Geotech Report Revised 3-21-18.pdfLIU & ASSOCIATES, INC.
Geotechnical Engineering Engineering Geology Earth Science
August 4, 2016
(Revised 3/21/2018)
Mr. Mike Mietzner
Mietzner Home Builders, LLC_. C41F^�Y COPY
11611 Airport Road, Suite B-1
Everett, WA 98204
Dear Mr. Mietzner: RFSUB
Subject: Geotechnical Investigation and Infiltration Tests AUG Z 9 ?.018
Mietzner Plat v'LDING DLpAR
CITY Op FONDS N f
8609/8611/8615 - 244th Street SW
Edmonds, Washington
L&A Job No. 16-117
INTRODUCTION
We understand that the development a 16-lot plat residential project is proposed for the
subject property located at the above addresses in Edmonds, Washington. At your
request, we have completed a preliminary geotechnical investigation for the subject
project. The purpose of this investigation is to explore and characterize subsurface (soil
and groundwater) conditions of the project site and evaluate feasibility of onsite
stormwater disposal. Presented in this report are our findings of subsurface conditions
and recommendations for onsite stormwater disposal.
PROJECT DESCRIPTION
A three-story, above -grade, wood -framed, single-family residence is to be constructed on
each of the lots. The residence structures are to be supported on perimeter concrete
stemwalls, interior load -bearing walls, beams, and columns. The lots are to be accessed
19213 Kenlake Place NE - Kenmore, Washington 98028
Phone (425) 483-9134 - Fax (425) 486-2746
August 4, 2016 (Revised 3/21/2018)
Mietzncr Plat
L&A Job No. 16-117
Page 2
from 244th Street SW via a paved driveway entering the south side of and traversing
northward into the interior of the site, with a hammerhead at the north end of this
driveway.
SITE CONDITIONS
SURFACE CONDITION
The general location of the project site is shown on Plate 1 — Vicinity Map, attached
hereto. The site is situated on a gentle, southerly -declining slope. Within the site, the
ground is very gently sloped. It is bounded by 2440' Street SW to the south and adjoined
by residential development to the north, east, and west. The project site is a rectangle -
shaped land elongated in the north -south direction. The townhomes are to be accessed
via an access road with porous pavement.
GEOLOGIC SETTING
The Geologic Map of the Edmonds East and Part of the Edmonds West Quadrangles
Washin ton, by James P. Minard, published by U. S. Geological Survey in 1983, was
referenced for the geologic and soil conditions at the project site. According to this
publication, the surficial soil unit at and in the vicinity of the site is mapped as Vashon
Till (Qvt) deposits.
The geology of the Puget Sound Lowland has been modified by the advance and retreat of
several glaciers in the past one million years or so and the subsequent deposits and
erosions. The latest glacier advanced to the Puget Sound Lowland is referred to as the
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietzner Plat
L&A Job No. 16-117
Page 3
Vashon Stade of the Fraser Glaciation which had occurred during the later stages of the
Pleistocene Epoch, and retreated from the region some 12,500 years ago.
The deposits of the Vashon till soil unit were plowed directly under glacial ice during the
most recent glacial period as the glacier advanced over an eroded, irregular surface of
older formations and sediments. This soil unit is composed of a mixture of unsorted clay,
silt, sand, gravel, and scattered cobbles and boulders. The Vashon till soil over the top
two to four feet is normally weathered to a medium -dense state, and is moderately
permeable and compressible. The underlying fresh till soil, commonly referred to as
"hard pan", is very -dense and weakly -cemented. The fresh till soil possesses a
compressive strength comparable to that of low-grade concrete and can remain stable on
steep natural slopes or man -make cuts for a long period. The fresh till deposits can
provide excellent foundation support with little or no settlement, but are of extremely low
permeability and would hardly allow stormwater to seep through.
SOIL CONDITION
Subsurface conditions of the project site were explored with three backhoe test pits
excavated on August 1, 2016, with a tire -mounted backhoe to depths of 7.5 and 9.0 feet.
The approximate locations of the test pits are shown on Plate 2 - Site and Exploration
Location Plan. The test pits, designated as TP-1, TP-2 and TP-3, were located with either
a tape measure or by visual reference to existing topographic features in the field and on
the topographic survey map, and their locations should be considered as only accurate to
the measuring method used.
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietzncr Plat
L&A Job No. 16-117
Page 4
A geotechnical engineer from our office was present during subsurface exploration,
examined the soil and geologic conditions encountered, and completed logs of test pits.
Soil samples obtained from each soil layer in the test pits were visually classified in
general accordance with United Soil Classification System, a copy of which is presented
on Plate 3. Detailed descriptions of soils encountered during site exploration are
presented in test pit logs on Plates 4 and 5.
The test pits encountered a layer of topsoil, about 8 to 12 inches thick, mantling the site.
The topsoil is underlain by a layer of weathered soil of light -brown to brown, medium -
dense, silty fine sand with trace to some gravel, about 2.3 to 3.5 feet thick. Underlying
the weathered soil is underlain to the depths explored by a glacial till deposit of light -gray,
very -dense, cemented, gravelly, silty, fine sand with occasional cobble.
GROUNDWATER CONDITION
Groundwater was not encountered in any of the three test pits excavated on the site. The
very -dense, cemented, glacial till deposit underlying the site at shallow depth is of
extremely low permeability and would hardly allow stormwater to seep through. This till
deposit would perch stormwater infiltrating into the more permeable surficial soils. The
amount of and the depth to the near -surface perched groundwater would fluctuate
seasonally, depending on precipitation, surface runoff, ground vegetation cover, site
utilization, and other factors. The perched groundwater would accumulate and rise in the
wet winter months and may dry up completely during the dryer summer months. The
project is in a local highland with a relatively small drainage basin. Therefore,
groundwater under the site would be limited.
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mictmer Plat
L&A Job No. 16-117
Page 5
ONSITE STORMWATER DISPOSAL RECOMMENDATIONS
General
Low Impact Development (LID) methods for onsite stormwater disposal, include storage
and reuse, splash blocks, surface dispersion, infiltration trenches, rain gardens (bio-
retention cells), porous pavement may be considered for onsite stormwater disposal.
These methods are discussed below.
Storage and Reuse
Roof runoff may be stored in cisterns or barrels during rainstorms. Water stored may be
used later for watering plants and irrigating lawns.
Splash Blocks
The proposed residences are of limited total impervious area. Therefore, using splash
blocks under roof downspouts to spread roof runoff onto grass covered yards would be
sufficient to dispose roof runoff. Downspouts should be extended to at least 6 feet away
from the structures where splash blocks are placed to create sheet flow onto the yards.
The yards should be re -graded as necessary to allow disposed stormwater to flow away
from the townhomes.
Infiltration Trenches
The project site is underlain at shallow depth by a very -dense, cemented, glacial till
deposit of extremely low permeability. Therefore, using infiltration trenches or rain
gardens to dispose stormwater solely by infiltration would require a large infiltration
bottom area, will be inefficient and may not work well. If used, infiltration trenches
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietzner Plat
L&A Job No. 16-117
Page 6
installed into till soil should be sized based on a design infiltration rate of 0.15 iph (inches
per hour).
Infiltration trenches should be located on the downhill side of adjacent structures, and
should be set back at least 5 feet from property lines and 10 feet from nearby structure
foundations or utility trenches. Also, the trench bottom should be at least 12 inches lower
than the adjacent footing foundations and utility trenches. The tightlines conveying
stormwater into infiltration trenches should have sufficient grade (1% minimum) to
generate flow by gravity. Tightlines conveying stormwater into infiltration trenches
should have sufficient gradient (1% minimum) to generate flow by gravity. A clay or
lean concrete dam should be constructed in the tightline trenches to form an impermeable
barrier to keep water in infiltration trenches from flowing backward to adjacent structures
or utility trenches.
The side walls (but not the bottom) of the infiltration trenches should be lined by a layer
of non -woven filter fabric (Mirafi 140NS). The trenches are then filled with clean, 3/4 to
1-1/2 inch washed gravel to within about 12 inches of the finish grade. The dispersing
pipes, consisting of 4-inch, perforated PVC pipes, spaced at no more than 4 feet on
centers, should be embedded in the gravel fill at about 2 feet below top of trenches. The
top of the gravel fill should then be covered with the same filter fabric and the remaining
trenches filled with onsite clean sandy soil. Infiltration trenches, if installed under access
road should have gravel fill placed in 10-inch lifts with each lift densified to a non -
yielding state with a vibratory mechanical compactor.
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietzner Plat
L&A Job No. 16-117
Page 7
Rain Gardens (Bio-retention Cells)
In addition to infiltration, rain gardens may also rely on evaporation into the air and
absorption by vegetation roots for stormwater disposal. Rain gardens should be about 3
feet deep with their bottom cut into weathered soil. If used, rain gardens installed into
glacial till soil should be sized based on a design infiltration rate of 0.15 iph (inches per
hour). Rain gardens should be located on the downhill side of adjacent structures and
should be set back at least 5 feet from property lines and 10 feet from adjacent structure
foundations and utility trenches. Tightlines conveying stormwater into rain gardens
should have sufficient gradient (1% minimum) to generate flow by gravity. A clay or
lean concrete dam should be constructed in the tightline trenches to form an impermeable
barrier to keep water from flowing backward to adjacent structures.
Soil samples should be obtained from the soil stratum into which stormwater is to be
disposed for cation exchange rate to determine whether the soil stratum has sufficient rate
to purify pollutant. If not, rain garden ponds (and infiltration trenches) should be lined
with a layer of amended soil at least 18 inches thick. The amended soil should consist of
adequate compost mixed with clean medium to coarse sand to achieve an organic content
of at least 10% by dry weight.
Rain garden ponds should be vegetated for erosion control and the vegetation should be
fully established before the ponds can be put in use for stormwater disposal. Planted
vegetation should be tolerant of ponding water and saturated soil conditions in the winter
months and drought in the summer months. In general, the predominant plants should be
of facultative species adapted to stresses associated with wet and dry conditions.
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21 /2018)
Mietzner Plat
L&A Job No. 16-117
Page 8
Typically, the plants may comprise of red twig dogwood, rushes, sedges, salmonberry and
twinberry and ornamentals such as royal ferns, big -leaved ligularias or various primroses.
Surface Dispersion
Runoff over roofs and paved driveways may be disposed onsite by surface dispersion. A
surface dispersion system should consist of a distribution trench and a vegetated flowpath
on the downhill side of the houses to be constructed on the lots. This method will work
well only if there is sufficient open space to install this surface dispersion system on each
lot.
Porous Pavement
General
Porous pavement may be used for driveways of the proposed development to allow runoff
to infiltrate into the ground. Two in -situ infiltration tests had been conducted within the
footprint of the proposed access road of the project site, with the test results presented in a
report titled "Infiltration tests, Mietzner Plat, 8609/8611/8615 — 244' Street SW,
Edmonds, Washington," dated August 3, 2017. These tests were conducted in summer on
July 3, 2017, and City of Edmonds requires that one additional infiltration test be
conducted in winter. Therefore, we completed one more infiltration test on February 7,
2018, to meet city's requirement. The results of this additional infiltration test are
presented in this report. This test was for the access road with porous pavement of the
over which runoff is to be disposed by seeping through porous pavement and infiltrating
into the subgrade soils underlying the road bed materials.
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietzner Plat
L&A Job No. 16-117
Page 9
In -situ Infiltration Test
The location of the additional infiltration test, designated as IT-3, is shown on Plate 2
attached hereto. The infiltration test pit was located inside the footprint of the proposed
access road. The bottom of the infiltration test pit was excavated to about 19 inches deep,
approximately the level of subgrade soils under the proposed access road, and was
excavated into a weathered deposit of brown, silty fine sand with trace gravel.
Dimensions of the infiltration test pit and the soil condition at bottom of the pits are
presented in the table below:
TEST PIT SIZE AND SOIL CONDITION
Test Pit Description of Soil
No. Size at Bottom of Test Pit
IT-3 3.58' x 3.67' Brown, silty fine SAND,
X 1.58' deep trace gravel
The in -situ infiltration tests were conducted in accordance with the Small Pilot Test
procedure outlined in Edmonds 2014 Stormwater Code. The infiltration test pit was first
filled with water to about 12 inches deep for six hours to soak the soils beneath the pit.
Clear tap water was used in the test. The infiltration test was then conducted in the pit in
accordance with the test procedure of the stormwater code. The test results were
presented in the APPENDIX attached to this report.
The initial infiltration rate of the infiltration test, Isat initial, is to be corrected according to
the following equation to get the design infiltration rate, KSat.
Ksat = C FT x Ksat initial , where C FT = C Fv x C Ft x C Fm
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietziicr Plat
L&A Job No. 16-117
Page 10
where, CF„ = factor of variability and number of locations tested, = 0.33 to 1.0
CFt = factor of uncertainty of test method, = 0.5 for small scale test, and
CFm — 0.9.
Use a middle value 0.65 for CFI,, thus, CFT = (0.65) (0.5) (0.9) = 0.29. The design Ksat
values, shown in attached APPENDIX, were thus determined to be 0.87 iph (inch per
hour) for Test IT-3. We recommend that an infiltration rate of 0.75 iph be used in design
of storm runoff disposal over permeable pavement of the access road.
Recommendations of Porous Pavement Road
A design infiltration rate of 0.75 iph (inch per hour) may be used for design of porous
pavement. A 10-inch thick layer of railroad ballast rocks (3/4 to 2-1/2 inch crushed rock)
is to be placed over prepared subgrade soils and compacted to a firm condition with a
vibratory compactor. The railroad road ballast rocks should be covered with a layer of
non -woven filter fabric (Mirafi 140NS) and topped with a 4-inch layer of 5/8-inch
crushed rock. This crushed rock base should also be compacted to a non -yielding state.
The porous pavement with a minimum thickness of 4 inches should then be constructed
over the crushed 5/8-inch crush rock base.
LIMITATIONS
This report has been prepared for the specific application to the subject project for the
exclusive use by Mietzner Homes, and its associates, representatives, consultants and
contractors. We recommend that this report, in its entirety, be included in the project
contract documents for the information of the prospective contractors for their estimating
and bidding purposes and for compliance to the recommendations in this report during
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietner Plat
L&A Job No. 16-117
Page I
construction. The conclusions and interpretations in this report, however, should not be
construed as a warranty of the subsurface conditions. The scope of this report does not
include services related to construction safety precautions and our recommendations are
not intended to direct the contractor's methods, techniques, sequences or procedures,
except as specifically described in this report for design considerations.
Our recommendations and conclusions are based on subsurface conditions encountered in
the infiltration test pit, our engineering analyses, and our experience and engineering
judgment. The conclusions and recommendations are professional opinions derived in a
manner consistent with the level of care and skill ordinarily exercised by other members
of the profession currently practicing under similar conditions in this area. No warranty,
expressed or implied, is made.
The actual subsurface conditions encountered during construction may vary from those
encountered in the test pits. The nature and extent of such variations may not become
evident until construction starts. If variations occur then, we should be retained to re-
evaluate the recommendations of this report, and to verify or modify them in writing prior
to proceeding further with the construction work.
LIMITATIONS
This report has been prepared for the specific application to this project for the exclusive
use by Mietzner Home Builders, LLC, and its associates, representatives, consultants and
contractors. The conclusions and interpretations in this report, however, should not be
construed as a warranty of subsurface conditions of the site. The scope of this
investigation does not include services related to construction safety precautions and our
LIU & ASSOCIATES, INC.
August 4, 2016 (Revised 3/21/2018)
Mietzner Plat
L&A Job No. 16-117
Page 12
recommendations are not intended to direct the contractor's methods, techniques,
sequences or procedures, except as specifically described in this report for design
comWeratioris. All geotcchnical construction Wrk should be monitored by a
geotechnical engineer during construction.
CLOSURE
We are pleased to be of service to you on this project. Please feel free to contact us if you have
questions regarding this report or need further consultation.
Five plates attached
Yours very truly,
LIU & ASSOCIATES, INC.
J. S. (Julian) Liu, Ph.D., P.E.
Principal
LIU & ASSOCIATES, INC.
KULSWFN Q9 1 ' \` iM sa 9a „ lLan st w 1224TH_I I I ; �• w ,r _a T
sel T _�_' "� - a mi 224TH
Li
ALf1D?IQUIN ' 226TH_ ST S t5M 1s� 9stwn9rl al t � ='l SW aE 22M ST_ ` s Sw
n^ N • •Sa 2 �; p z Z
FaaxrS �F 22mr �I K s
STt O o le"M �` 1 228TNI_ 50 5T ( u
` . �10 Cf1lEiERr - sw
DEER E.OR < 1 O 22ATN PI SV Ft ttptx n9n� 1a tt sw
PARK fI OE s�`) Lpip 1 J' a O I ST1i I i d. 3 4
RESER J `/ { r f 1 y a �, �O� a yy 4 aMgt
t- a.sr•� 2
h' <t 92 - 231ST ST ?'a
3L.SY. z32tlp 1s1' FS` '~— +' ?,
I - 1 , 5 Pik- .� 'taaon rDLLY LN ar---
1 1 r 1 ? r` { ELMFON 232tA _ ,; ST 511 = �233R0: (2320 PL SW) a
�� ,�� $ 1410Q/AY St>c cc Sr su PL $Ht-NAPLE--- LH �c i=• '" I Q•
;. f04� Ii .a`�Its �� HS 234TH ". - _4 it SW I <N1AvL U1 —??Ant. : St�Q,
�j 1gTTlN6IIW "I- ~I - I ik a, i Il n 9rayK111 a '
Z35TH Yt 5W Q
s 2J6T11 ST S11< <i
a•V•PL Sll/.1, MSEErts MT RD) �'236THI d'��'--' Q: ST
7
a.Ci
4 1 ; ) 4 rj0� p: nw. F /`
ST4 SW I Q�1` I� a � S
a 235n sr sw° imx 238TH ST SW N -'-
s---�,,�
i • ' '� G -.1 z S, sr i
Irr- a In Ri s► �" 1� a -NFSfIiIAtNi o m a 16 r� �
1 '� 210i115i5�1 �-A 110WRIAL'jgm'51 - P-MP.m �"'H.r
' no I PARK 4`' _.�- E: ,.240T11 S7 i•.
_ at Ai' I MIST Sr Su a pp� h= rD. ENTER AV) Is —
> OWII 1GOLE n I Gist Yk, i
�o o >sr'' o PROJECT '
t= c Q F I B 1 R} — = q! 42NU�' _ STa�I �+ Sw
SITE
--- r 62,9 1 STnvf ra.N sf Z4JRD 'Ly+�j .I �y
NorLmM!, 3" ta1T3i s t? R2osrNS� r �. �val)i Rf� If W "
„� °'J,o,Q' �� •,� War 201st sST i i''.
! _—; �S• tN oIr q'4p
}/ ST = Q In'y 2ozaw sr r a• dtfi�_sY stp' a G 203N0 ST= +
•�Y: HW` �I 1?9TH _ I STD_ At y
(sf t; eLV� 1 HU `� i S ? 1 ST I _1? ALt3 �
LL , H 2O1ST ST ,URVA4 PJL�Aa _
—{ 1•ST gI -i W 1 ST as >t{ iz - 200i11: yT t3 u _{ Ck7frF; -A:
N ; at I
- 1971H Sr7er SYgf s,wnLt �` 2007H ST
N 1 am. r. M M1$ ~sTl�i ter Z 199iH' s
1 ia, i^ I y'< �'i �Sw IoY�ri :�9�rH - <I (1199fN1i_r ST
F1 �a NW 195TH gT IM: s, r `'
immix sr �' ica 9s»fGn1y 19sm a
�`
l,� < I93Rn 2. fcy gyp. 5TH I� �N sT•=
1� �c
�� w 1PINOr �� <; �NDiv � \� 19JJv S,M10 9 I �+t �� K!l0.iS> 1�0 MJ �• -s
1= g Si o aaasr��4.T, t1 1931t0. �' J
NY' 90T sT I f.Ve_,y' 19ISF
1 Q — fNf rsaol{ , 5I n 4!L $
? 3 fill s I rARi� !Y +, , N 192N0 S:r
RI 1 4a �' 1I`sr �le9rn AV ! ST
18BTH�ST Rt Ro op Nj Ln! s:O_ .= : ST 11�4=
F RICHMOND W 16" t* — 1`r ' N <Il ST
186TH ST
RIEACH_ST a0./µR 3 r BfACH a sr _ n� - 1 -
ae
PARK ,� J NW 185 o
\A , I Si 9 o ti N 1 5 tl ,ST E
\! r
,(✓� Rrr,i tMtx st N 1&tlll sr .
a- Irw le>PpQ Si
vflry tmo s1 <� v N 1B3R0 ST fr i
.g ro fM ISIST N ST k9 I T
t� 1MTN mi I1BpT11 5Y=j�_ • Sr a ° ST PL �,z <,
tisi �! -)- t •l a N < 1 �f N ST' ,N
7a J nu �TNIIL •'nr_ N 179TIt PL
< tar 1�p'�'•'}'sr N 178TH T " im
JNNIS 77j7 NW 177TH: PL�, r 1KS ff IL 1 S, O 3
Sre - x ( srlrruN 1771)1 sr n Imo!' �r x1N 17 ST 1
ARDEN ` 3r -.• ��TM Nw P qt6 w {'4i Q `
f RESERVE j� ^` < %1157H ST ' *rs NAh L'' t a 8
a / a 175TH 19 ST
gfL•. = y a Is
N 175TH ST
a - T
AV NIL1f��J flp7>of 11 � nT;se` n rRs
SNOREVIEW ZN 7200 5T GRfQ��a v sr RE)r)00 N ll
A rronl
< PARK s� 5`)'ii , "17t5� STn s TV
HS
lip 172N0 `
�f �y <': j
1 � N rM �� � � : h r_r ),orH_ sr
SITE AND EXPLORATION LOCATION PLAN
LIU & ASSOCIATES, INC. MIETZNER PLAT
8615 - 24TH STREET SW
G_ eotechnical Engineering _Engineering Geology • Earth Science EDMONDS, WASHINGTON
JOB NO. 16-117 1 DATE 8/3/2016 1 PLATE
s,`eQ,2, s�fLt�k
�-r YP-)
0
TP
1-1
P
15+�
�'{58'
Dr"Ve .4i'sic I'-"'
-5 1 11 11 I
Pk � DIc�
p K9
N A ,5 F
39'
Itu
Ic
- 861s zN`I�" SF. Sw
EA► -ids , u1�, R$ o'i c,
dab POvG2l N,,x,�� ,
- o0�if,33o3looso3
-oowla33o5 too 105
oo` 1 s3o%%ool Oy
7D+dt = 3R, 00a sF
16
un;+s
Sole s6 6L k
3 e, 4-Hn9 S)rtgbe f i"17
cFfoo` h.ov,,,s on ?rap"
1' 3` Slarj SFI`s
-,A( �Wd,,n uH'.ts. =16
g,� U.'n Tj� of Cm-0,uJi&\
Per NBC -
as.
fro„r ,tetlp�K
Koft N07- TO SCALE-CIIIIVKA1au,,j w IDT}}l
LIU & ASSOCIATES. INC.
Geotechnical Engineering • Engineering Geology • Earth Science
SITE AND EXPLORATION LOCATION PLAN
MIETZNER PLAT
8615 - 24TH STREET SW
EDMONDS, WASHINGTON
OB NO. 16-117 1 DATE 8/3/2016 I PLATE .
UNIFIED SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS
GROUP
GROUP NAME
SYMBOL
GRAVEL
CLEAN
GW
WELL -GRADED GRAVEL, FINE TO COARSE GRAVEL
COARSE-
MORE THAN 50% OF
GRAVEL
GP
POORLY -GRADED GRAVEL
GRAINED
COARSE FRACTION
GRAVEL WITH
GM
SILTY GRAVEL
SOILS
RETAINED ON NO.4 SIEVE
FINES
GC
CLAYEY GRAVEL
SAND
CLEAN
SW
WELL -GRADED SAND, FINE TO COARSE SAND
MORE THAN 50%
MORE THAN 50% OF
SAND
SP
POORLY -GRADED SAND
SAND WITH
SM
SILTY SAND
RETAINED ON THE
COARSE FRACTION
NO. 200 SIEVE
PASSING NO.4 SIEVE
FINES
SC
CLAYEY SAND
FINE-
SILT AND CLAY
INORGANIC
ML
SILT
GRAINED
LIQUID LIMIT
CL
CLAY
SOILS
LESS THAN 50%
ORGANIC
OL
ORGANIC SILT, ORGANIC CLAY
MORE THAN 50%
SILTY AND CLAY
INORGANIC
MH
SILT OF HIGH PLASTICITY, ELASTIC SILT
PASSING ON THE
LIQUID LIMIT
CH
CLAY OF HIGH PLASTICITY, FAT CLAY
NO. 200 SIEVE
50% OR MORE
ORGANIC
OH
ORGANIC SILT, ORGANIC SILT
HIGHLY ORGANIC SOILS
PT
PEAT AND OTHER HIGHLY ORGANIC SOILS
NOTES: SOIL MOISTURE MODIFIERS:
1. FIELD CLASSIFICATION IS BASED ON VISUAL EXAMINATION DRY - ABSENCE OF MOISTURE, DUSTY, DRY TO
OF SOIL IN GENERAL ACCORDANCE WITH ASTM D2488-83. THE TOUCH
2. SOIL CLASSIFICATION USING LABORATORY TESTS IS BASED SLIGHTLY MOIST - TRACE MOISTURE, NOT DUSTY
ON ASTM D2487-83. MOIST - DAMP, BUT NO VISIBLE WATER
3. DESCRIPTIONS OF SOIL DENSITY OR CONSISTENCY ARE VERY MOIST - VERY DAMP, MOISTURE FELT TO THE TOUCH
BASED ON INTERPRETATION OF BLOW -COUNT DATA, VISUAL WET - VISIBLE FREE WATER OR SATURATED,
APPEARANCE OF SOILS, AND/OR TEST DATA. USUALLY SOIL IS OBTAINED FROM BELOW
WATER TABLE
LIU & ASSOCIATES, INC.
UNIFIED SOIL CLASSIFICATION SYSTEM
Geotechnical Engineering Engineering Geology • Earth Science
PLATE 3
Logged By: JSL
TEST PIT NO.
Date: 8/1 /2016
1
Ground El. #
Depth
ft
USCS
CLASS.
Soil Description
Sample
No.
IN
%
Other
Test
_
OL
Dark -brown, loose, organic, silty fine SAND, some roots, moist
1
--------
(T(iPSOI9-------
_
SM
Light -brown, medium -dense, silty fine SAND, some gravel, dry
2
3
SM
Light -gray, very -dense, gravelly, silty, fine SAND, occasional
5
cobble, cemented, slightly -moist (VASHON TILL)
6
7
B
9
_
Test pit terminated at 9.0 ft; groundwater not encountered.
10
Logged By: JSL
TEST PIT NO.
Date: 8/1 /2016
OA,
Ground El. t
Depth
ft
USCS
CLASS.
Soil Description
Sample
No.
w
%
Other
Test
OL
Dark -brown, loose, organic, silty fine SAND, some roots, moist
1
(TOPSOIL)
2
SM
Brown, medium -dense, silty fine SAND, trace gravel, moist to wet
3
4
SM
Light -gray, very -dense, gravelly, silty, fine SAND, occasional
s
cobble, cemented, very -moist to moist (VASHON TILL)
7
8
9
10
LIU & ASSOCIATES, INC.
Geotechnical Engineering - Engineering Geology • Earth Science
TEST PIT LOGS
MIETZNER PLAT
8615 - 24TH STREET SW
EDMONDS, WASHINGTON
JOB NO. 16-117 1 DATE 8/11/2016 1 PLATE 4
Logged By: JSL
TEST PIT NO.
Date: 8/1 /2016
3
Ground El. ±
Depth
ft
USCS
CLASS.
SOII Description
Sample
No
W
%
Other
Test
_
OL
Dark -brown, loose, organic, silty fine SAND, dry
1
SM
__(TOPSOIL/FILLI___ ___ __ ___ ____
Light -brown, loose, silty fine SAND, some gravel, with gravel and
2
cobble size angular rocks, glass bottles, brick fragments, dry
3
4
SM
Light -gray, very -dense, gravelly, silty, fine SAND, occasional
_
cobble, cemented, slightly -moist (VASHON TILL)
5
6
7
8
9
Test pit terminated at 7.5 ft; groundwater not encountered.
10
Logged By:
TEST PIT NO.
Date:
Ground El. ±
Depth
ft.
USCS
CLASS.
Soil Description
Sample
No.
w
%
Other
Test
1
2
3
4
5
6
7
8
9
10
LIU & ASSOCIATES, INC.
Geotechnical Engineering • Engineering Geology • Earth Science
TEST PIT LOGS
MIETZNER PLAT
8615 - 24TH STREET SW
EDMONDS, WASHINGTON
JOB NO. 16-117 DATE 8/11/2016 1 PLATE 5