MA0405-SY040913 Rone Engineers
GEOTECHNICAL ENGINEERING September 13, 2004
CONSTRUCTION MATERIALS TESTING
ENVIRONMENTAL CONSULTING Mr. Keith Marvin, P.E.
City of Coppell
FORENSIC ENGINEERING 255 Parkway Boulevard
P.O. Box 9478
Coppell, Texas 75019
Re: Geotechnical Investigation
Paver Evaluation - MacArthur Boulevard
Irving, Texas
Rone Project No. 04 -9130
Dear Mr. Marvin:
We have completed our geotechnical investigation for the referenced site in
accordance with Rone's Proposal No. 04 -6379 dated June 18, 2004. This letter
presents the results of our investigation and our recommendations for design
and construction.
The project is located along MacArthur Boulevard from Riverchase Drive to
Samuel Boulevard in Coppell, Texas. We understand the project consists of
evaluating portions of seven intersections along MacArthur Boulevard where
paver blocks are used for the surface of the roadway. The pavers have been in
place for about 20 years. In some areas the pavers have experienced vertical
displacement and other forms of distress, while in other areas the pavers are still
performing well. Evaluation of the sections will include the pavers themselves,
the cushion sand layer between the concrete and the pavers and the conditions
of the paver subgrade and subgrade soils.
FIELD INVESTIGATION
Subsurface conditions were determined by 14 sample borings drilled to a depth
DALLAS
8908 AMBASSADOR ROW of 5 feet below the existing surface of the pavers. The borings were drilled in
DALLAS, TEXAS 75247 August 2004. The borings were placed in locations near areas where vertical
TELEPHONE 214- 630 -9745 movements have occurred and near locations where no vertical movements
FACSIMILE 214- 630 -9819 have appeared to occur. In addition, the existing pavers and concrete were
FORT WORTH cored at each of the boring locations to determine their thickness. Thickness
2696 GRAVEL DRIVE results can be found on the boring logs. The soil samples obtained were sealed
FORT WORTH, TEXAS 76118 to preserve moisture and transported to our laboratory for further examination
TELEPHONE 817- 284 -1318 and testing.
METRO 817- 429 -4328
FACSIMILE 817- 284 -1585
Approximate boring locations are shown on the Boring Location Diagrams,
HOUSTON attached as Plates A.1 through A.4.
6300 ROTHWAY, SUITE 150
HOUSTON, TEXAS 77040
TELEPHONE 713 - 996 -9979
FACSIMILE 713 - 996 -9972
City of Coppell
Rone Project No. 04-9130
September 13, 2004
Page 2
LABORATORY TESTING
Laboratory testing on soil samples obtained included visual classification, moisture content
determinations, Atterberg Limits tests and unconfined compression tests. The tests were performed
in general accordance with applicable ASTM procedures. The laboratory test results are shown on
the Logs of Boring enclosed (Plates A.5 through A.18). Plates A. 19 and A.20 describe
nomenclature used on the boring logs.
SITE CONDITIONS
Subsurface Conditions
Based on available surface geology maps and the borings, the site appears to be located within
alluvial/fluvial deposits associated with the Trinity River system, overlying the Eagle Ford Shale
formation. Descriptions of the various strata and their approximate depths and thickness are shown
on the boring logs. A brief description of the stratigraphy indicated by the boring logs is given below.
The paver thickness was about 2-½ inches and the sand layer beneath the pavers in 12 of the 14
borings was I to 2 inches thick. In the remaining two borings (Borings B-10 and B-13) no sand layer
was encountered. The concrete encountered in the borings underlying the sand or pavers ranged in
thickness from about 8 to 11 inches. The materials encountered in the borings beneath the
concrete consisted of sandy clay fill, shaley clay and sandy clay. Our assessment of fill is based on
visual examination of the samples. In nine of the borings sandy clay fill was encountered beneath
the concrete to their termination depth of 5 feet. In the remaining five borings native sandy and
shaley clays were encountered beneath the concrete to their termination depth of 5 feet.
Groundwater Conditions
The borings were advanced using auger drilling and intermittent sampling methods in order to
observe groundwater seepage levels. Groundwater was not encountered during drilling, and these
boreholes appeared to be dry upon completion of drilling.
Future construction activities may alter the surface and subsurface drainage characteristics of this
site. It is difficult to accurately predict the magnitude of subsurface water fluctuations that might
occur based upon shorf-term observations. The risk of encountering groundwater is increased
during and after pedods of precipitation.
ANALYSIS AND RECOMMENDATIONS
Observations
The following observations were made on the pavement sections where the borings were placed:
· the pavers were about 2-½ inches in thickness and appear to be in good condition;
· bedding sand between the pavers and concrete was found to be between 1 and 2 inches in
thickness in 12 of the sections evaluated. In the other two sections bedding sand was not
found between the pavers and concrete;
· concrete beneath the bedding sand or pavers was found to be between 8 and 11 inches in
thickness and appeared to be in good condition. However, in the core samples we obtained
no reinforcing steel was encountered;
City of Coppell
Rone Project No. 04-9130
September 13, 2004
Page 3
the subgrade soils appeared to be in a relatively well compacted condition; however, in the
samples we recovered from our borings there was no indication of prior lime stabilization.
(Cross section A-A, sheet 7 of 9, Project No. MA 02-03 dated April 7, 2004 prepared by The
City of Coppell shows pavers followed by 2-inches of bedding sand and 10-inches of concrete
base over lime-treated subgrade).
Conclusions & Recommendations
In summary, it appears that failures within the paver crosswalk areas were initiated by bedding sand
loss. Loss of the bedding sand allowed pavers to be "jostled" by traffic resulting in damage and/or
loss of pavers. Subsequently, repeated traffic allows the damage zone to extend to the perimeter
pavement. Our analysis of the underlying concrete base indicates the section remained generally
intact except in areas where prolonged exposure had resulted in unanticipated loading of the
concrete base section. It was noted that the absence of lime-treatment of the concrete soil
subgrade may have contributed to a general weakness of the overall section.
Based on our observations and conclusions there are a number of repair alternatives available.
Several of these alternatives are presented below for your review and consideration:
· Since the existing section has performed adequatelyfor almost 20 years, localized repair of
failed zones may be considered as a suitable repair alternative. We understand color match
has been an issue with prior spot repairs. In order to avoid color match issues we
recommend complete removal of existing pavers from a selected intersection. The removed
pavers may be replaced with new ones from a new production run and the removed pavers
may be used as replacements for spot repairs at other paver repair zones.
· Full removal of the paver/concrete cross-section and replacement with flowable fill and
stamped concrete. For this scenario, the pavers and the underlying concrete base course
are completely removed exposing the soil subgrade. The soil subgrade should be inspected
for soft spots and repaired to provide a suitable bearing surface. Flowable fill with a
compressive strength of 75 to 150 psi may then be used to bring the subgrade to the desired
bottom of pavement elevation. Concrete may then be placed for the surface pavement
section and stamped at the surface with the desired pattern. Pattern width may vary to
accommodate specific intersection criteria. Concrete may be colored or painted to attain the
desired architectural effect.
· Full removal of the paver/concrete cross-section and replacement with engineered fill and
stamped concrete. For this scenario, the pavers and the underlying concrete base course
are completely removed exposing the soil subgrade. The subgrade should then be scarified
and compacted to 95 to 100 of the materials maximum standard Proctor dry density (ASTM
D698) at a moisture content of optimum to +4 percent for clays and sandy clays. Clayey
sands should be compacted in a similar fashion at a workable moisture content of +/- 2
percent of optimum. Engineered fill may then be used to bring the subgrade to the desired
bottom of pavement elevation.
Engineered fill may consist of select fill or processed native clay, sandy clay or clayey sand.
Select fill should consist of a sandy clay or clayey sand with a liquid limit less than 35 and
plasticity index between 5 and 15. The fill should be placed in loose lifts less than 10 inches
thick, and compacted to a minimum of 95 percent of the material's maximum standard
Proctor dry density. The moisture content of the select fill should be within 2 percentage
points of the optimum moisture content as determined by the standard Proctor test.
City of Coppell
Rone Project No. 04 -9130
September 13, 2004
Page 4
Native clay, sandy clay and /or clayey sand may also be used as engineered fill. Native
materials should be tested by Rone to verify they are suitable for use as engineered fill. In
the event they are found to exhibit unfavorable characteristics, it may be necessary to
stabilize the materials with cement or lime. We would anticipate 6 to 8 percent of lime or
cement may be necessary for this purpose. Lime or cement series tests may be performed
at the time of construction to determine percentages required. Native soils used as
engineered fill should be moisture conditioned and compacted as described above.
Concrete may then be placed for the surface pavement section and stamped at the surface
with the desired pattern. Pattern width may vary to accommodate specific intersection
criteria.
GENERAL COMMENTS
The analyses, conclusions and recommendations contained in this report are based on site
conditions as they existed at the time of the field investigation and further on the assumption that the
exploratory borings are representative of the subsurface conditions throughout the site; that is, the
subsurface conditions everywhere are not significantly different from those disclosed by the borings
at the time they were completed. If during construction, different subsurface conditions from those
encountered in our borings are observed, or appear to be present in excavations, we must be
advised promptly so that we can review these conditions and reconsider our recommendations
where necessary. If there is a substantial lapse of time between submission of this report and the
start of the work at the site, if conditions have changed due either to natural causes or to
construction operations at or adjacent to the site, or if structure locations, structural loads or finish
grades are changed, we urge that we be promptly informed and retained to review our report to
determine the applicability of the conclusions and recommendations, considering the changed
conditions and /or time lapse.
This report has been prepared for the exclusive use of the City of Coppell and their designated
agents for specific application to design of this project. Services were provided using the degree of
care and skill ordinarily exercised under similar conditions by reputable members of our profession
practicing in the same or similar locality. No warranty, expressed or implied, is made or intended.
Thank you for the opportunity to provide services to you for this project. Please call if you have any
questions regarding this letter.® ' ��`�
Respectfully submitted, �!ft•..
i* \*A0
••••000 000 if 0
" Of. ROBERT A RMSTRONG, JR. I
/ i 92647 • 1
Robert D. Armstrong Jr., P.E. t l�~� �� ®' � Mark D. Gray, • .
Project Engineer •ok,®R "" �� A1. Vice President
Enclosures: Boring Location Diagram (Plates A.1 through A.4)
Log of Borings (Plate A.5 through A.18)
Unified Soil Classification System (Plate A.19)
Key to Symbols Used On Boring Log (Plate A.20)
B ~acARTHUR
BETHEL scHOOL RD.
.:
:: B-1
RIVER~HAS~
0 40 80
I I I
SCALE: f" = 40'
PLATE A.1 PROJECT NO: 04-9130.00
BORING LOCATION DIAGRAM r,LE.^ME:
Ron~e eng~~ DRAWING BY: DF DATE: 09/10/04
REVISED BY: DATE:
PAVER EVALUATION Mac, ARTHUR BOULEVARD REVISED BY: DATE:
COPPELL, TEXAS ^PPROVED EY: DA DATE: 09/10/04
PRIVATE DR.
MacARTNUR BLVD.
VILLAGE PARKWAY S.
CONDOR DR.
I [ r CITY FIRE S TA TION
BORING LOCATION DIAGRAM FILENAME: 049150A2*DWG
PAVER EVALUATION Mac. ARTHUR BOULEVARD REVISED BY: DATE:
COPPELL, TEXAS APPROVED BY: OA , DATE: 09/10/04
B-11
~'~ VILLAGE PARKWAY NORTH
.
0 40 80
I I I
SCALE: I"=40'
PROJECT NO: 04-91 ~0.00
PLATE A.3
BORING LOCATION DIAGRAM ~,LE~A'~E:
RO?i~e ER~~ DRAWING BY: DF' DATE: 09/30/04
REVISED BY: DATE:
PAVER EVALUATION MacARTHUR BOULEVARD REVISED BY: DATF-
COPPELL, TEXAS APPROVED BY: DA DATE: 09/~0/04
,. SAMUEL BLVD.
Ma~ B-13
VILLAGE DR.
0 40 80
I I
SCALE: t ' = 40'
PROJECT NO.: 04-9150.00
pLATE A.4
BORING LOCATION DIAGRAM
Ron,~,~,~=e Engineers Ltd, REV,S~D S¥: D^TE:
W~ PAVER EVALUATION MacARTHUR BOULEVARD REVISED BY: DATE:
COPPELL, TEXAS APPROVED ElY: DA DATE: 09/10/04
t Project No. I Boring No Project Paver Evalution MacArthur Boulevard
04-9130 ] B-1 Coppell, Texas
Location Water Observations
nnacarthurC~Riverchase Groundwater seepage was not observed while drilling, and the borehole
n.b.
Completion"~"~''~--'-Completion appeared dry at completion.
Depth 5.0~ Date 8-10-04
! Sur face Elevation Type [
Auger ~-~ o
~ ~ ~ ~ ~ o ~ . . .~o .
~ ~ ~ ~'~
~- ~= ~ Stratum,,Description ~ o.:= ~:~-~ -~
~x ] ] PAVESTONE, 2.5 thick.
?~ CONCRETE, 105 thick.
ili[ ] SAND, 2" thick,
~. FILL SANDY CLAY, gray and reddish brown, 1.5 39 15 24 17 117 3200
~ w/limestone fragments. Fin~ to soft.
r~t 0.25 20
[ ,
~ Loa OF 8oRma ~o. B-1 Plate A.5
ring No. l Project Paver Evalution MacArthur Boulevard
B-2 ~ C~oppell, Texas __
-- , Water Observations
)~Riverchase~ Groundwater seepage was not observed while drilling, and the borehole
,repletion appeared dry at completion.
rte 8-10-04
Elevation Type
Stratum Description ~ ~ .~ ~ ~ ~ .
PAVESTO~, . thick
SA~, 2" thick.
CONC~TE, 10" thick. I
FILL SANDY CLAY, d~k brown ~d reddish brown. 05 28
Soft.
05
~ect No. ~
04-9130 ~
Location
s.b. MacArthur/
Completion ~ -
t Depth 5.o' ~_
Surface F
LOG OF BORINO NO. B-2 Plate A.6
~0~ - 913 0 = ~pell; Texas
Water Observations
.b. 1~ lethel Schoo Groundwater seepage was not observed while drilling~ and the borehole
Depth
-- ~ompletion appeared dry at completion.
fletion Dat~_10_04
5.0'
-- Surface Elevation Type
' '- '
~ r r~pt~on
....
~ ~ PAVESTO~, 25" thick.
~ / SAND, 2" thick.
*~ 17
F1LL SA~Y CLAY, brown ~d reddisb brown 2.5
~ 64 24 40 28 95 1400
~ Fl~d~f~LAY, brown ~d gray, w/calc~eous 1.75
LOG OF BORING NO. B-3 Plate A.7
-- No. · Pr~iect P~ :r Evalution MacArthur Boulevard
04-9130 B-4 C o~p_ell~ Texas
Location Water Observations
~.b. MacArthur~Bethel School Groundwater seepage was not observed while drilling, and the borehole
Completion Completion appeared dry at completion.
Depth 5.0~ Date 8.10.04
i [ ~, Surface E'evati°itrat:YP:,Descrlptloll
~ Auger
~l Stiff.
~ Plate A.8
~ LOG OF BORING NO. B-4
dution MacArthur Boulevard
Project No ~orlng '5 Coppell, Texas
04-9130 : -
Location Water Observations
n.b. MacArthur~Condor Groundwater seepage was not observed while drilling, and the borehole
appeared dry at completion.
~Completim* Completion
Depth 5.0' I Date 8.10.04 i
-- ! ~ Surface Elevation Type
I Auger
~ ~ ~ Stratum Description
~ ~ CONC~TE, 925 thru .
F LL SA~Y CLAY, reddish brown and gray, 3.25
~¢1 w~imestone fra~ents. Ve~ stiff
~ - FILL SA~Y CLAY, gray ~d t~ w~imestone 125 51 20 31 18
~ ~ Dagments Fi~
5
~ Plate A.9
~~oo OF ~O~mO NO. B-5
[¥roject No. I Boring No Project Paver Evalution MacArthur Boulevard "'
l 04-9130 I B-6 Coppell, Texas
Location Water Observations
s.b. MacArthur~Condor Groundwater seepage was not observed while drilling, and the borehole
'Completion Completion appeared dry at completion.
Depth 5.0' Date 8-10-04 [
Surface Elevation Type
[ I Auger
~ ~ Stratum,Description
7 ] SAND, 2" thick.
I
[ Plate
~ LOO OF BOmSO NO. B-6
Project Paver Evalution MacArthur Boulevard J~~
Project
No
BoringB.7No Coppell, Texas
04-9130 -
Localion Water Observations
n.b. MacArthur~Village Pkwy Groundwater seepage was not observed while drilling, and the borehole
~ ~ Co[~-mple~on appeared dry at completion.
Depth 5.0' I Date 8_10-04 --
Surface Elevation Type
Auger
~ ~ ~f . ~o .
Stratum Description '~ ~ ~ .~ ~ ~ ~ ._ .
~ PAVSSTO~, 2.5" thick
~ SA~ ]"thick, ~
CONCRETE, 10" thick
. SANDY CLAY, reddish brown 23 13 10 16
~ [oa oF ~omua ~o. B-7 Plate A.11
Prqject No. I Boring No I Pr~iect Paver Evalution MacArthur Boulevard
04-9130 i B-8 Coppell, Texas _
Location Water Observations
s.b. MacArthur~Village Pkwy Groundwater seepage was not observed while drilling, and the borehole
Completion Completion appeared dry at completion.
Depth 5.0' Date 8-10-04
Surface Elevation Type
Auger ~ ~o o .
¢ ~ Stratum Description , , .~
z~ I PAVESTONE, 2.5" thick
~ SAND, 1" thick.
~ } CONCRETE, 95" thick.
~ FILL SANDY CLAY, reddish brown, w/gravel. I 27 12 15 1 I
~oa OF 8ORINO NO. B-8 Plate A.12
ProJect No. Boring No -]'~ject Paver Evalution MacArthur Boulevard __RoneEnqineer]
04-9130 [ 1~-9 ~ Coppell, Texans
ocat~on -- / Water Observations
b. MacArthur~Parkway BIv~ Groundwater seepage was not observed while drilling, and the borehole
;ompletion Completion appeared dry at completion.
'epth 5'0' Date 8-10-04 -- I
i/Surface ElevatiOn T>~e Auger
Stratum Description
/ SA~ 1.5" thick.,
F i~g~5~i~ff~;;~,l br own and br own, 30 40 16 24 23
JOG OF BORING NO. B-9 Plate A.13
-- mvm
. Proiec No. I Boring No ~ Project Paver Evalution MacArthur Boulevard
1~04-9130 i B-10 ~__ ~Texas ~__
. L~Loocation -- Water Observations
Is.b. MacArthnr~Parkway Blvd Groundwater seepage was not observed while drilling, and the borehole
Completion (Completion appeared dry at completion.
Depth 5.0' Date 8-10-04__ __
Auger _ ~ ~ o .
~ Stratum Description ~ ~ ~ e ._ -., .
. CONC~TE, 105" thick.
FILL SA~Y CLAY, ~ay and brown Fi~ to sti~ 3.0 25
FILL SA~Y CLAY, reddish bro~ ~d brown, 2.0 44 14 30 ] 6 I 13
w/gravel. Stiffto ve~ stif~
5
LOG OF BORING NO. B-10
Plate A. 14
Prqject No. Boring No. Prqiect Paver Evalution MacArthur Boulevard
'04-9130 B-II Coppell, Texas
Location Water Observations
n.b MacArthur~Village Pkwy Groundwater seepage was not observed while drilling, and the borehole
Completion ' Completion appeared dry at completion.
Depth 5.0' Date 8-10-04
--~ Surface Elevation Type
~ Auger '~ ~o o ·
~ ~ ~ oo
~ ptlon
~ [ PAVESTONE, 2,5 lhick.
~ SA~. 1" thick.
~1 ~ CONC~TE, 9.5" thick.~
5 S~h~dish br°wn and gray' w/sand 2.0 66 29 37 34 91
1 5 35
LOG OF BORING NO. B-Il Plate A.15
Prqiect No BoringNo I Project Paver Evalution MacArthur Boulevard
04-9130 I D-~t.c ,.~oppen, texas
Location Water Observations
s.b. MacArthur~Village Pkwy Groundwater seepage was not observed while drilling, and the borehole
Completion Completion appeared dry at completion.
Depth 5.0' Date 8-10-04
Surface Elevation Type
I Auger ~-~ o ·
~ Stratum Description
~ / ~ SAND 1" thick.
[ t CONC~TE, 1 l" thick.
5 ~ ~ SHALEY CLAY, tan ~d ~ay, w/s~d seams. Soft 0.75 31
075 57 20 37 24 104 1400
~LOa OF 8OmNa NO. B-12 Plate A.16
Prqject Paver Evalution MacArthur Boulevard
i Project No. [ Boring No
04-9130 ; B-13 Coppell, Texas
~Location ' Water Observations
n.b. MacArthur~Samuel Blvd Groundwater seepage was not observed while drilling, and the borehole
Completion Completion appeared dry at completion.
Depth 5.0' Date 8-10-04
-- i Surface ELevation Type i
I__ ~ =o o .
Auger
~ ~ Stratum,,Description '
~ / CONC~,8 ~Jck
~ ~ i SHALEY CLAY, reddish brown ~d gray, w/s~d 4.5+ 72 28 44 25
'
45+ 23
5
~oa OF ~o~ma ~o. B-13 Plate A. 17
ProJect No. Bonn Project Paver Evalution MacArthur Boulevard
04-9130 ¢:i4 Coppell, Texas
Water Observations
s.b. MacArthur~Samuel Blvd Groundwater seepage was not observed while drilling, and the borehole
Completion Completion appeared dry at completion.
Depth 5.0' I Date 8-10-04
Surface Elevation Type I [
~ Auger "u. ~ '~ o ·
~ ~ ~ Stratum Description o = . ~
~ I ~ SA~ l"~ick.
%~ CONC~, 7.75" thick.
1.0 59 24 35 33
LOG OF BORING NO. B-14 Plate A.18
Grp Typical Names Laboratory Classification Criteria
Major Divisions Sym
~ -~ Well-graded gravels, gravel- ~ De° (D30)2
_ '~> ~--c GW sand mixtures,fines little or no ~ C~= ~)-~-~- greater than 4: = ............. between t and 3
o ._N ~ __~ Poorly graded gravels, gravel
N~' *--~ ~ ~ -=-- GP sand mixtures, little or no ~ u) u~ Not meeting all gradation requirements for GW
'~ v) ~ o~ ~ fines
ce D ~ zo ~~ Silty gravels, gravel-sand-silt ~ ¢ ~ :~ Liquid and Plasticlimits Liquid and plasticlimits
c:, ~_ GM ' '~ : ! ~ below"A" line or P.I.
c4 -- _c mixtures · ~ plotting in hatched zone
d =~.~ z= (~ ~' =b ._ :: i '~ greater than 4
= ~ 0~ ~ between 4 and 7 are
z ~c --~ ~ -~ .:_ o ~ : i ~ borderline cases
-- -- '*- N o : : ~ Liquid and Plastic limits
= z= ~ o o : : o requiring use ofdual
o ~ .~ > ,~ Clayey gravels, gravel-sand- '~
~ d :: :: ~ above "A" line with P.I.
~ h~ o I ~ ~ GC clay mixtures ~ z~ .u symbols
-~ greater than 7
~ E~= i o
$ .~ ~ ~' Well-graded sands, gravelly -.%-
~,~ ~ E = ¢- sands, little or no fines >~ cE D~o Dlo x Dso
~ ~o '~, O ~ SP gravelly sands, little or no ~c ~ '~ ~ Not meeting all gradation requirements for SW
~ ~_ >¢ J~ fines
r.o ~ ~ ~ "E ~ Liquid and Plastic limits
~ "8 ~ ~ ~ SM Silty sands, sand-silt mixtures ~ ~ ~ ~ below"A" line or P.I. less Liquid and plastic limits
~E ~ (~ E ~ oc¢ ~ ~ ~ ~ ~o than4 plotting between 4 and 7
.=: & ¢ ¢~ ~ ~ :-J'- o_~ ~:¢ ~n are borderline cases
._ 0~ ~ ~ requiring use of dual
~ ~ .~ .c_ Liquid and Plastic limits
E~ ~c ~ above "A" line with P.I. symbols
~c r~~ SC Clayey sandS,mixtures sand-clay
"' ~- ~ greater than 7
Inorganic silts and very fine
sands, rock flour, silty or
~' ML clayey fine sands, or clayey
c silts with slight plasticity
~ ~ Inorganic clays of Iow to
~ '~ ~ medium plasticity, gravelly
'~, - CE
o ~ ---- clays, sandy clays, silty clays, /
~ .=-: and lean clays
z 5 o~ ~ ~. CH
/
~0 OL Organic silts and organic silty
-: clays of Iow plasticity
~ ~E Inorganic silts, micaceous or =~
'~ MH diatomaceous fine sandy or ~- : .,~ OH ar d MH
~._ c(~ silty soils, elastic silts
c,
~ Inorganic clays of high /
~ ~ ~ CH
~ ~ c~ plasticity, fat clays
o ~ high plasticity, organic silts
Pe t and other h gh y organic P asticity Cha t
· 'r ~ ~ soils
UNIFIED SOIL CLASSIFICATION SYSTEM PLATE A.1
/
OH ar MH
4*%
c,
SOIL OR ROCK TYPES
GRAVEL LEAN CLAY --
· o ""~SAND SANDY
' i "·ISILT SILTY
: AYEY
C.A¥
LIMESTONE
SHALE
SANDSTONE
TERMS DESCRIBING CONSISTENCY, CONDITION, AND STRUCTURE OF SOIL
Fine Grained Soils (More than 50% Passing No. 200 Sieve)
Descriptive Item Penetrometer Reading, (tsf)
Soft 0.0 to 1.0
Firm 1.0 to 1.5
Stiff 1.5 to 3.0
Very Stiff 3.0 to 4.5
Hard 4.5+
Coarse Grained Soils (More than 50% Retained on No. 200 Sieve)
Penetration Resistance Descriptive Item Relative Density
(blows/foot)
0 to 4 Very Loose 0 to 20%
4 to 10 Loose 20 to 40%
10 to 30 Medium Dense 40 to 70%
30 to 50 Dense 70 to 90%
Over 50 Very Dense 90 to 100%
Soil Structure
Calcareous
Slickensided
Laminated
Fissured
Interbedded
Contains appreciable deposits of calcium carbonate; generally nodular
Having inclined planes of weakness that are slick and glossy in appearance
Composed of thin layers of varying color or texture
Containing cracks, sometimes filled with fine sand or silt
Composed of alternate layers of different soil types, usually in approximately equal proportions
TERMS DESCRIBING PHYSICAL PROPERTIES OF ROCK
Hardness and Degree of Cementation
Very Soft or Plastic
Soft
Moderately Hard
Hard
Very Hard
Poorly Cemented or Friable
Cemented
Degree of Weathering
Unweathered
Slightly Weathered
Weathered
Extremely Weathered
Can be remolded in hand; corresponds in consistency up to very stiff in soils
Can be scratched with fingernail
Can be scratched easily with knife; cannot be scratched with fingernail
Difficult to scratch with knife
Cannot be scratched with knife
Easily crumbled
Bound together by chemically precipitated material; Quartz, calcite, dolomite, siderite,
and iron oxide are common cementin~ materials.
Rock in its natural state before being exposed to atmospheric agents
Noted predominantly by color change with no disintegrated zones
Complete color change with zones of slightly decomposed rock
Complete color change with consistency, texture, and general appearance approaching soil
KEY TO CLASSIFICATION AND SYMBOLS PLATE A.2O