be used as
fill provided they are clean of all organic debris.
Perimeter Fill Slope Keys
The schematic land map indicates that fills may extend over cut
slopes. Kèyways will be needed to support these fills.
DimensiOns of these key will vary depending on upon speàific
conditions (bedrock orientations, descending . slope gradients,
etc.). and material type encountered. Deeper and wider keys would
be needed where claystone','. SL., are present. Key depth will probably
vary from two 'to seven feet while widths of fifteen to twenty
GeoSoils, Inc.
M.A.G, PROPERTIES S ( , .]1.JNE 6, 1990
W.01b 1047-SD PAGE 22
five feet should be anticipated. This could be further analyzed
when grading plans are available.
Typical stabilization type 'backdrain would' be recommended for
most of these keys. Drains will likely be recommended near the
base of the keys and also along sandstone/claystone contacts.
Removals
Removals should include all existing stockpiled/dumped fill,
topsoil, alluvium and highly weathered bedrock materials.' Due to
the soil cover encountered on existing natural slopes, removals
of natural'sojls should be anticipated to be on the :order of 3(±)
feet overall. Locally deeper and shallower areas of removals may
be encountered. Removal "depths of alluvium in lower canyon
bottoms and swal?s should be anticipated to be on the order of 6
to 7 feet. Locally deeper or shallower 'removals may be
encountered..
Shrinkage - Bulking
Sedimentary bedrock mat6ria1s 'on the project are anticipated to
bulk 0 to 3 percent. Vo1óanic 'rock will bulk, dependant on the
depth of cut, a range of 5 ,to 25 percent. Typically, rock should
bulk in' cuts up to 10 (±) feet approximately 5 to 10 percent.
Rock should bulk in cuts from 10 to 25(±) fe.ét.approximately .10'
to 20 percent, and rock in cuts greater than 25 feet should bulk
on the order of 25 percent. Topsoil and alluvium will likely
GeoSoils, Inc.
M.A.G. PROPERTIES . . ... JUNE 6, 1990.
W.O. 1047-SD, . . S •PAGE.23
shrink '10 to 15 percent. Dumpf ills would likely shrink 20.to 25
precent.
Subdrainage . .
Placement of. subdrains will need to be evaluated during grading
plan, reviews. Subdrãins will likely be' recommended below all
canyon fills and for all stabilization fills exceeding '8 feet in
height. " Drains would' likely be recommended 'for' perimeter'f ill
'slope keyways.
Due to the potential for groundwater 'accumulation and migration
"along the sandstone/claystone contact, an additional drainage
system: may be necessary to drain this contact- in certain areas.'
Stabilization of, cut slopes exhibiting this condition should also
be anticipated. This system, or combination of systems 'can 'best
be designed when grading 'plans are developed'.
Subdrains should extend up canyons to levels of ten feet below
finish fill grade but should not conflict with future utilities.'
Subdrains should be constructed in accordance with designs given
in 'Appendix II.
Fill' Placement
Guidelines for fill placement are presented in the' Grading
Guidelines enclosed as Appendix II.
A' large portion of cut material generated within areas of
GeoSoils, Inc.
M.A.G. PROPERTIES S 1 JUNE 61 1990
W.O. 1047-SD °.,, PAGE 24 ,
volcanic bedrock, either_`, from blasting • or ripping, will most
likely be unsuitable for.use as typial fill material. In order
to provide guidelines for conventional fill versus. rock fill the
following criteria has been developed for various materials:
Type 1: Materials comprised predominantly of 3/4 inch and
smaller particles with less than 40 percent rock
fragments eight (8) inch and smaller.
Type 2: Well graded,materials comprised dominantly of three (3)
inch and smaller particles with less than 40 percent
rock fragments eight (8). inch. and smaller.
Type 3: Material containing approximately 40 to 60 percent rock
fragments (8 inch to 2 feet). and approximately 40
percent: well graded matrix material comprised
dominantly of 3 inch and smaller particles.
Materials Types 1 and 2 may be placed as conventional fill.
Type 3 is considered suitable for placement Of, rock fill and
should be capped with a minimum of 5 feet of Type 1 and 2
materials in pads.
Based on available data, it is our opinion that the materials
excavated from volcanic rock on-site would fall within the above
categories assuming efforts are made to maintain fairly shallow
cuts. Materials containing minimal fines would also likely be
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990
W.O. 1047-SD PAGE 25
encountered, generally at depth greater than 15 to. 20 feet.
These will require mixing, crushing or possibly other special
handling techniques.
It is important that when needed, blasting procedures by utilized
which will produce 'dominantly 2 foot minus rock fragments. This
should not only result in dominantly, less than 2 foot rack but
also generate smaller material (less than .8 inches).
Grading. should be. scheduled to develop deeper cut areas, where
hard rock -and oversize, material are likely to encountered, in the
early stages of grading.. This provides more flexibility to
acco-inmodate blasted rock and oversize rock fragments in deeper
fills and may avoid major rock disposal problems (crushing,
export, etc.) in the late stages of grading. Stockpiling of
removals and shallow but 'material and mining of sandstone may be
considered depending on earth work balancing.
Piping Potential and Filter Blankets
The potential for piping (migration) of fine grained material
from the overlying conventional fill cap into rock fills will
need to be addressed.
The potential for particle migration is related to grain size
comparisons of materials present and in contact with each other.
Provided that 15 percent :ôf the.finer. soil is larger than the
effective pore size of thecoarse soil then particle migration is
GeoSoils, Inc.
.M.A.G. PROPERTIES . .. . 1 JUNE 6, 1990
W.O. 1047-SD •, '. . PAGE '26
substantially. mitigated. This can be accomplished with a well
graded matrix material for the rock fill and a zone .of fill
similar to the matrix above 'It . (e.g. 2 to 3 feet thick blanket of
Type 2 fill placed over Type 3 fill).'
The specific, gradation of - fill materials placed during grading
must be known to evaluate the need for any. type of filter that
may be necessary to cap the rock fills. This, unfortunately, can
only be accurately determined during construction. . .
In the event that poorly, graded matrix is used in the rock fills,
properly graded filter blankets (2 to .3 feet thick) separating
rock-fills and conventional fill may be needed. Alternately, use
of two layers of. filter .fabric (Mirafi 700 x or equivalent) could.
. '. be employed on top of the rock fill. One layer of fabric.'should
be placed on the rock.f ill surface after it has been, well broken
down and smoothed to mitigate excessive puncturing. Relatively
permeable fill material (with respect to overlying material) 1 to
2 feet thick should then "be placed and compacted. The second
layer of fabric should then be placed and conventional fill
placement continue.
Lot Capping
For transition lots it is recommended that the cut, and portions
of the fill area be overexcavated a minimum of five feet. and
brought to grade with compacted fill. This is to provide a
GeoSoils, Inc.
M.A.G. PROPERTIES
W.O. 1047-SD
JUNE 6, 1990
PAGE. 27
uniform' bearing material and greater insulation' against the
contrasting properties 'of 'transition materials involved (i.e.
expansion and seismic acceleration). Rock fills should be capped
with a minimum 5 foot thick 'soil fill.
Foundations . for any structure should' be entirely 'in uniform
gedrock or in compacted fill. . Placing highly 'expansive, soil
should be avoided in.' the upper five (5) feet of the building
pads, if possible.. . .. . .
Foundation Recommendations
Based upon our observations and test data, low expansive to
highly expansive 'soil exists onsite. xpansion tests should .be
performed for each :lot/building" site at the - 'completion 'of.
grading. Specific. recommendations for foundation design' and
construction will be presented when the detail plans become
available. Special' consideration will be needed in certain areas
particularly where significant
beneath individual buildings.
differential fill is present
Plan Review
Specific grading plans should be submitted to' this' office for
review and comment as they become available, to minimize any
misunderstanding between the plans and recommendations presented
herein. In 'addition, "fàundation excavations and. earthwork
construction performed on the'site should be observed and tested
GeoSoils, Inc.
'M.A.G. PROPERTIES JUNE 6, 1990 W.O. '1047-SD '. I , PAGE 28
by this office. If conditions are found 'to differ substantially
form those stated, appropriate recommendations would be offered
At that time..
LIMITATIONS'
Materials encountered on the project isite and 'utilized' in' our.
laboratory study are believed, representative' of the area;;
however, soil' and, bedrock materials vary in character, between
excavations and natural outcrops or conditions exposed during
mass grading.
'Since our study is based 'upon the site materials observed,
selective laboratory testing and enìgineering analysis,
' the
conclusion and recommendations are professional opinions. These
opinions have been derived in accordance with current' standards
of practice and no warranty is expressed or implied.
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990 W.O. 1047-SD PAGE 29
If you have any questions concerning tlis report, please call.
Very truly yours,
GeoSoils, Inc.
gra ti Me, 142 GE 782
Principal Geologist GeotP hni+licallngineer
<60P C r.-~risman Staff Geologist
S 782 -i
TEM/VS/RGC/mc : 12-31-93
O S Enclosures: Reference List 5 Appendix I, Test Pit and.B
Appendix II, Grading Guidein
Appendix III, Rock Hardness and Evaluation
Plates SH-1, SH-2 and SH-3! Test Diagrams Plate 11 Geotechnical Map
cc: (6) Rick Engineering Company, Mr. Ladwig
S
GeoSoils, Inc.
REFERENCS
Eisenberg, L.I, 1983, Pleistocene Inrine terrace and Eocene
geology, Encinitas and Rancho anta Fe quadrangles, •San
Diego County, California: San Diego State Master's Thesis
386p.
Eisenberg, L.I., '1985, Depositiona] Processes in the Landward
Part : S of an Eocene Tidal Lagoon, North, ern San Diego County: in Abbott, P.L. ed., On the Manner of Deposition Of Eocene
Strata in Northern San Diego Couny, San Diego Association
of Geologists Guidebook, 98 pp.
GeoSoils, Inc., 1982, Preliminary Geologic and Soils Engineering
Investigation, Parcels S.E. 13 and 14 in La Costa, 'City of
Carlsbad, California.
Greensfelder, Roger, 1974, Maximum credible rock acceleration• from earthquakes in California,;' Calif. Div. Mines" and
Geology, Map sheet 23.
Jennings, Charles w., 1975, Fault Nap of California; Calif. Div.
of Mines and Geology, Geologic Data Map series No. 1, to
750,000 scale,.
Ploessel, Michael R. and Slosson, JamnesLE., 1974, Repeatable High
Ground Accelerations - Important dsign criteria; California
Geology, Sept., p. 195-199.
Schanbel, P.B., Seed, H.B., 1973, Accelerations in Rock For Earthquakes in the Western United States: Bulletin 'of the
Seismological Society, of America, v. 63. no. 2, pp. 501-516.
Tan, S. J.,, 1987, Landslide Hazards in the Rancho Santa Fe
Quadrangle, San Diego County, California. Landslide Hazard
Identification Map #6, CD.M.G. Open File Report 86-15 LA.
Weber, F.H., 1982, Geologic'Map of the central-North Coastal Area
of San Diego. County, California, Showing Recent Slope
Failures and Pre-Development Landslides: California Div. Of Mines and Geology Open-File Report82-12 LA, Plate 1.
GeoSoils,. Inc.
EXPLORATORY TE9 PIT LOGS
Test Pit Depth (ft.) Natrial Description.
TP-1 0-4 Easy to moderately' difficult excavating.
4-4.5 ' Very difficult excavating.
0-0.5 TOPSOIL: Medithu brown, si1ty CLAY,
loose, brittle, porous, occasional small
to large gravel size'rock fragments,
common insect I3urrows and roots,' dry.
'0.5-1.5 ' SLOPEWASH: Brown to yellow brown,
gravelly CLAY, lOcally sandy, stiff,
medium hard, and brittle, very' slightly,
pliable, porou, common high 'angle open
fractures, occasional rootlets, slightly
moist.
1.5-3 HIGHLY WEATHERED BEDROCK (Jsp): Greenish
gray-rust-tan, highly weathered VOLCANIC
rock, 'locally 1ighly decomposed tOclayey
gravel, mediumdense to dense, brittle,
highly fracturad with common clayey rinds
' - representing ir' situ 'alteration,
'occasional rootlets, slightly moist.
3-4 Orange-gray-white, highly decomposed
VOLCANIC rock, predominantly silty clay,
medium dense, crumbly, slightly sticky,
occasional relict rootlets, no distinct
lineations, localized caliche, truncated
by soil, note rock stringers
incorporated, Slightly moist.
4-4.5 ; Medium brown-yellow brown gray, weathered
VOLCANIC rock, dense, brittle, blocky'
cleavage, moderately fractured, oxidized,
dry'.
Practical Refusal at 4.5 feet
Hole Backfilled
Apparent shear at 3' N70W/62SW
Prominent joint at 2 5' N38W/76SW
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990
W.O. 1047-SD
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-2 , 0-5 Easy to moderately very difficult.
excavating.
5-7 Moderately difficult to very difficult
excavating.
0-0.5 TOPSOIL: Medium .brown - silty CLAY,
' 'loose, brittle, porous, occasional small'
- ' tolarge gravel size rock fragments,
common insect' Iurrows and roots, dry.
0.5-2.5 , HIGHLY WEATHERED -BEDROCK (Jsp): 'Greenish
'gray-rust-tan, ,!highly weathered VOLCANIC
rock, locally highly decomposed to clayey
gravel, medium dense to dense, brittle,'
highly fracturd with common clayér rinds
representing in situ alteration,
occasional rootlets,* slightly moist.
2.5-4 ' Grayish green-rust, weathered VOLCANIC
'rock, medium dense, brittle,' highly
fractured with2"-1'(±) spacing,
fractures exhibit clayey crusts.(in situ
alteration), taces rootlets, locally
'highly decomposed to sandy clayey
materials, slightly moist.
4-7' .' ' Rust and gray with green and white random
sea king, irregularly '
wéathered/decontposed VOLCANIC rock,
medium dense,, medium hard, brittle,
fractured with :811-11 (±) spacing, locally
common randomly orientated discontinuous
stringers of crumbly green and white
clayey material with caliche '(highly.
decomposed zones?), locally very blocky,
oxidized, slightly-moist.
PrOminent joint set at 3.5' N55W/42-48SW
ProminEnt joint set at 4' N18E/68SE
Practical refusal at 7 feet
Hole Backfilled
-2-
GeóSoils, Inc.
M.A.G. PROPERTIES
/ JUNE 6, 1990
W.O. 1047-SD S
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-3 0-4 Easy to modratply difficult excavating.
4-5.5. Difficult :to.veiy difficult excavating.
Q-1/2 TOPSOIL: Mediun brown,, silty CLAY,
0 loose, brittle, porous, occasional small
to large graveli size rock fragments,.
.. ., . common insect burrows and roots, dry.
1/2-2 SLOPEWASH: Reddish brown,' clayey 'GRAVEL,
• medium hard and brittle, porous,
occasional rootlets, slightly moist.
2-3 ALLUVIUM: Yellpw brown to brown,
• . silty/fine sandy. CLAY, stiff, slightly
. pliable, occasional small gravel size
rock fragments,F isolated relict rOôtlets,
. . slightly moist to moist.
3-5 . HIGHLY WEATHERED BEDROCK (Jsp): Mottled
. . gray and orange, highly irregularly
.
' . .. . dedmposed VOLCANIC rock, predominantly
sandy clay with pockets or rock
' faents, medium dense, abundant
S S roandoliily orientated gray discontinuous
• stringers, material may represent zone of
contact metamorphic with Delmar Formation
to west, moist to slightly moist.
5 5-5.5 . Orange and gray weathered VOLCANIC rock',
. ' . S dense, hard and brittle, blocky with
. fragments up to 11 (±) in one dimension,
oxidized, common black manganese'(?)
S staining, dry. •. 0
Practical refusal at 5.5 feet
0
• Hole backfilled 0
S 'S• S •
-3-
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990 W.O. 1047-SD
,.
. .
EXPLORATORY TEST PIT LOGS .
Test Pit Deth (ft.) Material Description.
TP--4 0-3.5 Easy to moderately difficult excavating.
3.5-8.5 Moderately difficult to difficult - excavating.
0-05 . TOPSOIL: Medium dark brown, silty CLAY,
loose, porous, abundant rootlets and
insect burrows, dry.
0.5-3 . SLOPEWASH: Reddish brown, clayey GRAVEL,
medium hard andl brittle, porous,
occasional rootlets, slightly moist.
3-8.5 HIGHLY WEATHERED BEDROCK (Jsp): Tan-
olive gray-gray, irregularly decomposed
VOLCANIC rock, predominantly sãfldand
clayey with loc1ized. pockets/stringers
of hard rock, indiuia dense, common in
situ weathering/alteration-to clayey,
materials, oxidized, locally very crumbly
and friable, traces of caliche at 3'-
3.5'(±), slightly moist.
Joint set at 5' N50W/70NE
Practical refusal at 8.5 feet
Hole backfilled
Geó.Soils, Inc.
M.A.G. PROPERTIES ( JUNE 6; 1990
W.O. 1047-SD I
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Descrptjon
TP-5 '0-4 Easy to modérately difficult excavating.
4-10. Moderately difficult to difficult
excavating.
0-0.5 TOPSOIL: Medium dark brown, silty CLAY,
loose, porous, .!abundant rootlets and
•• insect burrows, dry.
0.5-2 SLOPEWASH: Reddish brown, sandy CLAY,
' local gravel, stiff, moderately porous,
slightly pliable, brittle, occasional
vertical open fractures, occasional' S
rootlets, moist.
2-10 ' HIGHLY WEATHERED BEDROCK (Jsp): :yellow
brown to gray nd black on broken'
surfaces, irregii1ar1y decomposed VOLCANIC
rock, locally very clayey and sandy (in
-' situ alteration), medium dense, locally
fracture, brittle and 'very hard, randomly
weathered, oxidized with black iii anese(?)' staining, slightly platy
cleavage with fragments averaging'511(±)
in.- one dimensidn, slightly moist.
'Prominent joint at 4' N5E/vertical S
Prominent joint at 4' N5W/85-90E
Prominent joint at -40 N46E/80-90Nw
Localized practical refusal at 10'
'S •
S ' Hole ba,ckfilled
-5-
GeoSouls, Inc.
I
M.A.G. PROPERTIES
. (
JUNE 6,'1990.
W.O. 1047-SD . ... S
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Matérial Description . .
TP-6 • . 0-1 Easy excavting.
14 : Difficult. excavating.
0-0.5.1 TOPSOIL: Medium brown, silty CLAY,
loose, brittle, porous, occasional small
to large gravel size rock fragments,
common insect burrows, and roots, dry
- .0.5-2 SLOPEWASH: Rddish brown, sandy CLAY,.
local gravel, stiff, moderately porous,
. •• slightly pliab1le, brittle, occasional
vertical open fractures, occasional
rootlets, moit.
3.4 S WEATHERED BEDROCK (Jsp): Rust and gray,
weathered VOLCANIC rock, dense, hái-d
brittle, blocky cleavage, fractured with
• S • S 211-511(±) spaciing, fragments average 311 (±)
in one dimensiion, dry.
S S •
. Local practical refusal at 1 to4 feet
•
S • Hole báckfilld
S GioSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990
W.O'. 1047-SD
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-7 0-5 Easy to moderately difficult excavating.
5-7 Moderately difficult to very difficult
excavating.
0-0.5 TOPSOIL: Brown], silty CLAY, occasional
to.'-.common surfape rock fragments1 porous,
brittle, abundant. rootlets, slightly
moist.
0.5-1.5 SLOPEWASH: Brown with orange mottling,
gravelly CLAY, medium stiff to stiff,
moderately porous, occasional rootlets,
moist.
1.5-7 WEATHERED BEDROCK (Jsp): Rust-brown-
gray, irregulaxjly weathered VOLCANIC
rock, medium dense, highly fractured with
random orientations, locally highly
decomposed to crumbly sandy/clayey
materials, traces of rootlets, odixized
with clayey crsts on prominent fractures
i n. situ altera!tion) in upper 1' (±),
slightly moist.
Pt6m1nént joint @1.5' N25W/50SW
Proinënt joint @5 ' N37W/62NE
• General lineation 3' N5W/60W
Practical refusal at 7 feet
Hole backfilled
GeoSoits, Inc.
.M.A.G. PROPERTIES 0
(
JUNE 6, 1990
W.O. 1047-SD
• EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-8, 0-1 Easy excavati4
: Difficult.éxcayating
0-0.5 TOPSOIL: Browj1, silty CLAY, occasional
to common surface rock fragments, porous,
• brittle, abundant rootlets, slightly
moist. •
0
0.5-1 SLOPEWASH: Orange brown-brown, sandy
CLAY, stiff, prous., slightly pliable and
sticky, occasional rootlets, moist.
1-3 WEATHERED BEDROCK (Jsp): Rust and gray,
• 0
• weathered VOL4NIC rock, dense, hard and
•• brittle, blocky cleavage, fractured with
2"-5" (±) spaciig, fragments averace 3" (±)
in one dimnensipn, dry.
• • Joint set at 1.5' N40W/70SW
Practical refual0 at 3 feet • Hole backfil1e 0
JUNE 6, 1990 M.A.G. PROPERTIES
W.O. 1047-SD
EXPLORATORY TEST PItT LOGS
Test Pit Depth (ft.) Material Description
TP-9 ' 0-1 . Easy excavating.
'1-7 Moderately diftificult to very difficult
excavating.
0-I TOPSOIL/SLOPEWkSH: Reddish brown, sandy
CLAY,. loose and porous to medium stiff,
crumbly, occaslional surface rock
fragments, oc'csional to common rootlets,
slightly moist.
1-7. WEATHERED BEDPOCX (Jsp): Tan-rust-gray,
irregularly deo]nposed' VOLCANIC rock,'
medium dense,' rocky to locally sandy and
ciayey, fractured with 2"-l' (±) spacing,
minor clayey crusts on fractures surfaces
, '(in 'situ a1tertion), trace relict
rootlets, oxidized, slightly moist.
Joints set at 141 N62W/85-90SW
Localized practical refusal' at 7 feet
Hole backfi1le1
TP-10 078 , Easy to .moderate1y difficult excavating.
0-i TOPSOIL/ALLUVIUM: Brown-orange brown,
'sandy CLAY, lo1ose to stiff, porous,
brittle crumbly to moderately. pliable,
common roots airid relict roots, moist.
3-8 ' ' 'HIGHLY WEATHE1E1) BEDROCK (Jsp): Rust-
gray-brown, irregular decomposed VOLCANIC
.rck,' predominantly gravelly with sandy
and clayey cru1inbly fragments, localized
hard rock bloc'ks, oxidized, no distinct
fractures, abundant in situ alteration,
moist. ••
Total depth= 81 feet
Hole backfil1e,
GeoSolls, Inc.;
I.
M.A..G. PROPERTIES ( JrJ1JE 6, 1990 W.O. 1047-SD
.
EXPLORATORY TEST PT LOGS
Test Pit Depth (ft.) Material Description
TP-11 0-5 Easy to modeatLely difficult excavating
0-1.5 TOPSOIL/SLOPEWASH Brown, sandy CLAY,
• loose, porous,coinmon' .roots/rootlets,
dry. .
. -5.WEATHERED BEDROCK (Jsp): Gray and brown,
S . irregularly weathered/decomposed VOLCANIC
rock, predominantly gravelly/cobbly up to
l'(±) in -one dimension, dense, platy
. S . cleavage, fractured with average 31t (±) •
S spacing, oxidi2ed, locally very clayey
(in situ alteration), dry.
Prominent joint at 2' N55W/65SW S •
Total depth= 5, feet
• Hole backfi1le S.
• S ,. . S
-10-
GeoSoils, Inc.
M.A.G. PROPERTIES . . . . . . JUNE 6,1990.
W.O. 1047-SD
- EXPLORATORY TEST Piir LOGS
Test Pit Depth (ft.). . Material Descrirption
TP-12 0-7.5. Easy to moderately difficult excavating.
7.5-9 Difficult to very difficult excavating.
0-0.5 TOPSOIL: Red brown,. sandy CLAY, loose,
• porous crumbly, slightly brittle, common
'roots, slightly1 moist.
0.573 SLOPEWASH: Mottled red-orange-brown-red
brown, sandy CIIAY with occasional rock.
fragments, stif, brittle, occasional
• relict rootlet, moist.
3-9 , HIGHLY WEATHD BEDROCK (Jsp): Red.
• brown-yellow brown -tans irregularly
decomposed VOLCANIC rock, predominantly
sandy and clayey with isolated, rock
. 'pockets, medium dense, slightly friable,
common in situ alteration, randomly - 0 • • . fractured with discontinuous
orientations, occasional white 1/8" clay
• seams along fra ctures in upper l'(±),
oxidized, s1ig1t1ymoist.
Localized pract!ical refusal at'9' 'feet
Hole backfilled
-11-
GeoSoils, Inc.
N.A.G. PROPERTIES
. ( JUNE 6, 1990
W.O. 1047-SD
'. .....
I
EXPLORATORY TEST PIT LOGS S
Test Pit Depth (ft.) Material Descrption .
0, •.' .1 .
TP-13, . 0-6 Easy to moder'ate1y difficult excavating.
6 Difficult to vry difficult excavating.
. 0-0.5 . TOPSOIL: Red* brown,. sandy. CLAY,, loose,
porous crumbly, slightly. brittle, common
roots, slightly moist.
0.5-2 SLOPEWASH: Red brown, gravelly CLAY,
stiff, brittle, porous, occasional
rootlets, moist.
2-3 HIGHLY WEATHERED BEDROCK (Jsp): Brown
red, irregularly decomposed VOLCANIC
rock, predominantly sandy gravelly clayey
materials with .jlocalized rock pockets,
medium dense, abundant in situ
alteration, cri.publy, moist.
3-8 WEATHERED BEDR6CK (Jsp): Mottled gray
and brown-rust, irregularly decomposed
VOLCANIC rock, predominantly small gravel
tQiarge cobbl size clayey crumbly rock
f]agments (in situ alteration),
ocôsional harq rocky pockets, irregular
discontinuous weathering patterns,
becoming rocky at 71 (±), slightly moist.
Practical refuai at 8 feet
Hole backfilled
-12-
GeoSoils, Inc.
M.A.G. PROPERTIES
W.O. 1047-SD.
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
JUNE 6, 1990
TP-14 0-5 . Easy to moderately difficult excavating.
. 0-0.5 . TOPSOIL: Red brown, sandy CLAY, loose,
porous crunbly, slightly brittle, common roots, slightly moist.
0.5-1 . . SLOPEWASH: Red brcrn, gravelly CLAY,
stiff, brittle, porous, occasional.
. rootlets, moist.
1-5 flIGRLY WEATHERED BEDROCK. (Jsp): Multi-
colored, irregularly decomposed VOLCANIC
. rdck, predominantly sandy gravelly clay
t.clayey gravel, medium dense,
indistinct in situ weathering/ alteration
. . •pátterrs, occasional roots from heavy
brush, slightly moist.
. Total depth= 5 feet-
Hole backfilled
TP-15 0-9 Easy excavating.
0-4.5 . SCATTERED St3RFICIAL DEBRIS AND ALLUVIUM:.
Mottled brown-gray-alive,. fine sandy
. CLAY, medium stiff, locally very porous,
. . occasional rock fragments, highly organic
. . to .1.5' (±), occasional roots, sticky,
moist.
4.5-9 THYRED BEDROCK (Xl): Greenish gray-
gay, CLAYSTONE, soft, spongey to 6 1 (=), medium dense to 9 1 , mottled with orance
and red brown stringers (oxidation ?)
sticky, highly pliable, moist, to wet
with no free water.
Total depth= 9 feet
Hole backfilled
-13-
GeoSoils, Inc.
PROPERTIES ( JUNE 6, 1990
W.O. 1047-SD
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-16 0-5.5 Easy to modetly difficult excavating.
5.5-6 Difficult excavting.
0-0.5 TOPSOIL: Medium dark brown, silty CLAY;
medium hard and brittle, blocky, highly
. . porous, abundant roots, clay.
0.5-2 SLOPEWASH: Bro.zn-red brown, gravelly
- .. CLAY, mediumnhard and brittle, porous,
crumbly occasional rootlets, slightly
moist.
2-5.5 WEATHERED BEDROCK (Ki): Olive brown,
rust, gravelly CLAYSTONE with localized
hard rock fragents up to 11 (±) in one
. dimension, inedi1uin.dense, pliable,
moderately sticky, oxidized,. moist.
5.5-6 WEATHERED .BEDROCK (Jsp): Gray. and rust,
weathered VOLCANIC rock, medium dense,
medium hard and very brittle, platy
cleavage, fractured with fragments
averaging 411(±) in one dimension, common
clayey rinds and crusts associated with
. . fractures and larger rock fragments (in
situ alteration/weathering), moist to
sliht1y moist.j . .
Total depth=. 6 feet
Hole backfilled
-14-
GeoSolls, Inc.
TP-17
TP-18 0-5
0-0.5
0.5-2.5
2.5-5
M.A.G. PROPERTIES . JUNE 6, 1990
W.O. 1047-SD
- EXPLORATORY TEST PuT LOGS
Test Pit Depth (ft.) Material Description
Easy. to ]noderately difficult excavating.
TOPSOIL/ALLUVIUM:. Dark brown gravelly
CLAY, loose, p9rous, slightly stiff and
pliable, abundant roots, moist.
WEATHERED BEDROCK (KU : Olive brown-
rust-gray, weatihered gravelly CLAYSTONE,
with rock fragments to 1011 ('±y in one
dimension,. med4um dense, slightly sticky,
indistinct weathering patterns,
occasional roots, oxidized, moist.
Prominent joint set at 3.5' N60W/43SW.
Total depth= 3.5 feet
Hole backfilled . . . .
Easy excavating. .
TOPSOIL: Medii4m dark brown, silty CLAY,
medium hard ana brittle, blocky, highly
porous, abundant roots, clay.
SLOPEWASH: Medium red brown with local
orange mottiin4, gravelly, sandy CLAY,
stiff, 's1ightl pliable, porous, common
vertical open ~ractures, moist.
HIGHLY WEATHERED BEDROCK (Jsp): 'Rust-
brown-gray, irifegularly decomposed
VOLCANIC rock, medium dense to dense,
hard, brittle, highly fractured with
irregular trends and common clayey crusts
along fracture (in situ alteration),
highly oxidized with occasional manganese
staining (dark brown black staining),
crumbly, trace relict rootlets, slightly
moist. ' ..
Total dëpth= feet
Hole backfilled .
-15-
GeoSoils, Inc.
.M.A.G. PROPERTIES ( JUNE 6, 1990
W.O. 1047-SD
EXPLORATORY TEST. PI'{F LOGS
.
.Test Pit Depth (ft.) Material Description
-TP-19. 6-4 Easy- to moderately difficult excavating. r Difficult to'vey difficult excavating..
0-0.5 TOPSOIL: Medium brown, fine sandy CLAY,
loose, crumbly, porous, occasional.'
. . gravel, size rok fragments, common
rootlets and insect burrows, dry.
0.5-3 SLOPEWASH: 'Brown sandy CLAY, medium
. hard, brittle ad blocky, -highly porous,
. occasional grav1, common open vertical
• fractures, .occarional relict rootlets,-
dry, slightly mist. -
3-5 WEATHERED BEDRObK(Jsp): Brown-gray-
orange, .weatherd VOLCANIC rock, dense,
hard, brittle-, platy cleavage, local
clayey zones an crusts surrounding. rock
• • . and in fracture (in situ alteration),
. ocitdized, very rare relict rootlets,
slightly moist.!
Prominent jointset.at 3.5' -N32E/85-90NW
.
. . . Practical refusal at .5 feet
Hole backfilled
-16-
GeöSoils, Inc.
Ii
M.A.G. PROPERTIES ' 'JUNE 6, 1990 W.O. 1047-SD
EXPLORATORY TEST 9T, LOGS...
Test Pit Depth (ft.). Material Descriipt'ion
TP-20 0-3 Easy to moderately difficult excavating.
3-6.5 Moderately difficult to diff1'cult
excavating.
6.5-7.5 Very difficult excavating.
0-0.5 " TOPSOIL: Medim brown, fine sandy CLAY,
loose, cruinbly, porous, occasional
gravel, size rock fragments, common
- rootletsand irsect'burrows, dry-
0.5-72 HIGHLY WEATHERED BEDROCK' (Jsp: Dark red
brown-gray brown, highly decómposëd
VOLCANIC rock, predominantly gravelly
sandy clay, me4iuin hard and brittle,
porous, common open vertical fractpres,
occasional relict rootlets, blocky,
slightly moist.)
2-7.5 ' WEATHERED BEDROCK (Jsp): , Tan-yellow
'brown-orange, VOLCANIC rock, dense,
moderately harc'to hard and, brittle,
moderately fractured with fragments
averaging 5"(±), in one dimensiOn, large
..crumbly sheets exposed in trench
excavation, oxidized, irregular 'upper
contact with ir situ' alteratIon to
gravelly claye materials to 31 (±),
slightly moist to dry.
Prominent join sets at 3.51 -4.5'
N32'EJ85-90NW, N 80E/55SE, N80W/62NE.'
Practical refusal at 7.5 feet
Hole backfilledi
-17-
GeoSoils, Inc.
M.A.G. PROPERTIES ( JUNE 6, 1990' W.O. 1047-SD I
'EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) MaterialDéscription
TP-21' 0-2 Easy to modeate1y difficult excavating.
2-4.5 Moderately'difficult to difficult
S ' excavating. :
0-1.5 TOPSOIL/SLOPEWASH: Brown-red, brown,
sandy gravelly CLAY, loose to stiff and
slightly .pliab]1e, porous, occasional
rootlets, moisi.
1.5-4.5. WEATHERED BEDRqCK (Jsp): 'Tan-yellow
brown-orange, VOLCANIC rock,, dense,
moderately .hard to hard and brittle,
moderately fraqtured with. fragments
averaging 5Tt(±),. in one dimension,
oxidized, irreg4ar upper contact with in
situ alteration to gravelly clayey
materials slightly moist to dry.
Prominent joint sets at 2-4 1 , NiE/vertical, N53W/72SW, N25E/85-9ONW.
TOtal depth=. 4.5 feet
Hole backfilled •
M.A.G. PROPERTIES . . .. . JUNE 6, 1990 W.O. 1047-SD
S
. EXPLORATORY TEST. PIT LOGS I
Test Pit Depth (ft.) Material Descrption .
TP-22 . 07-3 Moderately difficult to difficult
excavating.
3-4 Very difficult excavating. •
0-0.5 TOPSOIL: Red brown, gravelly CLAY,
loose, porous, and crumbly,. slightly
moist. •
0.5-4 WEATHERED BEDROCK (Jsp): Red brown to
gray onbroken surfaces, VOLCANIC rock,
blocky cleavage with.fragments up to
lt(±) in one dimension, hard,; brittle,
local in situ aateration/weathered along.
fractures creatling clayey material, to
2..51 (±), oxidizd, slightly moist.
Joint at 21 N45/72SW.
S Joint at 3' N30/61SW
- . . Practical refusal at 4 feet S Hole backfilledL
.
-19-.
GeoSoils, Inc.
N. A. G. PROPERTIES ( I JUNE 6, 1990 W.O. 1047-SD
- EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-23 0-5.5 Easy to moderately difficult excavating.
0-0.5 TOPSOIL: Medium dark brown, silty CLAY-,
medium hard and brittle, blocky,, highly porous, abundant roots, clay.
0.5-1. 5 SLOPEWASH: Red brown and olive brown,
sandy CLAY, stiff, brittle, platy
cleavage, 1oc'a]1y very porous, occasional
rootlets, moist.
1.5-5.5 HIGHLY WEATHERD BEDROCK (Jsp): YellOw brown, brown streaking, weathered
VOLCANIC rock, very sandy, medium dense, platy cleavage, fractured with 211 7B"(±) spacing., locally very crumbly to 311(±),
localized clayey thin clayey brown crusts
along fractures (in situ alteration),
highly oxidized 1, slightly moist.
Prominent joint set at 3' N45W/60SW
Prominent joint set at 3.5' N68E/68SE
Total depth= 5.5 feet
Hale backfilled •
N.A.G. PROPERTIES
I.
. . '' JUNE 6, 1990 W.O. 1047-SD ..
.
, .
EXPLORATORY TEST PIT LOGS'
Test Pit Depth (ft.) Material Description '
TP-24 0-5 , . Easy to moderately difficult excavating.
5-7.5' 'Difficult excav1ating.
0-0.5 TOPSOIL: Red rown, 'gravelly CLAY, loose, porous, and crumbly, slightly moist.
0.5-1.5 SLOPEWASH: Brown sandy CLAY, medium'
hard, brittle and bioäky, highly porous,
occasional, gravel, common open vertical
fractures, occasional relict rootlets,
slightly'moist.
1.5-3 . WEATHERED BEDROCK'(Jsp): Red brown,
'weathered VOLCANIC rock, medium deise to
dense, platy cleaVage, fractured with 311 -, :5"'(±)' spacing, iighlyoxidized, 'very
, F brittle, occasional relict'rootléts along
fractures, slightly moist.
3-7.5 Tan to yellow brown, weathered VOLCANIC
rock, very sand, dense, hard and brittle,
'fractures to fragments averaging' 411 (±). 'in one dimension, FOliliflOfl rhythmic fractures
to locally irregular fractures, common
dry clayey seam/crusts up to 0.511(±)' wide truncated by upper harder unit, 311-' "M spacing to prominent
shears/fracturer, slightly moist.
'Prominent joint set at 2' N10W/43W
Prominent joint set at 3.5' N40E/30NW
Praôtical Refusal at 7.5 feet
Hole backfilled
-21-
'GeoSoils, Inc.
M.A.G. PROPERTIES
, (
• JUNE 6', 1990 W.O. 1047-SD
• EXPLORATORY TEST PT LOGS
Test Pit Depth (ft.) Material Description
TP-25 , 0-4 ' Easy to inodeate1y difficult excavating.
48 • : Moderately dificult to difficult
' excavating. '
0-3 , TOPSOIL/ALIX1It: Medium dark brown and tan, CLAY and rave11y' CLAY, loose to
stiff, medium ard and brittle, porous,
occasional rootlets, slightly moist.-
3-8 HIGHLY WEAT1-thRD BEDROCK '(Jsp): Brown to gray on broken surfaces, ' • • decoinposed/weathered VOLCANIC rock,
• medium dense tq dense, hard, brittle,
highly shearedjfractured with random
orientations, commonly gravel to' small
- cobble sized f9agments, random clayey
rinds/crusts associated with
fractures/sheais, occasional clayey
pockets (in situ alteration/weathering),
slightly moist.!
Shear at 3.5' th5E/60NW
' Jdiñt at 4' N22E/53NW
. . . . Joint at 4' 4 5W/65NE . .
'Total depth. at 8 feet'
Hole backfilled
-22-
GeoSouls, Inc.
M.A.G. PROPERTIES JUNE 6, 1990 W.O. 1047-SD
- EXPLORATORY TEST P1 T LOGS
Test Pit Depth (ft.) Material Descriiption
TP-26 0-9 Easy to moderat1ely difficult excavating.
0-6.5 'TOPSOIL/ALLUVIUM:. Medium dark brown,
gravelly CLAY, loose to medium stiff and • moderately pliable, slightly sticky,
porous, occasional rootlets, occasional
• rock fragments up to'1.51 (±) in one
dimension moist.
6.5-9 HIGHLY WEATHERED BEDROCK (Jsp): 'Light
orange brown, 'weathered VOLCANIC rock,
very sandy, medium dense and moderately
• brittle to slightly friable, platy
cleavage, average rock fraginents'is.4(±)
in one dimension, oxidized, occasional
relict rootietsL, slightly moist.
• Total depth= 9
Hole illedi,
feet
-23-
GeoSoils, Inc.
M.A.G. PROPERTIES S
S (
JUE6, 1990 W.O. 1047-SD S
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Matérial Description 0
TP-27 '0-3 Easy to modeately difficult excavating.
3-7 Difficult.éxcavating.
0-0.5 TOPSOIL: Medium dark brown, silty' CLAY,
medium hard and brittle, blocky, highly
porous, abundant roots, clay.
0.5-2 SLOPEWSH: Brown red brown, sandy CLAY
with occasional rock fragments, medium
hard and brittle, blocky, common open
vertical fractures'. Occasional rootlets,
slightly moist.
2-7 WEATHERED BEDROCK (Jsp): Orange brown- yellow brown, weathered VOLCANIC rock,
medium dense to dense, hard and brittle,
blocky cleavage fractured with
approximately 10"(±) spacing, oxidized,
minor relict rootlets along fractures,
slightly. moist.:
Joint at 2.5' N62W/13SW
S • S • 'Joint at 3' N46W/50NE
Joint at 3' N48E/3ONW
Practical refusal at 7 feet
Hole backfil1éd
-24-
GeoSolls, Inc.
,M;A.G. PROPERTIES JUNE 6, 1990 W.O. 1047-SD
..
S .
'EXPLORATORY TEST PT LOGS
Test Pit Depth (ft.) Material Description.
.TP-28 . 0-1 " Easy excavatj.
171.5 Moderately. 'difificult to very difficult
excavating.. S ,' • S
5 0-0.5 , TOPSOIL: Red brown,. gravelly CLAYS,'
loose, porous, and crumbly, slightly
moist.
0.571.5 WEATHERED BEDROCK (Jsp): 'Rust and gray',
VOLCANIC rock,, dense, hard, brittle,
massive, oxidized, dry.
5
Practical refual at 1.5' feet
Hble Backfi11ec
-25-
GeeSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990 W.O. 1047-SD
EXPLORATORY TEST P]T LOGS
Test Pit Depth (ft.). Material Descriiption
TP-29 0-2.5. Easy to inoderatiely difficult excavating.
2.5-4 Difficult to very difficult excavating.
0-2.5 TOPSOIL/ALLUVIUM: Medium dark brown,
gravelly CLAY, .loose to medium.- stiff and moderately, plible, slightly sticky,
porous, occasional rootlets, occasional
rock fragments up to l'(±) in one
dimension, mois.
. 2.5-4 WEATHERED BEDROCK (Jsp): Brown and gray
on.broken surfaFes, VOLCANIC .rock, dense,
hard and brittle, highly fractured with
211-8"(±) spacing, platy cleavage,
oxidized, slightly moist to dry.
Prominent joint set at 3' N75W/80-90NE
Prominent joint set at 3' N15E/48NW
Prominent joint set at 351 N45W/43NE
Practical refusl at 4 feet
Hole backfi11ed
-26-
GeoSoIls, Inc.
1.
.M.A.G. PROPERTIES 1 H JUNE 6, 1990 W.O. 1047SD . .
- EXPLORATORY TEST PitT tocs
Test Pit Depth (ft.) Material Description
TP-30 . 0-1 Easy excavatin. ..0 1-4 : Difficult-to vry difficult excavating.
0-0.5. TOPSOIL: Red brown, gravelly CLAY,
loose, porous,and crumbly, slightly H
moist.
0.5-4 WEATHERED BEDROCK (Jspi: Tan and yellow
brown and gray differentially decomposed
. VOLCANIC rock, predominantly very hard and dense, brittle, highly fractured with
random orientalF ions, locally clayey (in
situ alteratioxi/weathering), blocky
cleavage with ¶raginents averaging 3"(±)
i-one dimension, dry.
Practical refual at 4 feet Hole backfil1ec..
-27-
GeoSoils, Inc. i
M.A.G. PROPERTIES ' ' ' , ' W.O. 1047-SD
EXPLORATORY TEST PIP LOGS
Test Pit Depth (ft.). Material Description
TP31 0-1 TOPSOIL: Dark brown, clayey SAND, loose, porous, abundant rootlets, crumbly, 'dry.
1-2 SLOPEWASH: Bron, clayey SAND with'
common rounded uetainorphic rock :fraents, medium hard,. slightly friable,
moderately porous, occasional rootlets,
slightly moist.l.
2-4.5 WEATHERED BEDROCK (Tdss): , Light orange,
medium to coarsp grain SANDSTONE, medium
dense, moderately, friable, conglomeratic
bed ,at 2.5-3(+)1, moderately well sorted,
permeable, slightly moist.
Total' depth= 415 feet '
Hole backfil1ed
GeoSoils, Inc.
MA.G. PROPERTIES
S I 'H . JUNE. 6, 1990 W.O. 1047-SD
• I
'EXPLORATORY TESTS PIT LOGS S
Test Pit Depth (ft.) Material Descript:ion
S
TP-32 0-2 TOPSOIL/SLOPEWAH: Browp to dark brown,
clayey SAND witi occasional rounded
metamorphic .rob fragments, loose to
S medium hard, slightly friable, porous,
S S S occasional rootlets, slightly moist. S
2-4 WEATHERED BEDROCK-(Td): Light orange, '
S medium to coarsb-grain SANDSTONE, medium S
, dense, friablejinoderately well sorted,'
slightly moist.
S
, Total depth= 4 feet S
Hole backfilledl
TP-33 ',
5 0-1 ' Easy tomoderatély difficult excavating.
1-3.5 Difficult to very difficult excavating.
5 0-1 TOPSOIL: Redb -own, clayey 'SAND/sandy
CLAY, loose to stiff, porous, crumbly, S 5 • • common rootléts, dry.
5 5
' 1-3.5 WEATHERED BEDR06K (Jsp): Red brown and
S gray 'on fresh sirfaces, weathered S S
S VOLCANIC rock, dense, hard and brittle,
blocky' cleavage with fragments averaging
S 5"(±) in one dimension, dry.
S S
S ' • •• Joint @2' N35W/85-90SW
S Practical 'rèfus1 at 3.5 feet S Hole backfilledt S
-29-
GeoSolls, Inc.
M.A.G. PROPERTIES
W.O. 1047-SD
- EXPLORATORY TEST PI'T LOGS
Test Pit Depth (ft.) Material Describtion
TP-34 .0-2 Easy to inoderat1y difficult excavating.
2-4.5 Difficult to.ve1ry difficult excavating.
0-1 TOPSOIL: Red brown, clayey' SAND/sandy
CLAY,. loose to stiff, porous, crumbly,'
'common rootlets, dry.
1-3 . HIGHLY WEATHERE1D BEDROCK (Jsp): Multi
colored, highly decomposed VOLCANIC rock,
predominantly gravelly clayey material's,
medium dense, cbininon,in situ alteration
associated with clayey rinds ,bf rock,.
occasional reliFt rootlets, slightly.
moist. ,
3-4.5. . WEATHERED BEDROCK: Multi-colored,:
decomposed VOL IC rock, predominantly
grave-cobble sized fragments with clayey
rinds and crusts, dense, brittle,
irregularly fratured, oxidized, dry..
Practical refus1'at 4.5 feet
Hole backfil1ed
K
M A G PROPERTIES j JUNE 6,.i.990.
W.O. 1047-SD
EXPLORATORY TEST, PIT LOGS
Test Pit Depth (ft.) Material Description
TP-35. 0-1.5 Easy to mode.rately difficult excavating.
1.5-3 Difficult to vtery difficult. excavating.
.0-1.5 TOPSOIL/SLOPE4SH: Brown-red brown,
sandy grave1l CLAY, loose to stiff and
brittle, porous, occasional rootlets,
slightly moist.
: 1.5-3 WEATHERED BEDIOCK (Jsp): Gray and brown,
weathered VOLCANIC rock, dense and very
hard, brittle, clayey to 2.51 (±)
represents in j situ alteration/weathering,.
moderately frctured with fragments.. up to
1' (±) in one imension, oxidized,
slightly mois to dry.
Practical refisa1 at 3 feet
Hole backfi1ld
TP-36 0-1.5 Easy excávatiig.
1.5-3 Difficult to very difficult excavating.
0-1.5 TOPSOIL/SLOP E'7ASH: Red brown, sandy CLAY
and gravelly pLAY, loose to stiff, porous
blocky, occasional rootlets, slightly.
moist.
1.573 . WEATHERED .BEDROCK (Jsp): Red brown and
gray on fresh surfaces, weathered
VOLCANIC rock, dense, hard and brittle,
blocky, cleavage with fragments averaging
511 (±) in one pilnension, dry.
Practical refusal at 3 feet
Hole backfi1ld
-31-
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990,
W.O. 1047-SD
-. EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-37 . 0-1 TOPSOIL: ..Bro,;.grave1ly CLAY, loose,,
porous, crumbly, occasional vertical open
fractures, common rootlets, slightly .
moist. H
1-2.5 HIGHLY' WEATflE1ED BEDROCK (Jsp): Rust-red
brown-yellow 1rown, decomposed VOLCANIC
rock, predominantly gravelly clay, -medium
dense, crumbl, occasional rare relict
rootlets, moist.
2.5-5 WEATHERED BEDI0CK: Gray rust, VOLCANIC
rock, medium. dense, brittle1 hard, highly•
. • fractured witlt 111_411(±), spacing,
crumbly, localized clayey. rinds-stringers
(in, situ alteiFation), oxidized, slightly
. '. oist.
Joint set at ' N45E/77SE.
• • • 'ibint set at 3 1 N25E/60NW
Total Depth= feet
• '
• •' Hole backfilled
-32-
GeoSoils, In!.
.M.A.G. PROPERTIES ( •; JUNE:6, 1990
W.O. 1047-SD I
EXPLORATORY TEST PkT LOGS
Test Pit. Depth (ft.) Matérial Descrpt.ion
TP-38 0-2.5 TOPSOIL: drciiyl.brown,.dry, loose to
medium dense, porous silty SAND, many
roots, hard, blocky structure.
@0.5' Becomes . ark brown, slightly, moist,
S
.. medium dense, porous clayey to silty
SAND, hard blocky. with common desiccation
cracks. •
@2' Becomes browii, many small carbonate
nodules and m9ttlings.
2.5-5 BEDROCK (Tdss)I: Yellow brown and gray,
slightly moist, dense, weakly laminated
silty, fine SANDSTONE. Common laminate
iron staining )and'very few carbonate
iuottlings.
Total depth= j5 'Feet S
S • No Groundwater
S Hole Backfil1d S S
M.A.G. PROPERTIES .. ; . . JUNE 6, 1990,
W.O. 1047-SD
EXPLORATORY TEST P±T LOGS
Test Pit Depth (ft.) Material Description
TP-39 0-1.5. . FILL: Yellow )rown, slightly moist,
loose porous, silty fine SAND.-
0.5-3 TOPSOIL: Browi, moist to very moist,
loose to mediuin dense, soft, porous,
silty lean.CLAu1 with occasional stringers
of yellow browp fine sand.
2-3 Grades to o1iv brown and brown, moist,
mediumdense, firm, slightly porous sand,.
lean CLAY withj few fine random fractures.
BEDROCK (Tdss) : Light gray, slightly,
moist, dense, eak1y laminated fine
grained SANDSTpNE. .
@4' Dark olive, moist, dense, stiff,
thinly laminated CLAYSTONE with carbonate
mottling near base of bedding attitude N-
S/8°W; N50W/6W.-. . . . . . .
Total Depth= r6.5 Feet
. No Groundwater .
Hole Backfi1ld
-34-
GéoSoils, Incl.
.M.A.G. PROPERTIES
. I
JUNE 6, 1990
W.O. 1047-SD
. ...,
. I .
. EXPLORATORY TEST PET LOGS
Test Pit Depth (ft.) Matérial Description
TP-40 0-0.5 TOPSOIL/COLtUVIrUN: Gray brown, dry,
loose, porous gilty SAND.. with, rounded
gravel float.
0.5-2 . TOPSOIL: Bro4l,. slightly moistto. dry,
medium, dense tp loose, hard, clayéy SAND.
Common random esiccation cracks.
.2-5 BEDROCK (Tdss)I: Mottled orange brown,
brown, and gray, medium dense, highly
.. . weathered and randomly fractured silty
fine SANDSTONE with some . clay.
@2.5' Grades to yellow brown and gray,
slightly moist,' dense, weakly laminated
silty fine SANDSTONE. Common laminate
iron staining and very few carbonate
mottlings.
Bedding attitde N30E/5NW.
Total Depth= 2.5 Feet
,' No Groundwater .
Hole Backfilld . .
TP-41 0-I. 5 TOPSOIL: Dar* brown, moist to slightly
moist, loose, blocky arid fractured clayey
'SAND.
1.5-5 BEDROCK (Tdss'Tdcs): Gray brown,
Slightly moist, medium dense, massive to
weakly laminated silty fine SANDSTONE.
@2.5 Grades to olive brown, moist, dense,
very thinly lmninated silty CLAYSTONE
with wavy laminate orange brown stains.
Bedding attitude N60W/14SW.
Total Depth= 5 Feet
No Groundwate
Hole Backfilld
-35-
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE 6, 1990
W.O. 1047-SD
- EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft..) Material Description
TP-42 0-3 TOPSOIL: Brow dry, loose, porous silty
SANDwith ciayf weak blocky and friable.
@1' Becomes gray brown, dry loose to
medium dense, porous, silty SAND with
many columnar 1esiccation fraôtures.
3-6 BEDROCK' (Tdss)l: Gray with orange brown
'stringers, dry, dense weakly laminated
fine SANDSTONE.
' @5' Grades to brown; dry, medium dense,
slightly porots. massive silty SANDSTONE
with common shell fossils in upper part.
@6' Grades to gray, dry, dense,' fine
SANDSTONE. '
'Bedding attit4de N80E/7NW.
Total Depth= 6.5 Feet •
No Groundwater
Hole Backfil14d
-36-
GeoSoils, Inc.
.M.A..G. PROPERTIES ( JUNE 6, 1990
W.O. 1047-SD
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Description
TP-43 0-1 C0LLDVTUM/TOPSIL: Brown, dry, loose,
• blocky, fractued, porous silty SAND with
many roots andl rounded pebbles.
1-3 TOPSOIL: Redd.sh brown, moist, soft to
firm, medium dnse sandy, lean CLAY.
3-5.5 BEDROCK (Tdss)t: Gray with lamellar red
- brown mottling, slightly moist, dense,
0 thinly laminat1e fine SANDSTONE.
Bedding attitide N20E/7NW.
Total Depth= .5.5 Feet
No Groundwater, .
Hole Backfi1ld
TP-44 0-0.5 COLLUVIUM/TOPOIL: Gray brown, dry,
loose, porous) silty SAND with many roots
. . and common rotLnded pebbles.
0.5-2.5 TOPSOIL: Redcish brown, moist, firm,
medium dense lightly porous, silty to
clayey SAND, 4esiccation cracks common.
2.5-5 BEDROCK (Tdss):Gray, dry, dense,
laminated fin 4 SANDSTONE. Some yellow
.. • brown staining along bedding.
0 • Bedding •attitiidé N50E/15°SE..
0 Total Depth= 5 Feet
• • No Groundwater
• Hole Backfilld
-37-
GeoSoils, Inc.
'M.A.G. PROPERTIES , JUNE 6, 1990,
W.O. 1047-SD.
EXPLORATORY TEST PT LOGS
Test Pit Depth (ft'.) Material Description
TP-45 0-1.5 FIlL: Brown,.1ight1y moist, loose,
porous, silty AND and trash (plastic
concrete, rock etc.).
1.5-2 TOPSOIL: Red brown, dry, medium dense,
slightly porou.. clayey SAND. '
2-5. BEDROCK (Tdss)I: Mottled gray and orange
brown, slightlr moist, medium. dense,
massive to weakly laminated fine
SANDSTONE. Gypsum intergrowths common.
• @4' • Becoinesery dense.
• Bedding attitde N15W/6°SW
• Total Depth= 4 Feet
No Groundwatei1
•
Hole Backfill4d
-38-
GeoSoils, Inc.
.M.A.G.. PROPERTIES
. f
' JUNE 6 1990
W.O. 1047-SD
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Naterial Description
TP-46 0-1.5 FILL: Gray brwn, dry, , loose silty, sand
, . , . and trash.-,'. .
1.5-2. . . COIfl/TOPSIL: Red brown, moist,
soft to firm, Fnedium dense, slightly
porous cIayey'.SAND with few, rounded
pebbles, desiccations cracks common.
.2-3 TOPSOIL: Brovin,.moist, firm,' medium
dense, sandy lean CLAY with few
desiccation cz1acks.
.3-8 BEDROCK. (Tdcs)k Brown, moist, stif,.
dense thinly laminated SILTSTONE to silty
LAYSTONE.
@5" Grades- t6 olive 'brown color.
'Bedding attitdê N30E/10°SE.
Total Depth= .8 Feet
No Groundwater
Hole Backfi1ld . .
-39-
GeoSoils, Inc.
N.A.G. PROPERTIES S
JUNE 6, 1990
W.O. 1047-SD
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.)' Material Descrilption
TP-47 •. 0-2.5 ARTIFICIAL FILL: Dark brown, slightly
moist, medium dense, porous, silty SAND
with many root4.
@11. Becomes , lightly brown friable
MID medium dense and. brown, slightly
moist, medium cense, hard -clayey sand.
@2' Becomes oange brown, moist, medium
dense gravellysilty SAND.
2.5-7 BEDROCK (Tdcs): Olive brown, moist,.
stiff, dense cnchoidally fractured,
thinly laminated, silty CLAYSTONE.
Attitude N65E/°NW.
Total Depth= 7 Feet
No Groundwater
Hole Backfilled .
TP-48 0-0.5 ALLUVIUM: Yellow brown, dry, loose,. •
porous, weakly stratified SAND.
0.5-2 BEDROCK (Tdss)1: Orange brown, dry, loose
. . to medium dens, slightly porous, fine
grained SANDST9NE. .
• @1.5.' Gray, s1ightly moist, dense,.
. massive to weakly laminated fine grained
SANDSTONE.
.
• Total Depth= 2 Feet
No Groundwater
Hole Backfille
-40-
GeoSoils, Inc.
M.A.G.-PROPERTIES : ( JUNE 6, 1990
W.O. 1047-SD
- EXPLORATORY TEST P±T LOGS .
Test Pit Depth (ft.) material Description
TP-49 0-2 : TOPSOIL: Red *rown, dry, loose, porous,
silty SAND'andcobble sized rock.
2-3 BEDROCK (Jsp):Red brown, dense,
weathered VOLC.N'IC rock, breaking to
gravely silty .and.
Practical refusal at 3 feet
Hole backfille . .
TP-50 . 0-3 TOPSOIL: Red brown, dry,. loose, porous,
silty SAND witi many roots.
@1' Grades to dark red brown, moist,
. firm, medium dense sandy lean CLAY with
common desiccajion cracks.
3_5 BEDROCK (Tdss): Light gray, dry, dense,
• • thinly laminated fine grained SANDSTONE.
Bedding attitude N50W/11°SW
• Total depth= 51 feet S ••
HOle backfille . S •
-41-
GeoSoils, Znc.
M.A.G. PROPERTIES ' ' ' JUNE '6, 1990
W.O. 1047-SD
-
EXPLORATORY TEST PIT LOGS
Test Pit Depth (ft.) Material Descrthtion
,TP-51 0-2.5 TOPSOIL: Red brown, dry, loose, porous,.
silty SAND wi th many roots.
2.5-4.5 BEDROCK (Tdss):
@3.5' Becomes gray, 'slightly moist,
' • , dense, very weakly laminates fine grained
SANDSTONE with common yellow brown
lamellar stains.
Total Depth= 4.5 Feet
No Groundwater
Hole Backfi1le1
TP-52 • 0-2.5 TOPSOIL: Browh, moist, medium dense firm
to stiff sandy clay with common
desiccation cracks. '
2.5-5 BEDROCK (Tdcs)I: Olive, moist, stiff,
déñse massive ICLAYSTONE..
• Total Depth= 5 Feet
• No Groundwater' •
, Hole Backfilled
' • •
-42-
GeoSoils, Inc
CLIENT_D.rn Crvrp- WO.279Sfl DATE DRILLEb 6/8/82 LOGGED By DM
PROJECT LpCpstp. S.E. 13 SURFACE. ELEV. DRIVING WT. 240o#
and 14 S .
39
--p- L&J Ui Li..
T I-
o
- a.'., <_.i
CD
.
S
. S
Cl) (I
(D
w zio
OzC°)-.
ca 0
W
IL (M Owl
-
Cl)cc z
.,
0 CL
0
-
Ui -
p-Ui.
3Z
28
•
FILL: Brown to tan Clay to Sand
mixtures, with a high percentage
of volcanic rock up to 24 inches,
moist, loose.
.40
-
1H
-
Q
-
-
-
-
7
i
3
C
C
C
98.6
.
102.5
102.:
S
•
6.2
- 19.2...
-
-
19.4...
-
-
-
-
-
-
•
--5- NATURAL SOIL: Brown Silty Clay to
Clayey Silt, stiff, moist.
Color grades to light brown. Clay
is moderately soft.
- __10
-
BEDROCK (Torrey Sandstone): Tan to
gray Sandstone-Siltstone, weath-
ered and soft in upper few feet_
firm to hard below, moist.
15—
Total Depth 13 feet. S
No Water.
No Caving.
J
BORING LOG: B-2
CLIENT_Daon Corp. W.,0.279-SD. DATE DRILLE66/8/82_'LOGGED BY*RCK/DM
PROJECT La'Costa, S.E. SURFACE ELEV.± 330 DRIVING WT. 2400,15'50#*
13 and 14
•
UJ
I-
-
Li..
I-. Q.
LLJ B:
'.
, '
'
Bedding '
0
-
LiJ04
zC>'
I-
- Cl) Z
Wc
Cfl'I -z
•
—
TOPSOIL: Medium brown Silty Clay,
firm to stiff. dii-ed.
-
-
-
-
-
-
-
-
-
=
-
-
-
5
8
8
7
7*
15
12
C
B
C
C
C
B
C
B
C
C'110.8U.Z
89.9
103.6
112.3
110.1
104.9
110.8
105.5
14.7
-
143-
-
13.1--
13.6
-
15.2-
-
24.6-
-
20.9-
' ,
BEDROCK '(Torrey Sandstone): Light
orangish tan Silty Sandstone,
slightly moist, very dense.
Grades to a light gray and orange
mottled Silty Sandstone, damp,
hard,, tight. Thin rust-colored.
seams indiFatenear horizontal'
structure' ' .
.' . .• .
Two inch thick Sandy S1tstone
interbed, B:.' N-S, 3-5 E.
. ' . .
... . . .
—
-
—
- 5-
-
—
—
-10- -
--15-
20
Medium orangish brown Sandy
Siltstonhafd damp.
' . .
B: N10E, 80 SE. .
Thin Sandstone interbed.
-
-25-
30 BEDROCK: (Del Mar Formation): '
Medium greenish brown Silty. Clay-_
stone with orange mottles, moist
hard. Thin gray Sand interlamin-
ations cross-cut by numerous
gypsum seams; tightly bedded.
Irregular random slicks throughout
Formation contact is irregular ani --35-
-', . .,. U _')
E30RING LOG B-2
CLIENT_Daon Corp. W.O.279-SD DATE DRILLEb/R!82 LOGGED BYRCK/DM
PROJECTLa Costa, S.E. SURFACE' ELEV.± 330 DRIVING WT. 1550*, 850**
13 and 14
•
-.
W
LL
.
I- a.
lU c,
__
0 UW.W
,00
CI,
(L
o
0
Zip
w30< zC (Jin >-.
a.O0
W 0
G
Z
'Cl)'— 0Z
-
•
—
-35-
Claystone becomes dark greenish
brown with black iron stains; some
slicks observed, hard, moist.
Six inch thick discontinuous frac-
ture zone, abundant fractured rock
with slick surfaces; no open
structures.
Rock becoming increasingly dense; •
'drilling is slowed. •
-
-
-
-
-.
-
-
-
20
**
15.
c
C
115.8
110.4
I J
-
-
-
14.87'
17.2
-
-
-
-
-
- 40-
__45-
-
•
--50
Total Depth 50'feet.
No Caving.
No Water.
S •• --55-
DI AT tLL)
OR
___ :IsJ;fl[cIaI -
CLIENT_Daon Corp. w;o._279-SDDATE .DRILLEb 618/82 LOGGED BY' RCK/JAS
PROJECT LaCosta, S.E SURFACE ELEV.+ 270 DRIVING WT. 2400, 15504*
1?n ti 14
w )- <
.11.
a.
Id
0
0
<-
____
.
J: Joint surface
B: Bedding 49
S: Shear surface OCC
0CL
a)u:I w
OCC
Z,,
U
Z
z 0 o
—
\
\\
\\
\\
TOPSOIL: Medium brown Silty Clay;
firm, upper foot is desiccated
and contains rOot hairs, very
moist below upper foot. -
-
-
-
-5
-.
-
-
-
-
-
-
-
-
-
-
-
-
2
3
7
11
5*
20*
S.
C
B
C
B
0
.
C
C
—
.1-16.7
104.8
111.0
115.1
121 6
119.4
120.7
- 19.6-
12.8-
-
-
15.6
-
14.1.-
11 4
-
13.6-
-
-
12.6-
-
-
-
-
WEATHERED BEDROCK: Grayish green
and red Clayey Silt with caliche
stringers to 4½ feet, slightly
moist, very stiff. Grades into,....
light brown Clayey Silt with
some coarse grains.
—
- 5-
—
-
—
—
--10 - BEDROCK (Del Mar Formation): Grayish
green Claystone with some reddish
orange streaks, no structure,
slightly weathered, damp, tight,
hard.
@ 9 feet.. J: Randomly oriented, . southeast gentle inclination
suggested.
10 feet. J: N45E, 25SE: No slick
surfaces.
@ 12 feet. Red.zones in grayish-
green Claystone
@ 13 feet. B: Relatively flat;
Claystone, more moist.
@ 14 feet. Claystone becomes brown
with grayand yellow mottling..
@ 15 feet. .; S: ;!-N80W, 22-32NE with
striae downdip, gray, soft, moist,
clay. Two inch, thick directly
above.
@ 15½ feet. Becomes an ochre, gray,
red, yellow and light brown mot-
tied Ciaystone(?) or weathered
tuff with angular volcanic frag-
ments, moist, hard. .
@ 17 feet. Local seepage; coarse
grains (volcanics) no longer pres.JE.
—
—
—
-
--20-
—
—
-25- -
-
—
—
—
— -35
11 .,. ......-
GOA0 Ci 0
S I
CLIENT Daon Corp. W.O. 279-SD DATE DRILLEb/8/82 LOGGED BY RCK/.JAS
PROJECT La Costa,. S.E. SURFACE ELEV. ±270 DRIVING WT. 2400#,1550#*
11ruA id
cr
U.
W
C)
-J S •'
S: Shear surface
B: Bedding
>_oU).
CL
Ui C
i u
(I)
W U) '
o
—
-
.
@ 19 feet. Claystone becomes a
gray color with orange-brown
zones.
@ 20 feet. S: :Nlow1 35NE: Red
stained shear., surface, polished,
large .grooves,
S: N10W, SONE
shear surface 5 inches below
previous surface.
€ 22 feet. Gray Claystone contains
occasional angular to subround
granular fragments; J: N40W, 70N}
Red-stained joints.
@ 23 feet. S: N28E, 308E; N70W,20NE
irregular shear surface, 'slightly
polished, yellow-stain; some free
moisture along fractures.
Below 23 feet. Hard, predominatel
gray Claystoné with random slick
surfaces land. 'random fracturing.
€ 25 feet.' 'S::N45W, 45NE: Shear
surface, slightly polished, poorly _ developed.'
B:(?) N40W,.10-15SW.
Pair of parallel surfaces.
-
-
-
-
-
-.
-
-
-
-
-
-
-
-. -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- -
* -
- - -
•
•
- - -
Total Depth 30 feet,.
Slight water seepage at 17 feet.
No Caving.
—
—
—
_ -
I
0 BORING LO.G B-4
______ RCK' CLIENT_Daon Corp. W. 0. DRILLEb 6-8-82 LOGGED BY________
PROJECTLa Costa SURFACE ELEV._270+- DRIVING WT. 2400-127
S.E. 13 & 14.
I-
--
a. w
0
wO.
D
--i
60
-
C 39.4 . 0
V)c
U;
W-
ZC.0)-
04 .CflI"
)-
0
- TOPSOIL: Medium brown Silty Clay
with interlenses of reddish-brown
Sandy Clay, very moist to wet,
soft tofirm.
21
-
-
-
-
-
-
-
-
1 C/r 99.4/
110.3
113.7
25.07
12.7 -
S -
12.2_
-
-
-
-
— Light to greenish brown Clayey Sand C/E
medium dense, very moist, abundant
caliche, volcanic rock fragments
present in varying amounts.
—
BEDROCK (Volcanics):
Tan Basalt,. weathered to a friable
consistency in upper 6"; hard and
blocky below..
@ 9 feet. Unable to continue cluing due--to hardness.
..10..
Total Depth at 9 feet. - No Water.
No caving. S
.°,' BORING LOG B5
CLIENT W. Corp. wo 2795' DATE DRILLEb_6982 LOGGED BY_RCK
PROJECT La Costa SURFACE ELEV.310± . DRIVING WTI 2400#, 1550#*
S. E. 13 & 14. .
__0
Cr
IQ.
LU IL
x a.o
5
CD
'I
S: Shear Surface .
. . B: Bedding S .
J: Joint Surface
>-
0 x
CD
(l,owu_w
C
w -
a. m
zO°.>- I' C.)
>- I-
w
CC.0 C)
-
__5
TOPSOIL: Medium brown Sandy Clay,
slightly damp, stiff, root hairs. CL
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
5
10
.
9
/8'
9
C
C
C
C
C
•
109.9
108.3
110.9
112.4
109.9
S
9.5
-
-
8.1_
-
10.0
-
-
18.1
-
-
-
-
-
-
-
-
-
.
BEDROCK (Torrey Sandstone):
Light orangi.sh-tan Silty Sandstone
to Sandy Siltstone, with brown and
gray mottle s. dense to hard, damp.
@ 4 feet. B:" .1435E; 3-514W
Light grayi'sh-orange.thin Sand
laminae.
. @ 6.5 feet. Sandstone grades to
the light grayish-tan Sandy.
Siltstone with brown mottles,
dense, damp, massive.
@ 15 feet. Gypsum infl1ing of
discontinuous fractures.
-
-
-
—
—
— —
--10-
.
__1
•
—
.
BEDROCK (Del Mar Formation):
Medium greenish-gray to dark
greenish-gray, Silty Claystone to
Clayey SIltstone with yellow and
i4i 7' orange mottling, hard, moist.
Contact irregular,—near horizontal.
@ 16 feet. Fracture Zone, 2' thick-
B: N65W; 14NE: Thin lamination
S: N35W; 52NE: Slick surface,
highly polished.
@ 18 feet. S: N-S, 69W:
Slick surface with iron staining;-,
gypsum infilling above surface.
@ 19 feet.. J: N60E; 79NW: Joint
S: N40W; 33SW: Highly
polished slick surface with
iron staining and gypsum.
Intersects and truncates the
joint. à,ça11e1, slick surface
'" h..1ciw;.
—
-
.2Q
—
-
•
-
—
-
- S - -
•
les C, • BORING "LOG B-5
CLIENT_DaOn Corp. W0279-SD DATE DRILLEb6-9-82 LOGGED BY_RCK
PROJECTLa Costa SURFACE ELEV.310+ DRIVING WT. 2400#, 1550#*
11L14
Iii
S
U.
:'-
0.
o
a.o
S S
S: Shear Surface S
J: Joint Surface
S
S S W -jW
>3U)
M
0
Øa•
U)c
UJU.
uj:t
z0
w
04
CAD asCr C.)
c1 Z
U
06
>—
Z
3z 0 'XC.)
S
_____
@ 19.5 feet. J: N40E; 43SE: Join
@ 22.5 feet: 5: N75W; 20SW:
Slick Surface
@ 24 feet. J: N57W; 26NE: Joint
.@ 25 feet. S: N55W; 41SW: Zone
of parallel slick surfaces, S
2 thick
@ 26.5 feet. J: N-S, 76E
@ 30.5 feet. S: N15E; 20-40SE:
2' thick zone of subparallel S
slick surfaces.
@ 34.5 feet. J: N70W; 2ISW.
@ 38 feet. Drilling slow as
Claystone becomes denser.
S • • S •
-
-
—
-
—
-
9*
S
15'
15'
18
S
C
C
C
S
C
106.1
107.5
106.4
10.9.4
-
20.3-
-
- 19.ñ
-
-
19.2-
18.
=
-
-
-.
•
—
40
S
Total Depth at 40 feet.
No Water.
No Caving. S
CLIENT_Daon Corp. w.o._279_SDDATE DRILLEb.982 LOGGED byRCK
PROJECT - La Costa SURFACE. ELEV. 285+ DRIVING WT. _2400#, 1550#*
S.E. 13 &14
-
•
-
U.
-
W
_
C)
0
.
J: Joint Surface
S: Shear Surface
B: :Bedding
Cl)
o
)-C
CI)
WlZ.
3t zc
Li
'
.•
_ Z
Z 0 0
_
FILL: Medium brown Silty Clay, moist
loose to firm, intermingled
grasses; popcorn texture •
-
-.
-
-
-
-
-
-
-
-
-
-
:
-
••
5
7
9
9*
•
3*
C
C
C
C
• C
102.8
112.8
.
106.8
•
109.6
•
109.0
1
1
23. JO
15..QJ
J
19.2
-
-
-
18..-
-
-
-
17.5
-
-
. .
•
BEDROCK (Del Mar. Formation):
Medium greenish-gray Silty Clay-
stone to Clayey Siltstone, with
brown and oraThge mottles, moist,
hard.
@ 4.5 feet. .2 feet thick fracture
truncated by2 parallel slick
surfaces: S: N50E; 26E:
slick surfaces polished, grooved
and iron-stained
8 feet. •J: N30E; 50NW.
.@ 9 feet. J: N20W; 84SW.
@ 11.5 feet. J: N-S; 67E
Subparallel joint set.
@. 15 feet. J. N-S, 81E.
Subparallél joint set.
..: N75E; 7SE: • Intersects previous joint.
@ 16. feet. S:.N70W; 15NE: •
Polished S11CJ surface.
@ 17 feet. 6" thick orange • Silty layer, irregular.
@ 17.5 feet. Grades to dark .-
gréénish-gray Clayey Siltstone,
tight, hard, moist.
@ .18.5 feet. J: N25E; 12SE:..
Fracture infilled with gypsum.../
__5
—
-
—
20
--25-
—
-
I
/ L1UUU'U'It
CLIENT_Daon Corp. W.O.279 DATE DRILLEb982 LOGGED BY RCK
PROJECT La Costa SURFACE ELEV., 285+ DRIVING WT. 2400#., 1550#*.
S.E. 13 & 14 :
--,-. ILl U.
1 CL
0
C)
0 J: Joint Surface
S: Shear Surface
B: Bedding
>-cjC
BI:0
!
jr
Z Uj
@ 21 feet. B: Thin orjeSilt
lamination, near hori
@ 22 feet.. Fracture zo
thick,truncated at b
slick surface:
S: N55W; •34SW.
@ 25 feet. Random gyps
crystals.-
-
'
H
'Total Depth at '30 feet.
No Water.
No Caving.
.. .--U - " V
ce BORING ,LOG B-7,
CLIENT Daon Corp. W.n.279-SD DATE DRILLEb 698kOGGED 'BYRCK
PROJECTLa Costa SURFACE ELEV._260± DRIVING WT. 24001,' 1550#
S.E. 13&14
U
<
U,
U,
U, 0
IL CD
o_
B: Bedding
S: Shear Surface
-
)U)
U
U)O I-
Lii
o<
-
Z
.
U-.-
. cn I-•
0 U.
TOPSOIL: Reddish-brown Clayey Sand,
moist, medium dense, caliche.
-
-
-.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
5
4
7
5
6*
2*
C
C
C
C
C
C
CL - 113.4
109.0
107.0
-
L08.].
-04.9
107.5
14.1
16.2.....
-
-
9.6_
-
-
-
-
-
-
-
16.4 -
-
-
-
20.6
-
-
18.3—
-
-
-
—
SLUMP DEBRIS(?): Silty Sand with
angular Siltstone fragments,
1 yellow-brown, firm, no structure,
irregular contact at base.
-
5 -
-
-
BEDROCK (Torrey Sandstone);
Light orangish-brown to orangish-
tan Sandy Siltstone with occasional
thin gray and brown laminae of
Silty Sandstone, damp, dense to
hard.
@ 8 feet. J: N20E; 44NW.
with 2" thick greenish-gray Clay.
@ 10 feet. B::, N40E; 1ONW:
Brown and 'gray thin Sand
Lamination.
14 feet. Coquina layer, white,
well cemented, 1' thick.
@ 15 feet. B: N70W; 15SW:
Basal contact of coquina layer
with orangish-tan Sandy Silt-
stone. J
@ 17 feet. B: E-W; 8-10s:
Formation contact, irregular.
--25-
10
-.
-
15
\
-
—
-
-
BEDROCK (Del Mar Formation):
Medium td. dark :greenish-gray
Clayey Silts one to Silty Claystone
with orange and brown mottling,
moist, hard, 'äalic.he and gypsum
1n upper 3'
__30-
-
ce B-7 BORING LOG -7
.CLIENT Corp.. w.O.279'D DATE DRILLEb692 LOGGED BYRCK
PROJECT La Costa _SURFACE ELEV. 260± DRIVING WT 2400#, 1550*
S.E. 13 & 14
Id
-
o_ W 0
•
S. ...
U)U Cl)
S Cn
:
Cr 0
____________________
WI'
0 Z)
Id—
CL MI
,w
Cr o4
' oo
-
in
-
- o
I
S
@ 19 feet. J: N30E; 40NW, orange -
stained. -
@ 19.5 feet. J: N60E; 26NW, -
orange stained.
@ 20.5 feet. Random fractures, -
gypsum infilled.
@ 22 feet. I-1/2' thick fracture
zone, randorii 4 órientations.
@ 23.5 feet. S: N70W; 40SW. -
Multiple parallel slid surfaces -
at base of fracture zone. -
26 feet. Claystone becomes
tight and hard.
Total Depth at 30, feet.
No water. . -
No caving. S
•
-
-
-
-
S -
-
-
-
- - -
S
-
-
ST
1
OA
TABLE I
TEST PIT LOGS W.O. 279-SD
U.S..C.S. MOISTURE DRY
CVMnnT onmrrrmm i nir't'v tocf
o - 1½ ' 0 TOPSOIL: Reddish brown Silty Clay
• ' dry, porous.
1½ - 3 S ' ' Yellow-brown Silty Clay, moist, stiff.
3 - 4 '
' BEDROCK (Volcanics):
Basalt, mottled tan to brown,
fractured, blocky, hard.
Total Depth 4 feet.
No Water.
- No Caving
'0 - 2½ ' TOPSOIL: Reddish brown Clayey Silt
0 with angular volcanic rock fragments,
porous, dry and loose at surface,
moist and firm below 1 foot.
2½ - 6 - BEDROCK (Volcanics):
'Tan basalt, weathered to a friable
consistency in upper 3 feet; hard
• 0 • and blocky below.
Total Depth 6 feet.
No Water. 0 • -
- S No Caving. "
-
S PLATE C-i
DETAILED DESCRIPTION
TABLE. 1
TEST PIT LOGS W.O. 279-SD
ST U.S.C.S. MOISTURE DRY
T # DEPTH (ft.) GROUP SYMBOL CONTENT (%) DENSITY (pef) DETAILED DESCRIPTION
3 0 - 4 " TOPSOIL: Medium brown Clayey Silt,
dry in upper 1 foot, moist and firm
below.
4 - 6 BEDROCK, (Torrey Sandstone): White to
yellow-tan Silty Sandstone,,-damp-to
slightly moist, tight, hard, massive.
Total Depth 6 feet. '
No. Water.
No Caving.
4 0 - 2 .TOPSOIL: Medium brown Cläyey Silt,
porous, loose, dry.in upper 1 foot.
Firm and moist below.
2 - 5 . , BEDROCK (Torrey Sandstone): White to
yellow tan -Silty- Sandstone,-s-l-ightly
damp, hard, generally massive but
thin laminae suggest near horizontal.
• .
.
•
bedding.
• ' Total Depth 5 feet. • No Water.
• • No Caving. •'
•
I-
.' - PLATE C-2
TABLL I
TEST PIT LOGS W.O. 279-SD
,ST U.S.C.-S. MOISTURE DRY
:T # DEPTH (ft.) GROUP SYMBOL CONTENT (%) DENSITY (pcf) DETAILED DESCRIPTION
5 0 - 3 ALLUVIUM: Dark brown Clayey Sand
with volcanic rock fragments, very .
- moist, medium dense.
3 - 5 Yellow brown Silty Clay to 'Sandy
Clay, moist to very, moist, stiff,
.
.
. scattered volcanic rock fragments,
• - (weathered bedrock?) '
5 - 6 . . ' BEDROCK (Vlcanics);
• '
. Basalt, mottled tan and brOwn,
fractured,,hard,. blocky, red
staining
Total Depth 6'feet. '
No Water
No Caving.
6 0 -' 3 ' S ' ' ' TOPSOIL:' Dark brown Silty Clay,
dry and loose in upper 1 foot,
moist and stiff below.
3 • - 6 'S ' BEDROCK (Volcanics);
Basalt, yellow tan to brown with
,red and gray mottles,' weathered to
a 'friable consistency in upper 2½
inches, hard, and blocky below.'
Total Depth 6 feet.'.
No Water. '
'No 'Caving..
PLATE C-3
TABLL I
TEST PIT LOGS W.O. 279-SD
ST U.S.C.S. MOISTURE DRY
:T # DEPTH (ft..) GROUP SYMBOL CONTENT (%) DENSITY (pcf) DETAILED DESCRIPTION
7 0 - 2½ . .
0 ALLUVIUM: Light brown Silty. Sand
loose and dry in upper 6 inches,
. slightly moist and medium dense
below.
2½ - 6 . . . Dark. gr.eenish'brown Sand-Clay mix,
very moist to wet, firm (weathered-.
bedrock?) .. .
6 - 7 ,. . BEDROCK(Del Mar Formation): -.Medium
greenish gray Sandy Claystohe., moist,
hard, upper 2 inches weathered to
-. - light greenish gray. Sandy Clay
Total Depth 7 feet..
No- Water.
No Caving.
8 0 - .1 . .
. ALLUVIUM: -Lght-brown silts-ànc1,
moist, loose, porous. . .
5 . . 0 Dark greenish brown Silty Clay,
very moist, stiff, (weathered .
bedrock?) .
BEDROCK (Del Mar Formation): Medium
greenish gray Clayey Siltstone,
moist, hard, massive.
• Total Depth 6 feet.
No Water. • .
• No Caving. •..
- PLATE C-4 .
TABLE -
TEST PIT LOGS W.O. 279-SD
ST U.S.C.S. MOISTURE. DRY
T # DEPTH (ft.) GROUP -SYMBOL CONTENT (%) DENSITY (pcf) DETAILED DESCRIPTION
9 0. - 4 ALLUVIUM: Dark brown.Silty Clay,
moist, firm.
4 - 6 Dark greenish brown Silty Clay,
very moist to wet, stiff (weathered
bedrock?)
6 - 7 BEDROCK (Del Mar Formation): Mottled
red and greenish gray Clayey Siltstone
hard, moist to Silty.. Claystone.
Total Depth 7 feet
No Water.
No Caving.
10 0 - 3½ TOPSOIL: Dark brown Silty Clay, firm,
- dry and porous in upper one foot, • stiff,ànd moist below.
3½ .- 4½ • Light yellow brown Silty Clay, moist,
stiff.
4½ - 5½ BEDROCK (Volcanics):
Dark green and black basalt, with
• • orange and brown mottles, blocky,
• • • hard, fractured. .
• • • Total Depth 5½ feet.
• No Water.
• •
•• No.Caving. • • •
• •
• PLATE C-S
I TABLE 1,
TEST PIT LOGS
EST U.S.C.S. MOISTURE DRY
IT # DEPTH (ft.) GROUP SYMBOL CONTENT (%) DENSITY (pcf)
11 o 5 - V
12
'ALLUVIUM: Brown Clayey Silt, moist,
firm, grades to green colored Silty
• - Clay with depth.
5 - 7 , V ' ' ' BEDROCK (Del Mar Formation): Clay-
stone, green color, random slick
- • ' surfaces throughout. Soapy-texture'.
hard, moist. V
• V , ' ' Total Depth 7 feet'. V
• ' ' No Water.
No 'Caving. V
O. - 5 • ' - ALLUVIUM: Light brown Clayey Silt,
soft, very moist from .3 feet, grades
to green color, becomes moderately'
stiff.
5 - 7 V ' BEDROCK (D1 Mar Formation): Clay-
stone, green color. Soapy texture
with occasional slick surface, '
V
' ' moderately hard, moist.
V ' ' Total Depth 7 feet.-
No Water.
' No Caving. ' •
' PLATE'C-6 V
DETAILED DESCRIPTION
W.O. 279-SD
TABLE £
TEST PIT LOGS W.O. 279-SD
:ST U.S.C.S. MOISTURE DRY
:T # DEPTH (ft.) GROUP SYMBOL CONTENT (%) DEIJSITY (pcf) DETAILED DESCRIPTION
13 O - 3 ALLUVIUM: Brown Clayey to Sandy
Silt, moist, stiff.
3 - 8 BEDROCK (Del Mar Formation): Sand-
stone,-white color. Fine to coarse
grain, massive, friable to moderately
well cemented, moist.
Total Depth 8 feet.
No Water.
No Caving.
14 0 - 3 TOPSOIL Dark brown Sandy Silt with
• • Clay, moist, stiff.
3 - 6 SLUMP DEBRIS(?): Tan to gray, mottled,
• Silt and Sand. Contains Siltstone
fragments throughout. Moist, medium
dense.
6 - 8 BEDROCK (Del Mar Formation): Silt-
• stone, Clayey tan to gray color.
•
• Abundant gypsum throughout. No
apparent structure. Moderately hard,
may be creep affected.
Total Depth 8 feet.
No Water.
• No Caving.
PLATE C7
I
TABLE I
TEST PIT LOGS W.O. 279-SD
ST U.S.C.S. MOISTURE. DRY
:'r # DEPTH (ft.) GROUP SYMBOL CONTENT (%) DENSITY (paf) DETAILED DESCRIPTION
15 0 - 2 TOPSOIL: Dark brown Clayey Silt,
moist, hard.
2 - 14 SLUMP DEBRIS(?): Tan colored Silty
Sand, occasional fossil shell fragment.
No structure,-porous. Soft, slightly
- - moist.
From 6 feet grades to dark brown -
Clayey Silt, moist, hard.
From 8 feet, color is yellow-red,
mottlod.
14 - 15 BEDROCK (Torrey SandsLon):
At 1.4 feet, tan Sandstone, fractured,
tight, moderately well cemented.
Total Depth 15 feet.
No Water. -
No Caving. -
• PLATE • -
GeoSoils,, Inc.
GRADING GUIDELINES . . .
Grading should be performed to at least the minimum requirement
of the governing agencies,. Chapter 70 of the Uniform Building
Code and the guidelines presented below: S .
Site Clearing .
I
Trees, dense vegetation, and other deleterious materials should
be removed from the site. Non-organic debris or concrete may be
placed in deeper fill areas under direction of the Soil Engineer.
Light, dry grasses may be thinly scattered and incorporated into
the fill under direction of...... Soils Engineer, provided
concentrations of organics are not developed.
Subdrainage
Subd.raina.ge systems should be provided in all canyon
bottoms and within buttress . and stabilization fills
prior to placing fill. Subdrains should.. conform to
schematic diagrams GS-I, GS-3., and GS-4, approved by
the Soils Engineer. .
For canyon subdrains, runs less than 500 feet may use six
inch pipe. Runs in excess of 500 feet should have the lower
end as eight inch minimum. .
Filter material should be Class 2 permeable filter .
material per California Department . of Transportation
Standards tested by the Soil Engineer to verify its
suitability. A sample of the material should be
Geo Soils, Inc. .. S
M.A.G. PROPERTIES ' ' ' ' JUNE '6, 1990
W.O. 1047-SD
GRADING GUIDELINES PAGE 2 '
'provided to the Soil Engineer by 'the contractor at
least two' working days 'before it is delivered to the
site. The filter should be clean with a wide range of
sizes.', As an alternative to" the Class ,2 filter, ,the
material may be a 50/50 mix' of pea gravel and clean
concrete sand which is well mixed,, or clean'' gravel
wrapped in a suitable filter fabric.
3. An exact delineation of anticipated subdrain locatiàiis
may be determined, at 40 scale plan review stage.
During grading,th' Engineering Geologist should
evaluate the necessIt"of placing additional drains.
4; All subdrainage systems should be observed by the
Engineering Geologist and Soils Engineer during
construction and prior to covering with' compacted fill'.
5. Consideration should' be given to having subdrains
located by the project surveyors. Outlets, should be
located and protected.
Treatment of Existing GrOund
1. All heavy vegetation, 'rubbish and other deleterious
'materials should be' disposed of off site.
GeoSolls, Inc.
'M.A.G. PROPERTIES ... . : JUNE 6, 1990
W.O. 1047-SD .
GRADING. GUIDELINES PAGE 3
All suricial deposits of allium and colluvium should
be removed (see Plate. GS-1) unless- otherwise indicated
in the text of .this report'. Groundwater existing in the
alluvial areas may make excavation difficult. Deeper
removals than indicated in the text of the report may
be necessary due to saturation during winter months.
Subsequent to removals, the natural, ground should be
processed to a depth of six inches, moistened to near,
optimum moisture conditions and compacted to fill
standards. . .
Fill Placement
All site soil and bedrock may be reused for compacted
Ira bw'd,me ;0041-1081 z' q, P
Material used in' the compacting process should be
evenly, spread, moisture conditioned, processed, and
compacted in thin lifts not to exceed six inches in
thickness to obtain a uniformly dense layer. . The fill
should be placed and compacted on a horizontal plane,
unless otherwise found acceptable by. the' Soil Engineer.
GeoSoils, Inc.
M.A.G. PROPERTIES JUNE '6, 1990
W.O.- 1047-SD
GRADING GUIDELINES PAGE 4 Ii
3. If the moisture content or relative density varies from''
that acceptable to the Soil Engineer, the Contractor
should -rework the fill until it is in accordance with
the following:
Moisture content of the fill should 'be at or above,
optimum moisture. Moisture. should be , evenly
distributed without wet and dry pockets. Pre-watering
of cut or removal areas should be consid&red in
addition to •watering during fill ,plaOement,
particularly in clay or dry surficial soils.
Each six' inch layer should' be compacted to at least 90
percent of the maximum density in compliance! with the
testing method specified by the controlling
governmental agency.' In this case', the testing method
is ASTN Test, Designation D-].557--78.
4. Side-hill fills shOuld have an equipment-width key at their
toe excavated through all surficial soil and into competent
material and tilted back into the, hill (GS-2, GS-6.). As the
fill is elevated, it should be benched through surficial
soil, and slopewas, 'and into competent bedrock or, other
'material 'deemed suitable by the Soil Engineer.
GeoSoils, Inc.
M.A.G. PROPERTIES . .. JUNE 6, 1990
.W.O. 1047-SD-
GRADING-GUIDELINES PAGE 5
5. Rock fragments less;than eight ,inches in diameter may
be utilized_inhQ1, provided:
a) They'are not placed in concentrated pockets;
There is a sufficient percentage of fine-grained
material to surround the rocks;
ç) The distribution, of the rocks .is supervised by the•
Soil Engineer.
6. Rocks greater than eight inches in diameter should be
taken off site, or placed, in accordance with the
recommendation's of the Soil Engineer , in areas
designated as suitable for. 5ock disposal (See GS-5).
7'. In clay soil large chunks or blocks are common; if' in excess
of eight (8.) 'inches., minimum dimension then they are
considered as oversized. Sheepsfoot compactors or other
suitable methods'should be used to break the up blocks.
8 The Contractor should be required to obtain a minimum
relative, compaction of 90 percent out to the' finished
slope face of fill slopes. This may be achieved by
either overbuilding the slope and cutting 'back to the
compacted core, or by direct compaction of the slope
face with suitable equipment.
GeoSoils, Inc.
M.A.G. PROPERTIES S JUNE 6, 1990
W.O. 1047-SD . . .
GRADING GUIDELINES PAGE 6
If fill slopes are built "at grade" using direct compaction
methods then the slope. construction should be performed so
that a constant gradient is maintained throughout
construction. Soil should not be "spilled" over the slope
face nor should slopes be "pushed out" to obtain . grades.
compaction equipment should compact each, lift along •the
immediate . top of slope. Slopes should be back rolled
rolled approximately every 4 feet vertically as the slope is
built. '
Density tests should be taken periodically during grading on H
the flat surface of the fill three to five feet horizontally
from the face of" the slope.
In addition, if a method other than over building and
cutting back to the compacted core i's'to be employed, slope
compaction testing .'during , construction should include
testing the outer six inches to three feet in the slope face
'to'deterinine if the required compaction is being achieved.
Finish grade testing of the slope should be performed after
construction' is complete. Each day the Contractor should L
receive a copy of the Soil Engineer's "Daily Field
Engineering Report" which would indicate the "results of
field density tests that day. . S
GeoSoils, Inc. ' ' '
M.A.G. PROPERTIES JUNE 6, 1990
W.O. 1047-SD
I
GRADING GUIDELINES PAGE 7
9. Fill over cut slopes should be,' constructed in the following
manner: S
All stirficial soils and weathered rock materials should
be removed at the cut-fill interface.
A key at least 1 equipment width wide and tipped at
least 1 foot into slope should be 'excavated into:
competent äeria1s and observed by the soils engineer
or his representative.
C) The cut portion of the slope should be constructed
prior to fill placement to evaluate if stabilization is
necessary, the contractor should be responsible for any
additional earthwork created by placing fill prior to
cut excavation.
10. iTransition lots (cut and fill) and lots above stabilization
fills should be .capped with a three foot thick compacted
fill blanket.
11. Cut pads should be. observed by the Engineering
Geologist to evaluate the need for overexcavation and
replacement with fill. This may be necessary to reduce
• water infiltration into highly fractured bedrock or.
other permeable zonés,and/dr due to differing expansive
GeóSoils, Inc.
M.A.G. PROPERTIES JUNE -6, 1990
W.O. 1047-SD
GRADING GUIDELINES PAGE 8
potential of materials beneath a structure. The
overexcavation should-be at least three feet Deeper
overexcavation may be recommended in some cases.
12. Exploratory backhoe Or dozer trenches still remaining
after site removal should be excavated and filled with
compacted fill if they can be located.
Grading Observation and Testing
Observation of the fill placement should be provided ,by
the Soil Engineer during the progress of grading..
In general,. density tests would.be made at intervals
not exceeding two feet of fill height or every -1,000
cubic yards of fill placed. This criteria will vary
depending on soil conditions and the size of the fill.
In any event, an adequate number of field density tests
should:be made to evaluate if the required compaction
and moisture content is generally being obtained.
3• Density tests may be. made on the surface material, to
receive fill, as-required by the Soil Engineer.
4. .Cleanouts, . processed ground to receive • fill, key
excavatibns,subdrains and rock disposal should be
observed by the Soil Engineer prior to placing any
GeoSoils, Inc.
M.A.G. PROPERTIES . . JUNE 6, 1990
W.O. 1047-SD .
. . . GRADING GUIDELINES PAGE 9 .
fill. It will be the ContraorsS responsibility to
. notify the Sail Engineer when such areas are ready for
observation.
5,. An. Engineering Geologist should observe subdrain
construction. . .
6. An Engineering Geologist should observe benching prior
to and during placement of fill. . .
Utility Trench Backfill . .
Utility trench backfill should . be placed to the following.
standards: .
Ninety percent of the laboratory standard. if native
material is used as backfill.
As an alternative, clean sand may be utilized and
flooded into place. No specific relative compaction
would be required; however, observation, probing, and
if deemed necessary, testing may be required.
Exterior trenches,. paralleling a footing and extending
below 'a 1:1 plane projected from the outside bottom
edge of the footing.,...should be compacted, to 90 percent
of the . .. . . .
GeoSoits, Inc.
K.A.G. PROPERTIES ' JUNE 6, 100
W.0.' 1047-SD
GRADING GUIDELINES PAGE. 10 ,
'laboratory standard. Sand backfill, until it is similar' to
the inplace fill, should not be allowed in these, trench
backfill areas. • '
Density testing along with probing should be. accomplished to
verify the desired results. • • '
Final Grade ..\
Origin a I ground
Loose Surface Deposits
Suitable
Suitable
Material
-i— 4 -
Material
Bench where slopeI -
exceeds 5:1 \
•
Subdrain
• • . •
•
•• • (See Plate GS-3)
.. •
• TYPICAL TREATMENT OF
NATURAL GROUND
S :• •.Y ______________________________
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
Geo.SoI,. DATE 6/90 1047-SD GsI O
Soil Mechanics • Geology • Foundation Engineering
TOE SHOWN ON
/ GRADING PLAN -
/ -
I -
- F
/1 1•'•l
PROJECTED )
r
4 'I I
jl Typica
O
NATURAL Ij.iv—IO Typical
SLOPE
'
110, J t/
'I I- -
Minimum '
$5 Minimum —
Note: Where natural ppe gradient is 5:$ or less,
benching is nôt necessary unless stripping
did not remove all compressible material.
TYPICAL FILL OVER NATURAL SLOPE
GeoSoilI, c GSI In. DATE 6/90 W. 0. ± NO47SD IBy
• •
. Soil Mechanics • Geology 'Foundation Engineering
BEDROCK OR FIRM
FORMATION MATERIAL
II AT (Ilb -if
SOIL SLOPEWASH
JJ* 0 ALLUVIUM REMOVED
TO BEDROCK
S%\ •%I ...
BEDROCK
Canyon subdrain : 6'
perforated pipe with
9 cu. 'ft. gravel per ft.
of drain wraped with -
filter fabric.
- I ALTERNATE 2
/
/ , .; 6' perforated pipe with
9' Cu. ft. gravel per ft.
of drain wraped with
filter fabric.
CANYON SUBDRAIN DESIGN
AND CONSTRUCTION
GeoSoils, Inc. DATE 6 /9 0 WO NO.1o47-SD tBY CST
Soil Mechanics • Geology • Foundation Engineering
oR
A
36" THICK FILL CAP
FINISHED 1 .
2%_]
SURFACE . - . •
COMPACTED
FILL
-' --•
1<
d e.t oil)
- -.
4perforated pipe
(or approved- equivalent)
placed in I Cu. ft.-per
linear ft. of. graded •
filter material. I-
Pipe to extend- .
full length of
buttress;---
[----'-above___
4"nonperforated
pipe.lateral to. Pipe I
slope face at
10.0' intervals J' bench
Gradéd filter material to
conform to State of Calif.
Dept. Public Works standard
specifications for Class 2
permeable material
&. Buttress slope to have a bench
at every 20 to 30 feet.
Buttress key depth varies. (see
S preliminary reports)
Buttress key width varies. (see
preliminary reports)
Baôkdraiflsand lateral drains
located at elevation of every
bench drain. First drain at
elevation just above lower lot
grade. Additional drains.may
be required at discretion of
GeoSoils, inc.
GàoSoiliInè.
/ 1\ •E-5;? c
' 4:)
TYPICAL BUTTRESS. SECTION
DATE r,/q _IW.0..N0_iiL47-sn!BY ci
Soil Mechanics • Geology • Foundation Engineering
DI ATJ (-4
FILL I SLOPE
A A
V CLEAR ZONE I
,
LEQUIPMENT WIDTH- Soil shall be pu shed
over rocks -and flooded
into voids. Compact
around and over each
windrow.
Stack boulders end to:. end.
Do not pile upon each other.
1O' Tyical : FILL SLOPE
Stagger rows rows
• 0 imu ____ im 3' m I .h i m:u rn n
CO 0
/ FIRM GROUND /\ /
-. /
ROCK DISPOSAL DETAIL
GeoSoils,1nc. DATE 6/90 IWO NO 1047-SD IBY GSI -
..... . Soil Mechanics • Geology *-Foundation Engineering
01 AT f•.Q_;'
REMOVE ALL TOPSOIL,
S
-CQLLUVIUM AND CREEP
MATERIAL FROM TRANSITION FILL
I •-
/
7 0 -•-•. I'
I. -S CO O
Typical
_.- i.— I- I_ /
•
• > F tO' Ty pica H
0.00
CUT SLOPE .j I5' Minimum __t_t. I
, BEDROCK OR FIRM
-
-- - FORMATION MATERIAL
: TYPICAL FILL OVER CUT SLOPE
1) I
GeoSoils,Inc. DATE 6/90 Iwo NO 1047_SDIBy GSI
• Soil Mechanics. Geology • Foundation Engineering
M A -re
GeoSoils, Inc.
ROCK HARDNESS AND 'EVALUATION .
Volcanic bedrock materials are moderately hard to hard, brittle
and dense. To estimate excavation. charécteristics onsite, six
shallow seismic refraction profiles'were made in representative
areas of volcanic: bedrock. In addition to the seismic profiles,
much of recent site exploration used a Komatsu PC220LC. This
equipment we feel is approximately equivalent to a 'Caterpillar
225. . The depth of practical refusal on hard rock with this
machine, roughly 'approximates the limit of production ripping.
Approximate locations of the seismic profiles and excavator test
pits are shown on the enclosed Geotechni,cal.Map (Plate 1).
Refraction, profiles were made using a GeoMetrics, Inc., Model
117C seismic timer which provided velocity characteristics of
bedrock at various depths below the, surface. Table A indicates
the average, velocity interpretations of each seismic line. This
velocity information is specific to the area of each survey;
variations should be expected at other locations.
Depth of practical refusal and difficulty of excavation using the
Komatsu PC220LC is noted on the test pit logs.
In areas where excavation utilizing conventional grading
equipment is possible, it should, be anticipated that oversize
material (boulders) would be generated and local hard. zones
requiring blasting may be encountered. Trenching for utilities
into the volcanic rocks will,be difficult. This can be mitigated
G.IeóSoils, Inc.
M.A.G. PROPERTIES 'JUNE '6, 1990
W.O. 1047-SD
ROCK HARDNESS PAGE 2
by over-excavating utility areas to below utility line invert
levels' and rebuilding to grade with. compacted fills.
While it is difficult t'b'ácburate1y predict rippability and
associated fill quality on any site, we typically find 'the.
following in volcanics:
Seismic velocities varying from 5000 to 6000 feet per second
(fps) represent the start of blasting. .
Material displaying velocities of 5000 to .10,000 fps
necessitate light to moderate blasting and produce
reasonable, quality material to use as structural .rock, fills..
Materials with seismic velocities exceeding 10,000 fps
indicate moderate to heavy, blasting and pro.uce. relatively
clean rock with little 'if any matrix material..
Seismic velocities in the"10,000 fps range are indicated on all.
refraction profiles ranging from 6 to 23 feet deep.
At this stage of. project planning we suggest that cut depths in
volcanic rock be minimized as much as feasible, as this would
reduce grading costs. 'Additional rock hardness studies using
seismic refraction. and trenching with D-9L or equivalent would be
useful to assist in refining project budgets.
GeoSoils, Inc.
1 ..
TABLE. A
*seismic .: Depth Average Velocity
Refraction Direction **•Bedrock. (feet),., (It.—per second).,.-.
1 north-south Jsp 0-10 2,00
10+ 10,•000
• south—north.., 0-6 3,500
6+ 10,000.-
2 . no Jsp 0-3.5 1,300
3.5-23 3,500
. . '23+ 101 000
• south-north 0-14 . 2,500
.
.
. 14-27.5 . 10,000
27.5 10,000
.3 north-south '.' Jsp 0-4 1,400
.4-15. 5,000
15+ 10,000
south-,,north ' . • 0-3 11 100
3-15.5 2,500
15.5+ 10,000
4 . . .' north-south Jsp • • '0-9 1,100
9-23.5 5,500
23.5 10,000
south-'north .0-4 1,600
4+ 5,000
below 32 10,000
5. north-south Jsp • 0-3 1,200 •
3+ 3,250
below 32 10,000
south-north . . 0-6 900
6-17 5,000
17+ 10,000
6 31 2.50 north-'south . Jsp • . 0-9
• 9-24 61 000 •
• 24+ 10,000
south-north 0-14 3,500
. . 14+ • . 10,000
*See Plate 1 for location. .
**Jsp - Volcanic/metavolcanic rock.
GeoSoils, Inc. . •..• .
RESULTS
I phi angle = 270
I cohesion = 0.51 kst
3.0
2.5
LU 1.0
Cr)
0.5
U 0•5 I.P . 1.5 2.0 2.5 3.0
NORMAL 'PRESSURE —'KSF
KEY:
o reshear SHEAR TEST DIAGRAM
initial shear •
Remolded Shear
..:P•--'• .'
TP-43 @ 5 feet
GeoSoils,Inc. DATE 5/90 0 NO±7:SD 'BY GSI
oti mecnanics • eoiogy 0 -ounaaiion tngrnnny
SHEAR TEST DIAGRAM
CLIENT_Daon Corporation
PROJECT La Costa S.E. 13 .& 14
UNDISTURBED 0 REMOLDED W
NAT. MOIST. 0. SATURATED •
. . .
279-SD.
DATE 6-18-82
LOCATION See below
0
DEPTHSee_ below FT..
2.
Ii-
• • .cI)
2
.
• I—.
Wi
(1)
0 z
QH.I
w I.
(I)
0.
•••
•
5 - •
..
••
I
0
re
) -• __
51
- 0 05 1.0 1.5 2.0 2.5 3.0
• NORMAL PRESSURE -• KSF
• fl £'! ('U_P)