two-dimensionalparametricstudyofanembankmentonclay...

Research ArticleTwo-Dimensional Parametric Study of an Embankment on ClayImproved by an Artificial Crust Composite Foundation

Ying Wang12 Zhenhua Hu 1 Yonghui Chen2 and Hongtian Xiao1

1Shandong Key Laboratory of Civil Engineering Disaster Prevention and MitigationShandong University of Science and Technology Qingdao 266590 China2Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing 210098 China

Correspondence should be addressed to Zhenhua Hu skd994409sdusteducn

Received 21 April 2020 Revised 24 July 2020 Accepted 5 August 2020 Published 24 August 2020

Academic Editor Jia-wen Zhou

Copyright copy 2020 Ying Wang et al +is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

In order to reduce the foundation settlement conserve resources and be environmental-friendly while increasing the use of soilresources an artificial crust layer formed by in situ stabilization is proposed to combine with prestressed pipe piles over softground in road construction In this study a centrifuge test and two-dimensional coupled-consolidation finite-element analysesare conducted to simulate the construction of an embankment And a two-dimensional parametric study is conducted to study theperformance indicated by maximum long-term settlement excess pore water and tensile stress under various conditions +eresults of the centrifuge test clearly show that the measured settlement excess pore water and tensile stress are in good agreementwith the calculated results In addition the key factors of pile spacing and thickness and strength of the crust have an influence onthe maximum settlement stress of the foundation and tensile stress of the crust using the two-dimensional coupled-consolidationfinite-element analyses And the stress transfer regular of the foundation is analyzed under various conditions Moreover thefailure of the crust contained tensile cracking and shearing failure and the thickness of the pile that pierced the crust are alsoaffected by the key factors

1 Introduction

Settlement of the building and slope stability accidents areinduced by the construction of an embankment Obviouslyit is necessary to find an effective solution for treating softsoil Technological improvements of the foundation havebeen developed with conserving resources preventing en-vironmental pollution and increasing the use of soil re-sources Specifically it has been proposed to combineprestressed pipe piles with an artificial crust layer formed byin situ stabilization over soft ground during road con-struction in order to reduce the settlement of foundation

+e technology is called artificial crust compositefoundation or crust composite foundation +e artificialcrust formed by in situ stabilization with a higher com-pressive modulus and cohesion replaces the traditional sandcushion in pile-supported embankments which reduces thetotal and differential settlement and improves the global

stability of Earth structures on a deep soft soil layer It is acommon method to make the composite foundation withacceptable settlement so as to maintain the proper functionof the high standard road or the embankments on the softground

In order to conform to the engineering the interactionbetween foundation-cushion-load under rigid compositefoundation was studied by centrifugal model test [1ndash3]

It is common to apply numerical simulation method todescribe the characteristics of soil in the geotechnical en-gineering and the results of numerical analysis comparedwith the field engineering or model test are effectivedepending on the suited constitutive model of soil materialsIn addition it is difficult to obtain accurate results of theanalytical calculation owing to the limitation and com-plexity so there is a vast literature on methods to solve thebehavior of pile-supported embankments using the finite-element method (FEM) [4ndash17] +e values of numerical

HindawiAdvances in Civil EngineeringVolume 2020 Article ID 8858380 16 pageshttpsdoiorg10115520208858380

simulation method were determined based on the experi-ment [18ndash21] Plane-strain models are usually adopted inanalyzing the behavior of embankments on soft soil based onthe FEM while the columns are usually modeled as 1mcontinuous walls in a column-improved (including a pile-improved) deposit [22 23] +e results of lateral displace-ment and bending moment in the columns were incorrect inthe two-dimensional (2D) analysis under the toe of theembankment by Chai et al [23] However the results of thesettlement of the foundation and the excess pore pressurematch well with the results of the field-measured resultsusing a 2D model Based on these studies the maximumlong-term settlement and excess pore pressure could beanalysed by using the 2D FE model

+e work of a combined foundation improvementtechnology in this area is ongoing and varied For exampleJelisic and Leppanen [24] proposed the organic soft soiltreated by stabilization combined with lime piles anotherimportant constraint on all the work discussed in this area isthat no theoretical method exists +e primary method thathas been used in the literature [25 26] is a new method topredict the total settlement for a method combining sta-bilization and a floating-type deep cement mixing of the soilstabilization method based on several loading model testsAs far as we know there is no definite research on thebehavior study of an artificial crust combined with rigidpiles So in this study a centrifuge test and two-dimensionalcoupled-consolidation finite-element analyses were con-ducted to simulate the construction of an embankment forstabilization combined with rigid piles Based on the two-dimensional coupled-consolidation finite-element modelsthe impact of several key factors including pile spacingthickness and strength of the crust on the maximum long-term settlement excess pore water and tensile stress arediscussed Finally the influences of these factors are com-pared and evaluated according to their importance

2 Centrifuge Model Testing

+e centrifuge model tests were adopted in this paper +ecentrifuge model tests were performed at the GeotechnicalCentrifuge Facility of Hong Kong University of Science andTechnology [27] +e main purpose of the centrifuge modeltests is analyzing the stress and deformation in the crustcomposition foundation +e centrifuge test was performedat a centrifugal acceleration of 80 g (g denotes the Earthrsquosgravity) and completed in one flight+e plane dimension ofthe model box was 600mmtimes 100 mmtimes 310mm (ie48mtimes 8mtimes 248m in the prototype) the height of theembankment was 563mm (ie 45m in the prototype) thelength of the piles was 200mm (ie 16m in the prototype)the pile spacing was 375mm (ie 30m in the prototype)and the crust was with a thickness of 21mm (ie 168m inthe prototype) which are shown in Figure 1 Yao et al [28]had discussed the boundary effect of the side friction in thecentrifugal tests +e distance from the box edges was ap-proximately 100mm while in the paper the distance fromthe foot of the embankment to the box boundary was100mm

A digital camera was mounted at 450mm at the front ofthe transparent sidewall with a maximum resolution of2592times1944 pixels to capture digital images of the soil atvarious stages during the in-flight test Processing twosubsequent digital images quantified the movement of thesoil +e movement of the soil was corrected by particleimage velocimetry (PIV) analysis coupled with a close-rangephotogrammetry [29]

Model material and centrifuge modeling procedure weredescribed in detail by Wang et al [30 31] In this study porewater pressure sensors and strain gauges were used inaddition to measuring soil and pile motion In additionstrain gauges were installed at the bottom of the crust whichare shown in Figure 1 +e pore water pressure transducerswere installed underneath each embankment which wereadjacent to the middle pile to confirm the time effect atdepths of 313mm (ie 25m in the prototype) from thesurface of the ground

+e centrifuge model test was conducted to study theload responses and deformation in the crust compositefoundation In addition the deformation characteristics ofthe crust were also investigated Based on the investigationsthe following conclusions can be drawn

By the deformation it was found that the final middlesettlement of the crust composite foundation can be re-duced +e excess pore water pressure is lower during theloading period and the dissipation rate of the excess porewater pressure is slower at the same loading period +eexplanation for this event is that the stress can be spread andreduced due to the crust with the properties of plate +usthe consolidation rate became slower based on the lowpermeability of the crust

By comparing the axial force of the piles the axial forceof the middle pile is smaller However the axial force of sidepile is higher in the crust composite foundation +is can beexplained by the following observations the redistributionof foundation stress by the crust with the properties of platethe fully functioning bearing capacity of the side section andthe conflict between the crust and the subsoil +e largesttensile stress occurred in the middle of the crust and thecharacteristics of a similar plate were taken to depend on thetensile stress changing as well as on the maximum tensilestress occurring at the end of the construction In conclu-sion cracking damage of the crust occurred during theloading period

3 Finite-Element Analysis

31 Modeling +e centrifuge tests were backanalyzed topromote a better understanding of the centrifuge tests andcalibrate a constitutive model and its model parametersagainst the measured data

+e piles are usually modeled as continuous walls by thetwo-dimensional coupled-consolidation analyses using thefinite-element program PLAXIS 2D (Hohai University 2017Code CP12111492f4498588b0)

Due to symmetry only half of the finite-element modeland the boundary conditions were modeled as shown inFigure 2+emodeled area had a vertical thickness of 199m

2 Advances in Civil Engineering

from the ground surface and an overall horizontal width of24m +e soil and artificial crust domains were representedby 15-node triangular elements and the geosynthetic layerwas represented by 5-node geogrid elements +e pile iscalculated by plate element Slippage between the soil andthe piles was modeled by interface elements McDowell et al[32] assumed 01m thickness of the annulus +e bottomboundary displacements of the mesh were set to zero All thedegrees of freedom were constrained except for the verticalmovement

+e effective unit weight of filling below the groundwaterlevel was changed due to the effect of buoyancy when thefilling was settled into the groundwater with the loading theeffective unit weight decreased under the groundwater level+e update grid and water pressure were adopted in thisfinite-element program

32 Conversion of 0ree-Dimensional Problem into Two-Di-mensional Plane-Strain Model A three-dimensional modelwith a square column configuration can be simplified into atwo-dimensional plane-strain model in the equivalent areamethod [33] as follows

Dpprime

πD2p

4d (1)

where Dpprime is the width of the equivalent pile wall Dp is the

diameter of the isolated pile and d is the center-to-centerdistance in the direction perpendicular to the plane of theembankmentrsquos cross section However the three-dimen-sional character of the panel geometry cannot completely bereplaced by the equivalent area method +erefore theequivalent properties approach for the panels was adopted[5 34 35]

+e equivalent properties for the panels were calculatedbased on the weighted average area while keeping the panelwidth the same as in the three-dimensional geometry basedon the following equation

Eeq EpAp + EsAs

Ap + As

Eeq πDp

4dEp + 1 minus

πDp

4d1113888 1113889Es

(2)

Artificial crust layer

1875 115

125

562

521

25

221

25

248

75

275100400100

Geogrid

Embankment

A1

A2

A3

A4

A5

B1

B2

B3

B4

B5

Prestressed pipe with strain gauge

Strain gaugePorewater pressure transducer

(a)

Crust composition foundation

400100 100

100

375 (30m)

(b)

Figure 1 Schematic view and arrangement of a typical test model under (g) (unit mm) (a) Crust composite foundation (b) A planediagram

Advances in Civil Engineering 3

where Ep is the elastic modulus of the pile Es is the elasticmodulus of the soil Ap is the sectional area of the pile As isthe sectional area of the soil Eeq is the equivalent elasticmodulus of the panels

33 Constitutive Models and Parameters +e embankmentfill was modeled as an elastic-perfectly plastic material usingthe MohrndashCoulomb (MC) model +e firm clay at thebottom and the soft clay layers were modeled as the elastic-perfectly plastic materials using the Modified Cam-Clay(MCC) model +e material properties of the embankmentfill and the soil layers are presented in Table 1 In this tablethe values were determined based on experiment In addi-tion EA 1lowast 105 KNm was adopted for the geogrid Apartfrom these the model pile was modeled as a linear elasticmaterial +e elastic modulus of model pile was set 38GPaand the width of the equivalent pile wall and the equivalentelastic modulus of the panels were calculated by equations(1) and (2) and Poissonrsquos ratio was set as 015

Based on the hydraulic conductivity method by Chaiet al [23] the values of kv were estimated as twice the valuesof incremental loading consolidation tests deduced from thelaboratory +e values of the horizontal hydraulic conduc-tivity kh were set as 15 times the corresponding value of kvbased on the previous experiences

+e values of kv listed in Table 1 are initial values andduring consolidation they were allowed to vary with thevoid ratio according to the following equation

k k0 times 10 minus e0minuse( )ck)( (3)

where k0 initial hydraulic conductivity e0 initial voidratio k current hydraulic conductivity e current voidratio and ck a constant which was in this study assumedas ck 05e0

A permeability coefficient for cement treated soil in thepaper was 1lowast 10minus9

+e formation method for the artificial crust was thesame as that for the Deep Cement Mixing DCM columns+erefore the material properties of the crust are dependenton the DCM columns In the 2D FEmodel the artificial crustwas modeled as a linear elastic material and only the elasticmodulus of the crust was used After an extensive literaturereview Filz and Navin [4] proposed that the elastic modulusof DCM columns should be in the range of 50qundash250quwhenthe DCM columns are constructed by a dry mixing method+e values of quwere obtained from the laboratory un-confined compression test Bruce [36] and Porbaha et al [37]reported that the elastic modulus of DCM columns shouldbe 100qu Furthermore Yapage et al [35] suggested that thecorrelation between the elastic modulus and the unconfinedcompression strength E 118qu was used for the cement-stabilized soil

So E 100ndash300MPa was determined based on theunconfined compression strength and chosen for the 2D FEmodel And the Poisson ratio of artificial crust was set as015

4 Results and Discussion

In this paper interpretation of the results was only focusedon the responses of the ground and pile due to the

Drained

Fill

Artificial crust

Firm soil

Rigid pile

Geosynthetic

177

m2

2mPile spacing

20m

25m

ickness of the crust

10m

244

m

24m

Und

rain

ed

Und

rain

ed

So soil

x

y

0 4

112510 17 19 21 23

249 16 18 20 22 8

2 3

26

1

1312

6 7

75m 165m

Figure 2 +e 2D FE geometry model


construction of the embankment All results were presentedin the prototype scale unless otherwise stated

41 Results and Comparisons

411 Settlement Usually the settlement is one of the focusareas when an artificial crust composition foundation is usedfor supporting roadways railways etc In the past thesettlement at the base of the embankment had been focusedby most investigators because the long-term maximumsettlement occurred at this location However the post-construction settlement is actually a more direct indicatorand it is critical to the serviceability of the roads on theembankment [5] In this study the emphasis was placed onthe postconstruction settlement and the maximum long-term settlement

+e settlement based on the centrifuge experimentand the settlement-time history in the center of theembankment are shown in Figure 3 In addition Figure 3also shows the comparison between the measured andcomputed settlement values at the base of the embank-ment using the finite-element model +e settlement closeto the middle of the crust composite foundation mea-sured at the end of the construction (300 days) was180 cm On 2000 day assumed to be close to the end ofthe settlement period the maximum long-term settle-ment in the middle of the crust composite foundationswas 274 cm +e postconstruction settlement of the crustcomposite foundations was 94 cm in the prototype +isproject requires the residual settlement of the embank-ment and the road surface to be less than 03 m at thecompletion of construction [23]

+e measured maximum long-term settlement met theengineering requirements +e settlement was 254 cm at theend of the construction and the maximum long-term set-tlement in the middle of the crust composite foundationswas 284 cm using the finite-element model +e computedlong-term settlement values agreed well with the experi-mental measurements +erefore the influence of the key

factors on the settlement was demonstrated using the finite-element model

412 Excess Pore Water Pressure During the constructionand traffic loading excessive pore water pressure is gener-ated within soft soil which dissipates simultaneously in twoways hydraulically and mechanically (ie drainage and loadtransfer to the piles) [38] +e former way refers to a portionof the excessive pore water pressure dissipates by drainage+e corresponding load is transferred to the soil skeletonresulting in the increasing effective stress Meanwhile thelatter way mechanically as the effective stress in the soilincreases the soil tends to settle more than the piles Aportion of the load will be transferred to the piles on stresswithin the embankment because of the relative movementbetween the soft soil and the piles As a result the excessivepore water pressure in the soft soil will be dissipated muchfaster than by drainage alone

Traditional consolidation theories underestimate thedegree of consolidation owing to the artificial crust in theartificial crust composition foundation

In the study of the stress transfer and the consolidationrate of the subsoil the most direct performance was theexcess pore water pressure +e excess pore water pressure-time history curves are plotted in Figure 4 +e maximumexcess pore pressure near the surface of the ground wasapproximately 88 kPa based on the crust compositionfoundation and this value was recorded at the end of thesecond phase of construction +e maximum excessive porepressure in the clay was not high enough for a large portionof the embankment load was transferred to the piles as aresult of (1) soil arching within filling layers (2) shear stressdeveloping in the pile-soil interface and (3) dissipation ofgenerated excessive pore pressures during the construction[9]

In addition the stress was diffused owing to the highelastic modulus of the crust [26] +e comparison betweenthe measured and computed excess pore water pressureusing the finite-element model at the bottom of the crust is

Table 1 Material properties of the embankment and subsoil

Parameter Soft clay Firm clay Embankment fill+ickness (m) 177 22 45Material model MCC MCC MCMaterial type Undrained Undrained DrainedUnit weight c (kNm3) 152 166 19Saturated unit weight csat (kNm

3) 18 18 20Coefficient of lateral Earth pressure K0 09 063 mdashVoid ratio e0 159 20 mdashSlope of the isotropic normal compression line λ 04 0121 mdashSlope of the isotropic unload-reload line κ 0053 0011 mdashStress ratio M 0984 1277 mdashEffective friction angle φprime(degrees) mdash mdash 30Effective cohesion cprime(kPa) mdash mdash 01Poissonrsquos ratio ] 03 025 03Dilatancy angle Ψ mdash mdash 2Elastic modulus E (MPa) mdash mdash 20Permeability kv (cmday) 9times10minus4 8times10minus3 10


shown in Figure 4 +e computed maximum excess porepressure was approximately 84 kPa and the dissipation rateof the excess pore water pressure agreed well with the ex-perimental values +e finite-element model demonstrated

the influence of the key factors on the excess pore waterpressure

+e stress of soil in the crust composite foundation wasanalyzed by the pore water pressure+e pile that pierced the

30

25

20

15

10

5

0

30

25

20

15

10

5

0

Settl

emen

t (cm

)

Time (day)

Computed settlementMeasured settlement

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400

Figure 3 Measured and computed settlement at the base of the embankment

ndash2

0

2

4

6

8

10

ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

Computed valuesMeasured values

0 400 800 1200 1600 2000 2400

0 400 800

A

1200 1600 2000 2400

Figure 4 Measured and computed excess pore pressure at the base of the crust


crust was set at the contact position between pile and crustowing to the large difference in modulus between the crustand the rigid pile +e shear failure of crust occurred whenthe top stress of the pile reached the shear failure stress of thecrust oweing to the thickness of pile piercing the crust in-creased So the thickness of pile that pierced the crust isimportant to analyze in order to avoid the failure of thefoundation

Based on the analysis of the thickness of pile thatpierced the crust it is found that the thickness was relatedto the pile soil and crust as well as to the diameter andreplacement rate of piles +e thickness was analyzedbased on the theory of hole expansion in this paperFirstly it was assumed that (1) the soil between piles andthe crust was ideal elastic-plastic models +eMohrndashCoulomb failure criteria or Tresca failure criteriawere suggested to describe the materials (2) the shape ofthe pile at the top was hemispherical the internalpressure was assumed to be uniform and the internalpressures expand to the surrounding crust which was theinitial state According to the stress of foundationchanging the expansion pressure increased as the stressof the pile pp(0) at the top increased and the soil aroundthe spherical hole gradually entered the plastic state fromthe elastic state According to the stress developmentprocess see the following

When Pp(0)lePs the soil around the spherical hole wasin elastic state

ST r0(1 + ])pp(0)

EC

(4)

When Pp(0)gtPs the soil around the spherical hole wasin plastic state

ST r0

Ec

3(1 minus ])rp

r01113888 1113889

3

pe minus 2(1 minus 2])pp(0)⎡⎣ ⎤⎦ (5)

where pe is the ultimate expansion stresspe 4(c cosφ + σ0 sinφ)3 minus sinφ and pp(0) is the stress ofthe pile at the top

rp pp(0) + σ0 + c cotφ

pe + σ0 + c cotφ1113888 1113889

t

re

t 4 sinφ1 + sinφ

(6)

where σ0 is the initial stress and c φ are cohesion and frictionangle of the crust ST is the thickness of the pile that piercedthe crust

+e formula can be simplified as follows

ST a minus bpp(0) (7)

wherea 3(1 minus ])(rpro)3pe(r0Ec) b 2(1 minus 2])(r0Ec)r0 isequivalent diameter r0

s2π

radic s is the distance of pile and

rp is the diameter of the pile

According to equation (7) when the pile type was de-termined the thickness of the pile that pierced the crust wasrelated to the elastic modulus of the crust the distance ofpile and the stress of pile at the top

413 Tension Stress of the Crust +e cracking damage of thecrust in the crust composite foundation was likely to occurTo study the cracking destruction of the crust a strain gaugewas posted in the zone prone to cracking damage Addi-tionally as the artificial crust stress changed over time thetime of the maximum tensile stress should be known +etensile stress-time curves are shown in Figure 5 whichindicates that the largest tensile stress occurs in the middle ofthe crust [16] +e data presented in Figure 5 also show thatthe tensile stress increases with the load but decreases atequal loading because of the consolidation of the subsoilAccordingly the maximum tensile stress occurred at the endof the construction +us the cracking damage of the crustoccurred during the loading period

Based on the centrifuge model test the largest tensilestress occurred in the middle of the crust and the charac-teristics of a similar plate were taken to depend on the tensilestress changing as well as on the maximum tensile stressoccurring at the end of the construction So the crust cracksbecause of the bending in the transverse direction leading tohorizontal tensile stress and a corresponding verticalcracking

+e stress of the artificial crust layer cannot be directlydetermined by the 2D FE model A theoretical analysis ofelastic mechanics was carried out A plane-strain model wasused to analyze the relative deformation +e origin pointwas set on the left side of the crust layer and the orientationto the right was equal to the positive direction of the x-axisthe downward direction was equal to the positive directionof the z-axis +e width of the stabilization situation equaledB at this time According to the symmetry of stress theboundary conditions were set as a free boundary thereforeit was assumed that the deformation equation of thefoundation was as follows

w(x) 1113944infin

i135

Ai sin iπx

B+ Bi (8)

where Ai is the relative deformation of the crust layer and thedeformation of the foundation is Ai + Bi

According to the theory of elastic mechanics the stress ofthe artificial crust layer is expressed as follows

Mx minusDz2w

zz2 + μ

z2w

zx21113888 1113889 (9)

+e maximum tension stress is as follows

σx E

1 minus μ2z2w

zz2 + μ

z2w

zx21113888 1113889hrArrσxmax 1113944

infin

i13

EH

2 1 minus μ21113872 1113873μ

iπB

1113874 11138752Ai

(10)


where D EH312(1 minus ]2) is the bending rigidity of thecrust layer (in kN middot m) E is the modulus of compression μ isthe Poisson ratio and h is the distance of the base from theneutral axis H is the thickness of the crust layer

+e stress of the artificial crust layer in equation (10)showed that the stress was related to the elastic modulus thethickness the width of the crust and the deflection differ-ence Based on the above factors the deflection difference ofthe artificial crust was the key factor

+e deflection difference of the artificial crust wasconfirmed by the 2D FE model and the tension was cal-culated by equation (10) Subsequently the calculated ten-sion was compared with the measured tension as shown inFigure 5 At the end of the construction the measuredtension value was 93 kPa and the calculated value was966 kPa indicating that the calculated tension agreed wellwith the experimental value Moreover the measured resultsshowed that the tensile stress decreased at equal loadingbecause of the consolidation of the subsoil and the finaltensile stress was 856 kPa However the calculated tensilestress was 106 kPa which was different compared to themeasured tensile stress +is can be explained because thefoundation stress was changed owing to the piles beingmodeled as continuous walls in the 2D FE model Based onthese results the calculated tension equation and 2D FEmodel can be applied to the analysis of the tensile stress ofthe crust

42 Discussion In the artificial crust composition founda-tion the pile spacing and the thickness and strength of the

artificial crust are the main design factors when the pile sizewas determined In addition based on above analysis andthe summarized former research production [4 35ndash37] thestrength of the crust obtained from unconfined compressionstrength in the laboratory is related to the elastic modulus inthe finite-element model In this study the values of theinfluence factors have been listed in Table 2 As mentionedpreviously one parameter was changed from the baselinecase at one time to confirm the effect of that specific factor+e ranges of all the factors cover the typical ranges forpractical applications

421 Influence of Pile Spacing

(1) Settlement Pile spacing was an important design pa-rameter Once the size of the pile was decided the spacingpile was directly related to the area replacement ratio of thepiles (eg a larger pile spacing results in a smaller areareplacement ratio) In addition a large pile spacing can alsocause tension cracks in middle of the crust Figure 6 showsthat the pile spacing has a significant influence on themaximum settlement An increase in the pile spacing in all ofthese values as the column spacing extended from 20 to30m However within the range of the pile space it had alimited influence on the maximum settlement

An increase in the pile spacing from 30 to 35m onlyresulted in less than 1 mm increase in the maximum set-tlement +e major reason for this phenomenon may bebecause the area replacement ratio of the piles was large anda stable soil arch was formed Consequently Figure 6

120

100

80

60

40

20

0

120

100

80

60

40

20

0

Tens

ion

(kPa

)

Calculated resultsMeasured results

Time (day)0 250 500 750 1000 1250

0 250 500 750 1000 1250

Figure 5 Measured and calculated tensile stress at the base of the crust


20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35

Figure 6 Maximum settlement versus pile spacing

Table 2 Values of influence factors used

Parameter Range of value+ickness of the crust (m) 10 15 17 20Elastic modulus of the crust (MPa) 100 200 300Pile spacing (m) 20 25 30 35

ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400

Figure 7 Excess pore pressure versus time with different pile spacing


indicates that the maximum settlement is the main scope ofchange and increases by about 31 as the pile spacing in-creases from 20 to 30m

(2) Excess Pore Water Pressure +e influence of the pilespacing on the excess pore pressure is presented in Figure 7An increase in the pile spacing resulted in a great change inexcess pore pressure as the pile spacing increased from 20 to30m It was shown that the excess pore pressure increasedgradually with an increase in the pile spacing which indi-cates that the stress of the foundation increased and that lessload was transferred to the piles According to the analysis ofthe excess pore pressure dissipation rate the speed of thepore pressure dissipation was faster as the pile spacing in-creased As the effective stress in the soil increases withextending pile spacing this has attributed to the fact that thesoil tends to settle more than the piles A portion of the loadmay be transferred to the piles on shear stresses within theembankment due to the relative movement between the softsoil and the piles

As a result the excess pore water pressure in the soft soildissipated much faster In addition shearing failure of theartificial crust may happen at the top of the pile owing to thedifferent properties of the crust and the piles +e shearingfailure was related to the stress at the top of the pile Soaccording to the analysis of the stress of the pile as the pilespacing increased the probability of shearing failure is re-duced with an increase in the pile spacing +e thickness ofthe pile that pierced the crust is reduced with an increase inthe pile spacing by equation (7) the same as the results of thenumerical simulation method

(3) Tension Stress of the Crust +e stress of the artificial crustlayer described in equation (10) indicated that the deflectiondifference of the artificial crust was a key factor +e de-flection difference of the artificial crust increased with anincrease in the pile spacing at the same loading Figure 8shows that the deflection difference of the artificial crustincreased from 1439 cm to 2069 cm as the pile spacingincreased from 20 to 30m and the tensile stress increasedfrom 737 to 106 kPa as defined in equation (10) +eprobability of tensile cracks is reduced with a decrease in thepile spacing +e pile spacing had a considerable influenceon the type of the artificial crust damage and was a key factorin the engineering design

It is found that the pile spacing has a great change in thetype of failure of artificial crust with the impact of pilespacing on excess pore water pressure and tensile stress ofartificial crust +e probability of shearing failure is reducedwith an increase in the pile spacing However the probabilityof tensile cracks is increased So it is important to choose theappropriate pile spacing which avoids the tensile crack orshearing failure of the crust

422 Influence of the 0ickness of the Crust

(1) Settlement +e thickness of crust was a key design factorthe stress concentration occurring at the crust combined

with the rigid pile in the artificial crust composition foun-dation resulted in the rigid pile piercing the crust When theultimate stress was reached a cracking failure of the crustoccurred and the diffusion of the stress disappeared Basedon these conditions the crust has to possess sufficientthickness On the other hand the stress on the top of the pileincreased with the thickness increasing the cost of con-struction +erefore the appropriate thickness of the crusthas to be determined As the thickness increased from 10 to20m the maximum settlement changed significantly asshown in Figure 9 +e maximum settlement decreased byabout 4 with an increase in the thickness from 10 to 15mHowever the maximum settlement decreased by about 9as the thickness increased from 15 to 20m Compared withthe change in the ratio of the settlement the thickness hadrelatively little influence on the maximum settlement

(2) Excess Pore Water Pressure Figure 10 shows that theexcess pore pressure decreased with the increase in thethickness of the crust +is indicates that the stress of thefoundation was diffused quickly with the increase in thethickness of the artificial crust and as a larger amount of theload was transferred to the piles the rigid pile became proneto piercing the crust +e increase in the thickness of thecrust accelerated the dissipation of the excess pore waterpressure owing to the enclosed effect of the crust +ecomputed maximum excess pore pressure was approxi-mately 94 kPa with a 10m thick crust and 81 kPa with a 20thick crust a reduction of about 14 +is indicates that thediffusion effect of the stress was clear with the increase in thecrust thickness in the foundation On the basis of the stressbalance principle the load on the top of the pile increasedwith the increase in the thickness of the crust therefore thethickness of the pile that pierced the crust increased

(3) Tension Stress of the Crust +e deflection difference ofthe artificial crust decreased with an increase in the thicknessat the same loading Figure 11 shows that the deflectiondifference of the artificial crust decreased from 2030 to1883 cm as the thickness increased from 10 to 20m thedeflection difference of the artificial crust decreased by about26 However the tensile stress increased from 761 to1133 kPa (as described in equation (10)) an increase of 15times+e tensile stress was related not only to the deflectiondifference but also to the thickness Based on the aboveresearch it is found that the thickness of crust multiplyingthe deflection difference has influence on the tensile stressSo the tensile stress increased with the thickness increased

423 Influence of Elastic Modulus of Crust

(1) Settlement In this study the elastic modulus of the crustwas correlated to the undrained shear strength [4 35ndash37]When the modulus of the crust changed the cohesion wasadjusted correspondingly to maintain the same relationshipbetween the modulus and the cohesion +erefore themodulus of the crust was an indicator of both stiffness andstrength It was expected that the stiffness of the crust plays


an important role in the transmitting of the embankment+e effect of the elastic modulus of the crust on the max-imum settlement is presented in Figure 12

It shows that the modulus had a great effect on themaximum settlement and that the maximum settlementchanged linearly with a change in the elastic modulus of thecrust +erefore the elastic modulus of the crust had asignificant influence on the maximum settlement it alsoshowed that the strength of the crust had a great influence onthe settlement of the foundation

(2) Excess PoreWater Pressure Figure 13 shows that a higherdegree of consolidation resulted from the higher elasticmodulus of the crust +e accelerated dissipation of theexcessive pore water pressure was attributed to the transferfrom the soil to the piles

At the same position the stress was diffused quicklywith an increase in the crustrsquos modulus With the increasein the modulus the stress of the foundation soil wasreduced resulting in a transfer of a larger load from thesoil to the piles this was attributed to the characteristics ofthe plate with the increase in the stiffness of the artificialcrust

However the thickness of the pile that pierced the crustwas reduced due to the increase in the modulus as the crustrsquosthickness increased which is the same as the results of thecalculation by equation (7)

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm

Figure 8 Deformation versus time with different pile spacing

27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32

ickness of crust (m)

06 09 12 15 18 21 24

06 09 12 15 18 21 24

Figure 9 Settlement versus thickness of crust


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400

Figure 10 Excess pore pressure versus time with different thickness of crust

0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm

Figure 11 Deformation versus time with different thicknesses of crust


27

28

29

30

31

32

Settl

emen

t (cm

)

Elastic modulus of crust (MPa)

27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350

Figure 12 Settlement versus the elastic modulus of crust

ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400

Figure 13 Excess pore pressure versus time with different elastic modulus of crust


(3) Tension Stress of the Crust Figure 14 shows that thedeflection difference of the artificial crust decreased from2321 to 2069 cm as the elastic modulus of the artificial crustincreased from 100 to 300MPa the deflection difference ofthe artificial crust decreased by about 11 However thetensile stress of the artificial crust increased from 3964 to106 kPa (as described in equation (10)) an increase of 27times +e elastic modulus had a significant influence on thetensile stress of the artificial crust but a small influence onthe deflection difference of the artificial crust

Based on the above research it is found that the elasticmodulus of the artificial crust had a little effect on thesettlement and stress of the foundation but had a greaterimpact on the tensile stress of the artificial crust

5 Conclusions

A centrifuge test and two-dimensional coupled-consolidationfinite-element analyses were conducted to simulate the con-struction of an embankment for stabilization combined withrigid piles Based on the two-dimensional coupled-consoli-dation finite-element models the impact of several key factorsincluding pile spacing as well as the thickness and strength ofthe crust on the maximum long-term settlement excess porewater and tensile stress was discussed Based on the discus-sions the following conclusions can be drawn

A comparison of the results of the centrifuge test and thefinite-element analyses indicates that the measured settlementexcess pore water and tensile stress of the centrifuge test are ingood agreement with the calculated results therefore two-

dimensional coupled-consolidation finite-element analyseswere conducted to simulate the construction of an embank-ment for stabilization combined with rigid piles

+e pile spacing has a considerable effect on the set-tlement pore water pressure and tensile stress in the two-dimensional coupled-consolidation finite-element modelsWith an increase in the pile spacing the tensile stress of thecrust increased which resulted in an increasing potential forthe tensile failure of the crust however the thickness of thepile that pierced the crust is reduced so the potential of apunching failure of the crust can be reduced +e pilespacing is an important design parameter in the artificialcrust composite foundation

+e thickness and the elastic modulus of the crust have alittle effect on the settlement and the stress of the foundationin the two-dimensional coupled-consolidation finite-ele-ment models Based on the above research it is found thatthe increasing thickness and elastic modulus of the crusthave a greater impact on the tensile stress and the thicknessof the pile that pierced the crust was reduced as the in-creasing modulus and thickness of the crust

Data Availability

+e data used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

+e authors declare no conflicts of interest

300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm

Figure 14 Deformation versus time with different elastic modulus of crust


Acknowledgments

+is project was supported by the Natural Science Foun-dation of Shandong Province under Grants ZR2017BD037and ZR2019PEE044 the Post-Doc Creative Funding inShandong Province under Grant 201703023 and KeyLaboratory of Ministry of Education for Geomechanics andEmbankment Engineering Hohai University under Grant2019001

References

[1] L I Lian-xiang J I Xiang-kai L I U Jia-dian et alldquoCentrifugal model tests on lateral mechanical properties ofcomposite foundation under different additional loadsrdquoChinese Journal of Geotechnical Engineering vol 41 no S1pp 153ndash156 2019

[2] J Yang M Yang and R Luo ldquoDynamic centrifuge model testof composite foundation with rigid pile in soft clayrdquo ChineseJournal of Underground Space and Engineering vol 15 no 02pp 381ndash401 2019

[3] Q J Yang Y F Gao D Q Kong et al ldquoCentrifuge modellingof lateral loading behaviour of a semi-rigid Mono-pile in softclayrdquo Marine Geotechnology vol 47 no 3 pp 1205ndash12162019

[4] G M Filz and M P Navin ldquoStability of column-supportedembankmentsrdquo Rep No VTRC 06-CR13 Virginia Trans-portation Research Council Charlottesville VA USA 2006

[5] J Huang J Han and S Oztoprak ldquoCoupled mechanical andhydraulic modeling of geosynthetic-reinforced column-sup-ported embankmentsrdquo Journal of Geotechnical and Geo-environmental Engineering vol 135 no 8 pp 1011ndash10212009

[6] J L Borges and D O Marques ldquoGeosynthetic-reinforced andjet grout column-supported embankments on soft soilsnumerical analysis and parametric studyrdquo Computers andGeotechnics vol 38 no 7 pp 883ndash896 2011

[7] N Yapage S Liyanapathirana H G Poulos et al ldquo2D nu-merical modelling of geosynthetic reinforced embankmentsover deep cement mixing columnsrdquo in Anz 2012 GroundEngineering In A Changing World Conference Proceedings110 Australia-New Zealand Conference On Geomechanicsvol 15ndash18 pp 578ndash583 Melbourne Australia July 2012

[8] Y Jiang J Han and G Zheng ldquoInfluence of column yieldingon degree of consolidation of soft foundations improved bydeep mixed columnsrdquo Geomechanics and Engineering vol 6no 2 pp 173ndash194 2014

[9] M E Stewart and G M Filz ldquoInfluence of clay compress-ibility on geosynthetic loads in bridging layers for column-supported embankmentsrdquo Geo-frontiers Congress vol 156no 130 pp 1ndash14 2005

[10] P Ariyarathne and D S Liyanapathirana ldquoReview of existingdesign methods for geosynthetic-reinforced pile-supportedembankmentsrdquo Soils and Foundations vol 55 no 1pp 17ndash34 2015

[11] Y Pan Y Liu H Xiao F H Lee and K K Phoon ldquoEffect ofspatial variability on short- and long-term behaviour of ax-ially-loaded cement-admixed marine clay columnrdquo Com-puters and Geotechnics vol 94 pp 150ndash168 2018

[12] Y Pan Y Liu F H Lee and K K Phoon ldquoAnalysis ofcement-treated soil slab for deep excavation support - a ra-tional approachrdquo Geotechnique vol 69 no 10 pp 888ndash9052019

[13] Y Pan Y Liu A Tyagi et al ldquoModel-independent strength-reduction factor for effect of spatial variability on tunnel withimproved soil surroundsrdquo Geotechnique pp 1ndash17 2020

[14] T Namikawa and SMihira ldquoElasto-plastic model for cement-treated sandrdquo International Journal for Numerical and An-alytical Methods in Geomechanics vol 31 no 1 pp 71ndash1072007

[15] T Namikawa and J Koseki ldquoEffects of spatial correlation onthe compression behavior of a cement-treated columnrdquoJournal of Geotechnical and Geoenvironmental Engineeringvol 139 no 8 pp 1346ndash1359 2013

[16] A Tyagi Y Liu Y T Pan et al ldquoStability of tunnels incement-admixed soft soils with spatial variabilityrdquo Journal ofGeotechnical and Geoenvironmental Engineering vol 144no 12 Article ID 06018012 2018

[17] M Arroyo M Ciantia R Castellanza A Gens and R NovaldquoSimulation of cement-improved clay structures with abonded elasto-plastic model a practical approachrdquo Com-puters and Geotechnics vol 45 pp 140ndash150 2012

[18] M Hyodo Y Wu N Aramaki and Y Nakata ldquoUndrainedmonotonic and cyclic shear response and particle crushing ofsilica sand at low and high pressuresrdquo Canadian GeotechnicalJournal vol 54 no 2 pp 207ndash218 2017

[19] Y Wu N Li M Hyodo M Gu J Cui and B F SpencerldquoModeling the mechanical response of gas hydrate reservoirsin triaxial stress spacerdquo International Journal of HydrogenEnergy vol 44 no 48 pp 26698ndash26710 2019

[20] Y Wu H Yamamoto J Cui et al ldquoInfluence of load mode onparticle crushing characteristics of silica sand at high stressesrdquoInternational Journal of Geomechanics-ASCE vol 20 no 3Article ID 04019194 2020

[21] S Wang X Lei Q Meng J Xu M Wang and W GuoldquoModel tests of single pile vertical cyclic loading in calcareoussandrdquo Marine Georesources amp Geotechnology pp 1ndash12 2020

[22] J Huang and J Han ldquoTwo-dimensional parametric study ofgeosynthetic-reinforced column-supported embankments bycoupled hydraulic and mechanical modelingrdquo Computers andGeotechnics vol 37 no 5 pp 638ndash648 2010

[23] J-C Chai S Shrestha T Hino W-Q Ding Y Kamo andJ Carter ldquo2D and 3D analyses of an embankment on clayimproved by soil-cement columnsrdquo Computers and Geo-technics vol 68 pp 28ndash37 2015

[24] N Jelisic and M Leppanen ldquoMass stabilization of organicsoils and soft clayrdquo in Proceedings of the 3th InternationalConference on Grouting and Ground Treatment pp 552ndash561New Orleans LA USA February 2003

[25] R Ishikura H Ochiai N Yasufuku and K Omine ldquoEsti-mation of the settlement of improved ground with floating-type cement-treated columnsrdquo in Proceedings of the 4th In-ternational Conference on Soft Soil Engineering - Soft SoilEngineering pp 625ndash635 Vancouver BC Canada October2006

[26] R Ishikura N Yasufuku and M J Brown ldquoAn estimationmethod for predicting final consolidation settlement ofground improved by floating soil cement columnsrdquo Soils andFoundations vol 56 no 2 pp 213ndash227 2016

[27] C W W Ng ldquo+e state-of-the-art centrifuge modelling ofgeotechnical problems at hkustrdquo Journal of Zhejiang Uni-versity Science A vol 15 no 1 pp 1ndash21 2014

[28] M Y Yao S H Zhou and Y C Li ldquoBoundary effect analysisof centrifuge testrdquo Chinese Quarterly of Mechanics vol 25no 2 pp 291ndash296 2004 in Chinese

[29] D J White W A Take and M D Bolton ldquoSoil deformationmeasurement using particle image velocimetry (PIV) and


photogrammetryrdquo Geotechnique vol 53 no 7 pp 619ndash6312003

[30] Y Wang Y Chen Z Hu Q Feng and D Kong ldquoCom-parative analysis of load responses and deformation for crustcomposite foundation and pile-supported embankmentrdquoSains Malaysiana vol 46 no 11 pp 2231ndash2239 2017

[31] Z Hu Y Wang Y Chen et al ldquoDeformation and failuremechanism of rapid stabilization for dredger fill in roadengineeringrdquo Arabian Journal of Geosciences vol 33 no 6p 11 2020

[32] G R McDowell O Harireche H Konietzky S F Brown andN H +om ldquoDiscrete element modelling of geogrid-rein-forced aggregatesrdquo Geotech Engineering vol 159 pp 35ndash482006

[33] P Ariyarathne D S Liyanapathirana and C J LeoldquoComparison of different two-dimensional idealizations for ageosynthetic-reinforced pile-supported embankmentrdquo In-ternational Journal of Geomechanics vol 13 no 6 pp 754ndash768 2013

[34] K Chan and B PoonldquoDesigning stone columns using 2D FEAwith equivalent stripsrdquoin Proceedings of International Con-ference on Ground Improvement and Ground ControlB Indraratna C Rujikiatkamjorn and J Vinod Eds Uni-versity Of Wollongong Wollongong Australia pp 609ndash620January 2012

[35] N N S Yapage D S Liyanapathirana R B KellyH G Poulos and C J Leo ldquoNumerical modeling of anembankment over soft ground improved with deep cementmixed columns case historyrdquo Journal of Geotechnical ampGeoenvironmental Engineering vol 140 no 11 pp 1ndash10 2014

[36] D A Bruce ldquoAn introduction to the deep mixing methods asused in geotechnical applications volume 3 the verificationand properties of treated groundrdquo Rep No FHWA-RD-99-167 Federal Highway Administration Washington DCUSA 2001

[37] A Porbaha S Shibuya and T Kishida ldquoState of the art indeep mixing technology Part IIIgeomaterial characteriza-tionrdquo Proceedings of the Institution of Civil Engineers - GroundImprovement vol 4 no 3 pp 91ndash110 2000

[38] K-H Xie M-M Lu A-F Hu and G-H Chen ldquoA generaltheoretical solution for the consolidation of a compositefoundationrdquo Computers and Geotechnics vol 36 no 1-2pp 24ndash30 2009


simulation method were determined based on the experi-ment [18ndash21] Plane-strain models are usually adopted inanalyzing the behavior of embankments on soft soil based onthe FEM while the columns are usually modeled as 1mcontinuous walls in a column-improved (including a pile-improved) deposit [22 23] +e results of lateral displace-ment and bending moment in the columns were incorrect inthe two-dimensional (2D) analysis under the toe of theembankment by Chai et al [23] However the results of thesettlement of the foundation and the excess pore pressurematch well with the results of the field-measured resultsusing a 2D model Based on these studies the maximumlong-term settlement and excess pore pressure could beanalysed by using the 2D FE model

+e work of a combined foundation improvementtechnology in this area is ongoing and varied For exampleJelisic and Leppanen [24] proposed the organic soft soiltreated by stabilization combined with lime piles anotherimportant constraint on all the work discussed in this area isthat no theoretical method exists +e primary method thathas been used in the literature [25 26] is a new method topredict the total settlement for a method combining sta-bilization and a floating-type deep cement mixing of the soilstabilization method based on several loading model testsAs far as we know there is no definite research on thebehavior study of an artificial crust combined with rigidpiles So in this study a centrifuge test and two-dimensionalcoupled-consolidation finite-element analyses were con-ducted to simulate the construction of an embankment forstabilization combined with rigid piles Based on the two-dimensional coupled-consolidation finite-element modelsthe impact of several key factors including pile spacingthickness and strength of the crust on the maximum long-term settlement excess pore water and tensile stress arediscussed Finally the influences of these factors are com-pared and evaluated according to their importance

2 Centrifuge Model Testing

+e centrifuge model tests were adopted in this paper +ecentrifuge model tests were performed at the GeotechnicalCentrifuge Facility of Hong Kong University of Science andTechnology [27] +e main purpose of the centrifuge modeltests is analyzing the stress and deformation in the crustcomposition foundation +e centrifuge test was performedat a centrifugal acceleration of 80 g (g denotes the Earthrsquosgravity) and completed in one flight+e plane dimension ofthe model box was 600mmtimes 100 mmtimes 310mm (ie48mtimes 8mtimes 248m in the prototype) the height of theembankment was 563mm (ie 45m in the prototype) thelength of the piles was 200mm (ie 16m in the prototype)the pile spacing was 375mm (ie 30m in the prototype)and the crust was with a thickness of 21mm (ie 168m inthe prototype) which are shown in Figure 1 Yao et al [28]had discussed the boundary effect of the side friction in thecentrifugal tests +e distance from the box edges was ap-proximately 100mm while in the paper the distance fromthe foot of the embankment to the box boundary was100mm

A digital camera was mounted at 450mm at the front ofthe transparent sidewall with a maximum resolution of2592times1944 pixels to capture digital images of the soil atvarious stages during the in-flight test Processing twosubsequent digital images quantified the movement of thesoil +e movement of the soil was corrected by particleimage velocimetry (PIV) analysis coupled with a close-rangephotogrammetry [29]

Model material and centrifuge modeling procedure weredescribed in detail by Wang et al [30 31] In this study porewater pressure sensors and strain gauges were used inaddition to measuring soil and pile motion In additionstrain gauges were installed at the bottom of the crust whichare shown in Figure 1 +e pore water pressure transducerswere installed underneath each embankment which wereadjacent to the middle pile to confirm the time effect atdepths of 313mm (ie 25m in the prototype) from thesurface of the ground

+e centrifuge model test was conducted to study theload responses and deformation in the crust compositefoundation In addition the deformation characteristics ofthe crust were also investigated Based on the investigationsthe following conclusions can be drawn

By the deformation it was found that the final middlesettlement of the crust composite foundation can be re-duced +e excess pore water pressure is lower during theloading period and the dissipation rate of the excess porewater pressure is slower at the same loading period +eexplanation for this event is that the stress can be spread andreduced due to the crust with the properties of plate +usthe consolidation rate became slower based on the lowpermeability of the crust

By comparing the axial force of the piles the axial forceof the middle pile is smaller However the axial force of sidepile is higher in the crust composite foundation +is can beexplained by the following observations the redistributionof foundation stress by the crust with the properties of platethe fully functioning bearing capacity of the side section andthe conflict between the crust and the subsoil +e largesttensile stress occurred in the middle of the crust and thecharacteristics of a similar plate were taken to depend on thetensile stress changing as well as on the maximum tensilestress occurring at the end of the construction In conclu-sion cracking damage of the crust occurred during theloading period

3 Finite-Element Analysis

31 Modeling +e centrifuge tests were backanalyzed topromote a better understanding of the centrifuge tests andcalibrate a constitutive model and its model parametersagainst the measured data

+e piles are usually modeled as continuous walls by thetwo-dimensional coupled-consolidation analyses using thefinite-element program PLAXIS 2D (Hohai University 2017Code CP12111492f4498588b0)

Due to symmetry only half of the finite-element modeland the boundary conditions were modeled as shown inFigure 2+emodeled area had a vertical thickness of 199m





Dpprime

πD2p

4d (1)




Eeq EpAp + EsAs

Ap + As

Eeq πDp

4dEp + 1 minus

πDp

4d1113888 1113889Es

(2)


1875 115

125

562

521

25

221

25

248

75

275100400100

Geogrid

Embankment

A1

A2

A3

A4

A5

B1

B2

B3

B4

B5



(a)


400100 100

100

375 (30m)

(b)














Drained

Fill

Artificial crust

Firm soil

Rigid pile

Geosynthetic

177

m2

2mPile spacing

20m

25m


10m

244

m

24m

Und

rain

ed

Und

rain

ed

So soil

x

y

0 4

112510 17 19 21 23

249 16 18 20 22 8

2 3

26

1

1312

6 7

75m 165m




















30

25

20

15

10

5

0

30

25

20

15

10

5

0

Settl

emen

t (cm

)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


ndash2

0

2

4

6

8

10

ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800

A

1200 1600 2000 2400






ST r0(1 + ])pp(0)

EC

(4)


ST r0

Ec

3(1 minus ])rp

r01113888 1113889

3

pe minus 2(1 minus 2])pp(0)⎡⎣ ⎤⎦ (5)



pe + σ0 + c cotφ1113888 1113889

t

re

t 4 sinφ1 + sinφ

(6)





s2π







w(x) 1113944infin

i135

Ai sin iπx

B+ Bi (8)



Mx minusDz2w

zz2 + μ

z2w

zx21113888 1113889 (9)


σx E

1 minus μ2z2w

zz2 + μ

z2w

zx21113888 1113889hrArrσxmax 1113944

infin

i13

EH

2 1 minus μ21113872 1113873μ

iπB

1113874 11138752Ai

(10)










120

100

80

60

40

20

0

120

100

80

60

40

20

0

Tens

ion

(kPa

)


Time (day)0 250 500 750 1000 1250

0 250 500 750 1000 1250



20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35




ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





















0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References













































Dpprime

πD2p

4d (1)




Eeq EpAp + EsAs

Ap + As

Eeq πDp

4dEp + 1 minus

πDp

4d1113888 1113889Es

(2)


1875 115

125

562

521

25

221

25

248

75

275100400100

Geogrid

Embankment

A1

A2

A3

A4

A5

B1

B2

B3

B4

B5



(a)


400100 100

100

375 (30m)

(b)














Drained

Fill

Artificial crust

Firm soil

Rigid pile

Geosynthetic

177

m2

2mPile spacing

20m

25m


10m

244

m

24m

Und

rain

ed

Und

rain

ed

So soil

x

y

0 4

112510 17 19 21 23

249 16 18 20 22 8

2 3

26

1

1312

6 7

75m 165m




















30

25

20

15

10

5

0

30

25

20

15

10

5

0

Settl

emen

t (cm

)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


ndash2

0

2

4

6

8

10

ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800

A

1200 1600 2000 2400






ST r0(1 + ])pp(0)

EC

(4)


ST r0

Ec

3(1 minus ])rp

r01113888 1113889

3

pe minus 2(1 minus 2])pp(0)⎡⎣ ⎤⎦ (5)



pe + σ0 + c cotφ1113888 1113889

t

re

t 4 sinφ1 + sinφ

(6)





s2π







w(x) 1113944infin

i135

Ai sin iπx

B+ Bi (8)



Mx minusDz2w

zz2 + μ

z2w

zx21113888 1113889 (9)


σx E

1 minus μ2z2w

zz2 + μ

z2w

zx21113888 1113889hrArrσxmax 1113944

infin

i13

EH

2 1 minus μ21113872 1113873μ

iπB

1113874 11138752Ai

(10)










120

100

80

60

40

20

0

120

100

80

60

40

20

0

Tens

ion

(kPa

)


Time (day)0 250 500 750 1000 1250

0 250 500 750 1000 1250



20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35




ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





















0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References





















































Drained

Fill

Artificial crust

Firm soil

Rigid pile

Geosynthetic

177

m2

2mPile spacing

20m

25m


10m

244

m

24m

Und

rain

ed

Und

rain

ed

So soil

x

y

0 4

112510 17 19 21 23

249 16 18 20 22 8

2 3

26

1

1312

6 7

75m 165m




















30

25

20

15

10

5

0

30

25

20

15

10

5

0

Settl

emen

t (cm

)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


ndash2

0

2

4

6

8

10

ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800

A

1200 1600 2000 2400






ST r0(1 + ])pp(0)

EC

(4)


ST r0

Ec

3(1 minus ])rp

r01113888 1113889

3

pe minus 2(1 minus 2])pp(0)⎡⎣ ⎤⎦ (5)



pe + σ0 + c cotφ1113888 1113889

t

re

t 4 sinφ1 + sinφ

(6)





s2π







w(x) 1113944infin

i135

Ai sin iπx

B+ Bi (8)



Mx minusDz2w

zz2 + μ

z2w

zx21113888 1113889 (9)


σx E

1 minus μ2z2w

zz2 + μ

z2w

zx21113888 1113889hrArrσxmax 1113944

infin

i13

EH

2 1 minus μ21113872 1113873μ

iπB

1113874 11138752Ai

(10)










120

100

80

60

40

20

0

120

100

80

60

40

20

0

Tens

ion

(kPa

)


Time (day)0 250 500 750 1000 1250

0 250 500 750 1000 1250



20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35




ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





















0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References



























































30

25

20

15

10

5

0

30

25

20

15

10

5

0

Settl

emen

t (cm

)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


ndash2

0

2

4

6

8

10

ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)


0 400 800 1200 1600 2000 2400

0 400 800

A

1200 1600 2000 2400






ST r0(1 + ])pp(0)

EC

(4)


ST r0

Ec

3(1 minus ])rp

r01113888 1113889

3

pe minus 2(1 minus 2])pp(0)⎡⎣ ⎤⎦ (5)



pe + σ0 + c cotφ1113888 1113889

t

re

t 4 sinφ1 + sinφ

(6)





s2π







w(x) 1113944infin

i135

Ai sin iπx

B+ Bi (8)



Mx minusDz2w

zz2 + μ

z2w

zx21113888 1113889 (9)


σx E

1 minus μ2z2w

zz2 + μ

z2w

zx21113888 1113889hrArrσxmax 1113944

infin

i13

EH

2 1 minus μ21113872 1113873μ

iπB

1113874 11138752Ai

(10)










120

100

80

60

40

20

0

120

100

80

60

40

20

0

Tens

ion

(kPa

)


Time (day)0 250 500 750 1000 1250

0 250 500 750 1000 1250



20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35




ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





















0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References













































ST r0(1 + ])pp(0)

EC

(4)


ST r0

Ec

3(1 minus ])rp

r01113888 1113889

3

pe minus 2(1 minus 2])pp(0)⎡⎣ ⎤⎦ (5)



pe + σ0 + c cotφ1113888 1113889

t

re

t 4 sinφ1 + sinφ

(6)





s2π







w(x) 1113944infin

i135

Ai sin iπx

B+ Bi (8)



Mx minusDz2w

zz2 + μ

z2w

zx21113888 1113889 (9)


σx E

1 minus μ2z2w

zz2 + μ

z2w

zx21113888 1113889hrArrσxmax 1113944

infin

i13

EH

2 1 minus μ21113872 1113873μ

iπB

1113874 11138752Ai

(10)










120

100

80

60

40

20

0

120

100

80

60

40

20

0

Tens

ion

(kPa

)


Time (day)0 250 500 750 1000 1250

0 250 500 750 1000 1250



20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35




ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





















0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References


















































120

100

80

60

40

20

0

120

100

80

60

40

20

0

Tens

ion

(kPa

)


Time (day)0 250 500 750 1000 1250

0 250 500 750 1000 1250



20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35




ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





















0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References










































20

22

24

26

28

30

Settl

emen

t (cm

)

Pile spacing (m)

20

22

24

26

28

30

20 25 30 35

20 25 30 35




ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

30m25m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





















0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References




























































0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

Position (m)

0

4

8

12

16

20

24

28

32

30m25m20m

0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw30 = 2069cmΔw25 = 1843cmΔw20 = 1439cm


27

28

29

30

31

32

Settl

emen

t (cm

)

27

28

29

30

31

32


06 09 12 15 18 21 24

06 09 12 15 18 21 24



ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References










































ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

10m15m20m

ndash2

0

2

4

6

8

100 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400


0

3

6

9

12

15

18

21

24

27

30

33

Position (m)

Def

orm

atio

n (m

)

0

3

6

9

12

15

18

21

24

27

30

330 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

10m15m20m

Δw10 = 2530cmΔw15 = 2181cmΔw20 = 1883cm



27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References










































27

28

29

30

31

32

Settl

emen

t (cm

)


27

28

29

30

31

3250 100 150 200 250 300 350

50 100 150 200 250 300 350


ndash2

0

2

4

6

8

10

Exce

ss p

ore p

ress

ure (

kPa)

Time (day)

300MPa200MPa100MPa

ndash2

0

2

4

6

8

10

0 400 800 1200 1600 2000 2400

0 400 800 1200 1600 2000 2400





5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References












































5 Conclusions






Data Availability




300MPa200MPa100MPa

0

4

8

12

16

20

24

28

32

Def

orm

atio

n (m

)

0

4

8

12

16

20

24

28

32

Position (m)0 2 4 6 8 10 12 14 16

0 2 4 6 8 10 12 14 16

Δw300 = 2069cmΔw200 = 2161cmΔw100 = 2321cm



Acknowledgments


References










































Acknowledgments


References










































two-dimensionalparametricstudyofanembankmentonclay...

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