: .. -~ ... , :/ .. J,': ., .·

4_z.g

. ,: '· ··-, .

. ··'

..... :: 'F6R -REfERENCE .. . ~t to :he taken f~m this room

. ·.\'

.. ·., ,,'I • •

' . . ' - ~·

SOILS AND ~'OUNDATION INVESTIGATION

PEARL CI'I'Y APARTMENT COMPLEX • . .

.. WAIAWA, EWA, OAHU, HAWAII

:.".'

for · -~

·.·.'··.

DESIGN ENGINEERING, INC!' · T; M · k . - 9- 7 -';;'f.' ~6

~ ( C;b G-<Y'd~ T!Y1.K. . q -1--24:····2 ~

a.P.# --51G5.

/~

i

...

I•

·, ..

. '

. •

\, ' Sept;::,.nber 14, 1971

~olmty of Honolulu City i..;... . tne_x. s~.ts S.King Sti'QSt

Hon:;;iulu. H:'l.W?.ii Q0013

',

.··. >- .....

.....

·''...) ' ..

.· ..

. .. ~ . ·r·. ·,

. . . . -.-.------~ERN....,..·~· ...,..E_ST_K..,....~H;,.;,.i-.,.R_A_T_A_&_A_S_S_O_C_IA_T_ES_I_N_c_. -----Soils and Foun4ation Engineering

.' . . . 1157 South King Street • Honolulu, Hawaii 96814 • Phone 533-6529

.... : ,· .. ·: ..

' . -; ... • .; . ·. , .. • ~. J . • •(

September 14,· 1971 ' 'w.o. 121 '

Design Engineering, Inc. 747 Amana Street Honolulu, Hawaii 96814

:'/_:.

· ...

Attention: Mr. Hiromichi Asaoka

. ,!' :•.'· .... .. ' ' ~I ~

.... ·.

·. ·, .: '~ . . ... : ! ·: . 1'· 'i. >' • . . ' ~ ' ' . '•,, ! ' ~

,• .. 1'' -:.,

Subject: Soils and Foundation Investigation Pearl City Apartment Complex · · .:. . · ·':·. Waiawa, Ewa, Oahu, Hawaii

Gentlemen:

. ' . . . ' ···:·

The. following report titled "Soils and FoUndation Investigation, Pearl City Apartment Complex, Waiawa, Ewa, Oahu, Hawaii", dated

,September 14, 1971 our work order 121 is enclosed.

This investigation was authorized to determine the subsurface soil conditions at the site and to determine if any unusual .or adverse condition might exist which would affect the proposed development.

We found that the surface soils over the entire site consisted of a red to reddish brown clayey silt underlain by decomposed lava rock. The stratum of clayey silt was found to be deepest in the area just south of Acacia Road. Decomposed lava rock was encountered at the surface or just a few feet below along the ridge on the western portion of the site.

The site is feasible for the proposed development provided . the recommendations in this report are followed.

We appreciate this opportunity to. be of service ... . . ; ..,_,

Very truly yours, . '::.'

Ernest K. Hirata & Associates Inc. ..

' '.

':: 'i

Ernest K. Hirata

' )

TABLE. OF CONTENTS

INTRODUCTION .. •.• ..••...........•..... · ..... •.• .. ·.·

SITE DESCRIPTION ...•...............•.••......•. .. : .. \;,

PROPOSED GRADI·NG ••••••• o o o ••••.•••• · ••••••• • •••

FIELD EXPLORATION .. ·• .... ~ ........• ,• ......... . f·,! LABORATORY TESTS • • 0 • 0 • • • ~ • • • • • • • • 0 • • • • • • • • • • •

ENGINEERING ANALYSES ,' ...

I. Mass slope Stability •••••••••••••• '("'.

,· '' . ... ··:'

II • · Surficial Slope Stability • ;· •••••••. '' ,: ···1·:

. ~·· '.F.< ' .

Page 1

1.

2

3

5

6 .. ·

7

· ·/·;·'· III· •. ··. Groundwater ••• • •••••• •............. 7 . ' ~ ., ..

r) IV. Bearin9 Capacity •••••••••••••••••• ':::·,, .·· . ;· :::: ..

8

·.;

. ····"

;.·:-

,,,' ,·

' .. ·.

. ;.

·,,

~ ,!, .

. ~· . 1 I l , •

. '.· ·~ :;;··: .. :!:.

.. ·.: - ... '. '

. :<.

• ,< \

. .', ~.

v. Lateral Pressures •••••••••••• ,•. '!" • •. · 8

VI. Settlement of Fills'& ·Foundations • .- :,:

9

VII. Expansive Soil • • • • • • • • • • • • • • • • • • • • 9 . :(

VIII. Grading •••••••.•••••••••••••••••••• 9

CONCLUSIONS AND RECOMMENDATIONS ....... ··~ ~ .... 11 •

'• ··:., I;, APPENDICES

Appendix of Laboratory Testing • • • • • • • • • • • 1 through 4

Standard Grading Specifications ···•··~··· 1 through 6

PL~TES

••• Log of Borings ••••••••••••••••••••. Plates Al through A23

Direct Shear Tests • • • • • • • • • • • • • • '0 • . Plates Bl through B6

? .

-· ···r. ,1.

·i~ .. '• .

~ ., '

·, •'

'-.(··· .. ~ '.: :: ~· ,.

·•·,

,·:.·'

·~; . : ;"i. 1 ,',I

TABLE OF CONTENTS . ~ .

Consolidation Pressure Curves • 0 ••••• \ Plates Cl.through cs

Maximum Density Curves •••••••••••••• Plates Dl through D4

., · Laboratory Test Results •••••••••.•• •. Plates El through E3

Stability Calculations •••••••••••••• Plates Sl and s2;

Site Plan·

'•t ,• ',1 <· '·-;~1'·.·

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::: ···.\···· .... · t·

•.' SOILS 1\ND . FOUNDATION' t:i~l'VESTIGATION . ', .. ' :.:.~··

. :•.·

....

. ~~ .. - ··. >:·•',.

'- . . ;!".I 0

... : ·> PEARL CITY APARTMENT COMPLEX ': t'\ :• .

, ... ': ',' 1'

·'·i·,. .. . . . .

·, .

'(', . .. -~· . ::'_ · _ WAIAWA, EWA, OAHU, HAWAII . .:····

. ',· .

., .-.

··'·' .

. . . . ~. . . ;

INTRODUCTION · .....

' ~ i 'l· .• . . .. ·:·, . ~ ',• ·-:·;: The following report presents the results of a soils and . ··;

foundation investigation conducted on the subject property. . .'.~ ...

. -

A prelimi_pary site-plan showing the area covered by this

'• ., .~. ,. ; investigation and the approximate location of buildings is

enclosed in the Appendix. This investigation w_as authorized

to determine the subsurface soil conditions at the site and

---- to provide recommendations for .the proposed development.

•, .

SITE DESCRIPTION

The subject area is located north of Kamehameha liighway near

the junction of the Wahiawa and Waipahu turnoff. The northern

boundary is bordered by Acacia ~oad while portions of the '

southern boundary is bordered by Kamehameha Highway. The

·western boundary extends to the. top of a ridgeline with portions

of a naval housing area bordering the northwest corner. _The

eastern boundary is delineated by a drainage area extending

south to Kamehameha Highway. -' '.f : . .~ . .

.. ~. ,;. :· ·, .

'•\•' _: ,!:: ..•.

' ..

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··:;

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Page 2 w.o. 121

Topographically, the subject area consists of a ridge on the ·;~:J', :· , < :·· ,., · : western portions and a level plateau area along the northern

.. ; ,:\ .

I '•t .. portion along Acacia Road. A cut slope of approximately . ' ...

. .. . .. :~ .' . M\ ~ .... ~- •' ,'•

.:·: .. ·_.- · SO feet in height is exposed along Kameharneha Highway adjacent .· .....

··to the site composed of decomposed: lava rock ana some dike

..... '' •.;

,I .•: •,

: >

intrusions. The total area of the project encompasses approx-

• · ::·., mately 9.;6 acres. ·;· : .

J;' .. · · ...

e e·

·i.

The total relief for the subject site is approximately 56

feet. The slope of the existing ground surface along the .

ridge is approximately 15 percent. There is amoderate

growth .. of hale koa trees and brush over the entire site.

Several abandoned manholes were founc:l along the southwest

portion extending up to the top of the ridge. Surface water

was observed in the drainage way along the east boundary.

However, no groundwate:r was encountered in, any of , the. bor.ings • . ~ . . .. '; ' .... : ·> .. . ..

_, .

PROPOSED GRADING

The proposed development will consist of 16 apartment buildings·

ranging between three :.to four stories in. }leight~ .. · Grading ..

; .. :

. · ...

' '· ;· .. · ... · . ,, ''·

' . . .. '; :.: ~ .

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Page 3 w.o. 121

·": techniques of cutting and filling will be utilized to develop . · I :.

level pad areas and proper drainage. Final grading plans ...... ·::-

t ... . ' ... ,, :: . ..:~ have not been completed, however we understand that fill

. :~ ' . · .. ,•

.. ·slopes are planned at slope gradients of lJ:i:l and 2:1. The

,· , .. ·, .

~-

.... ,''

· ....

••

maximum height of fill slope ;is not expected to exceed 10 i· ..

feet vertically. Cut slopes are planned at slope·gradients

of 1:1 and lJ:i:l. The 'maximum height of cut. s.lope is not .

· ,. expected .to exceed 20 :feet vertically. ' . . . . ~

.;,_ . ~ i,.

; ' ; . .- ..

,·1'

FIELD EXPLORAT.ION

Field ~xploration was performed between August 16 through the

. 23rd, 1971 using a truck mounted, rotary auger drill rig •

In add~tion, visual examination of the existing cut slope

was made to correlate with the boring data.

A TD 24 Dozer and a front end loader were ,used to clear paths

. through the hale koa tre'es for the drill rig. Clearing oper-

ations exposed decomposed rock along the ridge on.the western . . ·. ·:·-.

portion of the site. ·' ...

\, .··

. ,. A total o.f 23 exploratory bo:r;ings were (lrilled ranging ill ,I • •

:·I ' • .:• I' ,

'I .--: .

... i··

. ·' i.

i

I ' t

·. ···.•·

... !.

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·'' ·.

,.:::: , ......

···. '· : ~- : .. :.: :

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.. · '•

.······

·,,·_ ...

' ., .

,•·.

Page 4 w.o. 121

. • ~ .• r .

depth from 3.5 to 20 feet • The soils were continuously logged . , ... ,.· ..

in accordance with the Unified Soil Class.ification System.

·~· :.:\. Undisturbed and bag samples were recovered from the borings ·

· ·. · ·, · for laboratory testing. Undisturbed samples were obtained

. -'· . by driving a thin-walled steel sampler with a 140 pound

. ·.f· hammer from a height of 30 inches. The required blow count ""'.

..... . •. • )! .

., ... ' '

for. each 6 inches of penetration is shown on the enclosed

Boring Logs. ·.: ... .:· . . '·

The surface soils consisted of a red to reddish brown clayey

silt.over the entire site. Penetration blow counts taken of

the,red cJ,.ayey.silt indicated that the material is in a stiff

to hard· condition. Underlying the clayey silt was a hard

decomposed lava rock. Depth to the decomposed rock varied

between borings, however borings 18, 19, 20, 22, and 23

indicated that the decomposed rock was only a few·feet below

the exi.sting ground surf,~~e along the. ~~de of,,the ridge • . ;

.. ,·. =· . . . . . . ';\ ....

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··.)'

LABORATORY TESTS

Page w.o.

5 121

Laboratory testing was performed on the undisturbed ·iind

bag samples. Laboratory tests included Atterburg Limits,

moisture-density relationships, shears, co.nsolidations,

compactions, swells, unconfine compression, remolded swells,

shear~, and consolidation tests. Test results and sampling

procedures are describecl. in the attached Appendix •.

... ·.·

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... ••' ·} .·

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.•\' ENGINEERING ANALYSES

. I •. ·· Mass Slope Stability

.!. ·: Page 6. w.o. 121

' __ ; ....... ' . ~.. . .

. ;. . ,. ' ... :.~ , .. ' '

•' . .,, ., . ·.I·,' •

... •' ,_;

' .'1'

A. · Fill Slopes: Laboratory test results on the remolded J •• ••

.. ··: J':· .• ·:· ·,·

' ..,

,, •. ,<' _: .. : .... : : .:.', ~'

'.· ... samples indicate that when the onsite soils are remolded ; ,. . , . . .

:-···· ., . · .. _.····;·.,

'·: .. :-.. their strength characteristics are very nearly equal . ~. .... ·.. . . .·

'!!- ;. ' '·). : ~: · .. ~ ·- ·' ... ,·,'

. I,:' to their undisturbed strengths. --~ • 1

Since the maximum

' ,.':

.....

... · feet vertically, slope gradients of 1~: 1 (horizontal · .'.: . . • 1 .

•' > :; , .. ·~· to vertical) may be used.

'·· ... , ,•. ·,

' :.,. . .• ~- ' ' ,.- .·.·. B. . Cut Slopes: Stability calculations were made for

.. -~

. ' 't

a 1:1 1 20 feet high CUt Slope COnSidering a rota~ ·. /

·.·: tional failure (see Plates Sl and S2). The results

'·. of these calculations indicate a safety factor in ' •:, ,.

excess of· 1.5 under the worst anticipated conditions.

W~ therefore recommend that cut•slopes along the ridge

may be cut· at slope gradients not to exceed 1:1 •

·.,. . However for cut slopes along the plateau area just

·. below Acacia Road, we recommend slope gradients not

e· _, .. to exceed 1~:1. The soils along the plateau area

are more susceptible to weathering as compared to the

decomposed rock comprising the ridge area.

' .. , ' •, .. • ;.•• ·. I >' ~,

·:. I . ,.·

. ' : ··~~

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'• •'I ' . · .... .. ~ ... ·Page 7 .:. ".',·

. '. ·.:: .... ·: .

I'"·: •I·'

·• ,,.-·.

'· '\. . . ... :: :·:.; :·· II.~ . Surficial Slope Stability

.... . w.o. 121 . . , .' ·· .. ,. , ... ' ... '

'.

' ·, '

'!,•',' ' A. Fill Slopes: A major factor contributing to surficial

'· .... ·, instability of compacted fill slopes is weathering of ··.·.·

··': .. ·~· .. ·~· .. ' {~: ~~!·<·. . . . ' '

'··. :· .·· . ·'

_·, I ,, ~··'\ ':;,, ~ • ; •;' ';, ' ',

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.. :.· .: :::;··· . :. ·.:'

... · ' . :·. ' '•' . ·.;

.:B •

of the slope face caused by alternate cycles of

wetting and drying. Planting, combined with careful

watering procedures, can be beneficial in retarding

weathering due to seasonal moisture variations. In

addition, if practical we recommend that fill slopes

be overbuilt and t~immed back to the. horizontally ... · .,>

compacted core.

Cut Slopes: Cu.t slopes also encounter surficial

instability due to weathering although not as

.rapidly as in fill slopes. Plan.ting of cut· slopes

is also recommended as soon as practical after

grading has :Peen completed • . :'t

·,

~ ., .

: :<·

.. ··:-.·.· .. ,·,. I ·.

. : .·

·. ·t ,,

III. Groundwater

Groundwater was not.encountered in any of the exploratory

borings and. the. need for.subdrains. is not .anticipated •

•• · ... ···:. · ... ': .... , .. ........ :,., ,·

i·.

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Page 8 w.o. 121

' ' ' I ' •

'•. ;, )

':.·_:_IV. Bearing Capacity

• I• : ' ~ ·, ' •

..... .;, . : '' ...... _;_ ..

·. -,.;

,'.

. ·"::·" .7.'

·-· . ,. . . ~. .\ '·,

Afi allowable bearing pressure of 3000 PSF may be used

for footings having a minimum width of 12 inches and a

minimum embedment of 24 inches in fill. (

. ',./ · .. ; ........ ·'. ,'·'· ...

. ~ ..

.· · .. · .. ·. •\' .... / . ' ' \

'­' .···

. ··, ·~. :.- . · ... ·

,, ,·, '

...... ',:• . ·.·.·

' ·~:•• ; I :

An allowable bearing pressure of 4000 PSF may be used

·:., . ;.: ~ '

for footings having a minimum width of 12. inches and a .· . .. ·.:··.,·.::··:-:··

..... ·. minimum embedment of 24 inches in cut.

. · ..... ·'

1-"-1 .·.,

. . . '~.:. >·

. .. · .. ,,

· ... •f.

-·:::_.

.·

'·.· . . ,' .··

··.·

Lateral Pressures

The bearing values indicated above are for a total of

' both dead and live load forces. -The values may be in-

cr.eased by one third for short duration loadings such

as wind or seismic forces. Resistance due to lateral

loads may be computed using a coefficient of friction

of 0.3 acting at the base of footings. -· .

An equivalent fluid pressure of 30 pounds per cubic

foot peJ: foot of depth may be used in the.d~sign of

retaining walls. ···.;: .. ,. l · .•.

,·· .. '1, ..

;'.· ~.' .

-~, (

,. .:-: : .. . ,'•,

·• •• ·.' .. t :... : ...... . ·<i.' ·.··.· ~-.. ·

· .. '·

. ·· ..

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_. .,. .... ' ... . Page g·.: w.o. 121

:! ' ..... :··; . • ,, .. , . . · . . , .. · .:•

···~:.:·~·:.':·.: \··:~VI. Settlement. of Fills and Foundations . - ·' ·~ ··.·., .

. ·"• ' . , ··.:· ... ': . If all vegetation and brush is removed prior to place-

... ·:· .l .... ·.· ,:'>'·

· · : .· :~· ment of fills, the maximum settlement of the underlying

!.

• • I (• ; .. :~,·

·'. .. ''.~.. ;· · strata as a result of fill placement is expected to be , . .. -~ ... '·\' ·.,·

·:. .. . , .

.. . ' . t: I';: •C ... , ' "' I

I I: .· .... ~ •'

· negligible •

•. ··r........ ..·· .

Settlement due to loadings imposed/by the structures

.· .. ·: is expected to be less than ~ inch. Differential ., :.···.

:, ,· ·· ·· : · · settlement is expected .to be negligible. ·.·'., ··· ... , ,··:·,·

'·.' . ·.·'

. ~· ' ' ' . :· .

_/' . . · ...

,.·

VII. Expansive Soil r'

. '·.·-

'· The onsite soils exhibit only slight volume change

': ... :.

potential with changes in moisture content in both

the undisturbed and remold,ed state~. We do not anti--

cipate problems due to expansive soils.

VIII. Grading

A •. Rippability: The major portionof onsite soils

~encountered during our investigation indicate .· ...... j;,·,'

... 1,' that excavations can be.made with conventional

,, ,_ .. ''

; ··~·

.. ~: ·. . ··:

,·.·.1_,;

. :-·.·.·;

;.: . · earth moving equipment •.. However there. may be some·· .. . ·. . ' .

;, __

··--

: ·,

...

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. . ~

· .. ..

:•,.

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: .' .· : _.;::' ... ·

"···

···:· :: ·. ··.:- ,. '

.,· · .. \.'

.,.· .... · Page 10 w.o. 121

areas along the ridge where blasting may be required. ' '•

_Blasting would probably be limi:ted to the area

faeing Kamehameha HighwaY.· )I· 'I

' . ~ . : : · ... · . ;..- .,.:.

·. : _: . _;,_-: ~ ',.,: ·~ .. •' ':_::.

~ .... :~···._. >::·~. B.· ·Insi_tu Moi.sture Content .... ·.,; .

· .. , ., . .. -~-~-. : ' ,. ,··.-.

, ..

• f ••

; •• '· _ ... , ' ··"!'· _; •...

. r:.·

.. ·,.

-, ., The average insitu moisture of the clayey. silt ,.'. ,·

·.·_,.,;'

material encountered is 25.7% which is about

~" below optimum. Compaction can be achieved. with-·.,·J

. ~.. • :· ,, ' .t

out any need for air drying of the soil. '·· ·.; .. ,: · .. ·

c. Embankment Shrinkage Due to Compaction

· .. '

. . ~· .

· .. - >

Approximately the upper 2 inches of soil can be

expected to be lost during grubbing operations.

In addition, we expect approximately a 2% shrinkage

of borrow soil due to compaction of the red clayey

silt. We anticipate a 1% swell, of borrow material

. " Qf the decomposeQ rock along the ridge area. .· .• t·; ,.::: ,! • :·; .... ' ·: •

'· ',· ' ,. '-~ .

·.\- .. ..

',-

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.. ·.··:.

._e<,;_.:··.·:··.··_.:, ·····.·· • ,,·•, . .,·, '"Y·::.•.

: ' : :'• ' >, t ' ;' '! ·.~ • 'I •: '

' ' :: ~;.' ·•. J . '·

...

. ,,· . •' . ~ ,'r •

'' '·~ .

. : .. : ... . ' . . '

' ;t ·'' '"·

Page 11 w.o. 121

,. •,

'.

;-·.

' ' '

' ...... · .. '} .

.· .. '. ::~: ,' . . '

,·· .. '· ...

'•';

CONCLUSIONS AND RECOMMENDATIONS . •· .·

. . ~~:

l. · The site is feasible for the proposed development. ..

.:''',, .J .: ._.:;. 2. Fill slopes should b.e grossly stable at slope ·gradients . ·,. ,·

' · .. ::. ·~ . ··.:r · .. ~.: ._, , .: .. t

of 1~: 1 (horizontal to vertical) •

. I

. ' ,:, , 3 ~,- Cut slopes along the ridge will be stable using a slope

. · .. _; ..

. . , :.-: · .. ~.

.. ' ' ~ ... )' ; .

· ' '· gradient of 1:1. >·;·_:·_ ...... :-".

However for cut slopes along the plateau :-· ·'t

~. ' 1 .. area, we recommend a· .slope gradient not exceeding 1~: 1.

-· ' .. · 4. In order to minimize surficial instability of compacted

-· · ..... "·~ ~- .~ fill and cut slopes, we reconimend that all slopes be . . ~ : ... '

planted as soon as practical upon completion of grading.

If practical, we recommend that fill slopes be overbuilt

and trimmed back to the horizontally compacted core.

5. The need for subdrains is not anticipated.

6. An allowable bearing pressure of 3000 PSF may be used

7.

for footings having a minimum wiqth of 12 inches and a

minimum embedment of 24 inches ,in fill.

An allowable bearing pressure of 4000 PSF may be used./ , ...

.F ·. 3-- ·.~;·- · 'J ~: 1 •

• ·1~' . • • •

' ' "·

'· ,•· • t .• •

: .:· . ~~ ,' . . ~ ..

.r:.

' '.

.-.: ... ~·.·

I'• ; . . ·:. ' . . . . ,

.. ......... :.··· ..... ··a . ;t, '. •

,, ,.· ..

· ... . :~ ..

Page 12 W.O. 121

for footings having a minirnum width of 12 inches and a

minimum embedment of 24 inches ;i.n cut.

Resistance due to lateral loads may be computed using

a coefficient of 'friction of 0.3 acting at the base of

footings.

9 •. An equivalent fluid pressure of 30 pounds per cubic

. : foot per foot o.f depth . may be used in·.· the design of

e. .... v ..

~ retaining.walls.

io. The maximum settlement of the underlying strata as a

result pf fill placement is expected to be negligible.

11. Settlement due to loadings imposed by the structures is

... • .

expected to be less than ~ inch. Differential seetlement

is expected to be negligible.

12. · We do not anticipate problems due to expansive soils.

13. The major portions of onsite soils can be excavated with

conventional earth moving equipment. However there may

be areas along the ridg~ where blasting may be required~

Blasting would probably be limited to the area facing .

Kamehameha Highway. .

• I'_'

.r ·,· ~ .. :'. ;

.,, ,:,_

Page 13 \ w.o. 121

• •' I

', -1 ••

14. The in situ moisture of borrow material is several percent.·

~.' ! . : •. "t '• • ••

r.· .·,:;,! .:~' ·: .....

···. . ·:

. ' . .

. below optimum moisture. Therefore, compaction can be

achieved without the need for air drying of the soil.

15. · Approximately the upper 2 inches of soil can be expected ' - ~ '. :~' '. .·, '

. . •. l

. ··,. ' .. ,.., _. ,•

-· .·.

.. .·. ;~ .\' '· .

·to be lost during grubbing operations. We expect approx~

. ' ... _ . .. ·: J_ .

•, .·

.. ;,·

. '. -~ . : ·. 1: · .. _;,

.. _../•· : ........ ..

16.

irnately a ~"· shrinkage of borrow soil due to compaction

of the red clayey silt. We anticipate a 1% swell of J

borrow material of the decomposed rock along the ridge

area. ·

Onsite soils are .suitable for fill material.

17. · All trees, roots, brush, and other deleterious materials

. ' ~

••

shall be removed and wasted from the site.

18. Oversize material shall not be placed within 10 -feet

of finish pad grade nor placed within.lO feet of any

slope face.

19~ Areas to receive. fill which are 5:1 or flatter shall be

scarified, watered, mixed, blended, and compacted to at

least 9~~ relative compaction to a Qepth of 12 inches· .·.·., _,· __

prior to placing of fill.· . :• ,lr

·--·..:·' ,·, I

·;; ,: ·-.; .;.: . . .•'

.··_.

... ' .. ~. ;

,"! "''

-~' . .< ·:". ' · .....

'··· .. ~ .. :

/ . •,.i.

.f

Page 14 w.o. 121

.·· .. · 't' .;· .. ,

. ' ' : .. , .

· ... :;,.

. 'l ~ "

. · ...

):·"'\ 20~ · Fill placed on surfaces which slope steeper than 5:1 ... · .. · ..

•' ;

shall be keyed and bench. . •, •'

..

.•. ~~ /·. :

21. · We recommend that any building pad which is in both ;~ a:;. : .";·r.··.:

.. · .' .

· •. ,; <': .< < •:·' cut and fill material be overcut a thickness equal to ~ . - • ; 4 r .(; ; ; .

,· .·. : j' •· ••• ·,,

the maximum thickness of fill on the pad up to a maximum

.;, . of three feet and replaced with a uniformly thick blanket ·,: ·;- 1 '

: I I.· .. ~:·, :, h ' •'

' . . . ' . . ' "?;. : ,,: of compacted fill.

~.: ...... :•'

;:· .:; ; ·22. All fill shall be compacted. to a minimum of 90% relative : .. ' ....

·.~ .. ::·< _.· ..

-.. · .. · .... ·. .',l'

- _.<::.· compaction as determined by ASTM D 1557~58T •

23. Pavement design recommendations will be submitted in ·'· ....

•",J ".' ......

. -"· . ...... ·.;) -' ~

.•.. : .. ' .

... ··.

an addendum report.

. We appreciate this opportunity to be of service. · Should you . .. ~ .: ..

have any questions, please call on us •. ·. ·.· ......... ~· ... ;· '·,·' .. , . ~.

-.-. ''•

' .·

Respectfully submitted, ' . . ·:·.

''·

. :--:::. · E:rnest K. Hira~a & Associates, Ipc. ·~.... . . . ~· . . ) : .. ·.

·L-L~··· .. Ernest K. Hirata . P.E •. 2732. ·.

- . . (

... •· ·'· ··.: .·

'• .. ..... ) .

.·' ·:·· ·. . .·,

• l ...

; ,'!.·

.,,·. . ..

,,

.. ·;

'· .. ,··

],) :,·.:.:, .

• r·.,...,"

·'' ···' .. :'; ,- .. ·~ ,. ' -

;, ·'·

. · .. ·. ~-

.. ~· ._.

Classification ·

.- ..

APPENDIX OF LABORATORY TESTING

'' •. ·' ' ~ ..

' .. : ..

'l' - .. ··:.;· ' .

·,.•

.·.,·'

'' ':

I'

'l'he field classif~cation is "erified in the labpratory, also . -~." ... ·,. .: .

. , in aceoraanee with the Unified Soil Classification System •

Laboratory classification is determined by both visual exam-··

'·. ' : ·~ .... :

ination and Atterburg Limit T~sts .~·. T,he . final. classifi~ation .r• .··

. . . .

' .. , .. , · is shown on the n Bor ~rig· Logs n ·• I' . .:-; . • . • ~ ••

:.,! ... :: ·•· ....

.. ·. . r.: ~'·' :.. ';

:f "· ... ·' . . . ; : ~. ~ ' ... '

l -l;.' ..

.. '

·,·: .::.:';':.'\·: .. :. -~ ' . ·~

' ,. ··.Moisture-Density ',·,

..• .i:.

0:.

., .

.. . . · · The field moisture content and dry unit weight are determined

·•·:···,· for each of the undisturbed soil samples. ·.The information is

.. - ; ~ .

_:-:•·" . . •.·· ·:'

-~ ... ' -: -\.··:·" • 1''

··.;:·.

. ... _ .. ,. ·,,

·,· :.

e e·

.useful in providing a gross picture of the soil consistency

· between b~rings ~nd any local variations. The dry unit weight

is determined in pounds per cubic fo.ot and shown on the 11Boring

Logs". The field moisture content is determined as a percentage ., ..

':. _· · ..

of the dry unit weight.:·· ·. ~-

, ... :, · .. ':_ .. '

. .. ~:·· .. · .' • • I" •

.·, " ..

Consolidation

Settlement predictions of the·soil's behavior under load are

' made on the basis of the consolidation tests. Loads are

applied .in several increments in a geometric progression, . · .. ·.i. ·. ·, ,t• ' ..

···,·-· .. ,

. . .~-~ ····.

Page 1