HomeMy WebLinkAboutKNOLL ON THE WOLD General Information
MUNICIPALITY OF ANCHORAGE
DEPARTIVIENT OF HEALTH & ENVIRONMENTAL PROTECTION
ENVIRONMENTAL HEALTH CASE REVIEW WORK SHEET
F~] PLATTING BOARD "%~ PLANNING & ZONING
CASE NUMBER NAME
S-5168 Knoll on the Wold
DATE RECEIVED
June 19, 1979
COMMENTTO PLANNING BY
July 5, 1979
FOR MEETING OF CASE OF
~'PUBLIC WATER NO,.,~T AVAILABLE 'FO PETITION AREA
[] PUBLIC SEWER NOT AVAILABLE TO PETITION AREA
R EVIEWER'S COMMENTS:
f
'
' : i,' ,'"' ....
71-014 (Rev. 2/78)
DEPARTMENT OF HEALTH AND ENVIRONMENTAL PROTECTION
PLATTING OR PLANNING AND ZONING CASE REVIEW
CASE NUMBER S-5168
PETITION FOR REZONING OF
SPECIAL EXCEPTION
VACATION
RE6UBDIVISION
DATE RECEIVED Ma.~ 2~ 1979
COMMENT TO PLANNING BY H&~7 18f 1979
Knoll of 'the Wold Subdivision
FOR MEETING OF
COMMENTS:
ENVIRONMENTAL SANITATION:
PUBLIC WATER NOT AVAILABLE
of . Cases
PUBLIC SEWER NOT AVAILABLE TO SE ,RVIC,E PETITION AREA. t
ENVIRONMENTAL ENGINEERING:
71-014 (9/76)
June 1~ 1979
At.t-~ntio~'~ Rod .V.c Connall
Health and f:nvironmental Protection
S--5168: Knoll of the Wold Subdivision
1'his department has reviewed soils and percolation tests
submitted~ the ({est show,~ soil to he adeq~a'te for a properly
designed septic system en lots of this size.
}~owever, the tope on the plat doe,qn't addre'r~s true tope of ti:e
'terrain.
'2e must keep in mind the ].ot~q must haw~ lO000O sq'aare :fee{: or
more of less than 25% slope as to support o~: site ,~ystems.
There is some concern on ]hots 3 and 4 ]3lock 3 as to the capability
of supporting a septic system. It is recommended congl.tning these
lo~s. It is the understanding of this denartment that some
redesig}:ing is planned.
Please submit info:mmti.on to the Nealth and ',invironmental Protection
!}epartment for }.~evi,ew prior to final approval.
If there are any ques{ions~ please contact this office at
Joh~'~ il, Lynn
!',nvi. ronmental Special
J~,,~L/1 j w
ANCHORAGE, ALASKA 99503
"T~ ' (907) 278-1551
May 22, 1979
W.O. ~A18859
Mr. Dick Fisher
c/o Security National Bank'
880 "H" St.
Anchorage, AK 99501
Subject: Shallow Subsurface Investigation for Suitability of On-
Site Wastewater Disposal Systems on a 24 Acre Parcel
Near Stuckagain Heights, Within the SW ]/4, Sec. 6,
T.12N, R.2W, SM, AK.
Dear Mr. Fisher,
We have completed a shallow subsurface investigation on the above
referenced property. (See Figure 1) The purposes of this J.nvesti.-
gation was to determine the suitability of -the area for on-site
wastewater disposal s~stems', and to make a nreliminary determina-
tion of 'the shallow subsur£ace conditions ~.~r planning purposes.
CONCLUSIONS
.Based on the results of this investiga'Lion, we believe the
sihe wi].l be suJ. tabl[e for construction of on-site wastewatcr
di.s]')(}sal systems. Soils were generally granular wit.h va]:~'ing
silt contents. We encountered no soils {~ICd~-~]_tl']or their
measured or estimated percolation rates exceed Municipality
Ground water was encountered only in test hole 3 -- all other
test holes were dry. Test. hole 3 was placed at tile edge of a
natural drainage basin. Excluding this small drainage
basin, we wou].d not expect grou,]d water to be present at
depths above 10 feet in the remainder of ghc property.
Drainage basins, water courses, and springs should be avoided
when placinq on-site wastewater disposal, systems. This
condition e~'ists along the southern boundary of the pre. perry.
Because of this there is probably not 40,000 square feet of
usable lot area on Lot 4, Block 3 as it is presently configured.
DISCUSSION
The subsurface inves[:igation consJ, sted of eight test holes to 1.5
feet of depth, two test: ])its to 32 feet d(3op, four perco]ak.ion
tests, and laborator'/ analysis of soil samples obtained during the
Mr. Dick FJ. sher
May 22, 1979
Page Two
drilling program. The test holes were drilled with a Nodwell-
mounted Mobile Drill B-50 rig equipped with a continuous flight
auger, owned and operated by Denali'Drilling, Inc. Drilling of
each test hole was under the direct supervision of Jordan E.
Jacobsen, geotechnical engineer, Alaska Testlab.
To evaluate the soil conditions, Mr. Jacobsen logged each test
hole while drilling was in operation and too]< samples directly off
the auger at 5 foot intervals. Each sample was placed in a sealed
plastic bag to preserve its water content. In the laboratory,
water content and dry strength were determined for each sample.
The samples were then placed in arbitrary groups according to
their color, texture, and grain size distribution. Grain size
analysis was then performed on the composite samples of these
arbitrary soil groups. Five distinct soil groups were encountered.
They are described below.
GROUP A
is a brown or gray Gravelly Silty, fine to coarse Sand.
This group has' occassional cobbles. This group is very
frost susceptible having a frost classification of F-3.
Its Unified Classification is SM. The grain size distri-
bution curve is shown on Shee~ 1.
GROUP B
is a brown or gray Silty Gravelly, fine to coarse Sand.
This group is moderately frost susceptible having a
fros~.~lassification of F-2. Its Unified Classification
is~S~~ The grain size distribution curve is shown on
Sheet 2.
GROUP C
GROUP D
GROUP E
is a gray Silty, fine to coarse Sand with some gravel.
This group is very frost susceptible having a frost
classification of F-3. Its Unified Classification is
SM. The grain size distribution curve is shown on Sheet
3. This soil type is found only in test holes 2 & 3.
is a brown or gray ~andy Gravel with a trace of si_lt.
This group is slightly, frost susceptible having a frost
classification of F-1. !ts Unified Classification is
GP. The grain size distribution curve is shown on Sheet
4. This soil type is found only in test holes 6 & 7.
is a brown fine to medium Sand. This group is non-frost
susceptible having a frost classification of NFS. Its
Unified Classification is SP. This soil type is found
only in test holes 6 & 8.
Mr. Dick Pisher
May 22, 1979
Page Three
The grain size distribution curve shows the range and percent,by
weight of particle sizes evident in each soil group. Larger
particles may be present in situ; however, the action of the auger
may exclude them.
To evaluate the property for possible use of on-site wastewater
disposal systems we proposed to run percolation tests in four of
the eight test holes. Test holes 1, 3, 5 and 6 were chosen because
they appeared to give a genera]_ representation of the property's
site's soi]_s. Percolation tests conducted in test holes 1 and 3
gave reasonable values for their soils and topographic position.
Test holes 5 and 6 did not give reasonable values. The drilling
logs indicated that test holes 5 and 6 should at least give perco-
lation rates comparable to test holes 1 and 3. To determine why
low percolation rates were obtained in apparently good permeable
soils we dug test pits with a backhoe in the area of test holes 5
and 6 to approximately 12 feet in depth. The test pits showed
good permeable soil ranging in water content from damp to wet. No
saturated soils were encountered in either test pit. It has been
our experience in situations similar to this that the percolation
test did not run pkoperly due to a plugging of the hole with
slumped material from the test hole walls plugging the slotted
pipe and net allowing percolation. This is usually a problem as a
result ef the seasonal frost thawing and is net a permanent condi-
tion. In test holes 5 and 6 beth the slumping and thaw seepage
problem occurred. Evidently, the thaw seepage water is a mi_nor
short-term pro]Diem. It percolates through the soil and dissipates
once all of the frost thaws, leaving tile damp highly permeable
soils found by the test pits. (See the following table.)
Percolation rates were determined by the following method: 1) insert-
ing a 1-1/4 inch PVC pipe into the test hole to assist in measuring
water level, 2) filling the test hole with water and letting i~
sit overnight, 3) refilling the test hole the following day with
water, 4) after refilling, measuring and recording the fall rate
of the water over the next 60 minutes. This test was conducted in
-test holes 1, 3, 5 and 6.
The following percolation rates were observed or 'estimated using
the aforementioned procedure.
Rated
Test Hole min/inch min/inch
1 3. 6 Same
3 6.7 Same
5 -- 3.0-5.0
6, -- 1.0-3.0
Mr. Dick Fisher
May 22, 1979
Page Four
The observed values in test holes 1 and 3 are acceptable and
shou'ld be used for wastewater system design. The estimated values
in test holes 5 and 6 are the proper, design number~ to use in
these areas.
Ground water was not observed in any test hole with the exception
of test hole 3. Test hole' 3 lies in a small drainage basin. It
is possible that the water observed in this test hole is ground
water and not just the short-term thaw seepage water. Thaw seepage
water was found in test holes 4, 6 and 7 at the time of drilling
and/or the following day. Evidence for this water being classi-
fied thaw seepage is that the test holes were checked a few days
after drilling and were devoid of water. This short-term water is
the major cause of our poor percolation tests as stated above.
The following figures, tables, and graphs complete this report.
vicinity Map
Site Plan and Test'Hole Location Map
Test ]{ole hogs
Standard Explanatory Infermation
Grain Size Distribution Curves
Figure 1
Figure 2
Table A
Sheets 1-3
Sheets 4-7
We trust the above meets your present requirements. If you have
~ny questions, or if we may be of further assistance, do not
hesitate to contact us.
Very sincerely,
ALAS ICA TESTLAB
Jordan E. Jacobsen
Geotechnical Engineer
Approved by:
Melvin R. Nichols, PE
Laboratory Manager
gEJ/ms
Test llole
Table A
WO ItA18859
Date: Play 2, 1979
Logged by: JEJ
pepth in Feet
From To
Soil Descri.ption
0 2
Brown Peat, damp, Pt
5
F-2, Tan Silty Gravelly well graded fine to
coarse 'Sand, damp, medium dense, subrounded
particles, maximum particle size := 6", SM,
Group A, hit a cobble at 6'
F-2, Gray Silty Gravelly well graded fine to
coarse Sand, medium dense, subrounded particles,
maximum particle size = 1/2", SM, Group A
Bottom of Test Hole:
7- /2
Frost Line:
Pree Water Level:
No
Sa.
No. Depth
2 1
Remarks: 1.
3.
4.
5.
6.
Type of Dry
Blows/6" M% Sample Strength Group Unified
10.0 N A SM
9.3 N A SM
Type of Sample, G=Grab, SP = Standard Penetration,
U = undisturbed.
Dry Strength, N=None, L=Low, M=Medit~, H=High.
Group refers to similar material, this study only.
General Information, see Sheet ~.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Ilole I~iA
Table A
WO I~A18859
Date: May 2, ]!)79
Logged by: JEJ
Depth in Feet
From To
0 2
2 9
9 12
12 ' / 15 /
Soil Description
F-4, Brown Peat and Organic Silt, damp,
soft, Pt
F-2, Gray silty Gravelly well graded fine
to coarse Sand, damp, medium dense, sub-
rounded particles, maximum particle size
= 2", SM, Group A
F-3, Gray Silty Gravelly well graded fine
to coarse Sand, wet, medium dense, sub-
rou]~~icles, maximum particle size
= 6~ SM,~/G~oup A, gravellier layers every
6".~ffe cobbles present
NFS, .Gray Silty Gravelly well graded Sand,
damp, medium dense, subrounde~d,,l~k~ticles,
; ' ' " U B
maximum particle s~ze = 1/2 ~SM,~Gro p ,
sandier than above group, alte~l~5~ating hard
and soft drilling every 6"
Bottom of Test Hole:
F-rest Line:
Free Water Level:
15
No
Sa.
No. Depth
1 5
2 10
3 15
Type of Dry
Blows/6" M% Sample Strength Group
8.1 N A
12.9 VL/L A
4.3 N B
Unified
SM
SM
SM
Remarks: 1 .
3.
4.
5.
6.
Type of Sample, G=Grab, SP = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, II=High.
Group refers to similar material, this study only.
General Information, see Sheet ~.
Frost and Textural_ Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole
Table
we t!A18859
Date: May 2, 1979
Logged by: JEJ
Depth in Feet
From To
0 2-1/2
2-1/2 6
Soil Description
F-4, Brown Peat, wet, Pt
F-4, Gray very Silty fine to coarse_ Sand
with occasiqn~Lal-__Gravel, saturated, soft,
subroun/d~ez-Jp~ic~s, maximum particle
F-3, Gray Gravelly Silty well graded fine
to coarse Sand, damp to saturate~
depth, med~particle size = 6~bif~
Group A, hit cobble at 11', alt~t-~g
hard and soft drilling every 6"
Bottom of Test Hole:
Frost Line:
Free Water Level:
15
0
No
Sa.
No. Depth
1 5
2 10
3 15
Type of Dry
Blows/6" M% Sample Strength Group Unified
Sat VL C SM
32.1
10.1 L A SM
11.2 L A SM
Remarks: 1.
3.
4.
5.
6.
Type of Sample, G=Grab, SP = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None~ L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural ClassJ_fication, see Sheet 2.
Unified Classification, see Sheet 3.
Test
Table A
WO IIA18859
Date: May 2, 1979
Logged by: JEJ
Depth in Feet
From 'PO
Soil Description
0 3-1/2
3-1/2 6
13
F-4, Brown Peat, wet, Pt
F-2, Brown Gravelly Silty well graded fine
to coarse Sand, wet, medium dense, subrounded
particles, maximum particle size = 1./2", SM,
Group A
13 F-4, Gray very Silty fine to coarse Sand with
occasional Gravel, wet, medium dense, sub-
~d particles-, maximum particle size = 1/2",
) ~_4~>~ SM, G~oup C, more gravel from 10-1/2' to 13'
F-3, Gray Gravelly Silt, well graded fine to
coarse Sand, damp, medium dense, suhr~u~~-h
particl~-~[ maximum particle size = i",/~SM-SP,ff
Group~2~ ~-~-------~
Bottom of Test Hole: 15
Frost Line: 0
Free Water Level: 6
Sa.
No. Depth Blows/6" M%
1 5 10.8
2 10 17.6
3 15 11.2
Type of
Sample
Dry
Strength Group 'Unified
VL A SM
L C SM
L A' SM
Remarks: 1.
2 o
3.
4.
5.
6.
Type of Sample, G=Grab, SP = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, It=High.
Group refers to similar material, this study only.
General Information, see Sheet ~.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test IIo].e' ti4
Table A
we llA].8859
Date: blay 2, ].979
Logqed by: JEJ
Depth in Feet
From To
o 1/2
Soil Description
F-4, Brown ]Peat, damp, Pt
1/2 9 P-2, Gray Gravelly very Silty well graded
fine to coarse Sand, damp, medium dense,
subroul~F~s~, maximum particle
9 ~ ~~!i [i~') size f~2~ .... ", SM, Groul/A~ .
NFS, Gray S~Ity Gravelly well graded fine
to coarse~ damp, medium dense, sub-
rou~m~irt~s., maximum particle size
Free Water Level: 4' thaw seepage
Sa. Type of Dry
No. Depth Blows/6" M% Sample .Strength Group Unified
1 5 10.3 L A SM
2 10 5.3 N B SM
3 15 4.2 N B SM
Remarks: 1.
3.
4.
5.
6.
Type of Sample, G=Grab, SP = Standard Penetration,
U = undisturbed.
Dry Strength, N=None, L=Low, M=Medium, It=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Table A
WO tlA]8859
Date: May 2, 197[)
Logged by: JEJ
Depth in Feet
From 'Po
o 1-1/2
1-1/2 8
8 10-1/2
10-1/21/ 15'
Bottom of Test Hole:
Frost Line:
Fr'ee Water' Level:
Soil Description
F-4, Brown Peat, damp, Pt
F-3, Gray Gravelly very Silty, well graded
fine to coarse, wet, medium dense, subrounded
particles, maximum particle size = 2", SM,
Group A
F-3, Gray Gravelly silty well graded fine to
coarse Sand, wet, medium dense, subroNn~d--'-~-~h
· ---- , . ,
particles, maxzmum particle szze =
roup A
NFS, Gray Silty Gravelly well graded fine to
coarse Sand, clamp, medium dense, subr~q~e~--~
particles,Group B maximum particle size =
15
No
Sa.
No. Depth
1 5
2 10
3 15
Type of Dry
Blows/6" M% Sample Strength Group Unified
12.1 L A SM
11.2 VL A SM
4.0 N B. SM
Remarks: 1.
o
3.
4.
5.
6.
Type of Sample, G=Grab, SP = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, ]{=High.
Group refers to similar material, this study only.
Genera]. In£ormation, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
1. ab].e A
WO ~fA].8859
Date: May 3, 1979
Logged by: JEJ
Depth in Feet
Prom TO
Soil Description
o
F-4, Brown Peat, damp, Pt
F-l, Brown Sandy Gravel with a trace of silt,
wet, medium dense, subrounde~p~t~cles,
max}mum particle size - lpg, GP, G~up , very
hard drilling from 5-1/2' tk}_~6-'~/~
12
12
NFS, Brown medium to coarse Sand, wet, dense,
SP, Group E
F-l, Brown Sandy Grave]. with a trace ef silt,
wet, medium dense, subrounded~p/anr~~,
maximum parnmcle size = 2-~./-2,, ~_GP_i~, ~r p D
Bottom of Test Hole:
Frost Line:
Free Water Level:
7' thaw seepage
Sa.
No.
pepth
5
2 10
3 15
Remark s:
3.
4.
5.
6.
Type of Dry
Blows/6" M% Sample S_.t r ength.
Sat
11.9
9.6
12.6
Group Unified
N D GP
N E 'SP
N D GP
Type of Sample, G=Grab, SP = Standard Penetration,
U = undisturbed.
Dry Strength, N=None, L=Low, M=Medium, [[=High.
Group refers to similar material, this study only.
General Information, see Sheet ~.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
Test
Table A
WO I!A18859
Date: May 3, 1979
Logged by: JEJ
Depth in Feet
From To
0 2
2 6-1/2
6-1/2
Bottom of Test Hole:
Soil Description
F-4, Brown Organic Silt overlain by heavy
Moss, wet, OL
F-3, Gray Gravelly Silty well graded fine
to coarse Sand, wet, medium dense, sub-
rounded pa~ticles~ maximum particle size
= 1", SM, Group A
F-3, Gray Silty Gravelly well graded fine
to coarse Sand, wet, medium dense, sub-
rounded particles, maximum particle size
= 2", SM, Group A
F-i, Gray Sandy Gravel with a trace of ....... _
snt, amp, medium dense, subroun e
particles, maximum particle size = [", _~P, ~ ~
Group D ~ ~
15
Frost Line:
F'ree Water Level:
0
4 thaw seepage
Sa.
NO.
pepth
5
2 10
3 14-1/2
Remarks: 1 .
3.
4.
5.
6.
Type of Dry
Blows/6" M% Sample Strength Group Unified
Sat VL A SM
11..9
7.9 N A /SM /h
6.4 N D
Type of Sample, G=Grab, SP = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High.
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification, see Sheet 2.
Unified Classification, see Sheet 3.
'Pest Nolo
Table A
WO I~A]8859
Date: Hay 3, 1.979
Logged by: JEO
Depth in Feet
From To
0 1
1 11-1/2
ll-1/2 15
Soil. Description
F-4, Brown Peat, damp, Pt
F-l, Brown medium Sand, damp to saturated
with depth, dense, SP, Group E, sand gets
finer with depth and siltier
F-2, Brown Gravelly silty medium Sand, wet,
medium dense, subrounded particle~, maximum
particle size = 1", SM, Group A
Bottom of Test Hole:
Fros~ Line:
Free Water Level:
15
0
. No
Sa.
Depth
5
10
15
Blows/6" M%
Type of Drv
Sample Strength Group unified
7.9 N E SP
Sat N E(/ ~ S 1~-2
31.0 ~ ...... ~
Sat VL A ~~
14.7
Remarks:
3.
4.
5.
6.
Type of Sample, G=Grab, SP = Standard Penetration,
U = Undisturbed.
Dry Strength, N=None, L=Low, M=Medium, H=High'
Group refers to similar material, this study only.
General Information, see Sheet 1.
Frost and Textural Classification,' see Sheet 2.
Unified Classification, see Sheet 3.
Test Hole Log- Description Guide
The soil descriptions shown on the logs ate the best estimate of the soil's
cbaracleristics at the time of field examination and as such do not acbieve tile
precision of a laboratory testing procedure. If the tog includes soils samples,
tbose samples receive an independent textural classification in the laboratory
to verify the field examination.
The logs often include tile following items:
Depth interval -- usually shown to 0.1 foot, within that zone no
significant change in soil type was observed through drill action, direct
observation or sltnlplillg.
Frost Classification - NFS, Fl, F2, F3, F4, see "Soil Classification
Cbart"
Texture ~1 Soil An engineering classification of the soils by particle
slz~e--,Ti~d proportion, see "S~il Classification Chart", note tile
prop~rtions are approximate and m~difications to the soil group due to
strat~flcati~n, inclusions and changes iii properties are included,
dan~p, moisture forms portion of color, less than plastic limit,
s,~turated, tree water may be squeezed out, if a free draining soil;
dilatent at natural moisture content, ifa non-plastic silt or fine
sand. (The moisture content is further defined by reference to PI,
l-W, NP, M%or dilatency.)
Density - refers to more-or-less lion-cohesive soils, such as sand gravel
~nixtures 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
Stiffness refers to more-or-less cohesive soils and fine grained silts of
~ clay-silt groups. Derived from drill action and/or sample data. Very
soft, soft, stifl', very stiff and bard are cammonly used terms,
Particle size The largesl particle recovered by the split spoon is
1-3/8", Shelby tube 3", auger flights (minute-man) 2", Auger flights
(B-50 hollow stem) 6"-8". Larger particles are described indirectly 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 the bole log must be considered for an:indication of
larger particles,
Unified Soil Classification - This is a two letter cf~de. See Unified
Classi~ sheet ~r--tber definition. In some cases AASHO and/or
FAA soil classifications may be shown as well as the unified.
Atterberg Limits - useful for fine grained and other plastic soils.
PI; natural moisture content believed to be less than plastic limit
PI+; hat.al moisture content believed to be between plastic and liquid
l~-mit s
L~w+; natural moisture content believed to be greater than liquid limit
NPi non-plastic, useful as a modifying description of some silty
mat/:rials.
Dilatencl - is the ability of water to migrate to the surface of a
saturated or nearly satm'ated soil sample when vibrated or jolted -- uled
as an aid to determine if a fine grained soil is a slightly or non-plastic
silt or a volcanic ash.
Rock flour ~ finely ground ~oil that is ~ot plastic but bt}}qnvise appear5
Organ c Content - usually described as Peat, PT, sometimes incmtles
discrete particlei suc aswood cea otc as a mod for oaninorganc
soil, Quantity described as; trace, or an estimate of volume, or, In case~
of all organic, - as Peat, This may include tundra, muskeg and bng
material,
Muck - a modifier used to describe very soft, semi-organic deposits
usually occuring below a peat deposit.
Amorphus peat - organic particles nearly or fnlly disintegrated,
Fibrous Peat - organic particles more-or-less intact,
Bottom ofTestholc - includes last sample interval.
Frost Line -- seasonal frost depth as described by drilling actinn and/<)r
~mples at the time of drilling.
Frozen Ground -- other than frost linc, 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. Tbis is
not necessarily the static water table at the time of drilling or at other
seasons, Static water table determination in other than very permeable
soils requires observation wells or piezometer installations, used only in
special cases,
Blow/6" - The number of blows ora 140 weight free falling 30" to
advance a 2" split spoon 6"; the number of blows for a 12" advance is,
by definition, the standard penetration.
,H% - natural moisture content of the soil sample, usually not
performed on dean sands or gravels below the water table,
Type of Sample
~, refers to 2" split spoon driven into the soil by 140 ponnd
weight, a disturbed sample,
~, thin wall tube, "Shelby" used to obtain undisturbed samples
of fine grained soil,
~, "grab" disturbed sample from auger flightsor walloftrencb,
~, cut sample, undist~bed sample from wall of trench.
Dr~ Strenstb - a useful indicator of a soil's clayey fraction, N=None,
L=~ow, M=Medium, H=Higb
Group -Tbe samples are placed into apparently similar groups based
on color and texture and ate arbitrarily assigned a group letter. Further
disturbed tests including Atterberg Limits, grain size, moisturedensity
relationship, etc. may be performed on the group and are assumed to
reflect the general distrubed characteristics of the soils assigned to thc
group. This is an important phase of [he soil analysis and is used to
standardize the various qualitative determinations and to reduce the
number of quantitative tests necessary to describe the soil mass.
SOIL CLASSIFICATION CHART
30% GRAVEL
CLAY
IA,
CLAYEY
OR
SILTY
SAND
CLAYEY CLAYEY CLAYEY
SILTY SILTY
~ SILTY
GRAVELLY SAND SANDY
GRAVEL
SAND GRAVELLY SAND SANDY GRAVEL GRAVEL
k \ \
0 1 0 20 30 40 50 60 70 80 90 100
GRAVEL (+#4 SCREEN) % BY WEIGHT
NONFROST SUSCEPTIBLE SOILS ARE INORGANIC SOILS CONTAINING LESS THAN 3% FINER THAN 0.02 mm.
GROUPS OF FROST-SUSCEPTIBLE SOILS:
F1 GRAVELLY SOILS CONTAINING BETWEEN 3AND 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) CONTAINING MORE THAN 15% FINER TPtAN 0.02 mm.
b. CLAYS WITH PLASTICITY INDEXES OF MORE THAN ].2. EXCEPT VARVED CLAYS.
F4 a. ALL SILTS INCLUDING SANDY SILTS.
b. FINE SILTY SANDS CONTAINING MORE THAN ].5% FINER THAN 0.02 mm.
c. LEAN CLAYS WITH PLASTICITY INDEXES OF LESS THAN 12.
d. VARVED CLAYS.
oo~
\,
NOT ~/L~D/V/D£D