Engineering Geology Volume 28 Issue 1-2 1990 [Doi 10.1016%2F0013-7952%2890%2990041-x] Jawad S. Al-Sulaimi; Mohammad a. Mollah; Muneer a. Matti -- Geotechnical Properties of Calcrete

8/11/2019 Engineering Geology Volume 28 Issue 1-2 1990 [Doi 10.1016%2F0013-7952%2890%2990041-x] Jawad S. Al-Sulai

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Engineering Geology, 28 (1990) 191-204 191

Elsevier Science P ubl i shers B.V., Amsterdam - - Pr in ted in T he N ether lands

T e c h n i c a l N o t e

G e o t e c h n i c a l P r o p e r t i e s o f C a l c r e t e S o i l G a t c h )

in K u w a i t

JAWAD S. AL-SULAIMI, MOHA MM AD A. MOLLA H and MU NEER A. MATTI

Kuwait Institute for Scientific Research, P.O. Box 24885, 13109 - - Safat Kuwait)

Government Laboratories and Testing Station, Ministry of Public Works, P.O. Box 8, 13001 - -

Safat Kuwait)

Formerly, Engineering Department, Kuwait Institute for Scientific Research, P.O. box 24885,

13109- Safat Kuwait)

(Received December 11, 1986; acce pted a fter rew sion J an ua ry 1, 1989)

ABSTRACT

A1-Sulaimi, J .S. , Mollah, M .A. and M att i , M .A., 1989. Geo technical pro pert ies o f calc rete soil

(gatch) in Kuwait. Eng. Geol., 28: 191-204.

This pape r presents the resu l t s of a comprehens ive labora tory tes t ing program car r ied out to

study th e geotechn ical prop ert ies of gatch (c alcrete soil) samples. A to tal o f 17 samples col lected

from 17 different s ites in Ku wa it City and i ts suburbs were used for the study. Th e test ing prog ram

included determ inat ion o f physical, index and eng ineering prope rt ies of gatc h samples. The

sensi t ivi ty of variou s geotechn ical propert ies of compacted gatch w as examined b y test ing

specimens a t variou s moisture con tents and also at different soakin g periods.

INTRODUCTION

G a t c h i s t h e l o c a l n a m e o f a p a r t i a l l y c o n s o l i d a t e d s e d i m e n t o f a m a s s i v e

c a l c r e t e t y p e f o u n d i n m a n y p a r t s o f K u w a i t a t v a r i a b l e d e p t h b u t g e n e r a l l y

a b o u t 2 m b e l o w t h e s u r f a c e . T h i s d e p o s i t w h i c h c a n a t t a i n t h i c k n e s s e s o f t e n s

o f m e t e r s , c o n s i s t s b a s i c a l ly o f q u a r t z s a n d s c e m e n t e d p r e d o m i n a n t l y b y

c a r b o n a t e s ( c a lc i te a n d / o r d o l o m i te ) .

S i n c e 1 95 0 a h u g e c o n s t r u c t i o n p r o g r a m h a s b e e n u n d e r w a y i n K u w a i t , i n

w h i c h g a t c h h a s b e e n u s e d p r i n c i p a l l y a s a s u b - b a s e m a t e r i a l f o r r o a d

c o n s t r u c t i o n , f o r t h e f o r m a t i o n o f e m b a n k m e n t s a n d f o r fi l l m a t e r i a l . G a t c h i s

a l so t h e s o i l o n w h i c h m o s t b u i l d in g f o u n d a t i o n s r e s t . C o n s i d e r a b l e f ie ld a n d

l a b o r a t o r y w o r k h a s b e e n c a r r i e d o u t i n t h e p a s t b y e n g i n e e r s e n g a g e d i n

s p e c i f i c p r o j e c ts , b u t s o f a r n o a t t e m p t h a s b e e n m a d e t o c o r r e l a t e t h e r e s u l t s o f

t h e s e s t u d i e s s o a s t o o b t a i n a g e n e r a l p i c t u r e o f g a t c h d e p o s it s . T h i s p a p e r

p r e s e n t s t h e g e o t e c h n i c a l p r o p e r t i e s a n d c h a r a c t e r i s t i c s o f g a t c h e n c o u n t e r e d

i n K u w a i t C i t y a n d i t s s u b u r b s . A t o t a l o f 17 d i s t u r b e d g a t c h s a m p l e s w e r e

r a n d o m l y c h o s e n f r o m d if f e r e n t a r e a s f o r a n i n t e n s i v e l a b o r a t o r y g e o t e c h n i c a l

t e s t i n g . T h e p r o g r a m o f t e s t i n g i n c l u d e d t h e d e t e r m i n a t i o n o f t h e b a s i c a n d

0013-7952/90/$03.50 1990 E lse w er Science Pu blis he rs B.V .


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192

J S AL-SULAI MI ET AL

stre ngth properties. The effect of sa tur at ion of various degrees on soil

properties was also examined.

GEOLOGICALSETTING AND CLIMATE

Kuwa it is a small country located in the northe aste rn edge of the Arabian

peninsula, bordered by the Ara bian Gulf in the east. The eastern part of the

Arabian Peninsula, known as the Arabian Shelf, consists of a sedimentary

succession in which the most common rock types are sa ndstone and carbonate

rocks (Powers et al., 1963).

The area of Kuwa it con stitutes a part of the interior homocline of the

Arabian Peninsula. The rocks exposed range in age from Eocene to Recent.

The Dammam Limestone Formation, of Eocene Age, crops out along the

Ahmadi Ridge abou t 40 km sou th of Ku wa it City and is the oldest rock exposed

m Kuwait. The Dammam Limestone is overlain by a sequence of terrigenous

sediments that range in age from Miocene to Recent. These sediments are

exposed in the Jal Az-Zor Escarpment northwest of Kuwait City. The rock

sequence of Ja l Az-Zor consists of three main formati ons named, from bottom

to top, Ghar, Fars and Dibdibah (Fuchs et al., 1968). The Dibdibah Formation

covers most of the n orthe rn area of Kuwa it and consists mainly of a fluviatile

sequence of cross-bedded sands and gravels usually cemented by gypsum and

carbonates. The rest of Kuwa it is covered by other Quat erna ry deposits.

The climate of Kuwa it is characterized by a typical desert environment, with

prolonged hot dry summers and mild to cool, relatively wet winters. Annual

pan evaporation is about 3500 mm per yea r which increases graduall y from a

minimum value of 2.1 mm/da y in winter (Januar y) to a max imum of 13 mm/day

in summer (June and July).

PETROGRAPHY OF THE GATCH

A typical fully developed simple soil profile m the study a rea can be divided

into five zones or horizons. In descending order t hese are: (1) aeo lian soil 0.5 to

10 m thick , but commonly less than 2 m; (2) up to 3 m thi ck of friabl e sand wi th

powdery calcrete or tightly cemented calcrete lumps (nodules) up to 30 cm m

diameters ; (3) massive calc ret e 0.2 to 2 m in thi cknes s (gatch); (4) a mottle d

calcre te zone up to 2 m in thickness ; an d (5) una lte red pare nt material.

Detailed accounts of the diagenesis and formtion of the different calcrete

zones have been published by A1-Sulaimi (1988).

The massive calcrete (gatch) is a white to light-yellowish, porcellaneous,

carbona te rock. It consists of variably c emented and replaced sand particles.

The car bonate in the massive calcrete (gatch) represents a su bstantia l replace-

ment of the original material. Mineral grains such as quartz and feldspar are

etched and replaced to varying extents by carbonate. The dominant cementing

materia l is largel y low-magnesium calci te (1-4 mole ~/o MgCO3) and]or micro-

crys talli ne dolomite. Mod era tel y coarse (up to 0.6 mm) dolomite usual ly

occurs as subhedral or small euhedral rhombs whereas the low-magnesium


3/11

GEOTECHNICAL PRO PERTIES OF CALCRETE SOIL GATCH) IN

KUWAIT

I

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Fig.I. Map of Kuwait City and its suburbs showing sampling locations.

pp.

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KUWAIT SUBURBS

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GEOTECHNICAL PROPERTIES OF CALCRETE SOIL (GATCH) IN KUWAIT 197

c a l c i t e o f t e n o c c u r s a s m i c r o s p a r i t e a n d s p a r i t e . T h e c a r b o n t e f r a c t i o n i n t h e

m a s s i v e c a l c r e t e a v e r a g e s 6 0 % ( r a n g e 1 5 - 9 0 ~ / o ) w i t h t h e d o l o m i t e c o n t e n t

a v e r a g i n g 4 0 % ( r a n g e 5 - 9 0 % ) . G y p s u m i s a l s o o b s e r v e d in a fe w g a t c h s a m p l e s

a n d i n s o m e c a s e s i t e ff e c t i v e ly c e m e n t s t h e a s s e m b l a g e a s a r e s u l t o f i n t e n s i v e

r e p l a c e m e n t o f t h e c a r b o n a t e . T h e m a i n e f f ec t o f t h e d i a g e n e t i c p r o c e s s e s o n

t h i s h o r i z on i s a n o v e r a l l d e c r e a s e i n p o r o s i t y a n d e f f e c ti v e p e r m e a b i l i t y o f t h e

g a t c h z o n e d u e t o c e m e n t a t i o n b y c a r b o n a t e ( A 1 -S u la im i , 19 88).

SAMPLING AND TESTING PROGRAM

T h i s s t u d y f o rm s a n i n t e g r a l p a r t o f t h e K u w a i t I n s t i t u t e f o r S c i e n ti f i c

R e s e a r c h p r o je c t e n t it l e d S t u d y o f t h e G a t c h D e p o s i t s i n K u w a i t C i t y a n d

S u b u r b s ( A 1 -S u l ai m i e t a l. , 19 84). O v e r 20 0 s a m p l e s o f g a t c h w e r e c o l l e c t e d

f ro m d i f fe r e n t lo c a t i o n s o f K u w a i t C i t y a n d i t s s u b u r b s t o s t u d y t h e g e o l o g i c a l

c h a r a c t e r i s t ic s . O u t o f t h e s e a t o t a l o f s e v e n t e e n m a s s i v e g a t c h s a m p l e s t a k e n

f ro m v a r i o u s l o c a t i o n s ( F i g . l ) w e r e m a d e a v a i l a b l e f o r g e o t e c h n i c a l a n a l y s is .

T h e s a m p l e s w e r e c o l l e c t e d f ro m d e p t h s r a n g i n g b e t w e e n 1 .0 a n d 6 .5 m f r o m

o p e n t e s t p it s a n d a l s o d u r in g v i s it s to v a r i o u s c o n s t r u c t i o n s i te s .

U p o n r e c e i p t o f t h e s a m p l e s i n t h e s o i l l a b o r a t o r y a v i s u a l c l a s s i f i c a t io n w a s

m a d e f o l lo w e d b y th e d e t e r m i n a t i o n o f t h e n a t u r a l m o i s t u r e c o n t e n t. A

s y s t e m a t i c l a b o r a t o r y t e s t i n g p r o g r a m w a s c a r r i e d o u t i n w h i c h f i r s t l y t h e

b a s i c a n d i n d e x p r o p e r t i e s o f a l l t h e s a m p l e s w e r e d e t e r m i n e d . T h e c o m p a c t i o n

c h a r a c t e r i s t i c s o f g a t c h w e r e d e t e r m i n e d e m p l o y i n g b o t h s t a n d a r d (2 .5 k g

r a m m e r ) a n d m o d i fi e d (4 .5 k g r a m m e r ) e n e r g i e s. A n i n t e n s i v e t e s t i n g p r o g r a m

w a s u n d e r t a k e n t o s t u d y th e s t r e n g t h p a r a m e t e r s i n t e n d e d f o r f o u n d a t i o n

d e s i g n a n a l y s is , a s w e l l a s s u i t a b i l i t y o f c o m p a c t e d g a t c h a s a s u b g r a d e

m a t e r i a l u s i n g f iv e s e l e c t e d s am p l e s . T h e s e t e s t s i n c l u d e d p e r f o r m i n g d i r e c t

s h e a r , C a l i f o r n ia b e a r i n g r a t i o ( C B R ) a n d p e r m e a b i l i t y t e s t s u s in g s p e c i m e n s

c o m p a c t e d b y b o t h e n e r g i e s . T h e e f f e c t o f s o a k i n g o n s t r e n g t h c h a r a c t e r i s t i c s

w a s s t u d i e d b y p e r f o rm i n g t e s t s a t d i f f e re n t s o a k i n g c o n d i t i o n s .

PRESENTATION AND DISCUSSIONSOF TEST RESULTS

Class i f i ca t ion tes t s

T h e s e t e s t s w e r e p e r f o r m e d a c c o r d i n g t o A S T M s t a n d a r d s , a n d t h e r e s u l t s

a r e s u m m a r i z e d i n T a b l e I. T h e g r a in - si z e a n a l y s i s i n d i c a t e s t h a t s a n d s i z e

d o m i n a t e s t h e p a r t i c le c o m p o s i t i o n o f t h e g a t c h , w i t h g r a v e l c o n t e n t v a r y i n g

b e t w e e n 0 n d 4 % . T h e p e r c e n t a g e o f f in e m a t e r i a l s h a v i n g t h e s i z e o f c l a y a n d

s i lt p a r ti c l e s v a r i e s b e t w e e n 8 a n d 3 3 % . T h e m e a n g r a in - si z e d i a m e t e r a n d

s p e c i f i c g r a v i t y o f s o i l s o l i d s v a r y f r o m 0 .1 5 t o 0 . 8 r a m a n d 2 .6 3 t o 2 .7 0,

r e s p e c t i v e l y .

T h e p l a s t i c i ty o f t h e g a t c h s a m p l e s w a s d e t e r m i n e d o n m a t e r ia l f r a c t i o n s

p a s s i n g U . S . s i e v e s iz e o f 4 25 pro. T e n o u t o f s e v e n t e e n s a m p l e s w e r e f o u n d t o

b e n o n -p l a s t ic ( N P ), a n d t h e r e m a i n d e r s h o w e d a l o w p l a s t i c i ty i n d e x ( P I)


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GEOTECHNICAL PROPERTIESOF CALCRETE SOIL (GATCH) IN KUWAIT 199

between 2 and 10%. When plotted on the Casagrande chart, the gatch samples

lie at or slightly above the A-line in the low plasticity region. Accordingly, the

United Soil Classification System (USCS) designation of the gatch is SM-SC.

For road works, the gatch belongs to a soil group of A-2-4. The results are in

full agreement with those reported by Riedel and Simon (1973) on samples from

three locat ions in Kuwait City, and by Ismael et al. (1984) on samples from the

A1-Andalus area about 20 km southwest of Kuwait City. The shrinkage limit

(SL) which is the moisture content of the soil below which little or no volume

change is to take place is recorded to vary from 12.5 to 21.0% with an average

of 17.0%. An examination of Table I reveals tha t the natu ral moisture conten t

(NMC) is well below the shrinkage limit at all locations indica ting a general

moisture deficiency. Upon saturation, these soils are liable to swell; this

explains why gatch soils at the surface crack once subjected to drying.

Compaction characteristics

Test results summarized in Table II show the maximum dry density together

with thei r corresponding optimum moisture content. The results obta ined are

similar to those reported by Riedel and Simon (1973). In constructions,

TABLE II

Summary of results of compaction tests

No. Loc ati on 2.5 kg ram mer 4.5 kg ram mer

and 305 mm drop and 457 mm drop

OMC ~dm.x OMC ?din.,

(%) (kg/m a) (%) (kg/m 3)

1 G-1 11.0 1950 9.0 2060

2 G-2 11.0 1915 9.0 1995

3 G-3 13.0 1860 11.5 1970

4 G-4 13.0 1880 9.5 2030

5 G-5 13.0 1825 9.5 1940

6 G-6 12.5 1870 11.5 1940

7 G-7 10.5 1985 9.5 2040

8 G-8 13.0 1895 8.0 2025

9 G-9 15.0 1810 12.5 1965

10 G-10 8.5 1880 7.5 1975

11 G-11 12.5 1940 10.0 2040

12 G-12 12.0 1850 8.0 1935

13 G-13 13.0 1850 10.5 1970

14 G-14 9.5 2000 7.5 2095

15 G-15 12.0 1910 8.5 2065

16 G-16 12.5 1880 9.0 2035

17 G-17 13.0 1875 10.5 2025

Av er ag e 12.1 1880 9.4 2005

OMC = optimu m moi stu re c ont ent ; ~dm.x= maximum dry density.


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J S AL-SULAIMI ET AL

c o m p a c t i o n i s d e e m e d a c c e p t a b l e w h e n i n - si t u d ry d e n s i t y e x c e e d s 9 5% o f t h e

d e n s i t y o b t a i n e d i n th e l a b o r a t o r y f o r t h e s t a n d a r d o f c o m p a c t i o n a p p l i e d . T h e

i n - si t u d r y d e n s i t y o f g a t c h s h o u l d b e a b o v e 1 90 0 k g / m 3 f o r t h e m o d i f ie d

P r o c t o r (4 .5 k g r a m m e r ) a n d 1 7 9 0 k g / m 3 f o r t h e s t a n d a r d P r o c t o r (2 .5 k g

r a m m e r ) .

T h e d e n s i t y o f g a t c h i s v e r y s e n s i t i v e to c h a n g e s i n m o i s t u r e c o n t e n t . O n c e

t h e o p t i m u m m o i s t u r e c o n t e n t i s e x c e e d e d , t h e r e i s a s h a r p d e c r e a s e i n d e n s i t y ,

a s t h e m a t e r i a l b e c o m e s r a t h e r s p o n g y a n d d i ff ic u lt t o c o m p a c t . F u r t h e r

i n c r e a s e s i n m o i s t u r e c o n t e n t w i ll c a u s e t h e m a t e r i a l t o fl ow u n d e r c o m p a c -

t i o n .

Strength characteristics

T h e s h e a r s t r e n g t h o f a s oi l c a n b e u s e d to d e t e r m i n e i t s u l t i m a t e b e a r i n g

c a p a c i t y . T h e t e s t r e s u l t s o f u n d r a i n e d s a m p l e s ( G - l , G -2 , G -5 , G - 8 a n d G -1 4)

c o m p a c t e d a t o p t i m u m m o i s t u r e c o n t e n t a r e g i v e n i n T a b l e II I . R e s u l t s s h o w e d

t h a t s o a k i n g f o r 2 4 a n d 9 6 h h a s l i t t l e e f f e c t o n s h e a r s t r e n g t h . T h e a n g l e o f

i n t e r n a l f r i c ti o n (~b) r e m a i n e d u n c h a n g e d a f t e r s o a k i n g f o r s a m p l e s c o m p a c t e d

b y 4 .5 k g r a m m e r a n d f o r s a m p l e s c o m p a c t e d b y 2.5 k g r a m m e r i t d e c r e a s e d b y

1 o n l y , w h i c h i s i n s i g n i fi c a n t i n p r a c t i c a l e n g i n e e r i n g w o r k . I n c r e a s i n g t h e

c o m p a c t i o n e f f o rt c a u s e d a n i n c r e a s e o f 3 to 4 i n t h e v a l u e o f , w h i c h

i n d i c a t e s i m p r o v e m e n t i n t h e s h e a r s t r e n g t h o f p r o p e r l y c o m p a c t e d s o il s. T h e

c o h e s i o n (c) v a l u e s w e r e v e r y s m a l l a n d r a n g e d f ro m 0 to 1 6 k N / m : f o r l o w

c o m p a c t i o n e n e r g y a n d f r o m 0 t o 2 8 k N / m 2 f o r h i g h e r c o m p a c t i o n e n e r g y .

I t is in t e r e s t i n g t o n o t e a n i n c r e a s e i n t h e v a l u e o f c w i t h s o a k i n g . T h i s c o u l d

b e d u e t o t h e w e t t i n g e f f e c t o f t h e f i n e r f r a c t i o n s o f t h e g a t c h w h i c h a l s o

c a u s e d t h e m a t e r i a l t o s w e l l .

Ca lifornm bearing ratio C BR )

T h e C B R t e s t s w e r e p e r f o r m e d o n f iv e s e l e c t e d g a t c h s a m p l e s ( G - l , G -2 , G -5 ,

G - 8 a n d G - 1 4 ) p r e p a r e d a t o p t i m u m m o i s t u r e c o n t e n t ( O M C ) . T h e t e s t r e s u l t s

a r e s u m m a r iz e d m T a b l e IV . T h e a v e r a g e C B R v a l u e r a n g e s f r o m 4 % t o 3 2 %

f o r u n s o a k e d s p e c im e n s c o m p a c t e d w i t h 2 .5 k g r a m m e r w h i l e t h e s o a k e d C B R

v a l u e s f o r s i m i l a r s p e c i m e n s r a n g e d f r o m 4 % t o 2 8 % . T h i s i n d i c a t e s t h a t t h e r e

i s a s li g h t d e c r e a s e i n s t r e n g t h d u e t o s o a k i n g b u t n o t s o s i g n if i ca n t . H o w e v e r ,

i n c r e a s i n g t h e c o m p a c t i v e e f f e c t r e s u l t e d i n 3 00 % i n c r e a s e i n C B R v a l u e a n d

t h i s e x p l a i n s w h y c o m p a c t i o n h a s t o b e c o n t r o l le d .

T h e s w e l l i n g o f t h e g a t c h w a s a l s o i n v e s t i g a t e d . I t w a s f o u n d t h a t t h e v a l u e s

r a n g e d f r o m 0 t o 0 .2 6 % , a n d t h a t s w e l l i n g d e c r e a s e d w i t h i n c r e a s i n g c o m p a c -

t io n . T h i s il l u s t r a t e s t h a t i f a s a t i s f a c t o r y c o m p a c t i o n c a n n o t b e g u a r a n t e e d ,

t h e g a t c h i s u n s u i t a b l e u n l e s s i t s p ro p e r t ie s a r e i m p r o v e d b y m e a n s o t h e r t h a n

c o m p a c t i o n a l o n e .

T h e g a t c h i s r e p o r t e d t o b e v e r y s e n s i t i v e to c h a n g e s i n t h e m o i s t u r e c o n t e n t

( B i s s a d a a n d Q a b a z a r d , 1974). A c c o r d i n g l y , t e s t s w e r e c a r r i e d o u t i n w h i c h t h e

m o l d i n g m o i s t u r e c o n t e n t a t t h e t im e o f c o m p a c t i o n w a s v a r i e d f ro m 4 t o 1 6% .


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9/11

2 0 2

T A B L E I V

R e s u l t s o f C B R t e s t s 1

J S AL-SULAIM[ET ~L

S a m p l e

U n s o a k e d , 2 4 h s o a k e d 9 6 h s o a k e d

C B R ( % ,

a v e r a g e o f C B R ( % , s w e l h n g C B R ( % ,

2 t e s t s ) a v e r a g e o f ( % ) a v e r a g e o f

2 t e s t s ) 2 t e s t s )

s w e l l i n g

(%)

U s i n g s t a n d a r d r a m m e r (2 5 k g )

G-1 8 6 0 6 0 15

G-2 32 28 0 11 28 0 07

G - 5 3 0 2 5 0 0 2 2 5 0 0 4

G-8 5 5 0 04 6 0 07

G-14 26 19 0 11 20 0 11

U s i n g h e a v m r r a m m e r ( 4 5 k g )

G-1 58 25 0 02 22 0 0

G-2 57 61 0 03 62 0 0

G - 5 6 6 5 2 0 0 9 5 4 0 1 6

G-8 93 50 0 11 43 0 20

G - 1 4 5 6 5 1 0 0 7 4 1 0 0 2

* 1 S p e c i m e n s c o m p a c t e d a t o p t i m u m m o i s t u r e c o n t e n t t o m a x i m u m d r y d e n s i ty

T h e s e t e s t s w e r e c a r r i ed o u t u s i n g 4 .5 k g r a m m e r o n 2 s e le c t e d s a m p l e s G -5

a n d G - 8 ) o n l y a n d t h e s o a k i n g c o n d i t i o n s w e r e v a r i e d a s u s u a l . T h e r e s u l t o f

t h e t e s t c o n t a i n s w h o l l y t h e fi n d i n g s o f B i s s a d a a n d Q a b a z a r d 1 97 4).

Permeability tests

P e r m e a b i l i t y t e s t s w e r e c o n d u c t e d u s i n g f iv e s e l e c t e d s a m p l e s ( G - l, G-2 , G -5,

G -8 a n d G -14). T h e s p e c i m e n s w e r e p r e p a r e d b y c o m p a c t i n g a t O M C b y b o t h

e n e r g ie s . T h e t e s t s w e r e c o n d u c t e d u s i n g t h e f a l l in g h e a d m e t h o d .

T h e r e s u l t s a r e s u m m a r i z e d i n T a b l e V . T h e p e r m e a b i l i t y c o e ff ic i e n t (k )

T A B L E V

R e s u l t s o f p e r m e a b l h t y t e s t s 1

S a m p l e

P e r m e a b l h t y ( m / s , 1 0 - 1 )

2 5 k g r a m m e r 4 .5 k g r a m m e r

G - 1 8 0 2 2

G - 2 4 2 0 3 0 5

G - 5 3 4 0 0 7 4 0

G - 8 4 6 0 6

G - 1 4 3 4 6 . 3 0

* 1 S p e c i m e n c o m p a c t e d a t O M C t o ydm a x


10/11

G E O T E C H N I C A L P R O P E R T I E S O F C A L C R E T E S OI L G AT CH ) I N K U W A I T 2 0 3

v a r i e s b e t w e e n 4 .6 a n d 3 40 0 1 0 - 1 m / s f o r s p e c i m e n s c o m p a c t e d b y 2 . 5 k g

r a m m e r , a n d 0 .6 a n d 7 40 1 0 - 1 m / s f o r s p e c i m e n s b y 4 . 5 k g r a m m e r . T h i s

i n d i c a t e s a f iv e -f ol d d e c r e a s e i n t h e p e r m e a b i l i t y f ig u r e s j u s t b y i n c r e a s i n g t h e

c o m p a c t i v e e f f o rt . T h e a v e r a g e p e r m e a b i l i t y c o e f f i c ie n t o f U n i t e d S t a t e s

B u r e a u o f R e c l a m a t i o n ( U S B R , 1 977) f o r s il t y a n d c l a y s a n d s v a r i e s f r o m 7 20 t o

4 8 0 . 1 0 - 1 m / s a n d t h e s o i l s a r e d e s c r i b e d a s : (1 ) i m p e r v i o u s w h e n k i s

< 1 0 0 . 1 0 - 1 m / s ; ( 2) s e m i - i m p e r v i o u s w h e n k i s 1 0 0 t o < 1 0 0 0 10 - 1 m / s ; (3 )

p r e v i o u s w h e n k is > 1 0 0 0 -1 0 - 1 0 m ] s.

A c c o r d i n g l y , g a t c h s o i ls a r e c o n s i d e r e d a s i m p e r v i o u s , c o m p a r i n g t h e

f ig u r e s w i t h t h e e x c e p t i o n o f t h o s e f r o m G - 2 a n d G -5 a r e a s w h e r e t h e g a t c h i s

s e m i - im p e r v i o u s . T h i s im p l i e s t h a t t h e u s e o f g a t c h r e q u i r e s p r o p e r d r a i n a g e

a r r a n g e m e n t s w h e n u s e d a s fill m a t e r i a l .

CONCLUSIONS

(1) M a s s i v e g a t c h i s p r e d o m i n a n t l y s a n d y w i t h t h e p e r c e n t a g e o f m a t e r i a l

f in e r t h a n 7 5 t an r a n g i n g f r o m 8 % t o 3 3 . I t i s e i t h e r n o n - p l a s t ic o r h a s a l o w

p l a s t i c i t y i n d e x , a n d c a n b e c l a s s if i e d a s S M - S C i n t h e U n i f i e d C l a s s i f i c a t i o n o r

A -2 (0 ) i n t h e A A S H T O c l a s si f ic a t io n . T h i s m a k e s i t s u i t a b l e f o r u s e i n r o a d

s u b g r a d e s . T h e a v e r a g e s h r i n k a g e l im i t i s 17~/o, w h i c h i s c o n s i d e r a b l y a b v o e

t h e n a t u r a l m o i s t u r e c o n t e n t . T h i s i s c r it i c a l, b e c a u s e it m e a n s t h a t t h e s o i l s

a r e l ia b l e t o s w e l l w h e n s a t u r a t e d a n d t o c r a c k w h e n d r y , a n d s u i t a b l e

d r a i n a g e a r r a n g e m e n t s m u s t b e m a d e t o e n s u r e t h e ir s t a b i li ty .

(2 ) T h e a v e r a g e v a l u e s o f t h e C a l i f o r n i a b e a r i n g r a t i o ( C B R ) f o r u n s o a k e d

s a m p l e s r a n g e d f r o m 5~/o t o 3 2 ~ w h e n c o m p a c t e d a t O M C u s i n g l o w e n e r g y ;

t h e s a m e s a m p l e s c o m p a c t e d a t h i g h e r e n e r g y g a v e a C B R v a l u e b e t w e e n 5 6%

a n d 93/0. T h i s i n d i c a t e s t h a t c e r t a i n t y p e s o f m a s s i v e g a t c h c a n b e u s e d a s s u b -

b a s e o r e v e n a s a b a s e c o u r s e f or r o a d c o n s t r u c t i o n . S o a k i n g o f g a t c h s a m p l e s

c o m p a c t e d a t t h e i r o p t i m u m m o i s t u r e c o n t e n t h a s l it t le e f f e c t o n t h e C B R

v a l u e . T h e C B R v a l u e i s v e r y s e n s i t iv e t o t h e m o i s t u r e c o n t e n t o f t h e g a t c h a t

t h e t i m e o f c o m p a c t i o n , a n d t h i s w i l l d i c t a t e t h e n e e d f o r g o o d q u a l i t y c o n t r o l

d u r i n g c o m p a c t i o n .

(3) T h e c o h e s i o n o f g a t c h i s v e r y l o w a n d a t t i m e s n e g l i g i b le , w h i l e o n t h e

o t h e r h a n d t h e a n g l e o f f r i c ti o n h a s b e e n f o u n d t o i m p r o v e c o n s i d e r a b l y w i t h

p r o p e r c o m p a c t i o n . T h e p e r m e a b i l i t y i s c o n s i s t e n t l y l ow ; t h e m a s s i v e g a t c h i n

t h e s t u d y a r e a i s e i t h e r i m p e r v i o u s o r se m i - i m p e r v io u s .

ACKNOWLEDGEMENTS

T h e a u t h o r s e x p r e ss th e i r g r a t i t u d e t o D r . A b d u l m a j i d J e r a g h , H e a d o f t h e

G o v e r n m e n t L a b o r a t o r i e s a n d T e s t i n g S t a t i o n f o r a l l o w i n g t o u se t h e s o il

l a b o r a t o ry . T h a n k s a r e a l s o d u e t o D r. H a m e d S a e e d y o f K u w a i t I n s t i t u t e f o r

S c i en t if ic R e s e a r c h f o r r e v i e w a n d u s e f u l c o m m e n t s o n t h e m a n u s c r ip t . T h e

K I S R p r o j e c t E E S - 4 6 s t a f f a r e a c k n o w l e d g e d f o r f ie ld a n d l a b o r a t o r y a s s is t -

a n c e .


11/11

204 J s AL-SULAIMIET AL

REFERENCES

A1-Sulalml, J , 1988. Calcrete and near surface geology of Kuwait City and suburbs, Arabian Gulf

Sediment. Geol., 54: 331-345.

A1-Sulaimi, J., El-Sayed, M.I., Youash, Y , Matt1, M., Akber, A., Mollah, M.A., Salman, A.S and

Mukhopadhyay, A., 1984 Study of the Gatch Deposits m Kuwait Ci ty and Suburbs KISR 1399,

Kuwait Institute for Scientffic Research, Kuwait (Unpublished)

Blssada, A.F. and Qabazard, J , 1974. Low cost road pavement situation in Kuwait. Arab Engineers

Federation Conference, Kuwait.

Fuchs, F., Gattmger, T.E. and Holzer, H.F., 1968. Exploratory Text to the Synoptic Geologic Map

of Kuwmt Geol. Surv. Austria, Vmnna

Ismael, N.F., A1-Khalidl, O. and Abdul-Hadl, S., 1984. Sub-soils Condit ion m A1-Andalus Area

Research Report, Government Laboratories and Testing Station, MPW, Kuwait (Unpubhshed).

Poers, R.W., Ramlres, L.F, Redmond, C.D. and Elberg, E.L., 1963. Geology of the Arabian

Peninsula; sedimentary geology of Saudl Arabia. Geol Surv Prof. Pap. 560-D

Rmdel, G. and Simon, A.B., 1973. Geotechmcal properties of Kuwait gat ch and their improve-

ment. Eng. Geol, 7. 155-165

Umted States Bureau of Reclamation, 1977. Design of Small Dams. Washington, D.C, rev 2nd ed.

Documents

Engineering Geology Volume 28 Issue 1-2 1990 [Doi 10.1016%2F0013-7952%2890%2990041-x] Jawad S. Al-Sulaimi; Mohammad a. Mollah; Muneer a. Matti -- Geotechnical Properties of Calcrete