2014
47
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Automatic Calibration of HECHMS Model Using MultiObjective Fuzzy Optimal Models
2
2
Estimation of parameters of a hydrologic model is undertaken using a procedure called “calibration” in order to obtain predictions as close as possible to observed values. This study aimed to use the particle swarm optimization (PSO) algorithm for automatic calibration of the HECHMS hydrologic model, which includes a library of different eventbased models for simulating the rainfallrunoff process. Since a flood hydrograph has different characteristics such as time to peak, peak discharge and total runoff volume, the calibration process is addressed using a singleobjective or multiobjective optimization model. In this context, the fuzzy set theory can be used to combine different objective functions and convert the multiobjective model to a singleobjective one. In this research, the Tamar basin, a subbasin of the GolestanDam Basin in north of Iran, was selected as the case study with four reliable measured flood events. The first three events were used for calibration and the fourth one for verification. As most of the models built in the HECHMS software were eventbased, the concept of recalibration of parameters related to a basin initial condition was also introduced. The comparison of results obtained from the single and multiobjective scenarios showed the efficiency of the proposed HMSPSO simulationoptimization approach in the multiobjective calibration of eventbased hydrologic models.
1

1
12


B.
Kamali
PhD. Student, College of Civil and Environmental Engineering, Amirkabir University of Technology, P.O. Box: 158754413, Tehran, Iran.
PhD. Student, College of Civil and Environmental
Iran


S.J.
Mousavi
Associate Professor, College of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran. P.O. Box: 158754413, Tehran, Iran.
Associate Professor, College of Civil and
Iran
jmosavi@aut.ac.ir
Automatic calibration
HECHMS
Particle swarm optimization
RainfallRunoff Modeling
[Bekele, E.G. and Nicklow, J.W. (2007). Multiobjective automatic calibration of SWAT using NSGAII, Journal of Hydrology, 341(34), 165176. ##Cheng, C.T., Oub, C.P. and Chauc, K.W. (2002). “Combining a fuzzy optimal model with a genetic algorithm to solve multiobjective rainfall–runoff model calibration”, Journal of Hydrology,26(14), 7286. ##Chow V.T., Maidment D.R. and Mays L.W. (1988). Applied Hydrology, McGraw, Inc., ISBN10: 0070108102, New York, USA. Pages 502. Table 15.1.2 SCS lag Equation. ##Duan, Q., Sorooshian, S. and Gupta, H.V. (1994). “Optimal use of the SCEUA global optimization method for calibrating watershed models”, Journal of Hydrology, 158, 265284. ##Eberhart, R.C. and Kennedy, J. (1995). “A new optimizer using particle swarm theory”, Proceedings of the Sixth International Symposium on Micro Machine and Human Science, Nagoya, Japan, Piscataway, NJ: IEEE Service Center, 3943. ##Iran Water Research Institute (IWRI). (2008). Report on hydrologic model calibration: Gorganroud flood warning system project, Water Resources Department, Tehran, Iran. ##Kamali, B., Mousavi, S.J. and Abbaspour, K. (2013). “Automatic calibration of HECHMS using singleobjective and multiobjective PSO algorithms”, Hydrological Processes, 27(26), 40284042. ##Liu, H. and Abraham A. (2007). “A fuzzy adaptive turbulent particle swarm optimization”, International Journal of Innovative Computing and Applications, 1(1), 3947. ##Madsen, H. (2000). “Automatic calibration of a conceptual rainfall–runoff model using multiple objectives”, Journal of Hydrology, 235, 276–288. ##Moussa, R. and Chahinian, N. (2009). “Comparison of different multiobjective calibration criteria using a conceptual rainfallrunoff model of flood events”, Journal of hydrology and Earth System Sciences, 13, 519535. ##Parsopoulos, K.E. and Vrahatis, M.N. (2002). “Recent approaches to global optimization problems through particle swarm optimization”, Natural Computing, 1(12), 235306. ##Reddy, M.J. and Kumar, D.N. (2007). “An efficient multiobjective optimization algorithm based on swarm intelligence for engineering design”, Engineering Optimization, 39, 4968. ##Scharffenberger, W.A. and Fleming, M.J. (2008). Hydrologic modeling system HECHMS user’s manual, US Army Corps of Engineers, 1290. ##Timothy D.S., Charles S.M. and Kyle E.K. (2000). “Equations for estimating Clark unit hydrograph parameters for small rural watersheds in Illinois”, Water Resources Investigations Report. Cooperation with the Illinois Department of Natural Resources, Office of Water Resources Urbana, Illinoise, ##USACE. (2008). Hydrologic modeling system HECHMS applications guide. US. Army Corps of Engineers, Hydrologic Engineering Center (HEC), Washington, DC. ##Yapo, P., Gupta, H.V. and Sorooshian, S. (1998). “Multiobjective global optimization of hydrologic models”, Journal of Hydrology, 204, 8397.##]
A Method of Function Space for Vertical Impedance Function of a Circular Rigid Foundation on a Transversely Isotropic Ground
2
2
This paper is concerned with investigation of vertical impedance function of a surface rigid circular foundation resting on a semiinfinite transversely isotropic alluvium. To this end, the equations of motion in cylindrical coordinate system, which because of axissymmetry are two coupled equations, are converted into one partial differential equation using a method of potential function. The governing partial differential equation for the potential function is solved via implementing Hankel integral transforms in radial direction. The vertical and radial components of displacement vector are determined with the use of transformed displacementpotential function relationships. The mixed boundary conditions at the surface are satisfied by specifying the traction between the rigid foundation and the underneath alluvium in a special function space introduced in this paper, where the vertical displacements are forced to satisfy the rigid boundary condition. Through exercising these restraints, the normal traction and then the vertical impedance function are obtained. The results are then compared with the existing results in the literature for the simpler case of isotropic halfspace, which shows an excellent agreement. Eventually, the impedance functions are presented in terms of dimensionless frequency for different materials. The method presented here may be used to obtain the impedance function in any other direction as well as in buried footing in layered media.
1

13
27


Morteza
EskandariGhadi
University of Tehran, Collage of Engineering, Dept. of Engineering Science
University of Tehran, Collage of Engineering,
Iran
ghadi@ut.ac.ir


Ali
Hassanpour Charmhini
University of Science and technology of Mazandaran
University of Science and technology of Mazandaran
Iran
ali_hassanpour_ch@yahoo.com


Azizollah
ArdeshirBehrestaghi
Mazandaran University of Science and Technology
Mazandaran University of Science and Technology
Iran
ardeshir_b_eng@yahoo.com
Circular Foundation
Function Space
Transversely Isotropic
Vertical Impedance Function
[Arnold, R.N., Bycroft, G.N. and Warburton, G.N. (1955). “Forced vibration of a body on an infinite elastic solid”, Journal of Appleid Mechanics, 22, 391. ##Awoboji, A.O. and Grootenhuis, P. (1965). “Vibration of rigid bodies on semiinfinite elastic media”, Proceedings of the Royal Society, Series A., 287, 27. ##Bycroft, G.N. (1956). “Forced vibration of a rigid circular plate on a semiinfinite elastic space and on an elastic stratum”, Philosophical Transactions of the Royal Society Series A., 248, 327. ##Churchill R.V. and Brown J.W. (1990). Complex variables and applications, New York, NY: McGrawHill. ##EskandariGhadi, M. (2005). “A complete solutions of the wave equations for transversely isotropic media”, Journal of Elasticity, 81, 119. ##EskandariGhadi, M. and ArdeshirBehrestaghi, A. (2010a). “Forced vertical vibration of rigid circular disc buried in an arbitrary depth of a transversely isotropic halfspace”, Soil Dynamics and Earthquake Engineering, 30(7), 547560. ##EskandariGhadi, M., Fallahi, M. and ArdeshirBehrestaghi, A. (2010b). “Forced vertical vibration of rigid circular disc on a transversely isotropic halfspace”, Journal of Engineering Mechanics, 136(7), 913922. ##EskandariGhadi, M., Mirzapour, A. and ArdeshirBehrestaghi, A. (2011). “Rocking vibration of rigid circular disc in a transversely isotropic fullspace”, Numerical and Analytical Method in Geomechanics, 35(14), 15871603. ##EskandariGhadi, M., Pak R.Y.S. and ArdeshirBehrestaghi, A. (2008). “Transversely isotropic elastodynamic solution of a finite layer on an infinite subgrade under surface loads”, Soil Dynamics and Earthquake Engineering, 28(12), 9861003. ##Ewing W.M., Jardetzky, W.S. and Press, F. (1957). Elastic wave in layered media, McGrawHill, New York. ##Lamb, H. (1904). “On the propagation tremors over the surface the surface of an elastic solid”, Philosophical Transactions of the Royal Society of London, A(203), 142. ##Luco, J.E. and Mita, A. (1987). “Response of a circular foundation on a uniform halfspace to elastic waves”, Earthquake Engineering and Structural Dynamics, 15(1), 105118. ##Luco, J.E. and Westmann, R.A. (1971). “Dynamic response of circular footings”, Journal of Engineering Mechanics, ASCE, 97(5), 13811395. ##Noble, B. (1963). “The solution of Bessel function dual integral equations by a multiplying factor method”, Mathematical Proceedings of the Cambridge Philosophical Society, 59(2), 351362. ##Pak, R.Y.S. (1987). “Asymmetric wave propagation in an elastic halfspace by a method of potentials”, Journal of Applied Mechanics, 54(1), 121–126. ##Rahimian, M., EskandariGhadi, M., Pak, R.Y.S. and Khojasteh, A. (2007). “Elastodynamic potential method for a transversely isotropic solid”, Journal of Engineering Mechanics, ASCE, 133(10), 11341145. ##Rajapakse, R.K.N.D. and Wang, Y. (1993). “Green’s functions for transversely isotropic elastic halfspace”, Journal of Engineering Mechanics, 119(9), 1724–46. ##Sneddon, I.N. (1966). Mixed boundary value problems in potential theory, NorthHolland Publishing Company, Amsterdam. ##Stoneley, R. (1949). “The seismological implications of aelotropy in continental structures”, Geophisical Supplements to the Monthly Notices of the Royal Astronomical Society, 5, 343–353. ##Tichmarsh, E.C. (1948). Introduction to the theory of Fourier integrals, 2nd (Ed.), Oxford, Clarendon Press.##]
Efficiency of Neural Networks for Estimating the Patch Load Resistance of Plate Girders with a Focus on Uncertainties in Material and Geometrical Properties
2
2
In this paper, a sensitivity analysis of artificial neural networks (NNs) is presented and employed for estimating the patch load resistance of plate girders subjected to patch loading. To evaluate the accuracy of the proposed NN model, the results are compared with the previously proposed empirical models, so that we can estimate the resistance of plate girders subjected to patch loading. The empirical models are calibrated, for improving the formulae, with experimental data set which was collected from the corresponding literature. NNs models are later trained and validated through using the existing experimental data. In this process several NNs architectures are taken into account. A set of good NNs models are selected and then analyzed regarding their robustness when confronted with the test data set and regarding their ability to reproduce the effect of uncertainty on the data. A sensitivity analysis is conducted herein in order to investigate the effect of variability in material and geometrical properties of plate girders. Thereafter, several estimates measuring the efficiency and the quality of the NN model and the calibrated models are obtained and discussed.
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29
42


Farzad
Shahabian
Associate Professor, Civil Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
Associate Professor, Civil Engineering Department,
Iran
fshahabianm@yahoo.com


Sidi Mohammed
Elachachi
Professor, University of Bordeaux1, I2MGCE, 33405 Talence, France.
Professor, University of Bordeaux1, I2MGCE,
France
sidimohammed.elachachi@ ubordeaux1.fr


Denys
Breysse
Professor, University of Bordeaux1, I2MGCE, 33405 Talence, France.
Professor, University of Bordeaux1, I2MGCE,
France
denis.breysse@ ubordeaux1.fr
neural networks
Patch Loading
Plate Girder
Sensitivity analysis
Variability
[Bakhary, N., Hao, H. and Deeks, A.J. (2007). "Damage detection using artificial neural network with consideration of uncertainties", Engineering Structures, 29(11), 28062815. ##Cevik, A. (2007). "A new formulation for longitudinally stiffened webs subjected to patch loading", Journal of Constructional Steel Research, 63(10), 13281340. ##Chacon, R., Mirambell, E. and Real, E. (2009). "Influence of designerassumed initial conditions on the numerical modeling of steel plate girder subjected to patch loading", Thinwalled Structures, 47(4), 391402. ##Chacón, R., Mirambell, E. and Real, E. (2010). "Hybrid steel plate girders subjected to patch loading, Part 1: Numerical study", Journal of Constructional Steel Research, 66(5), 695708. ##Chaves, I.A., Beck, A.T. and Malite, M. (2010). "Reliabilitybased evaluation of design guidelines for coldformed steelconcrete composite beams", Journal of the Brazilian Society of Mechanical Sciences and Engineering, 32(5), DecemberSpecial Issue, 442449. ##Fonseca, E.T, Vellasco, P.C.G. da S., Vellasco, M.M.B.R. and de Andrade, S.A.L. (2008). "A neurofuzzy evaluation of steel beams patch load behaviour", Advances in Engineering Software, 39(7), 558572. ##Fonseca, E.T., Vellasco, P.C.G. da S., de Andrade, S.A.L. and Vellasco, M.M.B.R. (2003). “A patch load parametric analysis using neural networks”, Journal of Constructional Steel Research, 59(2), 251267. ##Gozzi, J. (2007). "Patch loading resistance of plated girders ultimate and serviceability limit state", Doctoral Thesis, Lulea University of Technology, Lulea, Sweden. ##Graciano, C. and Johansson, B. (2003). "Resistance of longitudinally stiffened Igirders subjected to to concentrated loads", Journal of Constructional Steel Research, 59(5), 561586. ##Gracino, C., Casanova, E. and Martinez, J. (2011). "Imperfection sensitivity of plate girder webs subjected to patch loading", Journal of Constructional Steel Research, 67(7), 11281133. ##Granath, P. and Lagerqvist O. (1999). "Behavior of girder webs subjected to patch loading", Journal of Constructional Steel Research, 50(1), 4969. ##Guzelbey, I.H., Cevik, A. and Erklig, A. (2006). “Prediction of web crippling strength of coldformed steel sheetings using neural networks”, Journal of Constructional Steel Research, 62(10), 962973. ##The Joint Committee on Structural Safety, JCSS. (20012). Probabilistic model code, Part 3 Resistance models, structural steel, 3.02, http://www.jcss.byg.dtu.dk/Publications/Probabilistic_Model_Code. ##Kala, Z. (2005). "Sensitivity analysis of the stability problems of thinwalled structures", Journal of Constructional Steel Research, 61(3), 415422. ##Kutmanova, I. and Skaloud, M. (1992). “Ultimate limit state of slender steel webs subject to (i) constant an (ii) repeated partial edge loading”, Journal of Constructional Steel Research, 21(13), 147162. ##Lagerqvist, O. and Johansson, B. (1996). "Resistance of Igirders to concentrated loads", Journal of Constructional Steel Research, 39(2), 87119. ##Lanzi, L., Bisagni, C. and Ricci, S. (2004). “Neural network systems to reproduce crash behavior of structural components”, Computers and structures, 82(1), 93108. ##Liu, H. and Chen, W. (2004). "Probabilistic sensitivity analysis methods for design under uncertainty", Proceedings of the 10th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Albany, New York, 30 August  01 September. ##Markovic, N. and Hajdin, N. (1992). “A contribution to the analysis of the behavior of plate girders subjected to patch loading”, Journal of Constructional Steel Research, 21(13), 163173. ##McCabe, M.F., Franks, S.W. and Kalma, J.D. (2005). “Calibration of a land surface model using multiple data sets", Journal of Hydrology, 302(14), 209222. ##Rattanapitikon, W. (2007). “Calibration and modification of energy dissipation models for irregular wave breaking", Ocean Engineering, 34(1112), 15921601. ##Roberts, T.M. and Newark, A.C.B. (1997). “Strength of webs subjected to compressive edge loading”, Journal of Structural Engineering, 123(2), 176183. ##Roberts, T.M. and Rockey, K.C. (1979). “A mechanism solution for predicting the collapse loads ofslender plate girders when subjected to inplane loading”, Proceedings of the Institution of Civil Engineers, 2(67), 155175. ##Shahabian, F., Elachachi, S.M. and Breysse, D. (2013). "Safety analysis of the patch load resistance of pale girders: influence of model error and variability", Civil Engineering Infrastructures Journal (CEIJ), 46(2), 145160.##]
Prioritizing Roads Safety Based on the QuasiInduced Exposure Method and Utilization of the Analytical Hierarchy Process
2
2
Safety analysis of the roads through the accident rates which is one of the widely used tools has been resulted from the direct exposure method which is based on the ratio of the vehiclekilometers traveled and vehicletravel time. However, due to some fundamental flaws in its theories and difficulties in gaining access to the data required such as traffic volume, distance and duration of the trip, and various problems in determining the exposure in a specific time, place, and individual categories, there is a need for an algorithm for prioritizing the road safety so that with a new exposure method, the problems of the previous approaches would be resolved. In this way, an efficient application may lead to have more realistic comparisons and the new method would be applicable to a wider range of time, place, and individual categories. Therefore, an algorithm was introduced to prioritize the safety of roads using the quasiinduced exposure method and utilizing the analytical hierarchy process. For this research, 11 provinces of Iran were chosen as case study locations. A rural accidents database was created for these provinces, the validity of quasiinduced exposure method for Iran’s accidents database was explored, and the involvement ratio for different characteristics of the drivers and the vehicles was measured. Results showed that the quasiinduced exposure method was valid in determining the real exposure in the provinces under study. Results also showed a significant difference in the prioritization based on the new and traditional approaches. This difference mostly would stem from the perspective of the quasiinduced exposure method in determining the exposure, opinion of experts, and the quantity of accidents data. Overall, the results for this research showed that prioritization based on the new approach is more comprehensive and reliable compared to the prioritization in the traditional approach which is dependent on various parameters including the drivervehicle characteristics.
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43
58


Sajad
rezaei
MSc., Faculty of Civil Engineering, Iran University of Science and Technology, Tehran, Iran.
MSc., Faculty of Civil Engineering, Iran
Iran
sajad_rezaei@civileng.iust.ac.ir


Hamed
Nafar
MSc., Faculty of Civil Engineering, University Putra, Malaysia.
MSc., Faculty of Civil Engineering, University
Iran
hamed_kfz@yahoo.com


Hamid
Behbahani
Professor, Faculty of Civil Engineering, Iran University of Science and Technology, Tehran, Iran.
Professor, Faculty of Civil Engineering,
Iran
behbahani@iust.ac.ir
Analytical Hierarchy Process
Prioritizing
QuasiInduced Exposure
Road Safety
[Aldridge, B.H., Himmler, M., AultmanHall, L. and Stamatiadis, N. (1999). "Impact of passengers on young driver safety", Transportation Research Record, 1693, 2530. ##Carlson, W.L. (1970). "Induced exposure revisited", HIT Lab Report, University of Michigan, Ann Arbor. ##Carr, B.R. (1969). "A statistical analysis on rural Ontario traffic accidents using induced exposure data", Accident Analysis and Prevention, 1(4), 343358. ##Cerrelli, E.C. (1973). "Driver exposure  the indirect approach for obtaining relative measures", Accident Analysis and Prevention, 5(2), 147156. ##Chandraratna, S. and Stamatiadis, N. (2009). "Quasiinduced exposure method, Evaluation of notatfault assumption", Accident Analysis and Prevention, 41(2), 308–313. ##Chandraratna, S. and Stamatiadis, N. (2003). "Problem driving maneuvers of older drivers", Presented in the 2003 Transportation Research Board Meeting, Washington, D.C. ##David, J., DeYong, R.C. and Helander, C.J. (1997). "Estimating the exposure and fatal crash rates of suspended/revoked and unlicensed drivers in California", Accident Analysis and Prevention, 29(1), 1723. ##Hall, W.K. (1970). "An empirical analysis of accident data using induced exposure", HIT Lab Report, University of Michigan, Ann Arbor. ##Hing, J.Y. Stamatiadis, N. and AultmanHall L. (2003). "Evaluating the impact of passengers on the safety of older drivers", Journal of Safety Research, 34(4), 343351. ##Huang, H. and Chor Chin, H. (2009). "Disaggregate propensity study on red light running crashes using quasiinduced exposure method", Journal of Transportation Engineering, 135(3), 104111. ##Jiang, X. and Lyles, R.W. (2010). "A review of the validity of the underlying assumptions of quasiinduced exposure", Accident Analysis and Prevention, 42(4), 13521358. ##Jiang, X. and Lyles, R.W. (2007). "Difficulties with quasiinduced exposure when speed varies systematically by vehicle type", Accident Analysis and Prevention, 39(2), 649–656. ##Jiang, X. (2005). "Measuring the effectiveness of Michigan graduated driver licensing with quasiinduced exposure", Presented at the 84th Transportation Research Board Annual Meeting, (TRB), Washington DC., January. ##Joksch, H.C. (1973). "A pilot study of observed and induced exposure to traffic accident", Accident Analysis and Prevention, 5(2), 127136. ##Kirk, A. and Stamatiadis, N. (200la). "Crash rates and traffic maneuvers of younger drivers", Transportation Research Record, 1779, 6874. ##Kirk, A. and Stamatiadis, N. (200lb). "Evaluation of quasiinduced exposure", Final Report, College of Engineering, University of Kentucky. ##Lighthizer, D.R. (1989). "An empirical validation of quasiinduced exposure", Ph.D Dissertation, Department of Civil and Environmental Engineering, Michigan state University, E. Lansing, MI. ##Lyles, R.W. (1994). "Quasiinduced exposure: to use or not to use?", Presented at the 94th Transportation Research Board Annual Meeting, January, Washington DC. ##Lyles, R.W., Stamatiadis, P. and Lighthizer, D.R. (1991). "Quasiinduced exposure revisited", Accident Analysis and Prevention, 23(4), 275285. ##Rezaei, S. (2011). "Exposure, induced exposure and quasi induced exposure in determining the rate of accidents and road safety measure by using epidemiological methods", M.Sc. Thesis, Department of Civil Engineering, Iran University of Science and Technology. ##Saaty, T.L. (2012). "Decision making for leaders: the analytic hierarchy process for decisions in a complex world", Third Edition, RWS publications, Pittsburgh. ##Stamatiadis, N. and Puccini, G. (1998). "Fatal crash rates in the south eastern united states  why are they higher?", Transportation Research Record, 1665(1), 118124. ##Stamatiadis, N. and Deacon, J.A. (1997). "Quasiinduced exposure: Methodology and insight", Accident Analysis and Prevention, 29(1), 37–52. ##Xu, Z. (2000). "On consistency of the weighted geometric mean complex judgement matrix in AHP1", European Journal of Operational Research, 126(3), 683687.##]
Experimental Study of the Performance of Floating Breakwaters with Heave Motion
2
2
Nowadays, the application of floating breakwaters in small or recreational harbors has found more popularity. These types of breakwaters are more flexible in terms of design, configuration and especially installation compared with fixed breakwaters. In the current study, the performance of floating breakwater (FBs) under regular waves was studied using the physical modeling method. For the modeling practice, a wave flume with a flaptype wave generator and progressive wave absorber was designed, constructed and used in order to investigate the performance of FBs. In this regard, a number of geometrical and hydrodynamic parameters were chosen including the degree of freedom, width variation, FB shapes (pontoon, T and types) and draft depth. In each scenario the water level variation was measured in three points along the flume. Based on the measured water levels transmission, reflection and energy dissipation coefficients were obtained. The effect of each parameter on the performance of FBs was investigated and the best configuration was proposed for further studies. According to the collected experimental data, the mathematical descriptions for calculating the transmission coefficient were also proposed.
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59
70


Morteza
Kolahdoozan
Amirkabir University of Technology (Tehran Polytechnic)
Amirkabir University of Technology (Tehran
Iran
mklhdzan@aut.ac.ir


Mohammad Javad
Alizadeh
Amirkabir University of Technology
Amirkabir University of Technology
Iran
alizadeh.mohamadjavad@gmail.com


Ahmad
Tahershamsi
Amirkabir University of Technology
Amirkabir University of Technology
Iran
tshamsi@aut.ac.ir


A.
Abdolali
Ph.D. Candidate, Department of Civil and Environmental Engineering, University of Roma Tre.
Ph.D. Candidate, Department of Civil and
Iran
alireza_530@yahoo.com
Energy dissipation
Floating Breakwater
Hydrodynamics
Physical Modeling
Transmission
[Abdolali, A. and Kolahdoozan, M. (2011). “Comparison of analytical methods of wave decomposition for evaluating reflection coefficient”, Journal of Marine Engineering, 7(14), 105116. ##Abdolali, A., Kolahdoozan, M., Jandaghi Alaee, M. and Allahyar, M.R. (2012). ''On the comparison of analytical methods using for the decomposition Of wave characteristics'', Proceeding of the 8th International Conference on Coastal and Port Engineering, PIANC, COPEDEC VIII, Madras, Chennai, India. ##Abdolali, A., Franco, L., Bellotti, G. and Kolahdoozan, M. (2012). “Hydraulic and numerical modeling of the performance of type floating breakwaters”, Proceeding of the 10th International Conference on Coasts, Ports and Marine Structures (ICOPMAS 2012), Tehran, Iran, 1921 Nov., 12 pp. ##Abdolali, A. (2011). “Physical modeling of waves near floating breakwaters”, M.Sc. Thesis, Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran. ##Drimer, N., Agnon, Y. and Stiassnie, M. (1992). “A simplified analytical model for a floating breakwater in water of finite depth”, Applied Ocean Research, 14(1), 3341. ##Fuggaza, M. and Natale, L. (1988). “Energy losses and floating breakwater response”, Journal of Waterway, Port, Coastal and Ocean Engineering, ASCE, 114(2), 191205. ##Gesraha, M.R. (2006). “Analysis of the Π shaped floating breakwater in oblique waves: Impervious rigid boards”, Applied Ocean Research, 28(5), 327338. ##Goda, Y.andIppen, A.T. (1963). “Theoretical and experimental investigations of wave energy dissipators composed of wire mesh screens”, Hydrodynamics Laboratory Report, Department of Civil Engineering, Massachusetts Institute of Technology. ##Hsu, HH and Wu, Y.C. (1997). “The hydrodynamic coefficients for an oscillating rectangular structure on a free surface with sidewall”, Ocean Engineering, 24(2), 177199. ##Hwang, C. and Tang, F.L.W. (1986). “Studies on fixed rectangular surface barrier against short waves”, Proceedings of the 20th International Conference of Coastal Engineering, ASCE, Taipei, Taiwan, 19151928. ##Isaacson, M. and Byres, R. (1988). “Floating breakwater response to wave action”, Proceedings of the 21th International Conference of Coastal Engineering, ASCE, Torremolinos, Spain, 21892200. ##Koutandos, E., Prinos, P. and Gironella, X. (2005). “Floating breakwaters under regular and irregular wave forcing: reflection and transmission characteristics”, Journal of Hydraulic Research, 43(2), 174188. ##Kreizi, E.E., Karambas, Th.V., Prinos, P. and Koutitas, C. (2001). “Interaction of floating breakwaters with waves in shallow waters”, Proceedings of the International Conference on IAHR 2001, Beijing, China, 6976. ##Lee, J. and Cho, W. (2003). “Hydrodynamic analysis of wave interactions with a moored floating breakwater using the element Galerkin method”, Canadian Journal of Civil Engineering, 30(4), 720733. ##Lee, J., (1995). “On the heave radiation of a rectangular structure”, Ocean Engineering, 22(1), 1934. ##Mansard, E.P.D. and Funke, E.R. (1980). “The measurement of incident and reflected spectra using a least squares method”, Proceedings of the 17th International Conference of Coastal Engineering, Sydney, Australia, ASCE, Vol. 1, 154172. ##Pena, E., Ferrera, J. and Sanchez, F. (2011). “Experimental study on wave transmission coefficient, mooring lines and module connector forces with different designs of floating breakwaters”, Ocean Engineering, 38(1), 11501160. ##Rahman, M. and Bhatta, D.D. (1993). “Evaluation of added mass and damping coefficients of an oscillating circular cylinder”, Applied Mathematical Modelling, 17, 7079. ##Readshaw, J.S. (1981). “The design of floating breakwaters”, Proceedings of the Second Conference on Floating Breakwaters, Adee and Richey, (eds.), Seattle. ##Ruol, P., Martinelli, L. and Pezzutto, P. (2012). “Formula to predict transmission for πType floating breakwaters”, Journal of Waterway, Port, Coastal, and Ocean Engineering, 139(1), 1–8. ##Sannasiraj, S.A., Sundar, V. and Sundaravadivelu, R. (1998). “Mooring forces and motions responses of pontoontype floating breakwaters”, Ocean Engineering, 25(1), 2784. ##Sutko, A.A. and Haden, E.L. (1974). “The effect of surge, heave and pitch on the performance of a floating breakwater”, Proceedings of Floating Breakwater Conference, Rhode Island, 4153. ##Wang, H.Y, and Sun, ZH.CH. (2010). “Experimental study on the influence of geometrical configuration of porous floating breakwater on performance”, Journal of Marine Science and Technology, 18(4), 574579. ##Williams, A.N. (1993). “Dual floating breakwaters”, Ocean Engineering, 20(3), 215232. ##Williams, A.N., Geiger, P.T. and McDougal, W.G. (1991). “Flexible floating breakwater”, Journal of Waterway, Port, Coastal and Ocean Engineering, ASCE, 117(5), 429450.##]
Numerical Study of Progressive Collapse in Intermediate Moment Resisting Reinforced Concrete Frame Due to Column Removal
2
2
Progressive collapse is a chain reaction of failures propagating throughout a portion of the structure disproportionate to the original local failure occurring when a sudden loss of a critical load‐bearing element initiates a structural element failure, eventually resulting in partial or full collapse of the structure. Both General Services Administration (GSA) and United States Department of Defense (DoD) guidelines incorporate a threatindependent approach to progressive collapse analysis. Therefore, there is an international trend for updating structural design requirements to explicitly design structures to resist progressive collapse. This paper presents simple analytical approach for evaluating progressive collapse potential of typical concrete buildings, comparing four methods for progressive collapse analysis by studying 5 and 10story intermediate momentresistant reinforced concrete frame buildings, employing increasingly more complex analytical procedures: linearelastic static, nonlinear static, linearelastic dynamic, and nonlinear dynamic methodologies. Each procedure is thoroughly investigated and its common shortcomings are identified. The evaluation uses current GSA progressive collapse guidelines and can be used in routine design by practicing engineers. These analyses for three columnremoval conditions are performed to evaluate the behavior of RC buildings under progressive collapse. Based on obtained findings, dynamic analysis procedures easy to perform for progressive collapse determination yielded more accurate results.
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Seyed Mehdi
Zahrai
Associate Professor, Center of Excellence for Engineering and Management of Civil Infrastructures, School of Civil Engineering, College of Engineering, University of Tehran, P.O.Box: 111554563, Tehran, Iran.
Associate Professor, Center of Excellence
Iran
mzahrai@ut.ac.ir


Alireza
Ezoddin
Ph.D. Student, Faculty of Civil Engineering, University of Semnan, Semnan, Iran.
Ph.D. Student, Faculty of Civil Engineering,
Iran
szahrai@yahoo.com
Intermediate Moment Resisting Frame
Linear Dynamic Analysis
Linear Static Analysis
Nonlinear dynamic analysis
Nonlinear Static Analysis
Progressive Collapse
Reinforced concrete
[American Concrete Institute (ACI), (2008). Building code requirements for structural concrete and commentary (ACI 318m08), Detroit, Michigan. ##ASCE. (2005). SEI/ASCE 705 minimum design loads for buildings and other structures. Washington DC, American Society of Civil Engineers. ##BHRC. (2007). Iranian Code of Practice for Seismic Resistant Design of Buildings, Standard No. 2800 (3rd Edition), Building and Housing Research Center. BHRC Publication No. S – 465, 1st print. ##Buscemi, N. and Marjanishvili, S.M. (2005). "SDOF model for progressive collapse analysis", Proceedings of SEI Structures Congress, ASCE, Reston, Va. ##CSI, SAP2000 V14.0.0, (2009). Integrated finite element analysis and design of structures basic analysis reference manual, Computers and Structures Inc., Berkeley, CA, USA. ##Department of Defense (DoD). (2009). Design of buildings to resist progressive collapse, (UFC 402303).Washington D.C. ##FEMA 274. (1997). NEHRP Commentary on the guidelines for the seismic rehabilitation of buildings, Washington D.C., Federal Emergency Management Agency. ##FEMA356, (2000). Prestandard and Commentary for the Seismic Rehabilitation of Buildings, Prepared by American Society of Civil Engineers, Reston, Virginia, prepared for Federal Emergency Management Agency, Washington D.C., Nov. ##Grierson, D., Safi, M., Xu, L. and Liu, Y. (2005)."Simplified methods for progressive collapse analysis of buildings", Proceedings of Metropolis and Beyond Structures Congress, ASCE, Reston, VA. ##Hansen, E., Wong, F., Lawver, D., Oneto, R., Tennant, D. and Ettouney, M. (2005)."Development of an analytical database to support a fast running progressive collapse assessment tool", Proceedings of Metropolis and BeyondStructures Congress, ASCE, Reston, VA. ##Iranian code of practice for seismic resistant design of buildings. (2007). Standard 2800, 3rd Edition, BHRC Publication No. S – 465, 1st print. ##Kaewkulchai, G. and Williamson, E. (2003). “Dynamic behavior of planar frames during progressive collapse”. Proceedings of the 16th ASCE Engineering Mechanics Conference, University of Washington, Seattle. ##Kim, H.S., Kim, J. and An, D.W. (2009)."Development of integrated system for progressive collapse analysis of building structures considering dynamic effects", Advances in Engineering Software, 40, 1–8. ##Kim, J. and Kim, T. (2009). "Assessment of progressive collapseresisting capacity of steel moment frames", Journal of Constructional Steel Research, 65(1), 169  179. ##Marjanishvili, S. and Agnew, E. (2006). "Comparison of various procedures for progressive collapse analysis", Journal of Performance of Constructed Facilities, ASCE, 20(4), 365–374. ##Menchel, K., Thierry, J., Rammer, M.Y. and Bouillard, P. (2009)."Comparison and study of different progressive collapse simulation techniques for RC structures". Journal of Structural Engineering, ASCE, 135(6), 685697. ##Mohamed, O.A. (2009)."Assessment of progressive collapse potential in corner floor panels of reinforced concrete buildings", Engineering Structures, 31(3), 749757. ##National Institute of Standard and Technology (NIST 2007). Best practices for reducing the potential for progressive collapse in buildings, (Draft). U.S. Department of Commerce. ##Powell, G. (2005). “Progressive collapse: Case study using nonlinear analysis”, Proceedings of the 2005 Structures Congress and the 2005 Forensic Engineering Symposium, New York, 2185–2198. ##Pretlove, A.J., Ramsden, M. and Atkins, A.G. (1991). ##"Dynamic effects in progressive failure of structures". International Journal of Impact Engineering, 11(4), 539546. ##The US General Services Administration. (GSA), (2003). Progressive collapse analysis and design guidelines for new federal office buildings and major modernization projects, US General Service Administration, Washington D.C. ##Unified Facilities Criteria (UFC)DoD, (2005). Design of Buildings to Resist Progressive Collapse, Department of Defense, Washington D.C.##]
Bearing Capacity of Strip Footings near Slopes Using Lower Bound Limit Analysis
2
2
Stability of foundations near slopes is one of the important and complicated problems in geotechnical engineering, which has been investigated by various methods such as limit equilibrium, limit analysis, slipline, finite element and discrete element. The complexity of this problem is resulted from the combination of two probable failures: foundation failure and overall slope failure. The current paper describes a lower bound solution for estimation of bearing capacity of strip footings near slopes. The solution is based on the finite element formulation and linear programming technique, which lead to a collapse load throughout a statically admissible stress field. Threenodded triangular stress elements are used for meshing the domain of the problem, and stress discontinuities occur at common edges of adjacent elements. The MohrCoulomb yield function and an associated flow rule are adopted for the soil behavior. In this paper, the average limit pressure of strip footings, which are adjacent to slopes, is considered as a function of dimensionless parameters affecting the stability of the footingonslope system. These parameters, particularly the friction angle of the soil, are investigated separately and relevant charts are presented consequently. The results are compared to some other solutions that are available in the literature in order to verify the suitability of the methodology used in this research.
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89
109


Javad
Mofidi rouchi
M.Sc student, School of Civil Engineering, University College of Engineering, University of Tehran,
Tehran, Iran.
M.Sc student, School of Civil Engineering,
فرانسه
j.mofidi.r@gmail.com


Orang
Farzaneh
Assistant Professor, School of Civil Engineering, University College of Engineering, University of Tehran,
Tehran, Iran.
Assistant Professor, School of Civil Engineering,
فرانسه
ofarzane@ut.ac.ir


Faradjollah
Askari
Assistant Professor, International Institute of Earthquake Engineering and Seismology, Tehran, Iran.
Assistant Professor, International Institute
فرانسه
askari@iiees.ac.ir
Finite element method
Limit Analysis
Lower Bound
Slope
Strip Footing
[Azzouz, A.S. and Baligh, M.M. (1983). “Loaded areas on cohesive slopes”, Journal of Geotechnical Engineering, 109(5), 724–729. ##Castelli, F. and Motta, E. (2008). “Bearing capacity of shallow foundations near slopes: Static analysis”, Proceedings of the Second International British Geotechnical Association Conference on Foundations, ICOF 2008, HIS BRE Press, Watford, U.K., 1651–1660. ##Davis, E.H. and Booker, J.R. (1973). “Some adaptations of classical plasticity theory for soil stability problems”, Proceedings of the Symposium on the Role of Plasticity in Soil Mechanics, A.C. Palmer, ed., Cambridge University, Cambridge, UK, 24–41. ##de Buhan, P. and Garnier, D. (1994). “Analysis of the bearing capacity reduction of a foundation near a slope by means of the yield design theory”, Revue Française de Géotechnique, 68, 21–32. (in French). ##de Buhan, P. and Garnier, D. (1998). “Three dimensional bearing capacity of a foundation near a slope”, Soils Foundation, 38(3), 153–163. ##Drucker, D.C., Greenberg, W. and Prager, W. (1952). “Extended limit design theorems for continuous media”, Quarterly of Applied Mathematics, 9, 381–389. ##Farzaneh, O., Askari, F. and Ganjian, N. (2008). “Three dimensional stability analysis of convex slopes in plan view”, ASCE, Journal of Geotechnical andGeoenvironmental Engineering, 134(8), 11921200. ##Georgiadis, K. (2010). “Undrained bearing capacity of strip footings on slopes”, ASCE, International journal of Geotechnical and Geoenvironmental Engineering, 136(5), 677685. ##Hansen, J.B. (1961). “A general formula for bearing capacity”, Bulletin 11, Danish Geotechnical Institute, Copenhagen, Denmark, 38–46. ##Krabbenhoft, K., Lyamin, A.V., Hjiaj, M. and Sloan, S.W. (2005). “A new discontinuous upper bound limit analysis formulation”, International Journal for Numerical Methods in Engineering, 63(7), 1069–1088. ##Kusakabe, O., Kimura, T. and Yamaguchi, H. (1981). “Bearing capacity of slopes under strip loads on the top surface”, Soils Foundation, 21(4), 29–40. ##Lyamin, A.V. (1999). “Threedimensional lower bound limit analysis using nonlinear programming”, Ph.D. Thesis, University of Newcastle, Australia. ##Lyamin, A.V. and Sloan, S.W. (2002a). “Lower bound limit analysis using nonlinear programming”, International Journal for Numerical Methods in Engineering, 55(5), 573–611. ##Lyamin, A.V. and Sloan, S.W. (2002b). “Upper bound limit analysis using linear finite elements and nonlinear programming”, International Journal for Numerical and Analytical Methods in Geomechanics, 26(2), 181–216. ##Lyamin, A.V., and Sloan, S.W. (2003). “Mesh generation for lower bound limit analysis”, Elsevier Science, International Journal for Advances in Engineering Software, 34(6), 321–338. ##Lysmer, J. (1970). “Limit analysis of plane problems in soil mechanics”, J. Soil Mechanics Foundation Division, ASCE, 96 (SM4), 13111334. ##Meyerhof, G.G. (1957). “The ultimate bearing capacity of foundations on slopes”, The Proceedings of the Fourth International Conference on Soil Mechanics and Foundation Engineering, London, 384–386. ##Michalowski, R.L. (1989). “Threedimensional analysis of locally loaded slopes”, Géotechnique, 39(1), 27–38. ##Michalowski, R.L. (1995). “Slope stability analysis: a kinematical approach”, Geotechnique, 45(2), 283–293. ##Narita, K. and Yamaguchi, H. (1990). “Bearing capacity analysis of foundations on slopes by use of logspiral sliding surfaces”, Soils Foundation, 30(3), 144–152. ##Shiau, J.S., Lyamin, A.V. and Sloan, S.W. (2003). “Bearing capacity of a sand layer on clay by finite element limit analysis”, Canadian Geotechnical Journal, 40(5), 900–915. ##Shiau, J.S., Merifield, R.S., Lyamin, A.V. and Sloan, S.W. (2011). “Undrained stability of footings on slopes”, ASCE, International Journal of Geomechanics, 11(5), 381390. ##Sloan, S.W. (1988). “Lower bound limit analysis using finite elements and linear programming”, International Journal for Numerical and Analytical Methods in Geomechanics, 12(1), 61–67. ##Sloan, S.W. (1989). “Upper bound limit analysis using finite elements and linear programming”, International Journal of Numerical and Analytical Methods in Geomechanics, 13(3), 263–282. ##Sloan, S.W. and Kleeman, P.W. (1995). “Upper bound limit analysis using discontinuous velocity fields”, Computer Methods in Applied Mechanics and Engineering, 127(14), 293–314. ##Sokolovski, V.V. (1960). Statics of granular media, Butterworth Scientific Publications, London. ##Taylor, D.W. (1937). “Stability of earth slopes”, Journal of the Boston Society of Civil Engineers, 24(3), 197–247. ##Vesic, A.S. (1975). Bearing capacity of shallow foundation, Foundation engineering handbook, H.F. Winterkorn, and H.Y. Fang, (eds.), Van Nostrand Reinhold, New York.##]
Taguchi Modeling for TechnoEconomical Evaluation of Cr+6 Removal by Electrocoagulation Process With the Aid of Two Coagulants
2
2
The research aimed to apply the Taguchi method for technoeconomical evaluation of Cr+6 removal using the electrocoagulation process with the aid of two different coagulants (FeCl3 and PAC). Taguchi orthogonal array L27 (313) was applied for analyzing the effect of four variables including initial pH, reaction time, current density and coagulant types in an attempt to improve the chromium removal efficiency. Based on the signaltonoise ratio (S/N) and the analysis of variance (ANOVA), the results indicated that the reaction time was the most important variable on the hexavalent chromium removal efficiency. However, the current density, reaction time and coagulant types significantly influenced the operating costs. The optimum conditions for the mentioned variables were found to be an initial pH of 7, a reaction time of 60 min, a current density of 12.5 mA/cm2 and FeCl3 as a coagulant. Due to the interaction between the initial pH and coagulant type at pH 7, PAC also considered as a coagulant in this experiment. Under the mentioned conditions, the removal efficiencies of 92% and 95% were achieved using the chromium removal process by FeCl3 and PAC, respectively.
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Sepideh
Sadeghi
Amirkabir Uni. of Tech.
Amirkabir Uni. of Tech.
فرانسه
sepideh_idl@yahoo.com


Seyed Mohammad Reza
Alavi Moghaddam
Amirkabir University of Technology
Amirkabir University of Technology
فرانسه
alavim@yahoo.com


Mokhtar
Arami
Amirkabir Uni. of Tech.
Amirkabir Uni. of Tech.
فرانسه
arami@aut.ac.ir
Chromium Removal Efficiency
Electrocoagulation Process
Operating Costs
Taguchi Design
[Aber, S., AmaniGhadim, A.R. and Mirzajani, V. (2009). "Removal of Cr(VI) from polluted solutions by electrocoagulation: Modeling of experimental results using artificial neural network", Journal of Hazardous Materials, 171(1 – 3), 484490. ##Akbal, F. and Camci, S. (2010). "Comparison of electrocoagulation and chemical coagulation for heavy metal removal", Chemical Engineering Technology, 33(10), 16551664. ##Akbal, F. and Camci, S. (2011), "Copper, chromium and nickel removal from metal plating wastewater by electrocoagulation", Desalination, 269(1–3), 214222. ##American Public Health Association, American Water Works Association, Water Pollution Control Federation. (1998). Standard methods for the examination of water and wastewater, 20th Edition, Washington D.C. ##Asadi Habib, M., Alavi Moghaddam, M.R., Arami, M. and Hashemi, H. (2012). “Optimization of the electrocoagulation process for removal of Cr+6 using Taguchi method”, Journal of Water and Wastewater, 22(80), 28, (In Persian). ##BarreraD´ıaz, C.E., LugoLugo, V. and Bilyeu, B. (2012). "A review of chemical, electrochemical and biological methods for aqueous Cr(VI) reduction", Journal of Hazardous Materials, 223 224 (2012), 1–12. ##Bazrafshan, E., Mahvi, A.H., Nasseri, S. and Mesdaghinia, A.R. (2008). "Performance evaluation of electrocoagulation process for removal of Cr+6 from synthetic chromium solutions using iron and aluminum electrodes", Turkish Journal of Engineering Environmental Science, 32(1), 5966. ##Behbahani, M., Alavi Moghaddam, M.R. and Arami, M. (2011). "Technoeconomical evaluation of fluoride removal by electrocoagulation process: Optimization through response surface methodology", Desalination, 271(1–3), 209218. ##Bhatti, M.S., Reddy, A.S., Kalia, R.K. and Thukral, A.K. (2011). "Modeling and optimization of voltage and treatment time for electrocoagulation removal of hexavalent chromium", Desalination, 269(2–3), 157162. ##Bhatti, M.S., Reddy, A.S. and Thukral, A.K. (2009). "Electrocoagulation removal of Cr(VI) from simulated wastewater using response surface methodology", Journal of Hazardous Material, 172(1–3), 839846. ##Chafi, M., Gourich, B., Essadki, A.H., Vial, C. and Fabregat, A. (2011). "Comparison of electrocoagulation using iron and aluminium electrodes with chemical coagulation for the removal of a highly soluble acid dye", Desalination, 281(1), 285–292. ##Davila, J.A., Machuca, F. and Marrianga, N. (2011). "Treatment of vinasses by electrocoagulation–electroflotation using the Taguchi method", Electrochimica Acta, 56(22), 7433– 7436. ##Eary, L.E. and Dhanpat, R. (1988). "Chromate removal from aqueous wastes by reduction with ferrous ion", Environmental Science and Technology, 22(8), 972–977. ##Heidmann, I. and Calmano, W. (2008), "Removal of Zn+2, Cu+2, Ni+2, Ag+1 and Cr+6 present in aqueous solutions by aluminum electrocoagulation", Journal of Hazardous Materials, 152(3), 934941. ##Irdemez, S., Yildiz, Y.S. and Tosuno˘glu, V. (2006). "Optimization of phosphate removal from wastewater by electrocoagulation with aluminum plate electrodes", Separation and Purification Technology, 52(2), 394–401. ##Keles, O. (2009). "An optimization study on the cementation of silver with copper in nitrate solutions by Taguchi design", Hydrometallurgy, 95(3–4), 333–336. ##Keshmirzadeh, E., Yousefi, S. and Rofouei, M.K. (2011). "An investigation on the new operational parameter effective in Cr (VI) removal efficiency: A sudy on electrocoagulation by alternating pulse current", Journal of Hazardous Materials, 190(1–3), 119124. ##MartínezVillafa˜ne, J.F. and MonteroOcampo, C. (2010). "Optimization of energy consumption in arsenic electroremoval from groundwater by the Taguchi method", Separation and Purification Technology, 70(3), 302–305. ##Phadke, M.S. (1989).Quality Engineering Using Robust Design, Prentice Hall, New Jersey. ##Roy, R.K. (1990). A Primer on the Taguchi Method, Van Nostrand Reinhold. ##Secula, M.S., Cagnon, B., Oliveira, T.F., Chedeville, O. and Fauduet, H. (2012). "Removal of acid dye from aqueous solutions by electrocoagulation/GAC adsorption coupling: Kinetics and electrical operating costs", Journal of the Taiwan Institute of Chemical Engineers, 43(5), 767775. ##Shafaei, A., Pajootan, E., Nikazar, M. and Arami, M. (2011). "Removal of Co+2 from aqueous solution by electrocoagulation process using aluminum electrodes", Desalination, 279(1–3), 121126. ##Yildiz, Y.S. (2008). "Optimization of Bomaplex Red CRL dye removal from aqueous solution by electrocoagulation using aluminum electrodes", Journal of Hazardous Materials, 153(1–2), 194–200. ##Yurik, T.K. and Pikaev, A.K. (1999). "Radiolysis of weakly acidic and neutral aqueous solutions of hexavalent chromium ions", High Energy Chemistry, 33(4), 208–212. ##Zongo, I., Leclerc, J.P., Maïga, H.A., Wéthé, J. and Lapicque, F. (2009). "Removal of hexavalent chromium from industrial wastewater by electrocoagulation: A comprehensive comparison of aluminum and iron electrodes", Separation and Purification Technology, 66(1), 159166.##]
Rocking Rotation of a Rigid Disk Embedded in a Transversely Isotropic HalfSpace
2
2
The asymmetric problem of rocking rotation of a circular rigid disk embedded in a finite depth of a transversely isotropic halfspace is analytically addressed. The rigid disk is assumed to be in frictionless contact with the elastic halfspace. By virtue of appropriate Green's functions, the mixed boundary value problem is written as a dual integral equation. Employing further mathematical techniques, the integral equation is reduced to a wellknown Fredholm integral equation of the second kind. The results related to the contact stress distribution across the disk region and the equivalent rocking stiffness of the system are expressed in terms of the solution of the obtained Fredholm integral equation. When the rigid disk is located on the surface or at the remote boundary, the exact closedform solutions are presented. For verification purposes, the limiting case of an isotropic halfspace is considered and the results are verified with those available in the literature. The jump behavior in the results at the edge of the rigid disk for the case of an infinitesimal embedment is highlighted analytically for the first time. Selected numerical results are depicted for the contact stress distribution across the disk region, rocking stiffness of the system, normal stress, and displacement components along the radial axis. Moreover, effects of anisotropy on the rocking stiffness factor are discussed in detail.
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Seyed
Ahmadi
Department of Civil Engineering, School of Science and Engineering, Sharif University
of Technology, International Campus, Kish Island, P.O. Box 7941776655, Kish, Iran
Department of Civil Engineering, School of
فرانسه
ahmadi@kish.sharif.edu


Morteza
Eskandari
Department of Civil Engineering, School of Science and Engineering, Sharif University
of Technology, International Campus, Kish Island, P.O. Box 7941776655, Kish, Iran
Department of Civil Engineering, School of
فرانسه
eskandari@sharif.edu
Fredholm Integral Equation
Rigid Disk
Rocking Stiffness
SoilStructureInteraction
Transversely Isotropic
[Atkinson, K. (1997). The numerical solution of integral equations of the second kind, Cambridge, University Press, New York. ##Ding, H.J., Chen, W.Q. and Zhang, L. (2006). Elasticity of transversely isotropic materials, SpringerDordrecht. ##Eskandari, M. and Shodja, H.M. (2010). “Green’s functions of an exponentially graded transversely isotropic halfspace”, International Journal of Solids and Structures, 47(11–12), 1537–1545. ##EskandariGhadi, M. and Behrestaghi, A.A. (2010). “Forced vertical vibration of rigid circular disc buried in an arbitrary depth of a transversely isotropic half space”, Soil Dynamics and Earthquake Engineering, 30(7), 547–560. ##EskandariGhadi, M., Fallahi, M. and Behrestaghi, A.A. (2010). “Forced vertical vibration of rigid circular disc on a transversely isotropic halfspace”, Journal of Engineering Mechanics, 136(7), 913–922. ##EskandariGhadi, M., Mirzapour, A. and ArdeshirBehrestaghi, A. (2011). “Rocking vibration of a rigid circular disc in a transversely isotropic fullspace”, International Journal for Numerical and Analytical Methods in Geomechanics, 35(14), 15871603. ##Fabrikant, V.I. (1997). “Exact solution of tangential contact problem for a circular domain” Journal of Mechanics and Physics of Solids, 45(1), 113–134. ##Flavin, J.N. and Gallagher, J.P. (1976). “A rigid elliptic inclusion in an anisotropic elastic whole space”, International Journal of Solids and Structures, 12(9–10), 671682. ##Gladwell, G.M.L. (1969). “A contact problem for a cylindrical punch in adhesive contact with elastic halfspace, the case of rocking and translation parallel to the plane” International Journal of Engineering Science, 7(3), 295–307. ##Katebi, A.A., Khojasteh, A., Rahimian, M. and Pak, R.Y.S. (2010). “Axisymmetric interaction of a rigid disc with a transversely isotropic halfspace”, International Journal for Numerical and Analytical Methods in Geomechanics, 34(12), 1211–1236. ##Khojasteh A., Rahimian, M., Eskandari, M. and Pak, R.Y.S. (2008). “Asymmetric wave propagation in a transversely isotropic halfspace in displacement potentials”, International Journal of Engineering Science, 46(7), 690–710. ##Noble, B. (1963). “The solution of Bessel function dual integral equations by a multiplying factor method”, Proceedings of the Cambridge Philosophical Society, 59(2), 351–362. ##Pak, R.Y.S. and Gobert, A.T. (1990). “On the axisymmetric interaction of a rigid disc with a semiinfinite solid”, Journal of Applied Mechanics and Physics, 41(5), 684–700. ##Pak, R.Y.S. and Gobert, A.T. (1991). “Forced vertical vibration of rigid discs with arbitrary embedment”, Journal of Engineering Mechanics, 117(11), 2527–2548. ##Pak, R.Y.S. and Saphores, J.D.M. (1991). “Rocking rotation of a rigid disc in a half–space”, International Journal of Solids and Structures, 28(3), 389–401. ##Rahimian, M., GhorbaniTanha, A.K. and EskandariGhadi, M. (2005). “The Reissner–Sagoci problem for a transversely isotropic halfspace” International Journal for Numerical and Analytical Methods in Geomechanics, 30(11), 10631074. ##Selvadurai, A.P.S., Singh, B.M. and Au, M.C. (1991). “The inplane loading of a rigid disk inclusion embedded in an elastic halfspace” Journal of Applied Mechanics, 58(2), 362–369. ##Selvadurai, A.P.S. (1993). “The axial loading of a rigid circular anchor plate embedded in an elastic halfspace” International Journal of Numerical and Analytical Methods is Geomechanics, 17(5), 343–353. ##Selvadurai, A.P.S. (2009). “Boussinesq indentation of an isotropic elastic halfspace reinforced with an inextensible membrane”, International Journal of Engineering Science, 47(11–12), 1339–1345. ##Selvadurai, A.P.S. (1980a). “Asymmetric displacements of a rigid disc inclusion embedded in a transversely isotropic medium of infinite extent”, International Journal of Science, 18(7), 979986. ##Selvadurai, A.P.S. (1980b). “The displacement of a flexible inhomogeneity embedded in a transversely isotropic elastic medium”, Fiber Science and Technology, 14(4), 251259. ##Selvadurai, A.P.S. (1982). “Axial displacement a rigid elliptical disc inclusion embedded in a transversely isotropic elastic solid”, Mechanics Researcher Communications, 19 (1), 3945. ##Selvadurai, A.P.S. (1984). “The Rotation of a rigid elliptical disk inclusion embedded in a transversely isotropic elastic solid”, Mechanics Researcher Communications, 11(1), 4148.##]
Medium Term Hydroelectric Production Planning  A Multistage Stochastic Optimization Model
2
2
Multistage stochastic programming is a key technology for making decisions over time in an uncertain environment. One of the promising areas in which this technology is implementable, is medium term planning of electricity production and trading where decision makers are typically faced with uncertain parameters (such as future demands and market prices) that can be described by stochastic processes in discrete time. We apply this methodology to hydrosystem operation assuming random electricity prices and random inflows to the reservoir system. After describing the multistage stochastic model a simple case study is presented. In particular we use the model for pricing an electricity delivery contract in the framework of indifference pricing.
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152


BITA
ANALUI
PhD Candidate, Institute of Statistics and Operations Research (ISOR), University of Vienna, Vienna, Austria.
PhD Candidate, Institute of Statistics and
Austria
bita.analui@univie.ac.at


Raimund
Kovacevic
PhD, Institute of Statistics and Operations Research (ISOR), University of Vienna, Vienna,Austria.
PhD, Institute of Statistics and Operations
Austria
raimund.kovacevic@univie.ac.at
Hydroelectric Operation
Multistage Stochastic Programming
Risk Management
[Bühlmann, H. (1972). Mathematical methods in risk theory, Die Grundlehren der Mathematischen Wissenschaften. New York: Springer. ##Carmona, R. (2009). Indifference pricing: Theory and applications, Princeton University Press. ##Eichhorn, A. and Römisch, W. (2005). “Polyhedral risk measures in stochastic programming”, SIAM Journal of Optimization, 16(1), 6995. ##Eichhorn, A., Römisch, W. and Wegner, I. (2005). “Mean risk optimization of electricity portfolios using multi period polyhedral risk measures”, IEEE Power Tech Proceedings, St.Petersburg, Russia, 17. ##Giacometti, R., Vespucci, M.T., Bertocchi, M. and Adesi, G.B. (2001). “Hedging electricity portfolio for a hydroenergy producer via stochastic programming” Proceedings of Stochastic Optimization Methods in Finance and Energy, Springer, 163179. ##Heitsch, H. and Römisch, W. (2005). “Generation of multivariate scenario trees to model stochasticity in power management”, IEEE Power Tech proceedings, St. Petersburg, Russia. ##Kovacevic, R.M. and Paraschiv, F. (2013). “MediumTerm planning for thermal electricity production”, OR Spectrum, DOI:10.1007/s0029101303409. ##Kovacevic, R.M. and Pflug, G.C. (2013). “Pricing of energy contracts  from replication pricing to swing options”, In: R.M. Kovacevic, G.C. Pflug and M.T. Vespucci (eds.), Handbook of Risk Management for Energy Production and Trading, New York: Springer, pp. 393418. ##Labadie, J.W. (2004). “Optimal operation of multi reservoir system: State of the art review”, Water Resources Planning and Management, 130(2), 93111. ##Ledolter, J. (1978). “A general class of stochastic models for hydrological sequences”, Journal of Hydrology, 2(36), 309325. ##Papamichail, D.M. and Georgiou, P.E. (2001). “Seasonal ARIMA inflow models for reservoir sizing”, Journal of American Water Resource Association, 37(4), 877885. ##Pflug, G.C. and Römisch, W. (2007). Modeling, measuring and managing risk, Singapore: World Scientific. ##Rockafellar, R.T. and Uryasev, S. (2000). “Optimization of conditional valueatrisk”, Journal of Risk, 2(3), 2142. ##Ruszczynski, A. and Shapiro, A. (2003). Stochastic programming, 1st Edition, Handbooks in Operations Research and Management Science, Amsterdam: Elsevier.##]