Post on 18-Feb-2021
GEOTECHNICAL INVESTIGATION KAWAINUI MARSH RESTORATION OF ENDANGERED HABITATS & WETLANDS LEVEE AREA ACCESS ROAD OAHU, HAWAII DLNR JOB NO. D00CO44A
for
AECOM HIRATA & ASSOCIATES, INC. W.O. 19-6201 October 30, 2019
Hirata & Associates, Inc. W.O. 19-6201
TABLE OF CONTENTS
INTRODUCTION .....................................................................................................1
PROJECT CONSIDERATIONS ...............................................................................2 SITE CONDITIONS ..................................................................................................2 SOIL CONDITIONS .................................................................................................2 CONCLUSIONS AND RECOMMENDATIONS ....................................................3 Pavement Design ...........................................................................................3 Site Grading ...................................................................................................3 ADDITIONAL SERVICES .......................................................................................4 LIMITATIONS ..........................................................................................................5
Hirata & Associates, Inc. W.O. 19-6201
APPENDICES APPENDIX A Description of Field Investigation ................................................ Plates A1.1 and A1.2 Location Map ................................................................................ Plate A2.1 Boring Location Plan .................................................................... Plate A2.2 Boring Log Legend ....................................................................... Plate A3.1 Unified Soil Classification System ............................................... Plate A3.2 Boring Logs .................................................................................. Plates A4.1 through A4.3 APPENDIX B Description of Laboratory Testing ................................................ Plates B1.1 Modified Proctor Test Report ....................................................... Plate B2.1 CBR Stress Penetration Test Report ............................................. Plate B3.1
October 30, 2019 W.O. 19-6201
Hirata & Associates, Inc. Page 1
GEOTECHNICAL INVESTIGATION KAWAINUI MARSH RESTORATION OF
ENDANGERED HABITATS & WETLANDS LEVEE AREA ACCESS ROAD
OAHU, HAWAII DLNR JOB NO. D00CO44A
INTRODUCTION This report presents the results of our geotechnical investigation performed for the
proposed improvements to the levee area access road on the south side of
Kawainui Marsh. Our scope of services for this study included the following:
• A visual reconnaissance of the site and its vicinity to observe existing conditions which may affect the project. The general location of the project site is shown on the enclosed Location Map, Plate A2.1.
• A review of available in-house soils information pertinent to the site and
the proposed project. • Drilling and sampling three exploratory borings to depths ranging from
about 5.8 to 6.5 feet. A description of our field investigation is summarized on Plates A1.1 and A1.2. The approximate exploratory boring locations are shown on the enclosed Boring Location Plan, Plate A2.2, and the soils encountered in the borings are described on the Boring Logs, Plates A4.1 through A4.3.
• Laboratory testing of selected soil samples. Testing procedures are
presented in the Description of Laboratory Testing, Plates B1.1 and B1.2. Test results are presented in the Description of Laboratory Testing, and on the Boring Logs (Plates A4.1 through A4.3), Modified Proctor Test report (Plate B2.1), and CBR Stress Penetration Test (Plate B3.1).
• Engineering analyses of the field and laboratory data. • Preparation of this report presenting geotechnical recommendations for the
design of flexible pavement and site grading.
October 30, 2019 W.O. 19-6201
Hirata & Associates, Inc. Page 2 PROJECT CONSIDERATIONS
Information regarding the proposed project was provided by your office.
The project will generally consist of improvements to the south end of the levee
from Kailua Road along the maintenance access road for a length of about 350
lineal feet. Improvements will include the construction of a flexible pavement
surface.
SITE CONDITIONS The south end of the Kawainui Marsh maintenance access road slopes from
Kailua Road from an elevation of about 27 down to elevations of about 13 to 15.
The existing surface of the access road is covered by a layer of sandy gravel.
Moderate to heavy growth of vegetation borders the access road on both sides.
SOIL CONDITIONS Borings B1 and B3 encountered fill consisting of brown sandy and silty gravel in
a loose to medium dense condition. The fill extended to depths of about 3.5 feet.
Underlying the sandy and silty gravel was mottled brown clayey gravel in boring
B1 and mottled brown silty clay in boring B3. Boring B2 encountered mottled
brown silty clay in a medium stiff condition from the surface to the maximum
depth drilled.
Groundwater was encountered in Boring B3 at a depth of 4 feet.
October 30, 2019 W.O. 19-6201
Hirata & Associates, Inc. Page 3 CONCLUSIONS AND RECOMMENDATIONS
Based on the results of our exploratory borings and laboratory testing, the site is
feasible for proposed improvements to the maintenance access road at the Kailua
end of the Kawainui Marsh project.
Pavement Design The following section may be used in the design of flexible pavements.
2.0" Asphalt Concrete 6.0" Base Course (CBR = 85 minimum) 8.0" Total Thickness
Site Grading Site Preparation - The project site should be cleared of all vegetation and other
deleterious material. In areas requiring fill placement, the exposed subgrade
should be scarified to a minimum depth of 6 inches, moisture conditioned to about
2 percent above the optimum moisture content, and compacted to a minimum 95
percent compaction as determined by ASTM D 1557.
Temporary cuts into the onsite soils should be stable at gradients from 1H:1V or
flatter. However, it should be the Contractor's responsibility to conform to all
OSHA safety standards for excavations.
Onsite Fill Material - The onsite soils may be reused in compacted fills and
backfills, provided all rock fragments larger than 3 inches in maximum dimension
are removed.
Imported Fill Material - Imported structural fill should be well-graded, non-
expansive granular material. Specifications for imported granular structural fill
should indicate a maximum particle size of 3 inches, and state that between 8 and
20 percent of soil by weight shall pass the #200 sieve. In addition, the plasticity
index (P.I.) of that portion of the soil passing the #40 sieve shall not be greater
October 30, 2019 W.O. 19-6201
Hirata & Associates, Inc. Page 4
than 10. Imported structural fill should have a CBR expansion value no greater
than 1.0 percent and a minimum CBR value of 15 percent, when tested in
accordance with ASTM D 1883.
Compaction - Imported structural fill and onsite soils should be placed in
horizontal lifts restricted to eight inches in loose thickness and compacted to a
minimum 95 percent compaction as determined by ASTM D 1557.
Fill placed in areas which slope steeper than 5H:1V should be continually
benched as the fill is brought up in lifts.
ADDITIONAL SERVICES We recommend that we perform a general review of the final design plans and
specifications. This will allow us to verify that the design recommendations have
been properly interpreted and implemented in the design plans and construction
specifications.
For continuity, we recommend that we be retained during construction to (1)
review and/or perform laboratory testing on import borrow to determine its
acceptability for use in compacted fills, (2) observe structural fill placement and
perform compaction testing, and (3) provide geotechnical consultation as
required.
Our services during construction will allow us to verify that our recommendations
are properly interpreted and included in construction, and if necessary, to make
modifications to those recommendations, thereby reducing construction delays in
the event subsurface conditions differ from those anticipated
October 30, 2019 W.O. 19-6201
Hirata & Associates, Inc. Page 5 LIMITATIONS
The boring logs indicate the approximate subsurface soil conditions encountered
only at those times and locations where our borings were made, and may not
represent conditions at other times and locations.
This report was prepared specifically for AECOM and their sub-consultants for
design of the proposed improvements to the maintenance access road at the south
end of the Kawainui Marsh project. The boring logs, laboratory test results, and
recommendations presented in this report are for design purposes only, and are
not intended for use in developing cost estimates by the contractor.
During construction, should subsurface conditions differ from those encountered
in our borings, we should be advised immediately in order to re-evaluate our
recommendations, and to revise or verify them in writing before proceeding with
construction.
Our recommendations and conclusions are based upon the site materials observed,
the preliminary design information made available, the data obtained from our site
exploration, our engineering analyses, and our experience and engineering
judgment. The conclusions and recommendations in this report are professional
opinions which we have strived to develop in a manner consistent with that level
of care, skill, and competence ordinarily exercised by members of the profession
in good standing, currently practicing under similar conditions in the same
locality.
APPENDIX A
FIELD INVESTIGATION
October 30, 2019 W.O. 19-6201
Hirata & Associates, Inc. Plate A1.1
DESCRIPTION OF FIELD INVESTIGATION GENERAL
The site was explored on September 24, 2019, by performing a visual
reconnaissance of the site and drilling three exploratory borings to depths ranging
from about 5.8 to 6.5 feet with a Mobile B80 truck-mounted drill rig.
During drilling operations, the soils were continuously logged by our field
engineer and classified by visual examination in accordance with the Unified Soil
Classification System. The boring logs indicate the depths at which the soils or
their characteristics change, although the change could actually be gradual. If the
change occurred between sample locations, the depth was interpreted based on
field observations. Classifications and sampling intervals are shown on the boring
logs. A Boring Log Legend is presented on Plate A3.1, while the Unified Soil
Classification System is shown on Plate A3.2. The soils encountered are logged
on Plates A4.1 through A4.3.
The borings were located in the field by measuring/taping offsets from existing
site features shown on the plans. Surface elevations at boring locations B1 and
B2 were estimated based on the Topographic Survey Map provided by AECOM.
However the surface elevation for boring B3 was estimated using Google Earth.
The accuracy of the boring locations shown on Plate A2.2 and the boring
elevations shown on Plates A4.1 through A4.3 are therefore approximate, in
accordance with the field methods used.
SOIL SAMPLING Representative soil samples were recovered from the borings for selected
laboratory testing and analyses. Representative samples were recovered by
driving a 3-inch O.D. split tube sampler a total of 18 inches with a 140-pound
hammer dropped from a height of 30 inches. The number of blows required to
drive the samplers the final 12 inches are recorded at the appropriate depths on the
October 30, 2019 W.O. 19-6201
Hirata & Associates, Inc. Plate A1.2
boring logs, unless noted otherwise. A bulk soil sample was recovered from
boring B3 at a depth of about 0.5 to 3 feet below grade.
Reference: Bryan's Sectional Maps, 2008 Edition(Copyright J.R. Clere, used with permission)
PlateA2.1
Kawainui Marsh Restoration - Levee Access Road
W.O. 18-6201
Geotechnical Engineering
HIRATA & ASSOCIATES, INC.
LOCATION MAP
AutoCAD SHX TextPROJECT SITE
1" = 40'
GRAPHIC SCALE:
Approximate location of borings
LEGEND:
200 FT.8040
W.O. 18-6201
Kawainui Marsh Restoration - Levee Acess Road
BORING LOCATION PLAN A2.2
HIRATA & ASSOCIATES, INC.
Geotechnical EngineeringPlate
Kawainui Marsh Restoration - Levee Access Road
W.O. 18-6201
Inorganic silts, micaceous or diatomaceous finesandy or silty soils, elastic silts.
Peat and other highly organic silts.
MAJOR DIVISIONS
GM
CORAL
Poorly graded gravels or gravel-sand mixtures, littleor no fines.
Silty gravels, gravel-sand-silt mixtures.
Clayey gravels, gravel-sand-clay mixtures.
MH
CH
HIGHLY ORGANIC SOILS
FORMATIONS
Inorganic clays of high plasticity, lean clays.
Core Sample
OH
FRESH TO MODERATELY WEATHERED BASALT
Well graded gravels, gravel-sand mixtures, little orno fines.
Inorganic clays of high plasticity, fat clays.
COARSEGRAINED
SOILS(More than50% of thematerial is
LARGER thanNo. 200
sieve size.)
FINEGRAINED
SOILS(More than50% of thematerial is
SMALLER thanNo. 200
sieve size.)
SANDS(More than
50% ofcoarse
fraction isSMALLERthan the
No. 4sieve size.)
GRAVELS(More than
50% ofcoarse
fraction isLARGER than
the No. 4sieve size.)
CLEANGRAVELS(Little or no
fines.)
CLEANSANDS
(Little or nofines.)
SANDSWITH FINES(Appreciableamt. of fines.)
SILTS AND CLAYS(Liquid limit LESS than 50.)
SILTS AND CLAYS(Liquid limit GREATER
than 50.)
GW
GP
VOLCANIC TUFF / HIGHLY TO COMPLETELYWEATHERED BASALT
Well graded sands, gravelly sands, little or no fines.
Poorly graded sands or gravelly sands, little or nofines.
Silty sands, sand-silt mixtures.
Clayey sands, sand-clay mixtures.
TYPICAL NAMESGROUPDIVISIONS
PT
GC
SW
SP
SM
SC
ML
CL
OL
SAMPLE DEFINITION
PlateBORING LOG LEGEND
GRAVELSWITH FINES(Appreciableamt. of fines.)
3" O.D. Split Tube Sampler
2" O.D. Standard Split Spoon Sampler RQD: Rock Quality DesignationShelby Tube
Organic silts and organic silty clays of low plasticity.
Organic clays of medium to high plasticity, organicsilts.
Water Table
Inorganic silts and very fine sands, rock flour, silty orclayey fine sands or clayey silts with slight plasticity.
A3.1Geotechnical Engineering
HIRATA & ASSOCIATES, INC.
Kawainui Marsh Restoration - Levee Access Road
W.O. 18-6201
0 20 40 60 80 100
ML or OL
CH
MH or OHA-Li
neCL
PLA
ST
ICIT
Y IN
DE
X
COMPONENT DEFINITIONS BY GRADATION
SIZE RANGE
0
10
20
30
40
50
60
COMPONENT
Above 12 in.
3 in. to 12 in.
3 in. to No. 4 (4.76 mm)3 in. to 3/4 in.3/4 in. to No. 4 (4.76 mm)
No. 4 (4.76 mm) to No. 200 (0.074mm)No. 4 (4.76 mm) to No. 10 (2.0 mm)No. 10 (2.0 mm) to No. 40 (0.42 mm)No. 40 (0.42 mm) to No. 200 (0.074 mm)
Smaller than No. 200 (0.074 mm)
Boulders
Cobbles
Gravel Coarse Fine Gravel
Sand Coarse Sand Medium Sand Fine Sand
Silt and Clay
GRADATION CHART
PLASTICITY CHART
ML-CL
LIQUID LIMIT
PlateUNIFIED SOIL CLASSIFICATION SYSTEM A3.2Geotechnical Engineering
HIRATA & ASSOCIATES, INC.
42
18/6"
45/9"
106
83
94
13
17
26
FILL - Sandy GRAVEL (GM) - Brown, moist, mediumdense, clayey
Clayey GRAVEL (MH) - Mottled brown, moist, mediumdense to dense
End boring at 5.8 feet.
Neither groundwater nor seepage water encountered.
27.5 ±R
QD
(%
)
BLO
WS
PE
R F
OO
T
DRIVING WT.
DE
PT
H(f
t)
DROP 9/24/19
GEOTECHNICAL ENGINEERING
9/24/19
PROJECT NAME Kawainui Marsh Restoration - Levee Access Road
B1
END DATE
START DATE
SURFACE ELEV.
WORK ORDER NO. 18-6201
DR
Y D
EN
SIT
Y(p
cf)
MO
IST
UR
EC
ON
TE
NT
(%
)
BORING LOG
Boring No.
30 in.
CO
RE
RE
CO
VE
RY
(%
)
SA
MP
LE
140 lb.
GR
AP
HIC
LOG
RE
MA
RK
S/
SA
MP
LE N
O.
HIRATA & ASSOCIATES, INC.
Plate A4.1
MATERIAL DESCRIPTION
5
10
15
20
25
30
35
23
20
20
90
83
79
31
36
38
Silty CLAY (MH) - Mottled brown, moist, medium stiffto stiff, sandy
End boring at 6.5 feet.
Neither groundwater nor seepage water encountered.
13.5 ±R
QD
(%
)
BLO
WS
PE
R F
OO
T
DRIVING WT.
DE
PT
H(f
t)
DROP 9/24/19
GEOTECHNICAL ENGINEERING
9/24/19
PROJECT NAME Kawainui Marsh Restoration - Levee Access Road
B2
END DATE
START DATE
SURFACE ELEV.
WORK ORDER NO. 18-6201
DR
Y D
EN
SIT
Y(p
cf)
MO
IST
UR
EC
ON
TE
NT
(%
)
BORING LOG
Boring No.
30 in.
CO
RE
RE
CO
VE
RY
(%
)
SA
MP
LE
140 lb.
GR
AP
HIC
LOG
RE
MA
RK
S/
SA
MP
LE N
O.
HIRATA & ASSOCIATES, INC.
Plate A4.2
MATERIAL DESCRIPTION
5
10
15
20
25
30
35
86
17
9
120
10692
94
4
823
30
FILL - Silty GRAVEL (GM) - Brown, loose to mediumdense, clayey
Silty CLAY (CL) - Mottled brown, moist, firm, sandy
End boring at 6.5 feet.
Groundwater was encountered at 4 feet.
*Elevations taken from Google Earth.
15.0*R
QD
(%
)
BLO
WS
PE
R F
OO
T
DRIVING WT.
DE
PT
H(f
t)
DROP 9/24/19
GEOTECHNICAL ENGINEERING
9/24/19
PROJECT NAME Kawainui Marsh Restoration - Levee Access Road
B3
END DATE
START DATE
SURFACE ELEV.
WORK ORDER NO. 18-6201
DR
Y D
EN
SIT
Y(p
cf)
MO
IST
UR
EC
ON
TE
NT
(%
)
BORING LOG
Boring No.
30 in.
CO
RE
RE
CO
VE
RY
(%
)
SA
MP
LE
140 lb.
GR
AP
HIC
LOG
RE
MA
RK
S/
SA
MP
LE N
O.
HIRATA & ASSOCIATES, INC.
Plate A4.3
MATERIAL DESCRIPTION
5
10
15
20
25
30
35
APPENDIX B
LABORATORY TESTING
October 30, 2019 W.O. 19-2601
Hirata & Associates, Inc. Plate B1.1
DESCRIPTION OF LABORATORY TESTING CLASSIFICATION
Field classification was verified in the laboratory in accordance with the Unified
Soil Classification System. Laboratory classification was determined by visual
examination. The final classifications are shown at the appropriate locations on
the Boring Logs, Plates A4.1 through A4.3.
MOISTURE-DENSITY Representative samples were tested for field moisture content and dry unit weight.
The dry unit weight was determined in pounds per cubic foot while the moisture
content was determined as a percentage of dry weight. Representative samples
were obtained using a 3-inch O.D. split tube sampler. Test results are shown at
the appropriate depths on the Boring Logs, Plates A4.1 through A4.3.
PROCTOR TEST
A Modified Proctor test was performed in general accordance with ASTM D 1557
on a bulk soil sample obtained from boring B3 between depths of 0.5 and 3 feet
below grade. The test is used to determine the optimum moisture content at
which the soil compacts to 100 percent dry density. Results are shown on Plate
B2.1.
CALIFORNIA BEARING RATIO TESTS A CBR test was performed in general accordance with ASTM D 1883 on a bulk
sample obtained from boring B3 at depths between 0.5 and 3 feet below grade.
The test is used to evaluate the relative quality of subgrade soils to be used in the
design of flexible pavements. Results are shown on Plate B3.1.
100
110
120
130
10 20 30 40
Dry
Uni
t Wei
ght (
PC
F)
Description:Location:Soil Data
Test Results
%
Brown silty gravel with clayey sand
PlateB2.1
ASTM D1557
Moisture Content (%)
Optimum Moisture Content:Maximum Dry Density: 114.0
18.5
Boring B3 from 0.5 to 3 feet
PCF
MODIFIED PROCTOR TEST
Kawainui Marsh Restoration - Levee Access Road
W.O. 18-6201
Geotechnical Engineering
HIRATA & ASSOCIATES, INC.
0
100
200
300
400
500
600
700
800
900
0 0.10 0.20 0.30 0.40 0.50
Penetration (in)
ASTM D1883
Pen
etra
tion
Res
ista
nce
(psi
)
Soil Data
Test ResultsCBR Value:Expansion:
Location:Description:Sample Dry DensitySample Moisture Content
Boring B3 from 0.5 to 3 feetBrown silty gravel with clayey sand
PlateB3.1
43.8 % 1.0 %
16.4 % 113.1 pcf
CBR STRESS PENETRATION TEST
Kawainui Marsh Restoration - Levee Access Road
W.O. 18-6201
Geotechnical Engineering
HIRATA & ASSOCIATES, INC.
JHY:EKHHirata & Associates, Inc. W.O. 19-6201Hirata & Associates, Inc. W.O. 19-6201GEOTECHNICAL INVESTIGATIONKAWAINUI MARSH RESTORATION OFENDANGERED HABITATS & WETLANDSLEVEE AREA ACCESS ROADOAHU, HAWAIIDLNR JOB NO. D00CO44A