numerical analysis and monitoring of an embankment dam

Scientia Iranica A (2018) 25(2), 505{516

Sharif University of TechnologyScientia Iranica

Transactions A: Civil Engineeringhttp://scientiairanica.sharif.edu

Numerical analysis and monitoring of an embankmentdam during construction and �rst impoundingCase study: Siah Sang Dam

M. Rashidia;�, M. Heidarib, and Gh. Azizyanb

a. Department of Civil Engineering, Sharif University of Technology, Tehran, Iran.b. Department of Civil Engineering, University of Sistan and Baluchestan, Zahedan, Iran.

Received 12 October 2015; received in revised form 30 August 2016; accepted 12 November 2016

KEYWORDSEarth dams;Initial impounding;Numerical modeling;Instrumentation;Vertical displacement;Stress.

Abstract. Monitoring embankment dams is of crucial importance. In earth dams,the pore pressures, earth pressures, and displacements occurring during construction andfunction are measured at the time of the �rst impounding and exploitation by installingessential instruments, and so the dam's performance is evaluated and analyzed. Scope ofthe present research is the evaluation of Siah-Sang Dam performance through the results ofinstruments and back analysis, conducted by FLAC software. The Mohr-Coulomb elastic-plastic model has been considered as the behavioral model of the dam, and the e�ect ofthe upstream shell's materials deformation has been modeled at the time of the initialimpounding. Following that, comparing the results of the numerical analysis with themeasured values indicates that there is a proper consistency between these two values.Moreover, it was observed that the dam's performance was suitable regarding the createdpore water pressure, displacements, and stresses in the construction period as well as duringthe �rst impounding. In addition, susceptibility of the hydraulic fracturing was assessedby calculating the arching ratio. It was concluded that this dam is secure in comparisonwith the behavior of other similar dams in Iran and the world.© 2018 Sharif University of Technology. All rights reserved.

1. Introduction

Geotechnical structure designers are concerned withdi�erent kinds of anisotropic and heterogeneous ma-terials, which have complex and unstable behavior andgeometric characters. Designers select these elementsand behavior parameters because they are important inplanning and analyzing the steps. Monitoring is veryimportant because determination of exact stone, soil,

*. Corresponding author. Fax: +98 5433447092E-mail addresses: [email protected] (M.Rashidi); [email protected] (M. Heidari);[email protected] (Gh. Azizyan).

doi: 10.24200/sci.2017.4181

and earth dam characteristics is very di�cult. Thebehavior evaluation is achieved by installation of adevice called instrument. Monitoring and instrumen-tation consider structure action during building andutilization and adaption with predicted time. Di�erentfactors, such as liquefaction, pitched roof slippage,and piping a�ection complexity of soil behavior, arerequired to install a determining device in importantand critical places in order to consider and evaluatesoil forces and structure deformations. This device iscalled instrument in the technical literature to observethe actual behavior and prevent any failure caused bydi�erent factors; so, dam's continuous monitoring isnecessary. We use exact device to read data in di�erentperiods and evaluate data behavior. A back analysis isused to determine and reject instability factors.

506 M. Rashidi et al./Scientia Iranica, Transactions A: Civil Engineering 25 (2018) 505{516

Duncan [1] and Kovacevic [2] are the recent mainreferences on the state of the art in �nite-elementanalyses applicable to the deformation behavior ofembankments, mainly zoned rock�ll dams. Theydiscussed the methods of analysis, their limitations,available constitutive models of the stress-strain rela-tionship, and areas of uncertainty. As Duncan pointedout, most analyses from the literature are Class C1according to Lambe [3], i.e. after the event which mayaccount for the generally good agreement between thepredicted and observed deformation behaviors.

An important component of the modelling of em-bankment dams is the consideration of collapse verticaldisplacement of susceptible rock�lls and earth�lls inwetting. The e�ects of collapse vertical displacementare mostly noted for the upstream shoulder on initialimpoundment, but collapse vertical displacement hasalso been observed in the downstream shoulder, follow-ing wetting due to rainfall, leakage or tail-water im-poundment. Incorporating collapse vertical displace-ment into constitutive models adds further complexityand greater uncertainty to the estimation of materialparameters between laboratory and �eld conditions dueto the dependency of collapse vertical displacement oncompaction moisture content, compacted density, ap-plied stress conditions, and material properties. Justo[4] and Naylor [5] proposed methods for the incorpo-ration of collapse vertical displacement of rock�ll intoconstitutive models. The analysis of Beliche Dam, i.e.a central core earth and rock�ll dam, by Naylor [6] isan example where collapse vertical displacement of theupstream rock�ll is considered in the modelling.

The e�ect of pore water pressure dissipationin earth�lls during construction was also consideredby a number of authors, including Eisenstein andLaw [7] in modelling Mica Dam and by Cavounidisand H�oeg [8], amongst others. For these cases, theincremental embankment construction was modeledas a two-stage process: the �rst-stage modelling of anew layer construction using undrained properties forthe core; the second-stage modelling of pore waterpressure dissipation. In most cases, pore water pressuredevelopment in the core is ignored though. For wet

placed earth�lls, where high pore water pressures aredeveloped during construction, the core is often mod-elled using undrained strength and compressibility pa-rameters, and the permeability is assumed su�cientlylow so that pore water pressures will not dissipateduring the period of construction. In addition, Zumret al. [9] investigated the solution based on transientsimulation of seepage on earth dam through protection.Simulations were carried out by a two-dimensionalnumerical model based on Richards' equation for water ow in a porous medium. It has been shown that theproposed approach is suitable for large-scale engineer-ing applications.

This paper �rst introduces the Siah Sang Dam,Kurdistan, Iran, and reviews the results of monitoringthe instruments installed on the dam. Then, itintroduces numerical back analyses of the dam for theend of construction and the �rst impounding loading.Finally, this study presents the results of the analysesand compares them with the monitoring results.

2. Rock-�ll Siah Sang Dam

2.1. General characteristicsSiah Sang Dam is 33 meters high, the length of thecrest is 352 meters, and the volume of the containeris approximately 255,000 square meters. The dam isan earth dam with a clay core located in Kurdistanprovince in Iran. To make a graph of the dam'sbehavior, accurate instruments were chosen in 3 sec-tions including piezometers, total soil mass pressuremeasurement cells, and vertical displacement metersand inclinometers which were installed within them.Taking into account the foundation type, height ofthe earth-�ll dam, and depth of the valley, the mostcritical cross-section of Siah Sang Dam regarding theaccumulation of pore water, maximum vertical dis-placement, and tolerance is the pro�le located in 0+175kilometers. The evaluation and numerical analysis willbe done in this pro�le in this study. In addition, thematerial properties used in the numerical analysis wereextracted from certain soil mechanical laboratory testson the �ne and coarse materials of the dam. Table 1

Table 1. Initial amounts of material parameters in the body of the dam.

Elementsparameters

Dry uniteweight

(kN/m3)

Inner frictionangle

(degree)

Cohesion(kPa)

Elasticitymodule(MPa)

Poissoncoe�cient

Dilationangle

(degree)

Permeabilitycoe�cient

(m/s)

Core 16 30 15 5000 0.4 0 1.16 � 10�9

Upstream &downstream shell

18 34 1 15000 0.35 13 9.26 � 10�8

Filters &transition

18 36 3.5 10000 0.3 7 2 � 10�4

M. Rashidi et al./Scientia Iranica, Transactions A: Civil Engineering 25 (2018) 505{516 507

shows the parameters of Mohr-Coulomb elastic-plasticmodel for various zones of the dam [10].

3. Instrumentation results

In earth dams, with the premise that other conditionsare similar in all points, the most critical section re-garding stability is always the highest section. Further,most of the stresses, displacements, and pore waterpressures usually take place in this section. As seenin Figure 1, since there are three sections in Siah SangDam in which they have set up instruments and it isnot possible to analyze all these sections within thelimited duration of the present research, the researcherwill only present the stress-strain behavior in criticalsections. Clearly, if the behavior of the dam in criticalsections is understood accurately, this behavior couldbe generalized to all sections of the dam.

3.1. Evaluations of instrumentation resultsand dam behavior

3.1.1. Vertical displacementTo measure the displacement of the dam in pro�le Baccording to Figure 2, two tubes of inclinometers areinstalled in the downstream and upstream of the dam.The initial position of the casing is established in asurvey taken with the inclinometer probe. Groundmovement causes the casing to move from its initialposition. The rate, depth, and magnitude of thisdisplacement are calculated by comparing data fromthe initial survey with those from subsequent surveys.In Figure 3, vertical displacement amounts of the corein accordance with the dam's height are observablewhen the dam was constructed in six di�erent timeintervals. According to the graph, December 2006 isthe date when the construction of the dam ended, andthe maximum vertical displacement in the last reading

Figure 1. The plan view of Siah Sang Dam and arrangement of instruments in section B (critical section) [9].

Figure 2. The arrangement of Inclinometers and their details in Siah Sang Dam [9].


Figure 3. Upstream central core vertical displacement inaccordance with dam's height in di�erent times (measuredvalues are depicted).

Figure 4. Downstream central core vertical displacementin accordance with height in di�erent times (measuredvalues are depicted).

on this date was equal to 18 centimeters. The initial im-pounding of Siah Sang Dam also began in the Januaryof 2007, and then vertical displacement in the June of2007 was 20 centimeters. It was observed that from theinitial impounding to the dam exploitation, which tookapproximately 6 months, the vertical displacement wasonly 2 centimeters. This vertical displacement is 10%of the total vertical displacement of the dam, while90% of the vertical displacements was 18 centimeterswhich took place in the construction time as seen in thegraph at some points in time. In addition, in Figure 4,the vertical displacement amounts are presented fromthe vertical displacement meter tubes in downstream inaccordance to the levels in seven intervals. On the datewhen the hard operation of earth-�lling was �nished

Figure 5. Vertical displacement in di�erent heights incentral core upstream and downstream (measured valuesare depicted).

(December 2006), maximum vertical displacement was21 centimeters, located in the 15 meters of the heightof the body of the dam, whereas this amount duringimpounding was just 1 centimeter.

Figure 5 compares vertical displacement amountsat the end of construction operation (December 2005)in 2 inclinometer tubes. As seen, the di�erencebetween core vertical displacements of upstream anddownstream is not signi�cant, and that is due tothe di�erence between behavioral characteristics andcompressibility of the materials of the core, �lter,drainage, and shell. Considering the materials of theupstream, the downstream and central core are similar,and the di�erence between the vertical displacementsin the upper part of the dam is very little. It alsoshows vertical displacement amounts 6 months afterthe beginning of the initial impounding (June 2007).The important point is the increase of the upstream


shell vertical displacement in comparison to the down-stream. The reason for this is the hydrostatic pressureof water on the upstream shell, causing more verticaldisplacement.

3.1.2. Vertical stressTotal pressure cells are installed in three levels asseen in Figure 6 in 1810.5, 1817.5, and 1825. Thesecells have been installed in a bunch of 3, 5, and1, respectively. Figure 7 shows the changes in totalvertical stress in the pressure cells installed in 1810.5level in accordance with earth �lling. vertical stresschanges in the process is steady and in tune with theprogress of dam construction and �ll height.

In Figure 8, there are changes in the vertical stressin the width of the core and upstream and downstream�lters in the �rst level at di�erent points in time. Asit can be seen, with an increase in the levels of earth�lling, the stress level in all widths of the core and �lter

Figure 6. Total pressure measurement cells in di�erentlevels [9].

Figure 7. Changes in the total vertical stress in thepressure cells installed in the �rst level in accordance withtime (measured values are depicted).

Figure 8. Changes in total vertical stress in the width ofthe dam body in the �rst level of di�erent �ll levels(measured values are depicted).

increases. The maximum stress, most of the times, isrelated to TPC2-1 pressure cell, which is located within8-meter upstream of the dam axis inside clay whoseamount at the end of the construction operation is 325kilopascals.

3.1.3. Arching ratioShell materials, including rock�ll and gravel, weresti�er than the materials used in the core. Di�erence ofelasticity modulus between these two kinds of materialsmade various tendencies to vertical displacement. Inaddition, the friction between the core and shell materi-als caused a transfer of stress from the core to the shell,which could create a low-stress area in the core. Thisphenomenon is called arching in earth dams. Eq. (1)presents the arching ratio:

Ar =�v :h

; (1)

where �v is the vertical total stress (kPa), is the unitweight (kN/m3), and h is the embankment height (m)[11,12]. Since core is softer than shell, load transferoccurs from core to shell. As a result of this action,pore water pressure can become more than total stresswithin core. This action may make cracks due toexcessive water pressure. These cracks are calledhydraulic fracturing making holes from upstream todownstream. In addition, it causes a serious damageto the body of the dam, possibly leading to the damfailure. The higher the Ar, the less the archingphenomenon in the core, and the lower the probabilityof hydraulic fracturing would be.

In Figure 9, the changes in the ratio of verticalstress to the load, or to put it another way, the archingratios in the width of the core and the �lters in the�rst level (+1811.5) in the 21- and 26-meter �ll heightsare shown towards the end of construction operation.


Figure 9. Changes in arching ratio of the width of thedam body in the �rst level in di�erent �ll height(measured values are depicted).

As seen, the most critical arching ratio in 21-meter �llheight was about 0.7. This issue indicates the fact thatonly 69 percent of the load weight on the core in this�ll level is transferred to the materials underneath it,and 31 percent of the rest will be transferred to theshell and side �lters of the core. As seen, 26-meter�ll height of Siah Sang Dam, i.e. the most criticalarching, decreases 0.67 with the di�erence that thearching ratio in the upstream areas increases and evenreaches 0.72; however, in the downstream areas, thisamount is just under 0.69. It is notable to compareratios obtained by arching ratios of Iran's largest damsincluding Molla Sadra earth Dam with 72-meter heightwhose critical arching ratio is 0.45 and Gavoshan earthDam with 125-meter height whose critical arching ratiois 0.52. Therefore, the more the arching ratio is,the less the created arching will be. We reach thisconclusion that Siah Sang Dam will have no problemregarding hydraulic fracturing [13,14]. In addition, itshould be noted that the bulk density of the corematerial providing arching ratio in di�erent �ll heightsis 17.4 kN/m3.

4. Numerical analysis

Siah Sang Dam was modeled in 15 layers. The heightof the earth-�lling layers, with regard to the executiontime, was de�ned to be between 1.5 to 2 meters. First,the co�erdam was modeled with regard to the time itwas constructed, and then the layers were modeled.After constructing each layer and analyzing it, itsdisplacements on the layer became zero. One shouldconsider that the thickness of every layer should be oneelement; otherwise, the patterns of the changes in thevertical shapes of the body of the dam in the numericalmodel would be as disorganized curves. Siah SangDam impounding was done in 3 layers similar to its

construction, and the height of the layers was between7 and 9 meters. Each layer's impounding was carriedout considering the height code of the water behind thedam, which was obtained by instruments. The �rsttotal impounding of the dam was done in 6 months.It should be noted that, in the numerical analysis, therocky foundation was not modeled due to the mainreasons such as its little settlement during construction(0.5 centimeters), low permeability of 1 � 10�6 m/sapproximately, and concrete slab at the bottom of theclay core and its thickness reaching 50 centimeters; allthese add to the reasons why modeling the foundationwas avoided to accelerate analysis.

As seen in Figures 10 to 14, the results of the

Figure 10. Vertical displacement of the dam (beforestarting the initial impounding).

Figure 11. Vertical displacement of the dam (in the endof the �rst impounding).

Figure 12. Pore water pressure of the dam (beforestarting the initial impounding).

Figure 13. Pore water pressure of the dam (in the end ofthe �rst impounding).


Figure 14. Dam's vertical stress level curve (beforestarting the initial impounding).

analysis are presented in 2 phases of the impoundingof the dam. These phases include 27 meters of the �llbefore the beginning of the �rst impounding and at theend of �rst impounding.

The numerical analysis was done using FLACsoftware [15], and Mohr-Coulomb elasto-plastic modelwas used for the rock�ll, �lters, and earth-�ll cores.The limitations of using such a simplistic model wererecognized, but the main purpose of the analysis was toevaluate the stress conditions within the embankmentand then to use the stresses in the analysis andinterpretation of the monitored deformation records.In addition, for the �rst impounding analysis, the Justomethod was used separately in unloading the lowerlayers due to submerging [4]. Considering impoundinge�ect, the inner friction decreases the angle coe�cientof the material, which was imagined to be 20% re-garding the technical literature [16,17]. Decreasingcoe�cient of Young's modulus was also imagined tobe 50% with regard to the carried-out studies [18,19].

The steady-state seepage calculation was per-formed after the completion of the staged construction.Steady-state seepage of the dam for a 25 m water levelwas then performed without interaction with mechan-ical equilibrium. The �nal state of static equilibrium,called initial stress state, of the dam was then com-puted again after the steady-state seepage was reached.

4.1. Examining the degree of accuracy of thenumber of elements in the results ofnumerical analysis

The degree of the accuracy of the number of elementswas analyzed many times since the regression analysisoperations were carried out on the numerical analyses,and numerical computations were required. Two typesof models were generated for that. The propertiesof the materials and their geometric shape are inaccordance with Siah Sang Dam. The �rst sampleseen in Figure 15 has a coarse mesh size and 750elements, and the number of its layers is equal to that ofthe elements in the vertical direction in the numericalcomputation in time of construction, meaning that itsvertical displacements will be equal to zero after everylayer is constructed. Like the real construction time,the vertical displacement of all the elements will be zeroonce again.

Figure 15. The �rst and second samples' meshing.

Figure 16. Vertical displacement of the �rst and secondsamples.

The second sample has a �ne mesh size and 7500elements. The time the program needs to run is verylong for the second sample. The number of its layers is15 at the time of construction, like the �rst sample.The di�erence between them, however, is that eachlayer has a number of rows of vertical elements ontop of each other and is run after each layer; onlythe top element's vertical displacement will be equalto zero. This will lead to the vertical displacement, orthe dam vertical displacement results will be disorderlyand uctuated. Figure 16 shows the di�erence betweenvertical displacements in the �rst and second samples.

In addition, examining the accuracy degree of thenumber of elements in the results of the numericalanalysis made it clear that making the elements coarseand decreasing their number from 7500 to 750 elementswill increase the ratio of the total vertical stress andpore water pressure values up to 2 and 3 percent,respectively, and will decrease vertical displacement to4 percent. Nevertheless, the �rst sample or coarse meshwas also used in order to accelerate the computationsand to better show the changes in the vertical displace-ments.

4.2. Comparing the instrumentation andnumerical results

The evaluation will be completed in a case in whicha back analysis is carried out in order to control the


Figure 17. Back analysis method and solution algorithm.

degree of the accuracy and the level of con�dence ofthe measured behavior, since each of the measurementscould be controlled through comparing it to the modelobtained from the numerical model. This process andsolution algorithm are described in Figure 17.

4.2.1. Vertical displacement resultsThe internal vertical displacements of the dam arecategorized into three groups: vertical, horizontal, androtational movements. vertical movements show thevertical displacements in terms of material weight,compaction, and consolidation of the dam body.Horizontal movements mainly refer to the upstreammovements that occur during impounding in the damstorage due to faster reduction of the e�ective stress inthe upstream materials than in other parts of the dam.Downstream movement occurs due to the horizontalwater pressure of the dam storage. Furthermore,rotational movements that appear in the upstream anddownstream slopes are due to lower shear strength ofmaterials in the foundation or body of the dam. Usingsurveying points, inclinometers (vertical displacementtubes) and/or vertical displacement gauges are conven-tional ways to measure these deformations in earthdams. In this study, an evaluation was only madeup of the results of the vertical displacements in the

Siah Sang Dam obtained from inclinometers becausethe readings related to horizontal displacements werenot available due to poor archive in the early years ofthe dam construction by the consulting engineers of theproject.

In Figure 18, the vertical displacement of theupstream height of the central core is compared con-sidering the results obtained from instruments and theamounts from numerical modeling, respectively, in De-cember 2006 (towards the end of the construction oper-ation) and June 2007 (after the initial impounding). Asobserved, the analysis results are very close to realityin both times. Additionally, the downstream shell'svertical displacement obtained by the instruments andthe amounts obtained by numerical modeling in thetwo mentioned times in the last section were compared.At the end of construction operation, these resultswere close to each other. After the initial impound-ing, the results in the lower part of the dam wereconvergent. In addition, the reason for the undulationof the measured maximum vertical displacements frominstruments would be the di�erences in soil compactionand soil heterogeneity in di�erent layers of dam, whilethey should be theoretically smooth.

The inclinometers' readings are compared withnumerical models in relation to the vertical displace-ment changes in di�erent levels of the dam in ac-cordance with the time in Figure 19. As observed,tangible di�erences between them were only in lowerlayer (10 m) in relation to upper layer (19 m), whichwere close to each other. It also shows that the verticaldisplacements of the dam decreased signi�cantly after400 days (at the end of construction and at the startof initial impounding).

4.2.2. Vertical stress resultsIn Figure 20, the process of the appearance of thevertical stress in the piezometers located in the �rstlevel is shown in accordance with time. As observed,the analysis results are very close to reality, except forthe di�erences between vertical stresses in numericalmodel with the reality taken place after constructionin TPC2-1. These amounts are close to each otherbefore initial impounding, while divergent during initialimpounding. As expected, vertical stress increasedthe same way as the result of numerical analysis did;however, due to the broken piezometer, this amountremained steady in instruments' results. Furthermore,as demonstrated by the results in Figure 20, thereis a di�erence between the observed and calculatedvertical stresses in TPC2-2. The vertical stresses inthe pressure cells are lower than those obtained bythe numerical analysis. There are some reasons whythe results are divergent after the initial impounding(after 400 days) in upstream of the central core. Cal-ibration of the instruments for load and temperature


Figure 18. Comparing the results of the instruments and numerical modeling in relation to vertical displacement changesin the upstream (EX 2-1) and downstream (EX 2-2) heights of the central core towards the end of the constructionoperation and after the initial impounding.

Figure 19. Comparing the results from the inclinometers and numerical model in relation to the vertical displacementchanges in di�erent levels of the dam with accordance to time.


Figure 20. Comparing the measurement results and numerical model in relation with the total vertical pressure in thepiezometers located in the �rst level.

is a di�cult and expensive task, such that lack ofcalibration and destruction of instruments are assumedpossible [20]. In addition, to prevent any damage to thepressure cells, the soil around the cells was compactedin a lower density in comparison to other parts of thecore. Consequently, the reality of the soil sti�ness inthe body of the dam was mostly more than that aroundthe cells.

5. Summary and conclusion

The purposes of this study are two-fold: (1) To makee�orts to present a general evaluation of the functionof the dam during construction and initial impoundingthrough the data obtained by instruments from SiahSang earth Dam and (2) To utilize modeling andcarry out numerical analysis regarding the stress-strainbehavior of the dam. The results obtained from thisstudy are as follows:

� According to the numerical analysis, the verticaldisplacement results were consistent with the datarecorded by the instruments in terms of both qualityand quantity, showing that the maximum verticaldisplacement of the core was 18 centimeters at theend of construction. In the following 6 months afterconstruction (initial impounding and exploitationperiod), the accumulative vertical displacement ofthe dam was 20 centimeters. It is clear that

90% of the total vertical displacement of the damtook place during dam construction due to theclay core smashed in the wet side of the optimummoisture content. The aforementioned maximumvertical displacement showed that this value wasat the rate of about 0.7% of the height of thedam;

� Total vertical stresses, extracted from the numer-ical analysis, proved to be in a tolerable trendwith the data recorded at the pressure cells;however, there was a small di�erence in quan-tity. Inconsistency between the stresses obtainedfrom the numerical analysis and pressure cells wasmostly due to the local arching phenomena inthe installation place of the pressure cells, whichwas as a result of inadequate compaction aroundthese instruments that caused creating a low-stresszone;

� The arching ratios were calculated for the largestcross-section of Siah Sang Dam. The results demon-strated that the arching ratio in Siah Sang Dam wasbetween 0.67-0.76, which placed the dam on the safeside in terms of hydraulic fracturing. In addition,examining the accuracy degree of the number ofelements in the results of the numerical analysismade it clear that making the elements coarseand decreasing their number from 7500 elementsto 750 elements will increase the ratio of the total


vertical stress and pore water pressure values upto 2 and 3 percent, respectively, and decreasevertical displacement to 4 percent. Therefore, itis better to use the �rst sample or coarse meshin order to accelerate the computations and tobetter show the changes in the vertical displace-ments.

Finally, it is worth mentioning that the behavior ofthis dam in its largest cross-section was reasonable interms of vertical displacement and stresses at the endof construction and the �rst impounding.

References

1. Duncan, J.M. \State of the art: Limit equilibrium and�nite-element analysis of slopes", A.S.C.E., Journal ofGeotechnical Engineering, 122(7), pp. 577-595 (1996).

2. Kovacevic, N., Potts, D.M., and Vaughan, P.R. \Finiteelement analysis of a rock�ll dam", Proc. 8th Int.Conf. Computer Methods & Advances in Geomechs.,Morgantown, West Virginia, 3, pp. 2459-2464 (1994).

3. Lambe, T.W. \Predictions in soil engineering", Rank-ine Lecture. Geotechnique, 23(2), pp. 149-202 (1973).

4. Justo, J.L. \Collapse: Its importance, fundamentalsand modeling", In Advances in Rock�ll Structures,Kluwer Academic Publishers, Netherlands, pp. 97-152(1991).

5. Naylor, D.J. \Finite element methods for �lls andembankment dams", Advances in Rock�ll StructuresE. Maranha das Neves, pp. 291-340 (1990).

6. Naylor, D.J. \Collapse vertical displacement some de-velopments", Applications of Computational Mechan-ics in Geotechnical Engineering, Balkema, Rotterdam,pp. 37-54 (1997).

7. Eisenstein, Z. and Law, S.T.C. \Analysis of consoli-dation behaviour of Mica dam", A.S.C.E., Journal ofthe Geotechnical Engineering Division, 103(GT8), pp.879-895 (1977).

8. Cavounidis, S. and Hoeg, K. \Consolidation duringconstruction of earth dams", A.S.C.E., Journal of theGeotechnical Engineering Division, 103(GT10), pp.1055-1067 (1977).

9. Zumr, D. and C��slerova0, M. \Soil moisture dynam-ics in Levees during ood events-variably saturatedapproach", J. Hydrol. Hydromech., 58(1), pp. 64-72(2010).

10. Technical Reports of Siah Sang Dam, Consulting En-gineers Mahab Ghods (2007).

11. Terzaghi, K. \Stress distribution in dry and in satu-rated sand above a yielding trap-door", in Proceedingof First International Conference on Soil Mechan-ics and Foundation Engineering, Cambridge, Mas-sachusetts, pp. 307-311 (1936).

12. Terzaghi, K., Theoretical Soil Mechanics, New York,John Wiley and Sons (1943).

13. Nikkhah, M., Attaie, S., Tavakoli, H., and Hasan,Y. \Evaluation of instrumentation records of thedam body and foundation if embankment mollasadradam during construction and �rst stage impounding",ICOLD 75th Annual Meeting, Saint Petersburg, Russia(2007).

14. Rashidi, M. \Evaluation of the behavior of earth androck�ll dams during construction and �rst impoundingusing instrumentation data and numerical modeling",M.S. Thesis in Civil Engineering, Sharif University ofTechnology (2012).

15. FLAC version 4, USER MANUAL, Itasca ConsultingGroup, Inc (2002).

16. Alonso, E.E. and Oldecop, L.A. \Fundamentals ofrock�ll collapse", Proceedings of the Asian Conferenceon Unsaturated Soils, Singapore, Balkema, Rotterdam,pp. 3-13 (2000).

17. Soroush, A. and Aghaei, A.\Uncertainties in me-chanical behavior of rock�lls during �rst impoundingof rock�ll dams", 73rd Annual Meeting of ICOLD,Tehran, Iran, Paper No. 186-S5 (2005).

18. Soboya, J.R.F. and Byrne, P.M. \Parameters for stressand deformation analysis of rock�ll dams", CanadianGeotechnical Journal, 30(4), pp. 690-701 (1993).

19. Varadarajan, A. and Sharma, K.G. \Venkatachalam Kand Gupta A K testing and modeling two rock�ll mate-rials", Journal of Geotechnical and GeoenvironmentalEngineering, ASCE, 129(3), pp. 206-217 (2003).

20. Dunnicli�, J. and Green, G., \Geotechnical Instru-mentation for Monitoring Field Performance", Ed; AWiley Inter-Science Publication (1988).

Biographies

Mohammad Rashidi received his BSc degree in CivilEngineering from University of Tabriz and his MScdegree in Civil Engineering from Sharif Universityof Technology. He is currently a PhD student atthe University of Texas at El Paso. His researchinterests include numerical analysis, monitoring andinstrumentation, computational mechanics and geome-chanics, dam and geotechnical Engineering, pavement,geosynthetics, and road construction. He has presentedand published several papers in various internationalconferences and journals.

Mokhtar Heidari received his MSc degree fromUniversity of Sistan and Baluchestan, Zahedan, Iran inHydraulic Structures. His main research interests aredam engineering, ground water, hydraulic structures,seepage, and numerical analysis.

Gholamreza Azizyan received his BSc degree in Civil


Engineering from University of Sistan and Baluchestanin 1985, MSc degree from University of Tehran, Iranin Hydraulic Structures in 1991, and PhD degree inthe same �eld from University of Newcastle uponTyne, UK in 2009. He is currently an Assistant

Professor of Civil Engineering at University of Sistanand Baluchestan, Iran. His main research interestsare hydraulic engineering, water resources engineering,hydraulic structures, river mechanics, and groundwa-ter.

numerical analysis and monitoring of an embankment dam

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