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8/18/2019 Outline (Soil Liquefaction)
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Chapter 1
PROBLEM AND IT’S SETTING
1.1Backgroun o! the Stu"
The composition, moisture, and compaction of soil are all major factors
in determining the erosivity during rainfall. Sediments containing more clay
tend to be more resistant to erosion than those with sand or silt, because the
clay helps bind soil particles together.
Liquefaction is commonly used to be describing all failure mechanisms
resulting from the build-up of pore pressure during undrained cyclic shear
of saturated soil (astro an !oulos "#$$%.
&y narrowest definition, true liquefaction refers only to the flow of soil
under static shear stress that e'ceeds the undrained, residual shear
resistance of a contractive soil (astro "#$%. Liquefaction of loose,
cohensionless soils can be observed under both monotonic and cyclic shear
loads.
)lthough earthqua*es often triggers this increase in water pressure, but
activities such as blasting can also cause an increase in water pressure.
+hen liquefaction occurs, the construction above it decreases the strength
and the ability of a soil deposit to support the soil.
roundwater, sand and soil combine during seismic sha*ing to form
liquefaction during a moderate to powerful earthqua*e. ) quic*sand li*e
soil is the result of this process. +hen liquefaction ta*es place under
buildings the foundations sin* and the building collapse. )fter the
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earthqua*e, the soil firms again and the water settles deeper in the ground.
)reas with sandy soil and groundwater close to the surface are far more at
ris* of liquefaction.
arthqua*es accompanied with liquefaction have been observed for
many years. n fact, written records dating bac* hundreds and even
thousands of years have descriptions of earthqua*e effects that are now
*nown to be associated with liquefaction. /owever, liquefaction has been
so common in a number of recent earthqua*es that is often considered to be
associated with them.
The effects of soil liquefaction on the built environment can be
e'tremely damaging. &uildings whose foundations bear directly on sand
which liquefies will e'perience a sudden loss of support, which will result
in drastic and irregular settlement of the building causing structural damage,
including crac*ing of foundations and damage to the building structure
itself, or may leave the structure unserviceable afterwards, even without
structural damage. +here a thin crust of non-liquefied soil e'ists between
building foundation and liquefied soil, a 0punching shear0 type foundation
failure may occur. The irregular settlement of ground may also brea*
underground utility lines. The upward pressure applied by the movement of
liquefied soil through the crust layer can crac* wea* foundation slabs and
enter buildings through service ducts, and may allow water to damage the
building contents and electrical services (nstitution of !rofessional
ngineers of 1ew 2ealand, 3445%.
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The soil holding &ato lementary School is slope and steep. +ithout
further studies of the soil, its properties, type of soil, particle si6e analysis,
liquid limit, plastic limit, moisture content, specific gravity, porosity, void
ratio and unit weight, the structure and lives of students and teachers are in
ris* since soil liquefaction and erosion are such things that is unstoppable
by human.
The researchers resolve in leading on this study is to ensure the safety of
the students and the structure, to give them *nowledge and awareness on
their surroundings particularly for probable soil liquefaction.
1.# State$ent o! the Pro%&e$
This study aims to evaluate the condition of the soil for the possible
occurrence of soil liquefaction and erosion. Specifically, this study is
e'pected to answer the following questions7
". +hat *ind of soil &ato lementary School has8
3. +hat properties of soil do &ato lementary School has8
9. +ill soil liquefaction and erosion occur on this *ind of soil and load8
:. ;oes the soil need to be stabili6ed for it to hold the school8
5. ;oes the site needed to be evacuated8
1.'Theoret(ca& )ra$e*ork
1.+ Scope an L($(tat(on, o! the Stu"
This study is e'pected only to evaluate the soil of &ato lementary
School for the possible soil erosion and liquefaction to occur. n addition,
n-situ Soil Sample
(ndependent
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the design of the erosion control wall will be reliable in case of soil erosion
to occur.
1.- S(gn(!(cance o! the Stu"
The researchers believe that the findings on the test will give *nowledge
and awareness to the students and teachers of &ato lementary School
about the land they are stepping everyday. This study will show them how
important the stability of soil not only for structures but also for the living
things above it. =or the parents of the students, it will give them assurance
that their children is in a safe place to study. Since any parents always wants
their children to be away from harm and danger. 1o parent in the world
wishes their son>daughter to be injured.
1. De!(n(t(on o! Ter$,
n this section, definition of terminology is given so that the readers of
this study will easily refer to this section which will provide definition of
words that they might find hard to understand.
Bore /o&e- a narrow shaft bored in the ground, either vertically or hori6ontally.
Ero,(t(0(t"- is the ability to cause erosion.
S(&t- a granular material of a si6e somewhere between sand and clay, whose
mineral origin is quart6 and feldspar.
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C&a"- is a fine-grained natural roc* or soil material that combines one or more
clay minerals with traces of metal o'ides and organic matter.
San- is a naturally occurring granular material composed of finely divided
roc* and mineral particles.
C"c&(c Shear- is the distribution of forces (a*a stresses% that change over time
in a repetitive fashion.
Monoton(c
Shear- forces in which it does not change throughout the period.
Punch(ng Shear- a type of failure of reinforced concrete slabs subjected to
high locali6ed forces.
Sta%(&(t" o! ,o(&- is the potential of to withstand and undergo movement.
/o&ocene Epoch- is the current geological epoch which started some "",544
years ago when the glaciers began to retreat.
Ce$entat(on- The new pore-filling minerals form ?bridges? between original
sediment grains, thereby binding them together.
Shear Re,(,tance- the ability to resist sliding failure.
Pheno$enon- a fact or situation that is observed to e'ist or happen, especially
one whose cause or e'planation is in question.
Saturate So(&- ) condition of soil in which all easily drained voids (pores%
between soil particles are temporarily or permanently filled with water
D(&ate- ma*e or become wider, larger, or more open.
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Su,cept(%(&(t"- the state or fact of being li*ely or liable to be influenced or
harmed by a particular thing.
Gra0e&&" ,o(&- soil composed mostly of gravel.
Per$ea%(&(t"- is a measure of the ability of a porous material (often, a roc* or
an unconsolidated material% to allow fluids to pass through it.
P&a,t(c L($(t- is the water content, in percent, at which a soil can no longer be
deformed by rolling into 9.3 mm ("> in.% diameter threads without crumbling.
L(u( L($(t- is conceptually defined as the water content at which the
behavior of a clayey soil changes from plastic to liquid.
2n(t 3e(ght- the weight per unit volume of a material.
)au&t- n geology, is a planar fracture or discontinuity in a volume of roc*,
across which there has been significant displacement as a result of roc* mass
movement.
Tre$or,- a slight earthqua*e.
Ep(center- the point where an earthqua*e or underground e'plosion originates.
So(& )a%r(c- is the geometric or spatial arrangement of individual soil particles
and voids while structure includes the organi6ation of soil constituents into
larger aggregates or compound particles.
Propagat(on- The motion of a wave throughout a medium or the transfer of its
energy.
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RE4IE3 O) RELATED LITERAT2RE
This chapter presents the supporting information and details that might
be needed to perform the research study.
)ccording to @oud and !er*ins, "#$, Soils deposited prior to the
/olocene epoch (more than "4, 444 years old% are usually not prone to
liquefaction, perhaps due to wea* cementation at the grain contacts.
Liquefaction is a phenomenon wherein mass of soil loses a large
percentage of its shear resistance, when subjected to monotonic, cyclic or
shoc* loading and flows in a manner resembling of a liquid until the shear
stresses acting on the mass are as low as the reduced shear resistance
(Sladen, "#5%.
Liquefaction results from the tendency of soils to decrease in volume
when subjected to shearing stresses. +hen loose, saturated soils are
sheared, the soil tend to rearrange into a more dense pac*ing, with less
space in the voids, as water in the pore spaces is forced out. f drainage of
pore is impeded, pore water pressures increase progressively with the shear
load. This leads to the transfer of stress from the soil s*eleton to the pore
water precipitating a decrease in effective stress and shear resistance of the
soil. f the shear resistance decreases less than the static, driving shear
stress, the soil undergo large deformations and is said to liquefy (Aartin et
atB Seed and driss "#3%.
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+hen dense sands are sheared monotonically, the soil gets compressed
first, and then it gets dilated as sand particles move up and over one another.
+hen dense saturated sands are sheared, impeding the pore water drainage,
their tendency of volume increase results in a decrease in pore water
pressure and an increase in the effective stress and shear strength. +hen
dense sand is subjected to cyclic small shear strains under undrained pore
water conditions, e'cess pore water pressure may be generated in each load
cycle leading to softening and the accumulation of deformations. /owever,
at lager shear strains, increase in volume relieves the e'cess pore water
pressure resulting in an increased shear resistance of the soil (&iswas and
1ai*, 34"4%.
haracteristics of the soil grains li*e distribution of shapes, si6es, shape,
composition etc. influence the susceptibility of a soil to liquefy. +hile sands
or silts are most commonly observed to liquefy, gravelly soils have also
been *nown to have liquefied (Seed "#$#%.
shihara ("##9% gave the theory that non-plastic soil fines with dry
surface te'ture do not create adhesion and hence do not provide appreciable
resistance to particle rearrangement and liquefaction.
Coester ("##:% stated that sandy soils with appreciable fines content
may be inherently collapsible, perhaps because of greater compressibility of
the fines between the sand grains.
!ermeability also plays a significant role in liquefaction. +hen
movement of pore water within the soil is retarded by low permeability,
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pore water pressures are li*ely to generate during the cyclic loading. Soils
with large non-plastic fines content are more li*ely to get liquefied because
the fines inhibit drainage of e'cess pore pressures. The permeability of
surrounding soils also affects the vulnerability of the soil deposit. Less
pervious soils such as clay can prevent the rapid dissipation of e'cess pore
water pressures that may have generated in the adjacent saturated sand
deposit. Sufficient drainage above or below a saturated deposit may inhibit
the accumulation of e'cess pore water pressure and hence liquefaction.
ravelly soils are less prone to liquefaction due to a relatively high
permeability unless pore water drainage is impeded by less pervious,
adjoining deposits (&iswas and 1ai*, 34"4%.
So(& &(ue!act(on Occurrence (n the Ph(&(pp(ne,
Liquefaction was widespread in various parts of 1orthern Lu6on during
the recent "D Euly "##4 !hilippine arthqua*e which registered a magnitude
of $. on the Fichter scale. The !hilippine government, through the
;epartment of nvironment and 1atural Fesources (;1F% and the
;epartment of Science and Technology (;GST% is underta*ing steps to
mitigate the effects of future major earthqua*e not only in areas affected by
the above mentioned event but also in other developed and liquefaction
prone areas in the country. !art of that effort is the project study reported
herein (Feyes et al, 34""%
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Soil liquefaction and associated ground deformations caused e'tensive
damage to residential buildings and lifeline facilities in many areas in
hristchurch ity (1ew 2ealand% during the 34"4 ;arfield arthqua*e.
Twenty years earlier, the "##4 Lu6on (!hilippines% earthqua*e also caused
widespread damage in ;agupan ity due to liquefaction. This paper
compares the liquefaction phenomenon observed in bot earthqua*es, with
emphasis on the characteristics of the sites affected by liquefaction, the
e'tent of ground deformations observed and the influence of liquefaction-
induced settlement and lateral spreading on the built environment (Grense,
34""%.
+ith the anticipated magnitude $.3 earthqua*e triggered by the +est
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+ithout having any magnitude of earthqua*e, liquefaction occurred in
&enguet ity. Large area of soil in the hill of &enguet move and slideHs
down from the hill. Aany houses and structures that have been constructed
in the lower level in the hill are totally damaged (!hilippine ;aily nquirer,
34"5%.
)ccording to ;eocampo, ;avao city specialist of the !hivolcs, 34"5
that, starting last year, we have been updating young active fault map since
it has been done a decade ago. Gne of the initial things that the geologists
have seen was the new active faults within ;avao ity.
;eocampo, 34"5 stated, we are not releasing this initially and we will do
additional surveys and maybe some trenching for the actual location of the
fault and then we will ma*e it official. The !hilippine fault 6one is a very
active fault, so although won0t say alarming, it0s best to be prepared all the
time as we *now earthqua*e canHt be predicted.
n addition, even tremors felt in the ity of Aati can have a greater
impact in ;avao, since the city0s underlying soil material is softer compared
to Aati. +hat will happen is, the intensity here in ;avao will be higher than
in Aati due to ground sha*ing even Aati has the epicenter (;eocampo,
34"5%.
)actor, A!!ect(ng So(& L(ue!act(on
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Since liquefaction is associated with the tendency for soil grains to
rearrange when sheared, anything that impedes the movement of soil grains
will increase the liquefaction resistance of a soil deposit. !article cementation,
soil fabric, and aging I all related to the geologic formation of a deposit- are
important factors that can hinder particle arrangement (Seed, "#$#%.
Some investigators use the term Jlimited liquefactionK for conditions
where large deformations after initial liquefaction are prevented by an increase
in the undrained shear strength (=inn "##4%.
Stress history may also contribute to the liquefaction resistance of older
deposits. Gverconsolidated soils having been subjected to greater static
pressures in the past, are most resistant to particle rearrangement and
liquefaction. Soil deposits subjected to past cyclic loading are usually more
resistant to liquefaction as the soil grains tend to be in a more stable
arrangement but some deposits may loosened by previous sha*ing.
n addition, the frictional resistance between soil grains is proportional
to the effective confining stress. onsequently, the liquefaction resistance of a
soil deposit increases with the depth as the effective overburden pressure
increases. =or this reason, soil deposits deeper than about "5m are rearly
observed to liquefy ( Crinit6*y et al. "##9%.
haracteristics of the soil grains( distribution of si6es, shape,
composition, etc.% influence the susceptibility of a soil to liquefy ( Seed, "#$#%.
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+hile liquefaction is usually associated with sands or silts, gravely soils
have also been *nown to liquefy. Founded soil particles of uniform si6es are
generally most susceptible to liquefaction (!oulos et al, "#5%.
+ell-graded sands with an angular grain shapes are generally less prone
to liquefy because of a more stable interloc*ing of the soil grains. Gn the other
hand, natural silty sand sediments tend to be deposited in a looser state, and
thus are more li*ely to e'hibit contractive shear behavior, than clean sands.
(Seed, "#$%.
Coester ("##:%, suggests that sandy soils with a significant fines content
may be inherently collapsible, perhaps due to the greater compressibility of
fines between sand grains.
n addition, as pointed out by Selig and hang ("#"% and Fobertson
("##:%, it is possible for a dilative soil to reach a temporary condition of 6ero
effective stress and shear resistance.
;uring an earthqua*e, the upward propagation of shear waves through
the ground generates shear stresses and strains that are cyclic in nature. f a
cohesionless soil is saturated, e'cess pore pressures may accumulate during
seismic shearing and lead to liquefaction. ( Seed and driss, "#3%.
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Ero,(on Contro& 3a&& a, counter$ea,ure to earthuake5(nuce &(ue!act(on an
So(& ero,(on
arthqua*e-induced liquefaction is a major cause of damage that needs
to be controlled by engineers. ) popular option for protecting against
liquefaction is the installation of gravel drains to relieve generated e'cess pore
pressures. sing these, it was possible to determine a time varying e'tent of
drain effectiveness, and a 6one of influence consisting of a conical volume of
soil from which draining fluid left the ground via the drain (niversity of
ambridge, 344:%
Soil erosion and surface runoff occurs as water moves along the ground.
The more e'posed the soil and the faster the rate of flow, the greater the
damage and the bigger the concern. t is imperative to ma*e certain a slope is
covered or planted so that erosion is minimi6ed. rosion is prevented by
shortening a potentially long slope into a sequence of more level steps. This
allows heavy rains to soa* in rather than run off, ta*ing soil with it. Thin* of
terraces li*e steps in an emban*ment. Soil is cut out of the hill to create the
level tread or landing area. )s with garden steps, the level area is not e'actly
level. Sloped terraces ought to be graded by about 3M perpendicular towards
the incline in order to gently direct drainage towards one side or the other.
(Landers, &. 34""%
Fetaining walls are yet another way to slow runoff and erosion but their
primary function is to support and retain an emban*ment. /owever, whatever
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the weight, it has to be strong enough to contain bac* the pressure of a great
amount of soil weight, yet porous enough to be suitable for adequate drainage.
(Landers, &. 34""%
MET/ODOLOG6
This chapter presents the methodology used in the study. Type of research,
research design, research equipment, research process and investigation of the
problem are here discussed.
n addition, a more precise definition of liquefaction as given by Sladen et
al ("#5% states that JLiquefaction is a phenomena wherein a mass of soil loses
a large percentage of its shear resistance, when subjected to monotonic, cyclic,
or shoc*ing loading, and flows in a manner resembling a liquid until the shear
stresses acting on the mass are as low as the reduced shear resistanceK
1.7 RESEARC/ DESIGN
The research design that was used in the study is e'perimental. )n
e'perimental research design is concerned with the e'amination of the
effect of the independent variable on the dependent variable, where the
independent variable is tested through the process to observe its effect to the
dependent variable.
1.8 S2B9ECTS:PARTICIPANTS
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n performing the e'periment> testing of in-situ soil, the researchers used
the soil samples from &ato lementary School through the use of data from
bore hole.
1.; RESEARC/ INSTR2MENTS
=or this study, borehole is needed. ) borehole is used to determine the
nature of the ground (usually below Dm depth% in a qualitative manner and then
recover undisturbed samples for quantitative e'amination.
Gbviously the information gained from a borehole is an e'tremely limited
picture of the subsurface structure. t is therefore essential to compare the
results obtained with those that could have been e'pected from the des* study.
The greater the number of boreholes the more certain it is possible to be of the
correlation and thus to trust in the results
)pparatus of Standard !enetration test7
". Tripod
3. Standard split-spoon sampler.
n consists of three parts7
a. ;riving shoe, about $5 mm long.
b. Steel tube about :54mm long, split longitudinally in two halves having
inner diameter as 9mm and outer diameter as 54mm.
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c. oupling at the top of the tube about "54mm long.
9. uide !ipe
:. ;rill rod
5. ;rop hammer weighing D9.5 *g.
Field Investigation
=ield investigation by the S!T was to be done at &ato lementary
School. The number of boreholes cone penetrometer test positions in each
location are as follows7
Location 1o. of &orehole S!T
&ato lemetary School 9 9
n the field investigation, S!T was conducted to obtain the necessary borehole
data needed for the study. n the same manner, the storage of data is categori6ed
into the S!T data. )ll data gathered using the washboring (S!T% method are in
the S!T Table. ;ata tables are stored in database files that are (conceptually% in
tabular form and containing all field and (in case of the S!T% laboratory test
data.
Drilling Procedure
The S!T was done in accordance with )STA specifications. =or each test,
a 3-inch (54. mm.% outside diameter split spoon sampler is driven a total
distance of " inches (:D4 m.% by means of a ":4 lb. (D9.5 *g.% driving head
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falling free from a distance of 94 inches ($D4 mm.%. The number of blows
needed to drive the sampler in D-inch ("59 mm.% increments is recorded and the
number of blows needed to drive the last "3 inches (944 mm.% is ta*en as the
1-value. Soil samples were recovered using the spoon sampler and were ta*en
to the soils laboratory for analysis and testing.
1.1< RESEARC/ PROCED2RE
Laboratory Test !rocedure
The laboratory tests performed on soil samples from the boreholes are
briefly described as follows7
". lassification of Soils for ngineering !urposes
The nified Soil lassification System (SS% was used to classify the
soils.
3. !article Si6e )nalysis
Soil is passed through a series of sieves and the weight of soil retained in
each sieve determined. ) graph is drawn relating the percent finer by weight
and the particle si6e on a semi-long scale. ;54 or equivalent particle
diameter (in mm% that equally splits the soil in coarser and finer fractions is
read off from this graph.
9. Liquid Limit
The liquid limit is the moisture content at the point of change between the
liquid and plastic states of the soil.
:. !lastic Limit
The plastic limit is the moisture content at the transition between the
semi-solid state and the solid state.
5. !lastic inde'
!N LL-!LD. Aoisture ontent
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+N (+eight of water > weight of oven-dry soil% ' "44M
.
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!a N "44 *!a
n should not e'ceed a value of ".$
BIBLIOGRAP/6
9u$p up = Hazen, A. (1920). Transactions o t!e A"erican #ociet$ o %ivil
&ngineers 83' 111*+.
9u$p up = -eologists arrive to stud$ liueaction . /ne es. 10 #ete"3er 2010.
4etrieved12 ove"3er 2011.
9u$p up = %!ristc!urc! areas to 3e a3andoned . T!e e 5ealand Herald . 5PA.
6arc! 2011.4etrieved 12 ove"3er 2011.
9u$p up = &H4P reco""ended rovisions or seis"ic regulations or ne
3uildings and ot!er structures (F&6A *+0). 7as!ington D.%.' ational Institute o
8uilding #ciences. 200*.
9u$p up = &199:+'200* &urocode Design o structures or eart!ua;e
resistance. Part +' Foundations, retaining structures and geotec!nical asects.
8russels' &uroean %o""ittee or #tandardisation.
200*. http7>>www.astm.org>Standards>;"5D.htm
9u$p up =
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9u$p up = 5atsua, 6onosagu (200+). 8eare, sot ground and t!e standard
enetration test (in aanese). Pu3lic 7or;s 4esearc! Institute.
Status of the borehole disposal project implementation in the !hilippines by Aaria
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!tts'nees.orgdataget... Soil 20 Liquefaction 20Introduction.doc
!tt'.!ivolcs.dost.gov.!!t"ludate#/&PD1990@uzon&J6onogra!1
19120.!t"l
.o"ara.gov.on.caenglis!engineeracts12:0+C.!t"
!tt'."erria":e3ster.co"dictionar$3ore!ole
.geo:sloe.co"...liquefaction 20assess"ent20it!20geostudi...
.livescience.co"1C?+:Kaan:eart!ua;e:soil: liquefaction.!t"l
!tts'.crcress.co"#oil:@iueaction:A:%ritical:#tate:Aroac!eeries:
8een90*191?10
!tt'.a"azon.co"#oil:@iueaction:%ritical:#tate:Aroac!d0*191?10
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http://earthquake.usgs.gov/earthquakes/map/https://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttps://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttps://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttps://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttps://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttps://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttps://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttp://www.phivolcs.dost.gov.ph/html/update_SOEPD/1990LuzonEQ_Monograph/pp119/pp120.htmlhttp://www.phivolcs.dost.gov.ph/html/update_SOEPD/1990LuzonEQ_Monograph/pp119/pp120.htmlhttp://www.omafra.gov.on.ca/english/engineer/facts/12-053.htmhttp://www.merriam-webster.com/dictionary/boreholehttp://www.geo-slope.com/.../liquefaction%20assessment%20with%20geostudihttp://www.geo-slope.com/.../liquefaction%20assessment%20with%20geostudihttp://www.geo-slope.com/.../liquefaction%20assessment%20with%20geostudihttp://www.livescience.com/13765-japan-earthquake-soil-liquefaction.htmlhttp://www.livescience.com/13765-japan-earthquake-soil-liquefaction.htmlhttp://www.livescience.com/13765-japan-earthquake-soil-liquefaction.htmlhttp://www.livescience.com/13765-japan-earthquake-soil-liquefaction.htmlhttp://www.livescience.com/13765-japan-earthquake-soil-liquefaction.htmlhttps://www.crcpress.com/Soil-Liquefaction-A-Critical-State-Approach/Jefferies-Been/9780419161707https://www.crcpress.com/Soil-Liquefaction-A-Critical-State-Approach/Jefferies-Been/9780419161707http://www.amazon.com/Soil-Liquefaction-Critical-State-Approach/dp/0419161708http://studymafia.org/soil-liquefaction-seminar-report-with-ppt-and-pdf/http://studymafia.org/soil-liquefaction-seminar-report-with-ppt-and-pdf/http://earthquake.usgs.gov/earthquakes/map/https://nees.org/data/get/.../Soil%20Liquefaction%20Introduction.dochttp://www.phivolcs.dost.gov.ph/html/update_SOEPD/1990LuzonEQ_Monograph/pp119/pp120.htmlhttp://www.phivolcs.dost.gov.ph/html/update_SOEPD/1990LuzonEQ_Monograph/pp119/pp120.htmlhttp://www.omafra.gov.on.ca/english/engineer/facts/12-053.htmhttp://www.merriam-webster.com/dictionary/boreholehttp://www.geo-slope.com/.../liquefaction%20assessment%20with%20geostudihttp://www.livescience.com/13765-japan-earthquake-soil-liquefaction.htmlhttps://www.crcpress.com/Soil-Liquefaction-A-Critical-State-Approach/Jefferies-Been/9780419161707https://www.crcpress.com/Soil-Liquefaction-A-Critical-State-Approach/Jefferies-Been/9780419161707http://www.amazon.com/Soil-Liquefaction-Critical-State-Approach/dp/0419161708http://studymafia.org/soil-liquefaction-seminar-report-with-ppt-and-pdf/http://studymafia.org/soil-liquefaction-seminar-report-with-ppt-and-pdf/