HomeMy WebLinkAboutSTRUCK S-4220 ASg
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DEPARIM[NT OF IIEALTII AND ENVIRONMEtlTAii PROT[CTION
PLATI'IIIG OR PLANI,IING AND ZONIIiG CASE RI~VIEW
CASE NUMBER S-4220
PETITION FOR Rezoning
Special Excel]tion
VACATION
RESUBDIVIS ION
Date Received
COmlltent to Planning Dy
OF Struck'Sub
for meeting of
COMMENTS:
ENVIRONMENTAL SANITATION:
of
PUBLIC WATER NOT AVAILABLE
Cases
PUBLIC SEWER NOT AVAILABLE TO SERVICE
ENVIRONMENTAL ENGINEERING:
4040 "B" STREET,
ANCHORAGE, ALASKA 99503
PHONE: 907-279-2581
July 19, 1976
W.O. 17762
Mr. Dave ~adlock
SRA Bos 398A
Anchorage, AK '99507
Subject:
Subsurface Investigation for On-Site Sewer
System, Lot 2, Struck Subd., SE~, SW~, NW¼,
Sec. 24, T.12N., R.3W., S.M. AK.
Dear Mr. Madlock:
Transmitted herein in accordance with your instructions are
the results of the above referenced investigation as performed
by us on July 15 and 16, 1976. The scope of this project is
investigation for suitability of an on-site sewerage system.
included in this transmittal are:
Vicinity Map
Test Hole Location Sketch
Test Hole Log
Explanatory Information
Figure 1
Figure 2
Table A
Sheets 1-3
The exploration was conducted using a truck mounted Mobile
Drill Model B-50 drill rig with a continuous flight solid stem
auger. The rig is owned and operated by Denali Drilling Inc.
Drilling was supervised, the test holes logged and percolation
test performed by Mr. O. M. Hatch, Geologist with Alaska
Testlab.
The test hole was placed at the approximate location shown
on Figure 2. The log of this test hole is included as Table A
of this report. In interpreting the log it would be helpful
to utilize the explanatory information contained in Sheets
1 to 3 of this report.
When drilling was completed a 3/4" slotted PVC pipe was inserted
in the hole to aid in determining the free water level. For
the percolation test, the test hole was filled with water
and left overnight to saturate. On returning the next day,
the hole was refilled with water and the drop in the water
level carefully monitored over the next 60 minutes.
S 2 2 0 SEP 7 '1976
Mr. Dave ~adlock
July 19, 1976
Page Two
This procedure is not a standardized )ercolation test, however,
we understand that the Anchorage Department of Environmental
Quality prefers tests performed in this manner to evaluate
a site for a proposed on-site sewerage system.
Using the above test, the observed minimum percolation rate
was 2.5 minutes per inch.
No water table was observed during drilling, but it should
be noted that the free water level normally fluctuates season-
ally and with-precipitation.
We hope this report meets your present needs. If we can be
of further service, please feel free to contact us.
Very truly yours,
ALASKA TESTLAB
Melvin R. Nichols, C.E.
Laboratory ~4anager
MRN;gle
Attachments
,I
lO,Utility Esmt.
S890§5'45"W
£B
299.84
599,88 H.V.L ·
29994
S69O55'
299.82 N89e55'
T~sT" I¢OC~
Date: July i5, 1976
Logged By: Oo ~4~ Hatch
TABLE A
Lot 2, Struck Subd.
WO#17762
Depth in Feet
From To
SOIL DESCRIPTION
0.0' 1.0'
Brown Peat, PT, damp, soft
1.0' 10.0'
NFS/F-i, brown slightly Silt~ Sandy
Gravel, GP/G~, turning GM by 7.5',
damp, medium density, occassional
cobbles to
10.0' 16.0' F-4, brown Sandy. Silt, ML, damp, stiff,
less sand with depth, NP
Bottom of Test Hole:
Frost Line:
Free Water Level:
16.0'
None Observed
None Observed
Note: Soil visually classified in the field.
Remarks:
1)
2)
3)
Type of Sample, G=Grab, SP=Standard Penetration.
Dry Strength: N=None, L=Low, M=Medium, H=High.
Group refers to similar material this study only.
Test Hole Log - Description Guide
The soil descriptions shown on the logs are the best estimate of the soil's
characteristics at the time of field examination and as such do not achieve the
precision of a laboratory testing procedure. If the log includes soils samples,
those samples receive an independent textural classification in the laboratory
to verify the field examination.
The logs often include the following items:
Depth Interval - usually shown to 0.1 foot, within that zone no
significant change hr soil type was observed through drill action, dixect
observation or sampling.
Frost Classification - NFS, Fl, F2, F3, F4, see "Soil Classification
Chart"
Texture of Soil An engineering classification of the soils by particle
size and proportion, see "Soil Classification Chart", note the
proportions are approximate and modifications to the soil group due to
stratification, inclusions and changes in properties are included.
Moisture Content -- this is a qualitative measure:
dry, no or little apparent surface moisture,
damp, moisture forms portion of color, less than plastic limit,
wet, no free water, often soft, if cohesive soil,
saturated, free water may be squeezed out, ifa flee draining soil;
dilatent at natuxa! moisture content, if a non-plastic silt or fine
sand. {The moisture content Is turcher deiined by reterence to PI,
LW, NP, M%or dilatency.)
Density refers to more-or-less non-cohesive soils, such as sand gravel
mixtures with or without a fine fraction, derived from drilling action
and]or sample data; usually described as: very loose, loose, medium
dense, very dense. General intent is to portray earthwork
characteristics.
Stiffness - refers to more-or-less cohesive soils and fine grained silts of
~he clay-silt groups. Derived from drill action and]or sample data. Very
soft, soft, stiff, very stiff and hard are commonly used terms.
Particle size - The largest partic[e recovered by the split spoon is
1-318", Sbelby tube 3", auger flights (minute-man) 2", Auger flights
(B-S0 hollow stem) 6"-8". Larger particles are described indh-ectly by
action of the drilling and are referred to as cobbles, 3" to 8", or
boulders 8"+. Therefore when reviewing the gradation sheets, if any,
the description on tbe hole log must be considered for an indication of
larger particles.
Unified Soil Classification - Tbis is a two letter code. See Unified
Classification sbeet for further definition. In some cases AASHO and/or
FAA soil classifications may be shown as well as the uuified.
Atterberg Limits - useful for fine grained and other plastic sods.
P~I; natural moisture content believed to be less than plastic limi~
PI+; natural moisture content believed to be between plastic and liquid
I~mit s
L_~*; natural moisture content believed to be greater than liquid limit
N~P; non-plastic, useful as a modifying description of some silty
materials.
Dilatency - is tbe ability of water to migrate to the surface of a
saturated or nearly saturated soil sample when vibrated or johcd - used
as an aid to determble if a fine grained soil is a slighfly or non-plastic
Rock flour -- finely ground soil that is not plastic but otherwise appears
similar to a clayey silt.
Organic Content -- usually described as Peat, PT, sometimes includes
discrete particles such as wood, coal, etc. as a modifier to an inorganic
soil. Quantity described as; trace, or an estimate of volume, or, in case
of all organic, - as Peat. This may include tundra, muskeg and bog
material.
Muck -- a modifier used to describe very soft, semi-organic deposits
usually occuring below a peat deposit.
Amorphus peat - organic particles nearly or fully disintegrated.
Fibrous Peat -- organic particles more-or-less intact.
Bottom of Testhole -- includes last salnple interval.
samples at the time of drilling.
Frozen Ground -- other than frost line, described by samples, usually
includes description of ice content, often will include modified Unified
Classification for frozen soils this is a special case related to
permafrost studies.
Free Water Level - The free water level noted during drilling. This is
not necessarily the static water table at the time of drilling or at other
seasons. Static water table determination in other tban very permeable
soils requires observation wells or piezometer installations, used only in
special cases.
Blow/6" -- The number of blows of a 140 weight fi-ce falling 30" to
advance a 2" split spoon 6"; tbe nmnber of blows for a 12" advance is,
by definition, the standard penetration.
,,4% - natural moisture content of the sdil sample, usually not
~formed on clean sands or gravels below the water table.
Type of Sample -
S__P, refers to 2" split spoon driven into the soil by 140 pound
weight, a disturbed sample,
~S, thin wall tube, "Shelby" used to obtain undisturbed samples
of fine grained soil,
.G, "grab" disturbed sample from auger flights or wall of trench,
_C, cut sample, undisturbed sample from wall of trench.
Dry Strengtb- a useful indicator of a soil's clayey fraction, N=None,
L=Low, M=Mediu m, H=High
Group - The sa~nples are placed into apparently similar groups based
on color and texture and are arbitrarily assigned a group letter. Further
disturbed tests including Atterberg Limits, grain size, moisture-density
relationship, etc. may be performed on the group and are assumed to
reflect the general distrubed characteristics of tbe soils assigned to tbe
group. This is an inlportant pbasc of tbe soil analysis and is used to
standardize tbe various qualitative deterndnations and to reduce the
nulnbcr of quantitative tests necessary to describe the soil nlass.
SOIL CL. AS$1FICATION CHART
30% GRAVEL
CLAY
~ CLAYEY CEAYEY
CLAYEY CLAYEY
\ OR\
OR
SILTY SILTY
SILTY ~ SILTY
SAND GRAVEL
~ GRAVELLY SAND SANDY GRAVEL
SAN GRAVELLY SAND GRAVEL ;RAVEL
0 10 20 30 40 50 60 70 80 90 1 u0
'G:RAVEL {+#4 SCREEN) % BY WEIGHT
NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOLES CONTAINING LESS THAN 3% FINER THAN 0.02 mm.
GROUPS OF FROST-SUSCEPTIBLE SOILS:
F1 GRAVELLY SOILS CONTAINING BETWEEN 3 AND 20% FINER THAN 0.02 mm.
F2 SANDY SOILS CONTAINING BETWEEN 3 AND 15% FINER THAN 0.02 mm.
F3 a. GRAVELLY SOILS CONTAINING MORE THAN 20% FINER THAN 0.02 mm. AND SANDY SOILS
(EXCEPT FINE SILTY, SANDS) CONTA/NING MORE THAN 15% FINER THAN 0.02 mm.
b. CLAYS WITH PLASTICITY INDEXES OF MORE THAN 12. EXCEPT VARVED CLAYS.
F4 a. ALL SILTS INCLUDING SANDY SILTS.
b. FINE SILTY SANDS CONTAINING MORE THAN 15% FINER THAN 0.02 mm.
c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12.
d. VARVED CLAYS.
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