HomeMy WebLinkAboutEAGLE VISTA Subsurface ExplorationD
I
Alaska Land Development
2060 W. Dimcnd Blvd.
Ancko:age, Alaska 99502
Attention:
~.r. Bill Tucker
Subject:
Dear Mr. Tucker:
Eagle Vista
Transmitted herein are the results of the s~zbsurface ex-plorstion
performed on the subject property. Exploration consisted of ten
tes-~ holes drilled to !5' or rock refusal with a Bombardier
mou3rke:a Simco drill advancing a 6" solid core, continuous flight
auger. Drilling was supervised and the t~est hole was logg:~.d
by Bruce Kenworthy, technician of our staff. Grab samples were
taken at various intervals by pulling tke auger from the test
hole and removing the sample from the fligh%s near the bit. All
soils were visually classified in the fJ. el.~ in accordance with
sheets I through 3 following the text. This field c!assifica~.ion
~las verified in %he laboratory by visual review of the samples
based on the sa/ne criteria. The test hole logs follow the text.
The _seepage area required per bedroom by unified soil classification
(per the Greater Anchorage Area Borough) is as follows:
Soil Type
(Unified Classification)
ML
SM
GM
SP
SW
Seepage Area Required
275 ft2/%edroom
250 ft2/b edroom
225 ft2/bedroom
150 ft2/bedroom
125 ft2/bedroom
85 ft2/bedroom
JUN :1 8 1974
Alaska Land Develop~ent 2 ~ay 20, 1974
in this regard, for soils wi~-~ split classifications {(;P/G~{, see
criteria for split, unified, classification on sheet 2 following
the text), it is probably sufficiently accurate to average the
seepage area required for each of the two %Lnified classifications,
i.e.:
Split unified
Classification
GP/GM
~4/GM
sw/sM
Seepage Area
Required
155 fti/bedroom
155 ftZ/bedroom
188 ft~/bedroom
200 ftZ/bedroom
Soils requiring greater than 250 ft2/bedroom are not allowed
in seepage pit area calculations (per the Greater Anchorage
Area Borough).
Cursory review of the test hole~logs indicate that most of the
soils encountered below 1.5' (the depth of cover required over
a seepage pit) are sufficiently permeable to accept the effluent
from on-site sewer syste~, however, each pit should be checked
for an isolated exception. Furthermorg, the free water level was
not observed to the depths explored (generally equal to or
less than 15').
We trust this is sufficient for your i~u~ediate needs. All samples
will be held for 60 days should ~he need arise for additional
laboratory effort. Should additional exploration and a more
co~nprehensive soils study by required as the project d~ve!ops, please
feel free to contact our office.
Very. truly yours,
ALASKA TES~
J. ~4. Lambe
Approved:
J}~./p f
Attachments
Test HoLe 1
Elevation: Em:isting ground
,~.~. 16668
Depth in Feet
From To
0.0' 0.5'
0.5' ?.5'
1.5' 4.5'
4.5' ~5.0'
Bottom of Test Hole:
So~l Description
Or~an.ic, brown, wet
F-l: silty sandy gravel, brown, damp, high
density, occasional cobbles, sharp to
subrounded to 7", GP/G?~ (Some roots)
NFS/F-l, silty sandy gravel, some roots,
{estimate 5 - 10% s~lt)_ , brown, damp, many. ~
cobbles & boulders (to 9"0, high density,
NFS/F-l, silty sandy ~rav~l, brown, dry to
d~mp, many cobbles '~n~ boulders (to 18i~)
high density, some roots,
15.0'
Frost Line:
None observed
,Free Water Level: None observed
Sam~l~ Depth Type of Sampl~
I ~.5'-1.5' Gr~)
2 ~ 7.5'-4.5' Grab
4.5'-6.5' Gr~b
12'-13' Grab
15.0' Grab
Remarks: 1. Date of exploration: ~4aV 16, 1974
Test Hole 2
Elevation: Existing ground
Depth in Feet
W.O. 16668
From To
0.0' 1.0'
1.0' 3.0'
3.0' 11.0'
Soil Description
F-4, brown silt. ~L
F-4,- reddished brown sandy 9rave!!}f silt,
gravels to 2" subrou~ded, ~
NFS/F-l, brown silty_ .. sandy___ gravel, damp,
medium density (est. 10% silt), heavier
gravel at 5' - 8', occasional cobble to
7" , GP/GM
Bottom o.f Test Hole: 11.0'
Frost Line:
Free Water Level:
None observed
Sample .Depth
'~1 5.0'
Ty~e of Sample
Grab
10'-11' Grab
Remarks:
1. Refusal at 11.0'
2. Date of exploration:
May 16, 1974
Test Hole 3
Elevation: Existing gro~%d
W.O. 16668
Depth in Feet
From To
0.0' 0.~'
0.5' 4.0'
Soil Description
F-l, reddish brown sandy silty gravel,
damp, subrounded cobbles and boulders to
24" , G?~
NFS/F-l, b~Own, silty sandy gravel, damp,
some roots, high density, sharp to subrounded
cobbles & boulders to 24", GP/~
Bottom of Test Hole: 4.0'
Frost Line:
3" to
Free Water Level: None observed
P~Emarks: Made 5 attempts within 100' area with refusal between
3' & 4'.
Date of Exploration: May 16, 1974
Test Hole 4
Elevation: Existing ground
W.O. ~6668
Depth in Feet
From To
Soil Description
0.0' 0.5'
F-4, biac~ organic, soft, wet
0.5' 4.0'
F-l, tan silty sandy gravel, wet, dilatent,
many cobbles & boulders, sharp to subrounded
to 24" (est. 30% - 35% silt), G}{
Bottom of Test Hole: 4.0'
Frost Line:
None observed
Free Water Level:
None observed
Sample Depth
Type of Sample
3' - 4' Grab
Remarks:
1. 3 attempts with refusal at 3' - 4'
2. Date of exploration: May 16, 1974
Test Hole 5
Elevation: Existing ground
Depth in Feet
From To
0.0' 0.5'
0.5' 2.5'
2.5' 9.0'
Bottom of Test Hole:
Frost Line:
Free Water Level:
Sample Depth
"~ 7' - 9'
Remarks: 1.
W.O. 16668
Soil Description
F-4, black organic, wet, soft, (humus)
F-4, reddish brown gravelly sandy silt,
soft, some organic, occasional cobbles,
Sharp to subrounded to 4", ~
F-2, tan silty sand, high density, damp,
many sharp to subrounded cobbles & boulders
to 18",
9.0'
~one observed
None observed
Type of Sample
Grab
Date of exploration: May 16, 1974
Test Hole 6
Elevation: Exis%ing ground
Depth in Feet
From To
0.0' 1.5'
1.5' 15.0'
Bottom of Test Hole:
Frost Line:
Free Water Level:
Sample Depth
1 13'-15'
W.O. 16668
Soil Description
F-4, reddish brown gravelly sandy silt,
damp, soft, few sharp to subrounded
cobbles to 6", .~
F-2, tan ~ravelly silty sand, damp, high
density, occasional cobble & boulders,
sharp to subrounded to 12", SM
15.0'
None observed
None obs el~ed
Type of Sample
Grab
'Remarks:
Date of exploration: May 16, 1974
Test Hole 7
Elevation: Existing ground
W.O. 16668
Depth in Feet
From To
0.0' 1.0'
1.0'
1.0' I 1.5'
1.5' 4.0'
4.0' 10.5'
Bottom of Test Hole:
Soil Description
F-4, o'rganic (silt & Veg), dark brown, ~et,
soft
F-4, reddish brown gravelly sandy silt,
wet, few cobbles, some roots & other organic
material, }~
F-2, reddisk brown si'!t¥ gravelly sand,
damp, many cobbles, & boulders, sharp
to subrounded to 9", high density, SP/SM
F-2, tan gravelly silty sand~, damp,
occasional cobble, sharp to subrounded
to 5", high density, S.~
10.5'
,.Frost Line:
Free Water Level:
None observed
None observed
Z_ample Depth
1 2.5'-3.0'
2 9.5'-10.5'
Remarks: 1.
2.
Type of Sample
Grab
Grab
Refusal at 10.5'
Date of exploration
}lay 16, 1974
Test Hole 8
Elevation: Existing ground
Depth in Feet
From To
0.0' 1.5'
'1.5' 10.0'
Bottom of Test Hole:
Frost Line:
Free Water Level:
~Sample Depth
1 3.5'-4'
2 i0'-11'
Remarks: 1.
W.O. 16668
Soil Description
F-4, reddish brown gravelly sandy s.i~,
wet, soft, some roots & other organic, ML
NFS/F-l, brown silty sandy gravel, damp,
high density, occasional cobbles to 6",
GP/GM
F-l, tan silty sandy gravel, wet, occasional
cobbles to 7", GM
11.0'
None observed
None observed
T~e of Sample
Grab
Grab
Date of e~loration: May I6, 1974
Test Hole 9
Elevation: Existing gro ~und
Depth in Feet
From To
0.0' 2.0'
2.0' 2.5'
2.5' 3.5'
3.5' 17.5'
Bottom of Test Hole:
Frost Line:
Free Water Level:
$'am~le Depth
1 2'-2.5'
2 2.5'-3.5'
3
Remarks:
W.O. 16668
Soil Description
F-4, reddish brown ~raveil¥ sandy silt,
wet, soft, many cobbles & boulders, ~
NFS, grey sand, damp, random small gravel,
high density, SP
F-l, tan silty sandy gravel, wet, high
density, gravels to 0.5", GM
F-l, grey silty sandy ~rave!, damp, few
cobbles, high density, GP/G~!
17.5'
None observed
None observed
Type of Sample
Grab
Grab
16'-17.5' Grab
1. Date of exploration:
May 16, 1974
Test Hole 10
Elevation: Existing ground
Depth in Feet
From To
0.0' 1.5'
1.5' 4.0'
4.0' 5.5'
5.5' 16.0'
W.O. 16668
Soil Description
F-4, tan silt, wet, soft, with organic
material, occasional cobbles
F-l, tan silty sandy gravel, damp, trace
organic, high density, many cobbles and
boulders to 14", GP/~M
F-4, tan sandy silt, wet, hard, occasional
cobbles, to 4", ~
F-l, tan silty sandy gravel, damp, high
density, many cobbles and boulders to 24",
Bottom of Test Hole: 16.0'
Frost Line:
None observed
Free Water Level: None observed
Saraple Depth Type of Sample
1 6'-7' Grab
Remarks: 1. Date of exploration, May 16, 1974
DESCRIPTION AND CLASSIFICATION OF FROZEN SOILS
ALASKA TESTLAB
CONSULTATION ~ TESTING · EXPLORATION · CHEMICAL · MATERIALS · iNSPECTION
CHART
GRAVEL
CLAY EY CLAYEY
\
<3// OR
SILTY
SI LTY ~ \
SAND \
\ DY \GR. AVEL
GRAVELLY \ SAND
\
0 lO 20 ;50 .~0 50 60 70 80 90 I00
GRAVEL (+~IOSCREEN) % BY WEIGHT
NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN O. 02mm.
GROUPS OF FROST-SUSCEPTIbLE SOILS:
FI
F2
F~ a.
bo
F4 a.
b.
¢.
d.
GRAVELLY SOIL5 CONTAINING BETWEEN ;5 AND 20~S FINER THAN O.02mm.
SANDY SOILS CONTAINING BETWEEN $ AND 15% F~N~_R THAN O,02mm,
GRAVELLY SOILS CONTAINING MORE THAN 20% FINER THAN O.02mm. AND sANDY SOILS
(EXCEPT FIN~ SILTY~ SANDS) CONTAINING MORE THAN 15~ FINER THAN 0.02 mm.
CL~YS WITH PLASTICITY INDEXES OF MORE THAN !~. EXCEPT VARVED CLA~S.
ALL SILTS INCLUDING SANOY SILTS
FINE SILTY S~NDS CONTAINING MORE THAN t5% FINER THAN O.03mm.
LEAN CLAYS WITH PLASTICITY iNDEXES OF LESS THAN 12,
VARVED CLAYS,
TEST HOLE LOGS
SOILS DESCRIPTIONS
The soil descriptions shown on the logs are the best estimate of the soil charac-
teristics at the time of field examination. Such examinations do not achieve the
precision of laboratory tests for the various properties.
1. The relative type of soil and the frost cla.~sification is shown on the sheet
"Soil Cla s sification Chart."
2. Other criteria:
Boulder - greater than 8"
Cobble - approximately 3" to 8"
Blow Count - blows/6" of !40 lb. weight falling 30"; 2" split spoon. (The
standard penetration is blows/12".)
Density - estimated by the rate of drilling, type of soil, blow count and
moisture range
PL - Plastic Limit, moisture content betng approximated as; above (+) or
below (-) plastic limit (PL) or liquid limit (Lw) as appropriate
Lw - Liquid Limit, see PL
Dilatency - is the ability of water to migrate to the surface upon vibration
or jolting of a sample, an aid in determining whether a soil is pre-
dominately a clay or silt
Well graded - uniformity coefficient greater than 7
Poorly graded .- uniformity coefficient less than 7 {Uniform particles,
gap graded)
Organic Content - estimated by volume, not pa~icularly precise
Clayey Soils - a field method now being used as an aid to identification
of these soils as a combination ball drop, amd rolled thread test in
which a 2" diameter ball of the Sand-Silt-Clay fraction is dropped
2' until a l" thick pat develops. The dia:neter of a thread at
crumbling rolled from the resultant pat determines whether clay
or silt predominates.
Dry Strength - a small sample of the soil is formed into a cube and air
dried, and crashed between the fingers. High dr,/ strength indi-
cates clays and low indicates silts.
Water Table - the apparent water table at the time of observation. Often
the actual water table may be higher unless the hole is allowed to
remain open or is converted to an observation well.
Capillary Fringe - change from moist to very damp, or saturated soil,
usually indicates that water table is close.
Peat - Fibrous material of macroscopic and microscopic fragments of de-
cayed vegetable matter; very compressible, unsuitable for founda-
tion or embankment. Color light brown to black. ',
Ao - The upper layer, surface soil or topsoil, containing humus and/or
organic debris, not satisfactow for foundation.
ALA$~ T~STLA8
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