KAEA3233 SOIL MECHANICS II SM1 OEDOMETER TEST GROUP 1
Name MUHAMMAD A!REEN "IN SI#EMAT MOHAMMED HA!IMIN "IN SALAM MOHAMMAD IR&AN "IN GA!ALI MOHAMMAD ASNA&I "IN AMIRUDDIN NUR LI)ANA "T HASSAN
INTRODUCTION
Matrices No. KEA11$$2% KEA11$$22 KEA12$$2' KEA12$$2( KEA12$$*$
Consolidation of soft soil is the process of dissipation of excess pore water pressure in a row of time. When a surcharge is applied to saturated compressive soil, excess pore water pressure is built up causing an increase in pore water pressure. Due to the higher incompress incompressible ible behavior of pore water compared to soil, the excess pore water will initially initially carry the load. After some time, the drainage path opens and water starts moving from region of higher pressure to the region of lower pressure. Since dissipation of pore water pressure occurs simultaneously with the squeeing out of the pore water, then pore water pressure begins to decrease linearly linearl y or non!linearly. Afterwards the load will be transferred to the soil s"eleton and compression occurs resulting in decreased volume of the soil mass. #his phenomenon is called consolidation of soil. Consolidation of soil will cause downwards displacement of buildings or ground structures that may destroy utilities and ris" lives. $edometer test is a "ind of geotechnical investigation performed in geotechnical engineering that is used to determine the magnitude and rate of consolidation of saturated soil specimen. #he soil specimen is extruded into the consolidation ring and set up in the oedometer apparatus before it is sub%ected to one dimensional consolidation pressure. &ertical drainage is allowed at top and bottom of the specimen. #he test is performed by applying different loads to a soil sample and measuring the deformation response. #he results with a sufficient number of data points are determined to describe the relationship between void ratio and effective stress for a soil. #he parts of oedometer apparatus are shown in picture below.
A stress!void ratio graph 'e!log p curve( is plotted in a semi!logarithmic scale as shown below.
We can also determine the Swelling )ndex 'C s(, Compression )ndex 'C c( and Coefficient of &olume Compressib Compressibility ility 'mv(. #h #hee coef coeffic ficie ient nt of cons consol olid idati ation on 'Cv( and and the rat rate of consolidation can also be measured using the results of thic"ness changes of sample against time during a load step. #hen, we will be able to predict how a soil in the field will deform in response to a change in effective stress.
O"#ECTI+ES
During this laboratory we will learn about* •
$ne dimensional consolidation equipment
•
Consolidation behavior of cohesive soils
•
#o determine the compression index 'C c(, swelling index 'C s( and coefficient of permeability '" v(
PREPARATION O THE SOIL SPECIMEN OR THE TESTS
#he diameter, height and weight of the consolidation ring are measured. #he consolidation ring is then lubricated with silicon grease. #he soil specimen is extruded to the consolidation ring from the sampling sampling tube. #he cutting wire is used to cut the soil sample upon extrusion. extrusion. +xcess soil sample from the extrusion is tested for its moisture content. PROCEDURE
With the lower porous disc located centrally on the base of the cell, the consolidation ring and specimen 'cutting edge upper most( are lowered centrally on to the disc. #he ring retainer and cell body are fitted around the ring so that it is securely held and the fixing nuts are tightened progressively. )n some types of cell, the body itself acts as the ring retainer. #he upper porous disc is placed centrally on top of the specimen, chec"ing that the clearance is equal all round. #he spigot is located on the loading cap into the recess into the upper disc, so that the caps fit centrally. #he cell is fitted in load frame and the loading yo"e is set up. #he beam is ad%usted and the dial gauge is set up.
Weights Weights are added to the load hanger to give the required pressure of , -, /, 0//, -//, 1//, 2//, 0// and 3-// "4a. 5owever the initial applied pressure is dependent on the softness of the soil. )n the test, the initial pressure pressure of - "4a is applied applied and the weight weight is placed carefully carefully on the load hanger. 6ill in water into the soil after - minutes. #he settlement readings are then ta"en at time of /, 0/, -/, 3/, 1/, /s 7 0, -, 1, 2, 0, 3/ min 7 0, -, 1, 2, -1 hours. After -1 hours, the weight is added and the quantity of weight must be twice more than the previously applied weight. 8nloading* After the maximum loading is applied on the soil and all the settlement readings are recorded, unloading should ta"e place not all at once but in a series of decrements. 8sual practice is to unload and allow swelling in about half the number of stages as were applied during consolidation, with not less than two loading stages. 9efore ta"ing off any weight from the hanger, the cloc" is set to ero, and the beam support is winded up so that it %ust touches the beam. #he beam is held down firmly against the support while the weights are removed: this requires a second person, except when only small weights are being removed. #he dial gauge is chec"ed so that it shows little or no movement. #he beam is released, and at the same instant the cloc" is started. #here is no need to wind down the wind support because the beam will rise as the specimen swells. #he upper loading cap is ensured to be remained covered with water. ;eadings of the compression gauge are ta"en exactly as the consolidation stages. After unloading, a specimen of the tested soil is ta"en for moisture content test in drying oven at 0/
a. #v = cv.t>'5>-(- at ?/@ and /@ degree of consolidation, with the corresponding time factor, #v = /.212 and /.0? respectively. b. With the use of #aylor #aylor and Berchant method '0?1/(, c v = /.212'5>-( ->t?/ where 5 is the specimen height c. With With the use of Casa Casagr gran ande de 'log 'log time time(( meth method od,, c v = /.0?'5>-(->t/ where 5 is the specimen height
d. Calculate Calculate the coefficient coefficient of volume volume compressib compressibility ility,, mv mv = 'e>p(0>'0Ee/((F = 5>'5/.p( where, e = change in void ratio eo = initial void ratio 5 = Change in specimen height 5/ = )nitial height of the specimen p = Goad increment '"H>m -( e. 4lot the the void ratio ratio versus versus the logarith logarithmic mic of pressur pressuree 'e!log p curve(. curve(. #hen determin determinee the compression and swelling indexes 'C / and Cs( f. Calcula Calculate te the the coeffi coefficien cientt of perm permeabi eability lity,, " v " v = cv.mv.Iw RESULT ROM E,PERIMENT
Jeneral data Bass of the ring E glass plate = 0.0 g Bass of specimen E ring = 01. g Bass of soil specimen = . g )nside diameter of the ring = 12. mm 5eight of specimen, 5 i = -/ mm Area of specimen, A = 023 mm - = 02.3 cm Specific gravity of solids, J s = -. After test Bass of can = 0. g Bass of can E wet soil = 011.// g
Bass of wet specimen = -./ g Bass of can E dry soil = 0-2.// g Bass of dry specimen, B s = . g 6inal moisture content of specimen, w f = =
72.50 – 56.5 56.5
x 100 =28.32
CALCULATIONS
Bass of dry specimen after test, B s = . g Bass of water in specimen after test, B wf = = wf x x Bs= /.-23- x . = 0.// g 5eight of solids, 5 s =
Ms A x Gs x ρw
56.5
=
−3 1863 x 2.7 x 1 x 10
= 00.-3 mm
'same before and after test and note K w = 0 g>cm3( Ms
Dry density before test, K d =
Hi x A
56.5
=
20.00 x 1863
=1.516 g>mm3
Da- 1 2* /o0rs Loa 245
#ime 's(
Dial gauge '/.//0 mm(
/ 0/ -/ 3/ 1/ / / 0-/ -1/ 12/ ?// 02// 3// 21//
/.?3 /./ /.0/.02 /.-/.- /.-? /.12 /.0 /.2/3 /.23 /.2 /.2/.23
Consolidation pressure =
force area
#otal #o tal settlement = /.23mm
Da- 2 *( /o0rs Loa *45
#ime 's 's(
Dial ga gauge '/ '/.//0 mm(
/ 0/ -/ 3/
0./0 0./23 0./? 0.0/3
=
mg πd ² / 4
=
2 × 9.81 1.863 × 10
−3
= 0/.3 "H>m -
1/ / / 0-/ -1/ 12/ ?// 02// 3// 21//
0.00/ 0.001 0.002 0.01 0.022 0.-3/ 0.-11 0.-0 0.- 0.-/
Consolidation pressure =
force area
#otal #o tal Settlement = 0.-/ mm
Da- 3 %2 /o0rs Loa ( 45
#ime's( / 0/ -/ 3/ 1/ / / 0-/ -1/ 12/ ?// 02// 3// 21//
Dial Jauge 'mm( 0.10/ 0.110 0.10.12 0.13 0.1 0.1/ 0.12? 0.0 0.2/ 0.?3 0.// 0./ 0./?
=
mg πd ² / 4
=
4 × 9.81 −3 1.863 × 10
= -0./ "H>m-
Consolidation pressure =
force area
mg
=
πd
2
8 × 9.81
=
1.863 × 10
4
−3
= 1-.03 "H>m-
#otal #o tal Settlement = 0./? mm
U67oa *45
#ime 's 's(
Dial ga gauge '/ '/.//0 mm(
//
0.-11
Consolidation pressure =
force area
=
mg πd ² / 4
=
mg πd ² / 4
=
4 × 9.81 1.863 × 10
−3
= -0./ "H>m -
Loa 245
#ime 's(
Dial gauge '/.//0 mm(
//
0.--1
Consolidation pressure =
force area
=
2 × 9.81 −3 1.863 × 10
= 0/.3 "H>m-
Loa 245
Taylor's (Root ( Root Time) Graph 0.00 0.65
5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00
0.7
0.75
Dial gauge readings (m (mm) m) 0.8
0.85
0.9
√T (min)
6rom #aylorLs #aylorLs ';oot time( graph, M#?/ = .- min #?/ = -./1 min
0.848
Cv =
( ) H
2
2
t 90
0.848
=
(
20
−0.873 2
)²
27.04
= -.22 mm>min
×
1440 x 365 6
10
= /.02 m ² >year Loa 245
Casagandre (Log Time) Graph 0.10 0.65
10.00
1000.00
0.7
0.75
Dial gauge readings (mm) 0.8
0.85
0.9
T (min)
100000.00
t/ = 1.1 min 0.197
Cv =
0.197
=
H
(
2
)²
t 50
(
20
−0.873 2
)²
4.4
= 1./? mm>min
×
1440 x 365 6
10
= /.-0- m ² >year
Loa *45
Taylor's (Root ( Root Time) Graph 0.00 0.95
10.00
20.00
1 1.05 1.1
Dial gauge readings (m (mm) m) 1.15 1.2 1.25 1.3
√T (min)
30.00
4 0. 0 0
6rom #aylorLs #aylorLs ';oot time( graph, M#?/ = 1.0 min #?/ = 0.20 min 0.848
Cv =
( ) H
2
2
t 90
0.848
=
(
20.00
−1.26
2 16.81
= 1.1-? mm>min
×
= /.-33 m ² >year
Loa *45
)²
1440 x 365 6
10
Casagandre (Log Time) Graph 0.10 0.95
10.00
1000.00
1
1.05
1.1
Dial gauge readings (mm) 1.15
1.2
1.25
1.3
T (min)
t/= -. min 0.197
Cv =
0.197
=
H
(
2
)²
t 50
(
20
−1.260 2
)²
2.6
= .- mm>min
×
= /.3/ m ² >year
1440 x 365 6
10
100000.00
Loa (45
Taylo T aylor's r's (R (Root oot Time) Time) Graph 0.00 0.0 0 5. 5.00 00 10 10.0 .0015. 015.0020 0020.0 .0025. 025.0030 0030.0 .0035. 035.0040 0040.00 .00 1.3 1.35 1.4 1.45
!ial "a#"e rea$i"s (mm) 1.5 1.55 1.6 1.65
√T (mi)
6rom #aylorLs #aylorLs ';oot time( graph, M#?/ = 3 min #?/ = ?./ min 0.848
Cv =
( )
2
2
t 90
0.848
=
H
(
20
−1.609 2
9.0
)²
= .? mm>min
= /.10? m
²
×
1440 x 365 6
10
>year
Loa (45
Casagandre (Log Time) Graph 0.10 1.35
10.00
1000.00
1.4
1.45
Dial gauge readings (mm)
1.5
1.55
1.6
1.65
T (min)
t/= 3.1 min
100000.00
0.197
Cv =
2
)²
t 50
0.197
=
H
(
(
20
−1.609 2
)²
3.4
×
= 1.2?? mm>min
1440 x 365 6
10
= /.- m ² >year
#hus, mv =
1
∆e ∆p
N
1
+e
0
=
∆ H H o ∆ p
1.609
=
20.00 x 42.13
= 0.?0/ × 0/!3 m->"H Choose higher value of C v from Casagrande and #aylor #aylor method, Cv = /.10? m->year " v = cv.mv.Iw = /.10? x 0.?0/ = .20 × 0/!3
×
0/!3 x ?.20
+oi Ratio ∆e
∆ H H S
=
H − H S
=
H S
&oid ratio, e = e / ! ∆ e e/
=
H 0 − H S H S
= '-/.// O 00.-3( > 00.-3 = /.20 6or -"g load, 0/.3 "4a ∆e
= /.23 > 00.-3 = /./2 = e/ ! ∆ e
e
= /.20 O /./2 = /./3 6or 1"g load, -0./ "4a ∆e
= 0.-/ > 00.-3 = /.00= e/ ! ∆ e
e
= /.20 O /.00= /.? 6or 2"g load, 1-.03 "4a ∆e
= 0./? > 00.-3 = /.013 = e/ ! ∆ e
e
= /.20 O /.013 = /.32 6or 1"g 'unloading(, -0./ "4a ∆e
= 0.-11 > 00.-3 = /.000
= e/ ! ∆ e
e
= /.20 O /.000 = /./
6or -"g 'unloading(, 0/.3 "4a ∆e
= 0.--1 > 00.-3 = /.0/?
e
= e/ ! ∆ e = /.20 O /.0/? = /.-
Loa8 P N
Lo5 P
0/3/ -0// 1-03/ -0// 0/3/
1./-1.3-3 1.- 1.3-3 1./--
∆ H
/.23 0.-/ 0/? 0.-11 0.--1
'mm(
+oi ratio8 e
/./3 /.? /.32 /./ /.-
Graph o% &oi$ Ratio a"aist o" 0.42 0.4 0.38
&oi$ Ratiio e
0.36 0.34 0.32 0.3 3.8
3 .9
4
4.1
lo"
6rom the graph of e against log p, Compression index, C c = the gradient 0.386− 0.338 = 4.47 −3.91 9 $.$(:
Swelling index, Cs
= the gradient 0.399−0.324 = 4.19−3.89 9 $.2;$
4.2
4.3
4.4
4.5
DISCUSSIO *osoli$atio is a metho$olo"y +y ,hi-h soils $imiish i ol#me. /s i$i-ate$ +y arl o Tera"hi -osoli$atio is ay pro-e$#re ,hi-h i-l i-l#$ #$es es a less lesse ei i" " i ,ate ,aterr s#+s s#+sta ta-e e o% imme immers rse$ e$ soil soil ,ith ,itho# o#tt s#+stit#tio o% ,ater ia air. as a r#le it is the metho$olo"y i ,hi-h $imiishmet i ol#me happes +y remoal o% ,ater #$er lo" ha#l stati- +#r$es. t happes ,he aiety is -oe-te$ to a $irt that -a#ses the the $irt $irt parti arti-l -les es to pa- pa- to"e to"eth ther er all all the the mor more rml rmly y i this this ,ay ,ay $imiishi" its mass ol#me. /t the poit ,he this happes i a $irt that is immerse$ ,ith ,ater ,ater ,ill +e presse$ o#t o% the $irt. The sie o% -osoli$atio -a +e ati-ipate$ +y ario#s strate"ies. the *lassi-al etho$ "re, +y Tera"hi soils are trie$ ,ith a oe$ometer test to %o-#s their press#re re-or$. This -a +e #tilie$ to ati-ipate the meas#re o% -osoli$atio. he h e st strress is rem emo oe$ e$ %r %rom om a -o -os sol oli$ i$at ate$ e$ so soil il th the e so soil il ,i ,ill ll re+o#$ re"aii" some o% the ol#me it ha$ lost i the -osoli$atio pro-ess. % the stress is reapplie$ the soil ,ill -osoli$ate a"ai alo" a re-ompressio -#re $ee$ +y the re-ompressio i$e. The soil ,hi-h ha$ its loa$ remoe$ is -osi$ere$ to +e oer -osoli$ate$. This is the -ase %or soils ,hi-h hae preio#sly ha$ "la-iers o them. The hi"hest stress that it has +ee s#+e-te$ to is terme$ the pre-osoli$atio
stress.
The oer -osoli$atio ratio or :*R is $ee$ as the hi"hest stress epe e peri rie e-e -e$ $ $i $ii i$e $e$ $ +y th the e -# -#rrre ret t str stress ess.. / so soil il ,h ,hii-h h is -# -#rr rre etl tly y eperieepe rie-i" i" its hi"he hi"hest st str stress ess is sai$ to +e ormally ormally -osoli$ate$ -osoli$ate$ a$ a$ to hae ha e a :* :*R R o% o oe. e. / so soil il -o -o#l$ #l$ +e -o -osi si$e $erre$ # #$e $err -o -os sol oli$ i$at ate$ e$ imme$iately a%ter a e, loa$ is applie$ +#t +e%ore the e-ess pore ,ater press#re press#r e has ha$ time to $issipate.
;rom the eperimet ,e hae #se$ seeral loa$s to o#r spe-ime i or$er to o+tai the re<#ire$ set o% "a#"e to plot the "raphs. =y o,i" the al#es o% oi$ ratio a$ -osoli$atio press#re the "raphs o% e>lo" p ,as $ra,. $etermii" the al#es o% * *asa"ra$e metho$ a$ Taylor T aylor metho$ are are #se$. *asa"ra$e?s step o% $etermii" *
!rthur Casagrande's graphi"al method @si" a -osoli$atio -#reA 1. *hoose +y eye the poit o% maim#m maim#m -#rat#re -#rat#re o the -osoli$atio -osoli$atio -#re. 2. !ra, a horio horiotal tal lie %rom %rom this poit poit 3. !ra, a lie ta"et ta"et to the -#re at the poit %o#$ i part 1. 4. =i =isese-tt th the e a a"l "le e ma ma$e $e %r %rom om th the e ho hori rio ot tal al li lie e i pa part rt 2 a a$ $ th the e ta"et lie i part 3. 5. Bte Bte$ $ the stra strai"ht i"ht portio portio o% the ir"i ir"i -ompressio -ompressio -#re (hi"h eCe-tie stress lo, oi$ ratioA almost erti-al o the ri"ht o% the "raph) #p to the +ise-tor lie i part 4. The poit ,here the lies i part 4 a$ part 5 iterse-t is the pre-osoli$atio press#re. *asa *a sa"r "ra a$e $e me meth tho$ o$ al also so o, o, as th the e lo lo" " ti time me me meth tho$ o$.. ;rom o# o#rr -al-#latio +y #si" *asa"ra$e?s metho$ ,e "et the * al#e is 0.350 m2Dyear ,hereas #si" Taylors metho$ * al#e is 0.419 m 2Dyear. The ,e $e $e-i -i$e $e$ $ to ta ta e th the e hi hi"h "hest est a al# l#es es to -a -all-#l #lat ate e th the e -o -oeE eE-i -ie ett o% permea+ility . The The -al-#late$ is 7.85110>3. Th#s *- -a +e $etermie$ +y -al-#late the "ra$iet o% -#re o% oi$ ratio s lo"arithmi- o% press#re (e>lo" p -#re) +y %ollo, this %orm#la A
P2 P1
¿ ¿
log ¿ C c =
e 2− e1
¿
;rom the eperimet al#e o% -ompressio i$e * - is 0.086. &oi$ ratio e is $epe$s o the loa$ p. /s the al#e o% p i-reases e ,ill -ease to $e-rease. Foil settlemet -a +e $ii$e$ ito 3 -ate"ories ,hi-h are Blastisettlemet (imme$iate settlemet) -a +e $es-ri+e$ +y the ooe?s la, rima rimary ry -osol -osoli$a i$atio tio settle settleme mett $#e to ep#l ep#lsio sio o% pore pore ,ater ,ater a$ Fe-o Fe-o$ar $ary y -osol -osoli$a i$atio tio settle settleme mett $#e to plasti plasti- a$#st a$#stme mett o% soil soil seletos. The meas#re o% soil ol#me -ha"e that ,ill happe is %re<#etly oe o% the represeti" -o"#ratio -riteria o% a #$ertai". : the oC -ha-e that the settlemet is ot ept as %ar as possi+leA the yeari" #tiliatio o% the str#-t#re may +e impe$e$ a$ the o#tlie li%e o% the str#-t#re may +e lessee$. t is -ose<#etly essetial to hae a metho$ %or epeepe-tat tatio io o% the meas#r meas#re e o% soil soil press# press#re re or -osoli -osoli$at $atio io.. t is lie,i lie,ise se -riti-riti-al al to o, o, the rate rate o% -osoli -osoli$at $atio io a$ i a$$iti a$$itio o the a""re"ate -osoli$atio ot o#t o% the or$iary. *osoli$atio all#$es to the press#re or settlemet that soils eperie-e as a rea-tio o% setti" +#r$e +#r $es s oto oto the "ro#$. "ro#$. /t the poit poit ,he ,he soae soae$ $ earth earth is sta- sta-e$ e$ remotely the ,ater ,ill -r#sh o#t o% the $irt oer <#ite a ,hile (+e-a#se o% lo, poro#sess o% the m#$). This prompts settlemets happei" oer <#ite a ,hile ,hi-h -o#l$ +e <#ite a lo" ,hile.
The "reatess o% the -ota-t settlemet relies o #po the a$apta+ility o% the esta+lishmet a$ the sort s ort o% soil. ;or sa$y soils ,hi-h are are pr pro% o%o# o#$ $ly ly pee peetr tra+ a+le le o por pore ,ei" ,ei"ht ht $ee $eelo lope pe$ $ ,he ,he ai aiet ety y i-remets. The pore ,ater $eplete$ a,ay <#i-ly. ;lei+le settlemet a$ a$ -os -osol oli$ i$at atio io happ happe e all all the the ,hil ,hile. e. ;or -lay -layey ey soil soils s ,hi,hi-h h are are e-e e-ept ptio ioa all lly y impe imperrmea+ mea+le le por pore ,ei" ,ei"ht ht is $ee $eelo lope pe$ $ ,he ,he ai aiet ety y i-remets. Ho prompt pore ,ater $epleti" e$lessly. e$lessly. t ,ill set asi$e ay lo"er time %or pore ,ater remoal. The pore ,ei"ht ,ill s-atter oer a lo" stret-h. *osoli$atio happes lo" a%ter a %ter Iei+le settlemet. The
oe>$imesioal
-osoli$atio
test
lie,ise
-alle$
the
oe$ometer or -osoli$ometer test ,hi-h is #tilie$ to a-<#ire settlemet a$ time parameters. The metal ri" limits the soil test alo" the si$e. *ose<#etly settlemet a$ seepa"e -a #st happe erti-ally i the -osoli -osoli$o $omet meter er (he-e (he-e%or %orth th oe>$i oe>$ime mesio sioal al). ). ;or ;or the "reat "reater er part part o% %#-tioal settlemet iss#es it is s#E-iet to -osi$er that +oth leaa"e a$ strais happe i oe -o#rse #stJ this typi-ally +ei" erti-al. /
"ee "eera rall
hypo hy poth thes esis is
%or %or
-os -osol oli$ i$at atio io
-os -osol oli$ i$at ati i" "
thr three> ee>
$imes $imesio ioal al stream stream e-tor e-tors s is -ool -ool#te #te$ $ a$ #st #st appro appropr priat iate e to a e-eptioally restri-te$ s-ope o% iss#es i "eote-hi-al $esi"i". /s a "ee "eera rall r# r#le le a eart earth h stra strat# t#m m ,ill ,ill $epl $eplet ete e ra$i ra$iall ally y ot, ot,it iths hsta ta$ $i i" " erti-ally. / 3>! test +e that as it may is e-eptioally tro#+lesome +oth to test a$ eamie. =esi$es there are a %e, slips happee$ i the eperimet that may iI#e-e the ea-tess o% the o#t-omes. ;irstly the paralla error s-ale per#si" opposite to his eye leel. There may +e a ero lapse o the istr#mets ,e #se to tae per#si". Het the i-oeie-e i tai" the the per# per#si si" " o% # #m+ m+er er o% $ial $ial "a"e "a"e $ii $iisi sio os s is aot aothe herr iss# iss#e e ,e -o%rote$ ami$ aalysis. There is a perio$ $iisio +et,ee the time ,here the eye,itess ,as to per#se the <#atity o% $ial "a#"e $iisios relati" to the -oe-te$ +#r$e a$ the real time ,here the spe-tator really too the per#si". oreoer eamples "ae may +e -ompa-te$
#$er hi"her +#r$e +ri"i" o the settlemet i the eamiatio ot all that sel%>ei$et. sel%>ei$et.
eepi" i mi$ the e$ "oal to $e-rease the lapses happee$ i the eperimet there are %e, steps sho#l$ +e tae. ;irstly maitai a strate"i- $ista-e %rom paralla mistae +y setti" the eye s#-h that the lie o% perspe-tie is opposite to the s-ale rea$. e hae a$$itioally -osi$er ero lapse o% istr#met. oreoer rehash the test %or a %e, times to "et the ormal al#es to "et more pre-ise res#lts.
CONCLUSION
6rom the experiment, we obtained that from CasagrandeLs method, we get the C v value is /.3/ m->year, whereas using #aylors method, C v value is /.10? m ->year. #he volume of compressibility, mv is 0.?0/x0/ !3 P ?.20 m->"H, and the compression index, Cc = /./2. #hus the swelling index Cs is /.-/ and coefficient of permeability permeabilit y is .20 x 0/ !3.
