2016
49
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172
Structural Reliability: An Assessment Using a New and Efficient TwoPhase Method Based on Artificial Neural Network and a Harmony Search Algorithm
2
2
In this research, a twophase algorithm based on the artificial neural network (ANN) and a harmony search (HS) algorithm has been developed with the aim of assessing the reliability of structures with implicit limit state functions. The proposed method involves the generation of datasets to be used specifically for training by Finite Element analysis, to establish an ANN model using a proven ANN model in the reliability assessment process as an analyzer for structures, and finally estimate the reliability index and failure probability by using the HS algorithm, without any requirements for the explicit form of limit state function. The proposed algorithm is investigated here, and its accuracy and efficiency are demonstrated by using several numerical examples. The results obtained show that the proposed algorithm gives an appropriate estimate for the assessment of reliability of structures.
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20


Naser
Kazemi Elaki
M.Sc. of Structural Engineering, University of Sistan and Baluchestan
M.Sc. of Structural Engineering, University
Iran
n.kazemi87@yahoo.com


Naser
Shabakhty
PhD of Civil Engineering
Department of Civil Engineering
University of Sistan and Baluchetsan
PhD of Civil Engineering
Department of Civil
Iran
shabakhty@iust.ac.ir


Mostafa
Abbasi Kia
Msc of Computer science. Department of Mathematics, university of Lorestan
Msc of Computer science. Department of Mathematics
Iran
m.abbasi.kia@gmail.com


Soroosh
Sanayee Moghaddam
M.Sc. of Hydrolic Structures, University of Sistan and Baluchestan
M.Sc. of Hydrolic Structures, University
Iran
soroosh.sanayee.moghaddam@gmail.com
Artificial Neural Network
Failure Probability
Harmony Search Algorithm
Implicit Limit State Function
Reliability Index
[Adhikari, S. (2010). “Sensitivity based reduced approaches for structural reliability analysis”, Sadhana Academy Proceeding in Engineering Science, 35(3), 319339.##Allaix, D.L. and Carbone, V.I. (2011). “An improvement of the response surface method”, Structural Safety, 33(2), 165172.##Bucher, C.G. (1998). “Adaptive sampling– an iterative fast Monte Carlo procedure”, Structural Safety, 5(2), 119126.##Castillo, E., Mínguez, R. and Castillo, C. (2008). “Sensitivity analysis in optimization and reliability problems”, Reliability Engineering & System Safety, 93(12), 17881800.##Cheng, J. (2010). “An artificial neural network based genetic algorithm for estimating the reliability of long span suspension bridges”, Finite Elements in Analysis and Design, 46(8), 657668.##Cheng, J. and Li, Q.S. (2008). “Reliability analysis of structures using artificial neural network based genetic algorithms”, Computer Methods in Applied Mechanics and Engineering, 197(45), 37423750.##Cheng, J. (2007). “Hybrid genetic algorithms for structural reliability analysis”, Computers and Structures, 85(19), 15241533.##Cheng, J., Zhang, J., Cai, C.S. and Xiao, R.C. (2007). “A new approach for solving inverse reliability problems with implicit response functions”, Engineering Structures, 29(1), 7179.##Coelho, L.S. (2009). “An efficient particle swarm approach for mixedinteger programming in reliability–redundancy optimization applications”, Reliability Engineering and System Safety, 94(4), 830837.##Deng, J., Gu, D., Li, X. and Yue, Z. (2005). “Structural reliability analysis for implicit performance functions using artificial neural network”, Structural Safety, 27(1), 2548.##Elegbede, C. (2005). “Structural reliability assessment based on particles swarm optimization”, Structural Safety, 27(2), 171186.##Fiacco, A.V. and McCormick, G.P. (1968). Nonlinear programming: sequential unconstrained minimization techniques, Wiley, New York.##Geem, Z.W., Kim, J.H. and Loganathan, G.V. (2001). “A new heuristic optimization algorithm: harmony search”, Simulations, 76(2), 6068.##Haldar, A. (2006). Recent developments in reliabilitybased civil engineering, World Scientific Publishing, Arizona, USA.##Harbiz, A. (1986). “An efficient sampling method for probability of failure calculation”, Structural Safety, 3(2), 109116.##Hasofer, A.M. and Lind, N. (1974). “An exact and invariant FirstOrder Reliability Format”, Engineering Mechanics, ASCE, 100, 111121.##Huang, C.L. (2015). “A particlebased simplified swarm optimization algorithm for reliability redundancy allocation problems”, Reliability Engineering & System Safety, 142, 221230.##Lebrun, R. and Dutfoy, A. (2009). “Do Rosenblatt and Natafiso probabilistic transformations really differ?”, Probabilistic Engineering Mechanics, 24(4), 577584.##Lee, K.S. and Geem, Z.W. (2004). “A new metaheuristic algorithm for continues engineering optimization: harmony search theory and practice”, Computer Method Applied Mechanic and Engineering, 194(36), 39023933.##Liu, P.L. and Der Kiureghian, A. (1991). “Optimization algorithms for structural reliability”, Structural Safety, 9(3), 161177.##Lopez, R.H., Torii, A.J., Miguel, L.F.F. and Souza Cursi, J.E. (2015). “Overcoming the drawbacks of the FORM using a full characterization method”, Structural Safety, 54, 5763.##Mahdavi, M., Fesanghary, M. and Damangir, E. (2007). “An improved harmony search algorithm for solving optimization problems”, Applied Mathematics and Computation, 188(2), 15671579.##Marti, K. (2008). Stochastic optimization methods. SpringerVerlag, Berlin Heidelberg.##McCulloch, W.S. and Pitts, W. (1943). “A logical calculus of ideas immanent in nervous activity”, Bull Math Biophysics, 5(4), 11533.##Moore, J.C., GlenncrossGrant, R., Mahini, S.S. and Patterson, R. (2012). “Regional timber bridge girder reliability: Structural health monitoring and reliability strategies”, Advances in Structural Engineering, 15(5), 793806.##Mucherino, A. and Seref, O. (2009). “Modeling and solving real life global optimization problems with metaheuristic methods”, Advances in Modeling Agricultural Systems, 25, 117.##Mun, S. and Cho, Y.H. (2012). “Modified harmony search optimization for constrained design problems”, Expert Systems with Applications, 39(1), 419423.##RamirezMarquez, J.E. (2008). “Portofentry safety via the reliability optimization of container inspection strategy through an evolutionary approach”, Reliability Engineering and System Safety, 93(11), 16981709.##Rodrigues, M., de Lima, B.S.L.P. and Guimarães, S. (2016). “Balanced ranking method for constrained optimization problems using evolutionary algorithms”, Information Sciences, 327(C), 7190.##Shao, S. and Murotsu, Y. (1997). “Structural reliability using a neural network”, JSME International, 40, 242246.##Stapelberg and Rudolph, F. (2009). Handbook of reliability, availability, maintainability and safety in engineering design, SpringerVerlag, London.##Zhang, Z., Jiang, C., Wang, G.G. and Han, X. (2015). “First and second order approximate reliability analysis methods using evidence theory”, Reliability Engineering & System Safety, 137, 4049.##]
The Elastic Modulus of Steel Fiber Reinforced Concrete (SFRC) with Random Distribution of Aggregate and Fiber
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2
The present paper offers a mesoscale numerical model to investigate the effects of random distribution of aggregate particles and steel fibers on the elastic modulus of Steel Fiber Reinforced Concrete (SFRC). Mesoscale model distinctively models coarse aggregate, cementitious mortar, and Interfacial Transition Zone (ITZ) between aggregate, mortar, and steel fibers with their respective material properties. The interfaces between fibers and mortar have been assumed perfectly bonded. Random sampling principle of Monte Carlo's simulation method has been used to generate the random size, orientation, and position of aggregate particles as well as steel fibers in concrete matrix. A total of 2100 twodimensional and threedimensional cube specimens (150 mm) with varying volume fractions of aggregate and fiber have been randomly generated. The commercial code ABAQUS has been used to analyze the specimens under tensile loading and the calculated elastic modulus has been compared to other analytical and experimental values. Results indicate that the nonhomogeneity of the matrix and random distribution of aggregate and fibers manage to disperse calculated efficiency factor of fiber with a standard deviation of 2.5% to 3.0% (for 150 mm cube specimens, it can be different for other specimens). Nevertheless, the mean value of the calculated efficiency factor agrees well with the value, recommended by Hull (1981), for uniformlydistributed fibers, equal to 0.353, and 0.151 for two and threedimensional models respectively.
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32


Reza
Saleh Jalali
Assistant Prof., Dept. of Civil Eng., Faculty of Eng., University of Guilan, PO Box 3756, Rasht, Iran
Assistant Prof., Dept. of Civil Eng., Faculty
Iran
rsjalali@gmail.com


Emran
Shadafza
MS Student, Dept. of Civil Eng., Faculty of Eng., University of Guilan, PO Box 3756, Rasht, Iran
MS Student, Dept. of Civil Eng., Faculty
Iran
shadafza.emran@gamail.com
aggregate
Elastic Modulus
Mesoscopic
Random Distribution
Steel Fiber Reinforced Concrete
[Ahmad, H.A. and Lagoudas, C.L. (1991). “Effective elastic properties of fiberreinforced concrete with random fibers”, Journal of Engineering Mechanics, 117(12), 29312938.##Bernardi, P., Cerioni, R. and Michelini, E. (2013). “Analysis of postcracking stage in SFRC elements through a nonlinear numerical approach”, Engineering Fracture Mechanics, 108, 238250.##CombyPeyrot, I., Bernard, F., Bouchard, P., Bay, F. and GarciaDiaz, E. (2009). “Development and validation of a 3D computational tool to describe concrete behavior at mesoscale; application to the alkalisilica reaction”, Computational Material Science, 46, 11631177.##Cox, H.L. (1952). “The elasticity and strength of paper and other fibrous materials”, British Journal of Applied Physics, 3(3), 7279.##Ding, Y. (2011). “Investigations into the relationship between deflection and crack mouth opening displacement of SFRC beam”, Construction and Building Materials, 25(5), 24322440.##Gal, E. and Kryvoruk, R. (2011). “Fiber reinforced concrete properties; a multiscale approach”, Computers and Structures, 8(5), 525539.##Grassl, P., Gregoire, D., Solano, L.R. and PijaudierCobat, G. (2012). “Mesoscale modeling of the size effect on fracture process zone of concrete”, International Journal of Solids and Structures, 49(13), 18181827.##Grassl, P. and Jirasek, M. (2010). “Mesoscale approach to modeling the fracture process zone of concrete subjected to uniaxial tension”, International Journal of Solids and Structures, 47(13), 957968.##Grassl, P. and Rempling, R. (2008). “A damageplasticity interface approach to the mesoscale modeling of concrete subjected to cyclic compressive loading”, Engineering Fracture Mechanics, 75(16), 48044818.##Hao, Y.F., Hao, H. and Li, Z.X. (2009). “Numerical analysis of lateral inertial confinement effects on impact test of concrete compressive material properties”, International Journal of Protective Structures, 1(1), 143145.##Hill, R. (1965). “A selfconsistent mechanics of composite materials”, Journal of Mechanics and Physics of Solids, 13(4), 213222.##Huang, Y., Yang, Z., Ren, W., Liu, G. and Zhang, C. (2015). “3D mesoscale fracture modeling and validation of concrete based on insitu Xray Computed Tomography images using damage plasticity model”, International Journal of Solids and Structures, 6768, 340352.##Hull, D. (1981). An introduction to composite materials, Cambridge University Press, London.##Hung, L.T., Dormieux, L., Jeannin, L., Burlion, N. and Barthélémy, J.F. (2008). “Nonlinear behavior of matrixinclusion composites under high confining pressure: application to concrete and mortar”, Comptes Rendus Mecanique, 336(8), 670676.##Islam, M., Khatun, S., Islam, R., Dola, J.F., Hussan, M. and Siddique, A. (2014). “Finite Element analysis of Steel Fiber Reinforced Concrete (SFRC): Validation of experimental shear capacities of beams”, Procedia Engineering, 90, 8995.##Jing, Li., Linfu, W., Lin, J., Juan, L. and Hu, L. (2011). “Numerical simulation of uniaxial compression performance of big recycled aggregatefilled concrete”, Electric Technology and Civil Engineering (ICETCE) International Conference, 13671370.##Kim, S.M. and Abu AlRub, R.K. (2010). “Mesoscale computational modeling of the plasticdamage response of cementitious composites”, Cement and Concrete Research, 41(3), 339358.##Mori, T. and Tanaka, K. (1973). “Average stress in matrix and average energy of materials with misfitting inclusions”, Acta Metallurgica, 21, 571574.##Nguyen, T.T.H., Bary, B. and Larrard, T. (2015). “Coupled carbonationrust formationdamage modeling and simulation of steel corrosion in 3D mesoscale reinforced concrete”, Cement and Concrete Research, 74, 95107.##Özcan, D. M., Bayraktar, A., Sahin, A., Haktanir, T. and Tüker, T. (2009). “Experimental and Finite Element analysis on the steel fiberreinforced concrete (SFRC) beams ultimate behavior”, Construction and Building Materials, 23(2), 10641077.##Qin, C. and Zhang, C. (2011). “Numerical study of dynamic behavior of concrete by mesoscale particle element modeling”, International Journal of Impact Engineering, 38(12), 10111021.##RashidDadash, P. and Ramezanianpour, A.A. (2014). “Hybrid fiber reinforced concrete containing pumice and metakaolin”, Civil Engineering Infrastructures Journal (CEIJ), 47(2), 229238.##Rizzuti, L. (2014). “Effects of fibre volume fraction on the compressive and flexural experimental behaviour of SFRC”, Contemporary Engineering Sciences, 7(8), 379390.##Roubin, E., Colliat, J. and Benkemoun, N. (2015). “Mesoscale modeling of concrete: A morphological description based on excursion sets of random fields”, Computational Materials Science, 102, 183195.##Salehian, H., Barros, J.A.O. and Taheri, M. (2014). “Evaluation of the influence of postcracking response of steel fiber reinforced concrete (SFRC) on load carrying capacity of SFRC panels”, Construction and Building Materials, 73, 289304.##Shahabeyk, S., Hosseini, M. and Yaghoobi, M. (2011). “Mesoscale Finite Element prediction of concrete failure”, Computational Materials Science, 50(7), 19731990.##Skarzynski, L. and Tejchman, J. (2010). “Calculations of fracture process zones on mesoscale in notched concrete beams subjected to threepoint bending”, European Journal of Mechanics, 29(4), 746760.##Smilauer, V. and Bazant, Z. (2010). “Identification of viscoelastic CSH behavior in mature cement paste by FFTbased homogenization method”, Cement and Concrete Research, 40(2), 197207.##Smilauer, V. and Krejci, T. (2009). “Multiscale model for temperature distribution in hydrating concrete”, International Journal for Multiscale Computational Engineering, 7(2), 135151.##Sun, B., Wang, X. and Li, Z. (2015). “Mesoscale imagebased modeling of reinforced concrete and adaptive multiscale analyses on damage evolution in concrete structures”, Computational Materials Science, 110, 3953.##Tailhan, J.L., Rossi, P. and DaviauDesnoyers, D. (2015). “Probabilistic numerical modeling of cracking in steel fiber reinforced concretes”, Cement and Concrete Composites, 55, 315321.##Teng, T.L., Chu, Y.A., Chang, F.A., Shen, B.C. and Cheng, D.S. (2007). “Development and validation of numerical model of steel fiber reinforced concrete for highvelocity impact”, Computational Materials Science, 42(1), 9099.##Teng, T.L., Chu, Y.A., Chang, F.A. and Chin, H.S. (2004). “Calculating the elastic moduli of steelfiber reinforced concrete using a dedicated empirical formula”, Computational Materials Science, 31(34), 337346. ##Titscher, T. and Unger, J.F. (2015). “Application of molecular dynamics simulations for the generation of dense concrete mesoscale”, Computers & Structures, 158, 274284.##Ulm, F.J. and Jennings, H.M. (2008). “Does CSH particle shape matter? A discussion of the paper ‘Modelling elasticity of a hydrating cement paste’, by Julien Sanahuja, Luc Dormieux and Gilles Chanvillard, CCR 37 (2007) 14271439”, Cement and Concrete Research, 38(8), 11261129.##Wang, X., Yang, Z. and Jivkov, A.P. (2015). “Monte Carlo simulations of mesoscale fracture of concrete with random aggregate and pores: a size effect study”, Construction and Building Materials, 80, 262272.##Wang, Z.L., Shi, Z.M. and Wang, J.G. (2011). “Analysis of postcracking stage in SFRC elements through a nonlinear numerical approach”, Engineering Fracture Mechanics, 108, 238250.##Wang, Z.L., Konietzky, H. and Huang, R.Y. (2009). “Elasticplastichydrodynamic analysis of crater blasting in steel fiber reinforced concrete”, Theoretical and Applied Fracture Mechanics, 52(2), 111116.##Wang, Z.M., Kwan, A.K.H. and Chan, H.C. (1999). “Mesoscopic study of concrete I: Generation of random aggregate structure and Finite Element mesh”, Computers and Structures, 70(5), 533544.##Williamson, G.R. (1974). “The effect of steel fibers on the compressive strength of concrete”, ACI Jouranl, 44, 195208.##Wriggers, P. and Moftah, S.O. (2006). “Mesoscale models for concrete: homogenization and damage behavior”, Finite Elements in Analysis and Design, 42(7), 623636.##Wu, M., Chen, Z. and Zhang C. (2015). “Determining the impact behavior of concrete beams through experimental testing and mesoscale simulation: I. Dropweight tests”, Engineering Fracture Mechanics, 135, 94112.##Xu, Z., Hao, H. and Li, H.N. (2012a). “Mesoscale modeling of dynamic tensile behavior of fiber reinforced concrete with spiral fiber”, Cement and Concrete Research, 42(11), 14751493.##Xu, Z., Hao, H. and Li, H.N. (2012b). “Mesoscale modeling of fiber reinforced concrete material under compressive impact loading”, Construction and Building Materials, 26(1), 274288.##Yazici, S., Arel, H.S. and Tabak, V. (2013). “The effects of impact loading on the mechanical properties of the SFRCs”, Construction and Building Materials, 41, 6872.##Zaitsev, Y.B. and Wittmann, F.H. (1981). “Simulation of crack propagation and failure of concrete”, Materials and Structures, 14(2), 357365.##Zhang, J. (2013). “Threedimensional modelling of steel fiber reinforced concrete material under intense dynamic loading”, Construction and Building Materials, 44, 118132.##Zheng, J.J., Li, C.Q. and Zhou, X.Z. (2005) “Thickness of interfacial transition zone and cement content profiles between aggregates”, Magazine of Concrete Research, 57(7), 397406.##Zhou, X.Q. and Hao, H. (2009). “Mesoscale modeling and analysis of damage and fragmentation of concrete slab under contact detonation”, International Journal of Impact Engineering, 36(12), 13151326.##Zhou, X.Q. and Hao, H. (2008a). “Mesoscale modeling of concrete tensile failure mechanism at high strain rates”, Computers & Structures, 86(2122), 20132026.##Zhou, X.Q. and Hao, H. (2008b). “Modeling of compressive behavior of concretelike materials at high strain rate”, International Journal of Solids and Structures, 45(17), 46484661.##]
The Effect of Spandrel Beam's Specification on Response Modification Factor of Concrete Coupled Shear Walls
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2
Response modification factor (R factor) is one of the seismic design parameters to be considered in evaluating the performance of buildings during strong motions. This paper has tried to evaluate the response modification factor of concrete coupled shear wall structures with various length/depth ratios of spandrel beams. The effect of diagonal reinforcement of spandrel beam was also evaluated on the R factor. The R factor directly depends on overstrength factor and ductility reduction factor. For this purpose, three conventional structures with 5, 10 and 15 story buildings (having various spandrel beam's length/depth ratio with and without diagonal reinforcement) were selected and the nonlinear static analyses were conducted to evaluate their overstrength and ductility reduction factors. Also for a 5story structure, nonlinear dynamic analysis (time history) was carried out in order to compare the results with nonlinear static analysis. It was concluded that the R factors using nonlinear time history analysis and nonlinear static analysis are almost the same. The results also indicate that by increasing the height of the structure, the overstrength reduction factor decreases; while the ductility reduction factor increases. Also, the response modification factor decreases with increasing length/depth ratio of spandrel beams. The coupled shear walls with diagonal reinforcement in spandrel beams have a greater R factor.
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43


Mussa
Mahmoudi
Shahid Rajaee Teacher Training University
Shahid Rajaee Teacher Training University
Iran
m.mahmoudi@sru.ac.ir


seyed Mohammad Reza
Mortazavi
Shahid Rajaee Teacher Training University
Shahid Rajaee Teacher Training University
Iran
mortazavimr@srttu.edu


Saeid
Ajdari
Shahid Rajaee Teacher Training University
Shahid Rajaee Teacher Training University
Iran
saeidazhdari@yahoo.com
Concrete Coupled Shear Wall
Ductility Reduction Factor
Response Modification Factor
Overstrength Factor
Spandrel Beam
[Abdollahzadeh, G. and Malekzadeh, H. (2013). “Response modification factor of coupled steel shear walls”, Civil Engineering Infrastructures, 1(1), 1526.##Baradaran M.Sh., Dupuis M.J., Macauley J., Elwood K.J., Anderson D.L., and Simpson R. (2014). “Seismic performance of shear wall building with gravity induced lateral demands”, 10th U.S. National Conference on Earthquake Engineering Frontiers of Earthquake Engineering, July 2125, 10 NCEE Anchorage, Alaska.##Bazargani, P. and Adebar, P. (2015). “Interstory drifts from shear strains at base of highrise concrete shear walls”, Journal of Structural Engineering, 141(12), 04015067.##Bhunia, D., Prakash, V., and Pandey, A.D. (2013). A conceptual design approach of coupled shear walls, Hindawi Publishing Corporation, ISRN Civil Engineering, Article ID 161502, 28 pages.##Borzi, B. and Elnashai, A.S. (2000), “Refined force reduction factors for seismic design”, Engineering Structures, 22(10), 12441260.##Building and Housing Research Center. (2005). Iranian code of practice for seismic resistance design of buildings, Standard No. 2800, 3rd Edition, Publisher: BHRC.##Computers and Structures Inc. (2006). PERFORM3D, nonlinear analysis and performance assessment for 3D structures, Version 4, Publisher: CSI.##Doran, B. (2003). “Elasticplastic analysis of R/C coupled shear walls: The equivalent stiffness ratio of the tie elements”, Journal of Indian Institute of Science, 83, 8794.##Eljadei, A.A. (2012), “Performance based design of coupled wall structures”, Ph.D. Dissertation, Swanson School of Engineering, University of Pittsburgh, Russia.##FEMA (2000). “Prestandard and commentary for the seismic rehabilitation of building”, FEMA356, Federal Emergency Management Agency, Washington, D.C.##Hadidi, A., Farahmand Azar, B. and Khosravi, H. (2003). “An investigation on the behavior of stiffened coupled shear walls considering axial force effect”, Journal of Structural Engineering, 22(18), 13901403.##Tasnimi, A.A. and Kiarash K. (2009). “Review of behavior of reinforced concrete shear walls at various performance levels”, 8th International Congress on Civil Engineering, Shiraz University, Shiraz, Iran.##UBC1997 (1997). Uniform building code, International Council of Building Officials (ICBO), Whittier, CA.##Hosseini, M., Sadeghi, H. and Seidali, H. (2011). “Comparing the nonlinear behaviors of steel and concrete link beams in coupled shear wall system by Finite Element analysis”, 12th East AsiaPacific Conference on Structural Engineering and Construction, City University of Hong Kong.##Khatami, S.M., Mortezaei, A. and Rui, C. Barros (2012). “Comparing effects of openings in concrete shear walls under nearfault ground motions”, 15th World Conference on Earthquake Engineering, Lisbon.##Shahbakhti, N. and Heshmati, S. (2007). “A review the effects of reinforcement upon the degree of ductility and response modification factor of reinforced concrete shear walls with openings”, Iranian Second National Conference on Improvement and Strengthening, Kerman, Iran. ##Mahmoudi, M. (2003). “The relationship between overstrength and members ductility of RC moment resisting frames”, 8th Pacific Conference on Earthquake Engineering, Singapore.##Mahmoudi, M. and Zaree, M. (2010), “Evaluating response modification factors of concentrically braced steel frames”, Journal of Constructional Steel Research, 66(10), 11961204.##Mahmoudi, M. and Zaree, M. (2011). “Evaluating the overstrength of concentrically braced steel frame systems considering members postbuckling strength”, International Journal of Civil Engineering, 9(1), 5762.##Meftah, S.A. and Mohri, F. (2013). “Seismic behavior of RC coupled shear walls with strengthened spandrel beams by bonded thin composite plates”, KSCE Journal of Civil Engineering, 17(2), 403414.##McGinnis, M., Barbachyn, S., Holloman, M., and Kurama, Y. (2013). “Experimental evaluation of a multistory posttensioned coupled shear wall structure. Structures Congress, Pittsburgh, Pennsylvania, United States, pp. 19501961.##MHUD (2009). Iranian national building code (part 9): Concrete structure design, Ministry of Housing and Urban Development, Tehran, Iran.##MHUD (2009). Iranian national building code (part 6): loading, Ministry of Housing and Urban Development, Tehran, Iran.##Newmark, N.M. and Hall W.J. (1970). Seismic design criteria for nuclear reactor facilities, Report No. 46, Building Practices for Disaster Mitigation, National Bureau of Standards, U.S. Department of Commerce, pp. 209236.##Ranjbar, M.M., Bozorgmehrnia, S. and Madandoust, R. (2013). “Seismic behavior evaluation of concrete elevated water tanks”, Civil Engineering Infrastructures Journal, 46(2), 175188.##Whittaker, A., Hart, G. and Rojahn, C. (1999). “Seismic response modification factors”, Journal of Structural Engineering, 125(4), 438444.##]
Investigating the Properties of Asphalt Concrete Containing Glass Fibers and Nanoclay
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2
The performance of asphaltic pavements during their service life is highly dependent on the mechanical properties of the asphaltic layers. Therefore, in order to extend their service life, scientists and engineers are constantly trying to improve the mechanical properties of the asphaltic mixtures. One common method of improving the performance of asphaltic mixtures is using different types of additives. This research investigated the effects of reinforcement by randomly distributed glass fibers and the simultaneous addition of nanoclayon some engineering properties of asphalt concrete have been investigated. The properties of a typical asphalt concrete reinforced by different percentages of glass fibers were compared with those containing both the fibers and nanoclay. Engineering properties, including Marshall stability, flow, Marshall quotient, volumetric properties and indirect tensile strength were studied. Glass fibers were used in different percentages of 0.2, 0.4 and 0.6% (by weight of total mixture), and nanoclay was used in 2, 4 and 6% (by the weight of bitumen). It was found that the addition of fibers proved to be more effective than the nanoclay in increasing the indirect tensile strength. However, nanoclay improved the resistance of the mixture against permanent deformation better than the glass fibers. The results also showed that the mixture reinforced by 0.2% of glass fiber and containing 6% nanoclay possessed the highest Marshall quotient, and the mixture containing 0.6% glass fibers and 2% nanoclay possessedthe highest indirect tensile strength.
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58


Hasan
Taherkhani
assistant professor, civil engineering department, university of zanjan, zanjan, Iran
assistant professor, civil engineering department,
Iran
taherkhani.hasan@znu.ac.ir
Asphalt Concrete
Glass Fiber
Nanoclay
Tensile strength
[Abtahi, S.M., Esfandiarpour, S., Kunt, M., Hejazi, S.M. and Ebrahimi, M.G. (2013) “Hybrid reinforcement of asphalt concrete mixtures using glass and polypropylene fibers”, Journal of Engineering Fibers and Fabrics, 8(2), 2535.##Abtahi, S.M., Sheikhzadeh, M., Alipour, R., Hejazi, S.M. (2009). “Physical and mechanical properties of fibersreinforced bitumen mixtures”, 7th National Conference on Textile Engineering Rasht, Iran.##Airey, G.D. (2002) “Rheological evaluation of ethylene vinyl acetate polymer modified bitumens”, Journal of Construction and Building Materials, 16(8), 473487.##Asphalt Institute (1997). Mix design methods for asphalt, 6th Edition, MS02, Asphalt Institute, Lexington, KY.##Becker, O., Varley, R. and Simon, G.P. (2002) “Morphology, thermal relaxations and mechanical properties of layered silicate nanocomposites based upon highfunctionality epoxy resins”, Polymer, 43(16), 4365–4373.##Chen, J.S. and Lin, K.Y. (2005) “Mechanism and behavior of bitumen strength reinforcement using fibers” Journal of material Science, 40(1), 8795.##Chen H., Li, N., Hu, C., Zhang, Z. (2004) “Mechanical performance of fibersreinforced asphalt mixture”, Journal of Chan University – National Science Ed., 24(2), 15.##Cheng, J., Shen, J. and Xiao, F. (2011) “Moisture susceptibility of warmmix asphalt mixtures containing nanosized hydrated lime”, Journal of Materials in Civil Engineering, 23(11), 15521559.##Chong, K.P. (2004). “Nanotechnology and information technology in Civil Engineering’, Conference Proceeding – Towards a Vision for Information Technology in Civil Engineering”, In: Ian Flood, (Ed.), 4th Joint International Symposium on Information Technology in Civil Engineering, November 1516, 2003, Nashville, TN, USA, 19.##Chow, W. (2003). “Development of thermoplastic nanocomposites based on blends of polyamide and polypropylene”, Ph.D. Thesis, Material and Mineral Resources Engineering, University of Sains Malaysia.##Echols J. (1989) “New mix method for fiberreinforced asphalt” Public Works, 119(8), 7273.##Esfahani, M.H., Abdollahi, A., Deshpande, S. and Abdollahi, A. (2013). “Laboratory investigation of the fracture properties of nanoclaymodified asphalt materials under direct tensile test”, International Journal of Mechanical Engineering and Robotics, 1(1), 6370.##Garcia, A., NovambuenaContras, J., Partl, M.N. and Schuetz, P. (2013), “Uniformity and mechanical properties of dense asphalt concrete with steel wool fibers”, Construction and building materials, 43(9), 107117.##Ghaffarpour Jahromi, S.G. and Khodaii A. (2009). “Effects of nanoclay on rheological properties of bitumen binder”, Construction and Building Materials, 23(8), 28942904.##Ghaffarpour Jahromi, S., Andalibzade, B. and Vossough, S. (2010). “Engineering properties of nanoclay modified asphalt concrete mixtures”, The Arabian Journal for Science and Engineering, 23(1B), 88103.##Ghasemi, M., Marandi, S.M., Tahmooresi, M. Kamali, R. and Taherzade, R. (2012) “Modification of stone matrix asphalt with nanoSiO2”, Journal of Basic Applied Science Research, 2(2), 13381344.##Ghile, D. (2006) “Effects of nanoclay modification on rheology of bitumen and on performance of asphalt mixtures”, MSc. Thesis, Delft University of Technology.##Goel, A., and Das, A., (2004). “Emerging road materials and innovative”, Proceedings of National Conference on Materials and their Application in Civil Engineering, Hamipur, India, August.##Goh, S.W., Akin, M., You, Z., and Shi, X. (2011). “Effect of deicing solutions on the tensile strength of micro or nanomodified asphalt mixture”, Construction Building Materials, 25(1), 195200.##Grim, R.E. (1959). “Physicaochemical properties of soils: clay minerals”, Journal of the Soil Mechanics and Foundations Division, ASCE, 85(SM2), 117.##Hinislioglu, S., and Agar, E. (2004). “Use of waste high density polyethylene as bitumen modifier in asphalt concrete mix”, Materials Letters, 58(34), 267271.##Isacsson, U. and Lu, X.H. (1999). “Laboratory investigation of polymer modified bitumens”, Journal of the Association of Asphalt Paving Technology, 68, 3563.##Isacsson, U. and Zeng, H. (1998). “Lowtemperature cracking of polymermodified asphalt”, Journal of Materials and Structures, 31(1), 5863.##Ghaffarpour Jahromi, S. and Khodaii, A. (2008). “Carbon fiber reinforced asphalt concrete”, Arabian Journal of Science and Engineering, 33(2B), 35564.##Khattak, M.J., Khattab, A., Rizvi, H.R. (2011). “Mechanistic characteristics of asphalt binder and asphalt matrix modified with nanofibers”, Proceedings of the Geofrontiers Conference, At Dallas, Texas, Volume: Geotechnical Special Publication (211), Advances in Geotechnical, 48124822.##Lan, T. and Pinnavaia, T.J. (1994). “Clayreinforced epoxy nanocomposites”, Chemistry of Materials, 6, 2216229.##Lan, T., Kaviratna, P. D. and Pinnavaia, T. J. (1995). “Mechanism of clay factoid exfoliation in epoxy–clay nanocomposites”, Chemistry of Materials, 7, 21442150.##Liu, Y.L., Hsu, C.Y., Wei, W.L. and Jeng, R.J. (2003). “Preparation and thermal properties of epoxy–silica nanocomposites from nanoscale colloidal silica”, Polymer, 44, 51591567.##Lu, X., and Issacson, U. (1997). “Rheological characterization of styrenebutadienestyrene copolymer modified bitumens”, Construction and Building Materials, 11(1), 2332.##Mahrez, A., Rehan Karim, M. and HerdaYatibt, K.H. (2005). “Fatigue and deformation properties of glass fiber reinforced asphalt mixes”, Journal of the Eastern Asia Society for Transportation Studies, 6, 9971007,##Maurer Dean, A., and Gerald, J.M. (1989). “Field performance of fabrics and fibers to retard reflective cracking”, Geotextiles and Geomembranes, 8(3), 239267.##Putman, B.J., Amirkhanian, S.N. (2004) “Utilization of waste fibers in stone matrix asphalt mixtures”, Resources, Conservation and Recycling, 42, 265274.##Roy, S., Hussain, F., Narasimhan, K., Vengadassalam, K., and Lu, H. (2007). “E glass/polypropylene nanocomposites: manufacture, characterization, and mechanical properties”, Polymers and Polymer Composites, 15(2), 91102.##Sukla, M., Tiwari, D. and Sitaramanjaneyulu, K. (2013). “Performance characteristics of asphalt concrete mix modified with glass fiber”, International Journal Pavement Engineering and Asphalt Technology, 15(1), 3850.##Vasiliev, V. and Mozorov, V. (2007). Advanced mechanics of composite materials, 2nd Edition, Elsevier, Oxford, UK, 57100.##Yildirim, Y. (2007). “Polymer modified asphalt binders”, Journal of Construction and Building Materials, 21(1), 6672.##Wu, S., Ye, Q., Li, N. and Yue, H. (2007). “Effects of fibers on the dynamic properties of asphalt mixtures”, Journal of Wuhan University of Technology – Material Science Ed., 22(4), 733736.##Wu, S., Liu X., Ye Q. and Li N. (2006). “Selfmonitoring electrically conductive asphaltbased composite with carbon fillers”, Transactions of Nonferrous Metals Society of China, 16(2), 512–516.##Wu, S.P., Mo, L.T., Shui, Z.H. and Chen, Z. (2005). “Investigation of the conductivity of asphalt concrete with conductive fillers”, Carbon, 43(7), 1358–1363.##Wu, S.P., Mo, L.T. and Shui, Z.H. (2002). “An improvement on electrical properties of asphalt concrete”, Journal of Wuhan University of Technology –Material Science Ed., 17(4), 6972.##Xiao, F., Amirkhanian, A.N. and Amirkhanian, S.N. (2011). “Influence of carbon nanoparticles on the rheological characteristics of shortterm aged asphalt binders”, Journal of Materials in Civil Engineering, 23(4), 423431.##Yoo, P.J., and Kim, T.W. (2015). “Strengthening of hotmix asphalt mixtures reinforced by polypropyleneimpregnated multifilament glass fibers and scraps”, Construction and Building Materials, 75, 415420.##You, Z., MillsBeale, J., Foley, J.M., Roy, S., Odegard, G.M. and Dai, Q. (2011). “Nanoclay modified asphalt materials: preparation and characterization”, Construction and Building Materials, 25(2), 10721078.##Yousefi, A.A. (2003). “Polyethelene dispersion in bitumen: The effects of polymer structural parameters”, Journal of Applied Polymer Science, 90, 31833190.##Zerda, A.S. and Lesser, A.J. (2001). “Intercalated clay nanocomposites: morphology, mechanics and fracture behavior”, Polymer Science, Part B, Polymer Physics, 39(11), 1137–1146.##]
Investigation of Peak Particle Velocity Variations during Impact Pile Driving Process
2
2
Impact pile driving is a multicomponent problem which is associated to multidirectional ground vibrations. At first, vibration is transferred from the hammer to the pile and then to the common interface of pile and soil. This is then transferred to the environment and has great impact on the adjacent structures, causing disturbance to residents and also damage to the buildings. It is of high importance to have sufficient estimation of pile driving vibration level in order to maintain the comfort of residents near the site and also to prevent the structural damage to buildings. In this study, a finite element model, using ABAQUS, with the ability of simulating continuous pile driving process from the ground surface, was introduced. The model was verified by comparing the computed peak particle velocities with those measured in the field. Parameters affecting the peak particle velocity (PPV), for example elastic modulus, shear strength parameters, impact force, pile diameter, etc. were considered, and variations of PPV was investigated. Results of present study indicated that PPV at the ground surface does not occur when the pile toe is located on the ground surface; as the pile penetrates into the ground, PPV reaches a maximum value at a critical depth of penetration. Moreover, the amplitude of vibration on the ground surface reduced logarithmically with increasing distance to the pile. Also, on the ground surface and radial distances of 3 to 20 m, maximum particle velocity occurred between 1 to 5 m depths of pile penetration. The results showed PPV as being directly proportional to the hammer impact force, pile diameter, friction angle and cohesion intercept and inversely proportional to the elastic modulus of the soil.
1

59
69


Maryam
Rezaei
School of Engineering, Kharazmi University, Tehran, Iran
School of Engineering, Kharazmi University,
Iran
nina.rezaei@gmail.com


Amir
Hamidi
School of Engineering, Kharazmi University, Tehran, Iran
School of Engineering, Kharazmi University,
Iran
hamidi@khu.ac.ir


Abtin
Farshi Homayoun Rooz
School of Engineering, Kharazmi University, Tehran, Iran
School of Engineering, Kharazmi University,
Iran
std_abtinfhr@khu.ac.ir
ABAQUS
Numerical analysis
Peak particle velocity
Pile Driving
[Bolton, M.D. (1986). “Strength and dilatancy of sands”, Geotechnique, 36(1), 6578.##Deckner, F. (2013). “Ground vibrations due to pile and sheet pile driving influencing factors, predictions and measurements”, B.Sc. Thesis, Royal Institute of Technology, Stockholm, Sweden.##Deeks, A.J. and Randolph, M.F. (1993). “Analytical modeling of hammer impact for pile driving”, International Journal for Numerical and Analytical Methods in Geomechanics, 17(5), 279302.##Henke, S. and Grabe, J. (2006). “Simulation of pile driving by 3dimensional finiteelement analysis”, Proceedings of 17th European Young Geotechnical Engineers’ Conference, SzavitsNossan V. (ed.), Zagreb, Croatia, Croatian Geotechnical Society, 215233.##Hope, V.S. and Hiller, D.M. (2000). “The prediction of ground borne vibration from percussive piling”, Canadian Geotechnical Journal, 37(3), 700711.##Karlsson, Å‐B. (2013). “Tillsätt haverikommission för att utreda byggmisstag”, Debate article from Dagens Nyheter’s web paper DN.se. Published online 11.01.2013, http://www.dn.se/debatt/ tillsattaverikommissionforattutredabyggmisstag/.##Kim, D.S. and Lee, J.S. (2000). “Propagation and attenuation characteristics of various ground vibrations”, Soil Dynamics and Earthquake Engineering, 19(2), 115126.##Leonards, G.A., Deschamps, R.J. and Feng, Z. (1995). “Driveability, load/settlement and bearing capacity of piles installed with vibratory hammers”, Final Report submitted to the Deep Foundations Institute, School of Engineering, Purdue University, West Lafayette, Indiana, USA.##Massarsch, K.R. and Fellenius, B.H. (2008). “Ground vibrations induced by impact pile driving”, 6th International Conference on Case Histories in Geotechnical Engineering, Arlington.##Masoumi, H.R., Francois, S. and Degrande, G. (2009). “A nonLinear coupled finite elementboundary element model for the prediction of vibrations due to vibratory and impact pile driving”, International Journal for Numerical and Analytical Methods in Geomechanics, 33(2), 254274. ##Saeedi Azizkandi, A.R. and Fakher A. (2014). “A simple algorithm for analyzing a piled raft by considering stress distribution”, Civil Engineering Infrastructures Journal, 47(2), 215227. ##Sheng, D., Eigenbrod, K.D., and Wriggers, P. (2005). “Finite element analysis of pile installation using largeslip frictional contact”, Computers and Geotechnics, 32(1), 1726.##Thandavamoorthy, T.S. (2004). “Piling in fine and medium sand; A case study of ground and pile vibration”, Soil Dynamics and Earthquake Engineering, 24(4), 295304.##Uromeihy, A. (1990). “Ground vibration measurements with special reference to pile driving”, Ph.D. Thesis, Durham University, Durham, UK.##Wiss, J.F. (1981). “Construction vibrations: Stateoftheart”, Journal of Geotechnical Engineering ASCE, 107(2), 167181.##Woods, R.D. and Jedele, P.L. (1985). “Energy attenuation relationships from vibrations”, Proceedings, Conference on Vibration Problems in Geotechnical Engineering, Detroit, ASCE, 229246.##Zhang, J. and Salgado, R., (2010). "Stressdilatancy relation for MohrCoulomb soils following a nonassociated flow rule", Geotechnique, ICE, 60(3), 223–226.##]
ThreeDimensional Interfacial Green’s Function for Exponentially Graded Transversely Isotropic BiMaterials
2
2
By virtue of a complete set of two displacement potentials, an analytical derivation of the elastostatic Green’s functions of an exponentially graded transversely isotropic bimaterial fullspace was presented. Threedimensional pointload Green’s functions for stresses and displacements were given in lineintegral representations. The formulation included a complete set of transformed stresspotential and displacementpotential relations, with the utilization of Fourier series and Hankel transform. As illustrations, the present Green’s functions were analytically degenerated into special cases, such as exponentially graded halfspace and homogeneous fullspace bimaterial Green’s functions. Owing to the complicated integrand functions, the integrals were evaluated numerically, and in computing the integrals numerically, a robust and effective methodology was laid out which provided the necessary account of the presence of singularities of integration. Some typical numerical examples were also illustrated to demonstrate the general features of the exponentially graded bimaterial Green’s functions which will be recognized by the effect of degree of variation of material properties.
1

71
96


Farzad
Akbari
School of Civil Engineering, College of Engineering, University of Tehran
School of Civil Engineering, College of Engineerin
Iran
akbari.farzad@ut.ac.ir


Ali
Khojasteh
School of Engineering Science, College of Engineering, University of Tehran
School of Engineering Science, College of
Iran
a.khojasteh@ut.ac.ir


Mohammad
Rahimian
School of Civil Engineering, College of Engineering, University of Tehran
School of Civil Engineering, College of Engineerin
Iran
rahimian@ut.ac.ir
BiMaterial
Displacement Potential
Exponentially Graded
Functionally Graded Material
Green’s Function
Transversely Isotropic
[Apsel, R.J., and Luco, J.E. (1983). “On the Green’s functions for a layered half space. Part II”, Bulletin of the Seismological Society of America, 73(4), 931951.##ArdeshirBehrestaghi, A., and EskandariGhadi, M. (2009). “Transversely isotropic twolayered halfspace under the tangent load to the surface in the frequency domain”, Journal of Faculty of Engineering, University of Tehran, 43(4), 335348 (In Persian).##Birman, V., and Byrd, L.W. (2007). “Modeling and Analysis of Functionally Graded Materials and Structures”, Applied Mechanics Reviews, ASME, 60(5), 195216.##Chan, Y.S., Gray, L.J., Kaplan, T., and Paulino, G.H. (2004). “Green’s function for a twodimensional exponentially graded elastic medium”, Proceedings of the Royal Society of London, Series A, 460 (2046), 16891706.##Eskandari, M., and Shodja, H.M. (2010). “Green’s functions of an exponentially graded transversely isotropic halfspace”, International Journal of Solids and Structures, 47 (1112), 15371545.##EskandariGhadi, M. (2005). “A complete solution of the wave equations in the transversely isotropic media”, Journal of Elasticity, 81 (1), 119.##EskandariGhadi, M. (2007). “Potential function method for transversely isotropic with axially symmetric”, Journal of Faculty of Engineering, University of Tehran, 41(6), 675681 (In Persian).##EskandariGhadi, M., Pak, R.Y.S., and ArdeshirBehrestaghi, A. (2009a). “Elastostatic Green's functions for an arbitrary internal load in a transversely isotropic bimaterial fullspace”, International Journal of Enginering Science, 47(4), 631641.##EskandariGhadi, M., Sture, S., Pak, R.Y.S., and ArdeshirBehrestaghi, A. (2009b). “A trimaterial elastodynamic solution for a transversely isotropic fullspace”, International Journal of Solids & Structures, 46(5), 1121–1133.##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.##EskandariGhadi, M., and AmiriHezaveh, A. (2014). “Wave propagations in exponentially graded transversely isotropic halfspace with potential function method”, Mechanics of Materials, 68, 275292. ##Kalantari, M., Khojasteh, A., Mohammadnezhad, H., Rahimian, M., and Pak, R.Y.S. (2015). “An inextensible membrane at the interface of a transversely isotropic bimaterial fullspace”, International Journal of Engineering Science, 91, 3448. ##Kashtalyan, M., and Rushchitsky, J.J. (2009). “Revisiting displacement functions in threedimensional elasticity of inhomogeneous media”, International Journal of Solids and Structures, 46 (1819), 34633470.##Khojasteh, A., Rahimian, M., and EskandariGhadi, M. (2006). “Three dimensional analysis of a transversely isotropic halfspace under the tangent load to the surface in the frequency domain”, Journal of Faculty of Engineering, University of Tehran, 40(5), 611624 (In Persian).##Khojasteh, A., Rahimian, M., and Pak, R.Y.S. (2008a). “Threedimensional dynamic Green’s functions in transversely isotropic bimaterials”, International Journal of Solids and Structures, 45 (1819), 49524972. ##Khojasteh, A., Rahimian, M., Eskandari, M. and Pak, R.Y.S. (2008b). “Asymmetric wave propagation in a transversely isotropic halfspace in displacement potentials”, International Journal of Engineering science, 46 (7), 690710. ##Khojasteh, A., Rahimian, M., Pak, R.Y.S., and Eskandari, M. (2008c). “Asymmetric dynamic Green’s functions in a twolayered transversely isotropic halfspace”, International Journal of Engineering Science, ASCE, 134(9), 777787.##Khojasteh, A., Rahimian, M., Eskandari, M., and Pak, R.Y.S. (2011). “Threedimensional dynamic Green’s functions for a multilayered transversely isotropic halfspace”, International Journal of Solids and Structures, 48 (9), 13491361.##Khojasteh, A., Rahimian, M. and Eskandari, M. (2013). “Threedimensional dynamic Green’s functions in transversely isotropic trimaterials”, Applied Mathematical Modelling, 37 (5), 31643180. ##Lambros, J., and Rosakis, A.J. (1995). “Dynamic decohesion of biomaterials: experimental observations and failure criteria”, International Journal of Solids and Structures, 32(1718), 26772702.##Lekhnitskii, S.G. (1963). Theory of Elasticity of an Anisotropic Elastic Body, Holden Day, San Francisco.##Li, X.F., Tang, G.J., Shen, Z.B., and Lee, K.Y. (2015). “Axisymmetric problems of a pennyshaped crack at the interface of a bimaterial under shear and compression”, International Journal of Solids and Structures, 6970, 403414. ##Martin, P.A., Richardson, J.D., Gray, L.J., and Berger, J.R. (2002). “On Green’s function for a threedimensional exponentially graded elastic solid”, Proceeding of the Royal Society of London, Series A, 458 (2024), 19311947. ##Noijen, S.P.M., Van der Sluis, O., Timmermans, P.H.M., and Zhang, G.Q. (2012). “A semianalytic method for crack kinking analysis at isotropic bimaterial interfaces”, Engineering Fracture Mechanics, 83, 825.##Pak, R.Y.S. and Guzina, B.B. (2002). “Threedimensional Green’s functions for a multilayered halfspace displacement potentials”, Journal of Engineering Mechanics, ASCE, 128(4), 449461.##Pan, E., and Yang, B. (2003). “Threedimensional interfacial Green’s functions in anisotropic bimaterials”, Applied Mathematical Modeling, 27 (4), 307326.##Rahimian, M., EskandariGhadi, M., Pak, R.Y.S. and Khojasteh, A. (2007). “Elastodynamic potential method for 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, ASCE, 119(9), 17241746.##Sallah, O.M., Gray, L.J., Amer, M.A. and Matbuly, M.S. (2010). “Green’s function expansion for exponentially graded elasticity”, International Journal for Numerical Method in Engineering, 82 (6), 756772.##Selvadurai, A.P.S. and Katebi, A. (2013). “Mindlin’s problem for an incompressible elastic halfspace with an exponential variation in the linear elastic shear modulus”, International Journal of Engineering Science, 65, 921. ##Sneddon, I.N. (1951). Fourier transforms, McGrawHill, New York.##Sneddon, I.N. (1972). The use of integral transforms, McGrawHill, New York.##Wang, C.D., Tzeng, C.S., Pan, E. and Liao, J.J. (2003). “Displacements and stresses due to a vertical point load in an inhomogeneous transversely isotropic halfspace”, International Journal of Rock Mechanic and Mining Sciences, 40(5), 667685.##Wang, C.D., Pan, E., Tzeng, C.S., Han, F. and Liao, J.J. (2006). “Displacements and stresses due to a uniform vertical circular load in an inhomogeneous crossanisotropic halfspace”, International Journal of Geomechanic, 6(1), 110. ##Wang, C.D. and Tzeng, C.S. (2009). “Displacements and stresses due to nonuniform circular loadings in an inhomogeneous crossanisotropic material”, Mechanics Research Communications, 36(8), 921932. ##Zhao, Y.F., Zhao, M.H., Pan, E. and Fan, C.Y. (2015). “Green’s functions and extended displacement discontinuity method for interfacial cracks in threedimensional transversely isotropic magnetoelectroelastic bimaterials”, International Journal of Solids and Structures, 52, 5671. ##]
Ultimate Load Capacity and Behavior of ThinWalled CurvedSteel Square Struts, Subjected to Compressive Load
2
2
There have been some experimental tests on hollow curvedsteel struts with thinwalled square sections, in order to investigate their general behavior, particularly their capacity for bearing differing loads. One set of square tubes are coldformed into segments of circular arcs with curvature radii, equal to 4000 mm. Different lengths of curved struts are fabricated so as to cover a practical range of slenderness ratios. The struts tests were pinended and had slenderness ratios, based on the straight length between ends ranging from 31126. The coldforming operation induces initial inelastic behavior and associated residual stresses. There is, therefore, an interaction among material effects, such as the strain hardening capacity, the Bauschinger effect, strain aging, and residual stresses, together with the significant geometrical effect of the initial curvature, caused by the coldforming operation. Eventually the results from three series of tests, which are taken on fullyaged and stressreliefannealed square curved struts, are compared. The variations in load carrying response are discussed.
1

97
109


S.Mohammad Reza
Mortazavi
Shahid Rajai Teacher Training University, Tehran
Shahid Rajai Teacher Training University,
Iran
mortazavi@srttu.edu


Behrouz
Zaeimdar
Shahid Rajaee Teacher Training University
Shahid Rajaee Teacher Training University
Iran
b.zaeimdar@srttu.edu
Bauschinger Effect
Curved Strut
Residual Stresses
Square Hollow Section
Strain Aging
Thin Walled
Ultimate Load Capacity
[Afshan, S., Rossi, B., and Gardner, L. (2013). “Strength enhancements in coldformed structural sections, Part I: Material testing”, Journal of Constructional Steel Research, 83, 177188.##American Society for Testing and Materials. (2000). “ASTM designation E 800 standard test methods for tension testing of metallic materials”, ASTM, West Conshohocken, PA, USA.##Gardner, L. and Nethercot, D.A. (2004). “Experiments on stainless steel hollow sections Part 1: Material and crosssectional behavior”, Journal of Constructional Steel Research, 60(9), 12911318.##Ghasemian, M., Mortazavi, M. and Schmidt, L.C. (1999). “Behaviour of hollow curved steel struts subjected to compressive load”, Journal of Constructional Steel Research, 52(2), 219234.##Jandera, M., Gardner, L. and Machacek, J. (2008). “Residual stresses in coldrolled stainless steel hollow sections”, Journal of Constructional Steel Research, 64(11), 12551263.##Linzell, D.G., Zureick, A. and Leon, R.T. (2003). “Comparison of measured and predicted response of manufactured circular steel tubular members under concentric and eccentric compressive and tensile loads”, Engineering Structures, 25(8), 10191031.##Raghavan, V. (2015). Physical metallurgy: Principles and practice, 3rd Edition, PHI Learning Pvt. Ltd.##Rezaie, F., Ahmadi, G. and Farnam, S.M. (2015). “Load test and model calibration of a horizontally curved steel BoxGirder bridge”, Civil Engineering Infrastructures Journal, 48(2), 323340.##RezaieePajand, M. and Mohtashmi, A. (2010). “Advanced analysis of plane steel frame having imperfect elements”, Civil Engineering Infrastructures Journal, 44(3), 365377.##Schmidt, L. and Mortazavi, S.M. (2007). “Influence of prestraining on tangent modulus of tubular struts”, Journal of Technology and Education, 1(2), 2128.##Rajan, T.V., Sharma, C.P. and Sharma, A. (2011). Heat treatment: Principles and techniques, PHI Learning, Pvt. Ltd., Delhi, India.##Zhao, W., Chen, M., Chen, S. and Qu, J. (2012). “Static strain aging behavior of an X100 pipeline steel”, Materials Science and Engineering: A, 550, 418422.##Zhao, X.L. (2000). “Section capacity of very high strength (VHS) circular tubes under compression”, ThinWalled Structures, 37(3), 223240.##]
Seismic Bearing Capacity of Strip Footings on PileStabilized Slopes
2
2
This paper develops an analytical method to calculate seismic bearing capacity of a strip footing, which is located on a slope reinforced with rows of pile. The resistance of passive pile is determined based on normal and shear stress of the soil around the pile, which is then compared to other analytical methods. This comparison indicates an acceptable agreement. The variants of the study include location of pile rows, location of footing with respect to the slope crest, foundation depth, and horizontal seismic coefficient. The footing seismic bearing capacity is calculated based on seismic slope stability with limit analysis method (yield acceleration coefficient of reinforced slope with pile row) as well as soil stability beneath the footing by means of virtual retaining wall method. The main objective is to determine and establish the relation between various parameters and seismic bearing capacities of the footing, and to find the best location of the pile row that gives the best improvement in the footing seismic bearing capacity. Results indicate that stabilizing the earth slope with rows of piles has a significant effect on the improvement of seismic bearing capacity of the footing. In addition, the results of the present method are compared with those, reported by others, to demonstrate a reasonable agreement.
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111
126


Maryam
Haghbin
Islamic Azad University (Islamshahr)
Islamic Azad University (Islamshahr)
Iran
haghbin@iiau.ac.ir


Mahmoud
Ghazavi
khajeh nasir university
khajeh nasir university
Iran
ghazavi_ma@kntu.ac.ir
analytical method
Footing
Footing Bearing Capacity
Pile
seismic
Slope
Yield Acceleration
[Auslio, E., Conte, E. and Dente, G. (2001). "Stability analysis of slopes reinforced with piles", Computers and Geotechnics, 28(8), 591611.##Azzam, W.R. (2010). "Experimental and numerical studies of sand slopes loaded with skirted strip footing", Electronic Journal of Geotechnical Engineering, 15(H), 795812.##Chen, W.F. (1975). Limit analysis and soil plasticity, Elsevier Publishing Company, Amsterdam.##Choudhury, D. and Rao, S. (2006). "Seismic bearing capacity of Shallow strip footings Embedded in Slope", International Journal of Geomechanics, 6(3), 176184.##Farzaneh, O., Askari, F. and Hadad, B. (2009). "Experimental modeling of three dimensional bearing capacity of footings on slopes", Civil Engineering Infrastructures Journal, 43(1), 8593. ##Hassiotist, S. and Chameau, J.L. (1997). "Design method for stabilization of slopes with piles", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 123(4), 314322.##Hansen, J.B. (1970). "A revised and extended formula for bearing capacity", Bulletin 28, Copenhagen, Danish Geotechnical Institute.##Ito, T. and Matsui, T. (1975). "Methods to estimate lateral force acting on stabilizing piles", Soils and Foundations, 18(4), 4359.##Liu, Y. and Geo, F. (2015). "Dynamic stability analysis on a slope supported by anchor bolts and piles", Electronic Journal of Geotechnical Engineering, 20(7), 18871900.##Mehmetl, M. (2009). "Determination of lateral loads on slope stabilizing piles", Journal of Pamukkale Universitesi Miihendislik Bilimreli Dergisi, 15(2), 194202.##Meyerhof, G.G. (1963). "Some recent research on the bearing capacity of foundations", Canadian Geotechnical Journal, 1(1), 1627.##Mofidi, J., Farzaneh, O. and Askari, F. (2014). "Bearing capacity of strip footings near slopes using lower bound limit analysis", Civil Engineering Infrastructures Journal, 47(1), 89109.##Mostafa, A. and Sawwaf, E. (2005). "Strip footing behavior on pile and sheet pilestabilized sand slope", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 131(6), 705715.##Munawi, A., Murni Dewi, S., Agoes Soehardjono, M. and Zaika, Y. (2013). "Bearing capacity of continuous footing on slope modeling with composite bamboo pile reinforcement", International Journal of Current Engineering and Technology, 3(2), 557562.##Munawir, A., Murni, D., Yulvi, Z. and Soehardjono, M. (2013). "Bearing capacity on slope modeling with composite bamboo pile reinforcement", International Journal of Engineering and Advanced Technology (IJEAT), 2(5), 114118.##Munawir, A., Murni Dewi, S. and Zaika, Y. (2013). "Safety factor of continuous footing on slope modeling with composite bamboo pile reinforcement", Electronic Journal of Geotechnical Engineering, 18(K), 21772186.##RenPing, L. (2009). "Stability analysis of cutting slope reinforced with antislide piles by FEM", GeoHunan International Conference, Changsha, Hunan, China.##Saran, S., Sud, V.K. and Handa, S.C. (1989). "Bearing capacity of footings adjacent to slopes", Journal of Geotechnical Engineering, ASCE, 115(4), 553562.##Wei, W.B. and Cheng, Y.M. (2009). "Strength reduction analysis for slope reinforced with one row of piles", Computers and Geotechnics, 36, 11761185.##Xinpo, L., Siming, H. and Yong, W. (2010). "Seismic displacement of slopes reinforced with piles", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 136(6), 11401155.##]
Bending Solution for Simply Supported Annular Plates Using the Indirect Trefftz Boundary Method
2
2
This paper presents the bending analysis of annular plates by the indirect Trefftz boundary approach. The formulation for thin and thick plates is based on the Kirchhoff plate theory and the Reissner plate theory. The governing equations are therefore a fourthorder boundary value problem and a sixthorder boundary value problem, respectively. The Trefftz method employs the complete set of solutions satisfying the governing equation. The main benefit of the Trefftz boundary method is that it does not involve singular integrals because of the properties of its solution basis functions. It can therefore be classified into the regular boundary element method. The present method is simple and efficient in comparison with the other methods. In addition, the boundary conditions can be embedded in this method. Finally, several numerical examples are shown to illustrate the efficiency and simplicity of the current approach.
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138


Amin
Ghannadiasl
Faculty of Engineering, University of Mohaghegh Ardabili
Faculty of Engineering, University of Mohaghegh
Iran
aghannadiasl@uma.ac.ir


Asadollah
Noorzad
School of Civil Engineering, the University of Tehran
School of Civil Engineering, the University
Iran
noorzad@ut.ac.ir
Annular Plates
Indirect Trefftz Method
Kirchhoff Plate Theory
Reissner Plate Theory
[Abdollahzadeh, G. and Ghobadi, F. (2014). “Mathematical modeling of columnbase connections under monotonic loading”, Civil Engineering Infrastructures Journal, 47(2), 255272.##Banerjee, P.K. (1981). The boundary element Methods in Engineering, 2nd Edition, McGrawHill Publication Co., New York.##Brański, A. and Borkowska, D. (2015). “Effectiveness of nonsingular solutions of the boundary problems based on Trefftz methods”, Engineering Analysis with Boundary Elements, 59, 97104.##Chen, J.T., Lee, Y.T., Yu, S.R. and Shieh, S.C. (2009). “Equivalence between the Trefftz method and the method of fundamental solution for the annular Green's function using the addition theorem and image concept”, Engineering Analysis with Boundary Elements, 33(5), 678688.##Chen, J.T., Kao, S.K., Lee, W.M. and Lee, Y.T. (2010a). “Eigen solutions of the Helmholtz equation for a multiply connected domain with circular boundaries using the multipole Trefftz method”, Engineering Analysis with Boundary Elements, 34(5), 463470.##Chen, W., Fu, Z.J. and Qin, Q.H. (2010b). “Boundary particle method with highorder Trefftz functions”, Computers, Materials and Continua (CMC), 13(3), 201217.##Cheung, Y.K., Jin, W.G. and Zienkiewicz, O.C. (1989). “Direct solution procedure for solution of harmonic problems using complete, nonsingular, Trefftz functions”, Communications in Applied Numerical Methods, 5(3), 159169.##Finlayson, B.A. (1972). The method of weighted Residuals and variational Principles, Academic Press, New York.##Ghannadiasl, A. and Noorzad, A. (2009). “Free vibration analysis of thin circular plates by the indirect Trefftz method”, Mesh Reduction Methods, 49, 317328.##Ghannadiasl, A. and Noorzad, A. (2007). “Exact mixedKirchhoff solutions for the bending analysis of axisymmetric Reissner plates”, Proceedings of International Symposium on Advances in Earthquake and Structural Engineering, Süleyman Demirel University, IspartaAntalya, Turkey.##Ghasemieh, M. and Shamim, I. (2010). “Influence of the axial force on the bending behavior of the extended end plate connections”, Journal of Faculty of Engineering, University of Tehran, 44(3), 413424.##Grysa, K. and Maciejewska, B. (2013). “Trefftz functions for the nonstationary problems”, Journal of Theoretical and Applied Mechanics, 51(2), 251264.##Jin, W.G. and Cheung, Y.K. (1999). “Trefftz method applied to a moderately thick plate”, International Journal for Numerical Methods in Engineering, 44(7), 10111024.##Jin, W.G., Cheung, Y.K. and Zienkiewicz, O.C. (1993). “Trefftz method for Kirchhoff plate bending problems”, International Journal for Numerical Methods in Engineering, 36(5), 765781.##Karageorghis, A. (2013). “Efficient Trefftz collocation algorithms for elliptic problems in circular domains”, Numerical Algorithms, 64(3), 427453.##Karas, M.S. and Zielinski, A.P. (2008). “Boundary‐value recovery by the Trefftz approach in structural inverse problems”, Communications in Numerical Methods in Engineering, 24(7), 605625.##Kita, E. and Kamiya, N. (1995). “Trefftz method: An overview”, Advances in Engineering Software, 24(1), 312.##Kretzschmar, F., Schnepp, S.M., Tsukerman, I. and Weiland, T. (2014). “Discontinuous Galerkin methods with Trefftz approximations”, Journal of Computational and Applied Mathematics, 270, 211222.##Ku, C.Y., Kuo, C.L., Fan, C.M., Liu, C.S. and Guan, P.C. (2015). “Numerical solution of threedimensional Laplacian problems using the multiple scale Trefftz method”, Engineering Analysis with Boundary Elements, 50, 157168.##Lee, M.G., Young, L. J., Li, Z.C. and Chu, P.C. (2010). “Combined Trefftz methods of particular and fundamental solutions for corner and crack singularity of linear elastostatics”, Engineering Analysis with Boundary Elements, 34(7), 632–654.##Lee, W.M. and Chen, J.T. (2009). “Free vibration analysis of a circular plate with multiple circular holes by using the multipole Trefftz method”, Computer Modeling in Engineering and Sciences (CMES), 19(2), 141160.##Lee, W.M., Chen, J.T. and Lee, Y.T. (2007). “Free vibration analysis of circular plates with multiple circular holes using indirect BIEMs”, Journal of Sound and Vibration, 304(3), 811830.##Li, Z.C., Lee, M.G. and Chiang, J.Y. (2013). “Collocation Trefftz methods for the stokes equations with singularity”, Numerical Methods for Partial Differential Equations, 29(2), 361395.##Li, Z.C., Lu, T.T., Hu, H.Y. and Cheng, A.H. (2008). Trefftz and collocation methods, WIT press.##Li, Z.C., Young, L.J., Huang, H.T., Liu, Y.P. and Cheng, A.H.D. (2010). “Comparisons of fundamental solutions and particular solutions for Trefftz methods”, Engineering Analysis with Boundary Elements, 34(3), 248258.##Li, Z.C., Lee, M.G., Chiang, J.Y. and Liu, Y.P. (2011). “The Trefftz method using fundamental solutions for biharmonic equations”, Journal of Computational and Applied Mathematics, 235(15), 43504367.##Liu, C. (2007a). “A highly accurate solver for the mixedboundary potential problem and singular problem in arbitrary plane domain”, Computer Modeling in Engineering and Sciences (CMES), 20(2), 111122.##Liu, C. (2007b). “A modified Trefftz method for twodimensional Laplace equation considering the domain's characteristic length”. Computer Modeling in Engineering and Sciences (CMES), 21(1), 5365.##Maciąg, A. (2011). “Trefftz functions for a plate vibration problem”, Journal of Theoretical and Applied Mechanics, 49(1), 97116.##Maciąg, A. and Pawinska, A. (2013). “Solving direct and inverse problems of plate vibration by using the Trefftz functions”, Journal of Theoretical and Applied Mechanics, 51(3), 543552.##Mirzapour, A., Eskandari Ghadi, M. and ArdeshirBehrestaghi, A. (2012). “Analysis of transversely isotropic halfspaces under the effect of bending of a rigid circular plate”, Civil Engineering Infrastructures Journal, 45(5), 601610.##Shahabian, F., Elachachi, S.M. and Breysse, D. (2013). “Safety analysis of the patch load resistance of plate girders: Influence of model error and variability”, Civil Engineering Infrastructures Journal, 46(2), 145160.##Pluymers, B., Van Hal, B., Vandepitte, D. and Desmet, W. (2007). “Trefftzbased methods for timeharmonic acoustics”, Archives of Computational Methods in Engineering, 14(4), 343381.##Qin, Q.H. and Wang, H. (2008). Matlab and C programming for Trefftz finite element methods, CRC Press.##Reddy, J.N. (2001). Energy principles and variational methods in applied mechanics, McGraw Hill, New York.##Reismann, H. (1988). Elastic plates: Theory and application, Wiley Pub. Co., New York.##Timoshenko, S.P. and WoinowskyKrieger, S. (1959). Theory of plates and shells, Mc Graw Hill, New York.##Wroblewski, A. (2005). “T‐complete functions for thin and thick plates on elastic foundation”, Numerical Methods for Partial Differential Equations, 21(1), 17.##Young, D.L., Chen, K.H., Chen, J.T. and Kao, J.H. (2007). “A modified method of fundamental solutions with source on the boundary for solving Laplace equations with circular and arbitrary domains”, Computer Modeling in Engineering and Sciences (CMES), 19(3), 197221.##Zenkour, A.M. (2003). “Exact mixedclassical solutions for the bending analysis of shear deformable rectangular plates”, Applied Mathematical Modelling, 27(7), 515534.##Zielinski, A.P. (1995). “On trial functions applied in the generalized Trefftz method”, Advances in Engineering Software, 24(1), 147155.##Zielinski, A.P. and Zienkiewicz, O.C. (1985). “Generalized finite element analysis with Tcomplete boundary solution functions”, International Journal for Numerical Methods in Engineering, 21(3), 509528.##]
Mechanical Behavior of Concrete, Made with MicroNano Air Bubbles
2
2
Nano materials have been widely used in laboratory and industrial scales in order to improve various properties of concrete and concrete mixture. The mainstream practice of the researches in this field is to add metallic nanoparticles into the concrete mixture. The present research focuses on adding MicroNano Air Bubbles (MNAB) into water before mixing it with aggregate and cement mixtures. It studies the compressive and tensile strength as well as other engineering properties of the concrete such as the initial and final setting time and the variation in temperature during the setting. The ratio of water/cement was 0.6 with three specimens, prepared for each mixed design to ensure the data quality. Results showed that MNABmade concrete had 19% higher compression and 16% tensile strength, while the initial and final setting times were significantly shorter (approximately a half) and hydration temperature was notably lower than ordinary concrete.
1

139
147


Amir
Arefi
Shahrood University of Technology
Shahrood University of Technology
Iran
amirarefi67@yahoo.com


Seyed Fazlolah
Saghravani
Shahrood University of Technology
Shahrood University of Technology
Iran
saghravani@shahroodut.ac.ir


Reza
Mozaffari Naeeni
Shahrood University of Technology, MINAB Toos New Technologies
Shahrood University of Technology, MINAB
Iran
reza_mozaffarei@yahoo.com
Compression Strength
Concrete
MicroNano Air Bubble
Setting Time
Tensile Strength
Workability
[Abdoli Yazdi, N., Arefi, M.R., Mollaahmadi, E. and Abdollahi Nejand, B. (2011). “To study the effect of adding Fe2O3 nano particles on the morphology properties and microstructure of cement mortar”, Life Science Journal, 8(4), 550554.##Behfarnia, K., Keivan, A. and Keivan, A. (2013). “The effects of TiO2 and ZnO nano particles on physical and mechanical properties of normal concrete”, Asian Journal of Civil Engineering, (BHRC), 14(4), 517531.##Boshehrian, A. and Hosseini, P. (2011). “Effect of nanoSiO2 particles on properties of cement mortar applicable for ferro cement elements”, Concrete Research Letters, 2(1), 167180.##Guo, M.Z., Ling, T.C. and Poon, C.S. (2013). "NanoTiO2based architectural mortar for NO removal and bacteria inactivation: Influence of coating and weathering conditions", Cement and Concrete Composites, 36(1), 101108.##Kosmatka, S.H., Kerkhoff, B. and Panarese, W.C. (2003). Design and control of concrete mixtures, EB001, 14th Edition, Chapter 8, AirEntrained Concrete, USA.##Li, H., Hu, L., Song, D. and AlTabbaa, A. (2014). "Subsurface transport behavior of micronano bubbles and potential applications for groundwater remediation", International Journal of Environmental Research and Public Health, 11(1), 473486.##Mozaffari Naeeni, R. (2014). “Investigation on the hydrodynamics standard pattern using micronano air bubbles", M.Sc. Thesis, Shahrood University of Technology, Iran.##Naji Givi, A., Abdul Rashid, S., Aziz F.N.A. and Salleh, M. (2010). “Experimental investigation of the size effects of SiO2nanoparticles on the mechanical properties of binary blended concrete”, Composites B, 41(8), 673677.##Nazari, A. and Riahi, Sh. (2011). “Effects of CuO nano particles on compressive strength of selfcompacting concrete”, Indian Academy of Sciences, Sadhana 36(3), 371–391.##Nazari, A., Riahi, Sh., Riahi, Sh., Shamekhi, S.F. and Khademno, A. (2010a). “Assessment of the effects of the cement paste composite in presence TiO2 Nnanoparticles”, Journal of American Science, 6(4), 4346.##Nazari, A., Riahi, Sh., Riahi, Sh., Shamekhi, S.F. and Khademno, A. (2010b). “Influence of Al2O3 nano particles on the compressive strength and workability of blended concrete”, Journal of American Science, 6(5), 69.##Nazari, A., Riahi, Sh., Riahi, Sh., Shamekhi, S.F. and Khademno, A., (2010c). “The effects of incorporation Fe2O3 nano particles on tensile and flexural strength of concrete”, Journal of American Science, 6(4), 9093.##Nazari, A., Riahi, Sh., Riahi, Sh., Shamekhi, S.F. and Khademno, A. (2009). “Mechanical properties of cement mortar with Al2O3 nano particles”, Journal of American Science, 6(4), 9497.##Pradesh, H. (2012). “Application of nanotechnology in building materials”, International Journal of Engineering Research and Applications (IJERA) 2(5), 10771082.##Rathi, V.R. and Modhera, C.D. (2014). “An overview on the influence of nano materials on properties of concrete”, International Journal of Innovative Research in Science Engineering and Technology, 3(2), 91009105.##Riding, K.A., Poole, J.L., Schindler, A.K., Juenger, M.G., and Folliard, K.J. (2006). “Evaluation of temperature prediction methods for mass concrete members,” ACI Materials Journal, 103(5), 357365.##Salemi, N., Behfarnia, K. and Zaree, S.A. (2014). “Effect of nanoparticles on frost durability of concrete”, Asian Journal of Civil Engineering (BHRC), 15(1), 411420.##Saloma (2013). “Experimental Investigation on Nanomaterial Concrete”, International Journal of Civil & Environmental Engineering, 13(3), 1520.##Tsuge, H. (2015). Micro and nano bubbles, fundamentals and applications, Pan Stanford Publishing.##]
Permeability Characteristics of Compacted and Stabilized Clay with Cement, Peat Ash and Silica Sand
2
2
The present paper investigates the influence of stabilization with cement, peat ash, and silica sand on permeability coefficient (kv) of compacted clay, using a novel approach to stabilize the clay with peat ash as a supplementary material of cement in the compacted and stabilized soil. In order to assess the mentioned influence, test specimens of both untreated and stabilized soil have been tested in the laboratory so that their permeability could be evaluated. Falling head and one dimensional consolidation tests of laboratory permeability were performed on the clay specimens and the chemical compositions of the materials as well as microstructure of the stabilized soil with 18% cement, 2% peat ash, and 5% silica sand were investigated, using Xray fluorescence and scanning electron microscopy respectively. Results show that for soil stabilization with up to 8% cement content (of the dry weight of the soil), the average value of coefficient of permeability (kv) is very close to that of untreated soil, whereas the kv value decreases drastically for 18% cement under identical void ratio conditions. It is further revealed that addition of 18% cement, 2% peat ash, and 5% silica sand had decreased the coefficient of permeability by almost 2.2 folds after 24 h, while about 1.7 folds increase was observed in coefficient of permeability once 13.5% of cement, 1.5% of peat ash, and 20% of silica sand were added. The partial replacement of cement with the 2% peat ash can reduce the consumption of cement for soil stabilization.
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149
164


Seyed Esmaeil
Mousavi
Civil Engineering Department, College of Engineering, Universiti Tenaga Nasional, IKRAMUNITEN Road, 43000 Kajang, Selangor, Malaysia
Civil Engineering Department, College of
Malaysia
matin_mousavi54@yahoo.com


Leong Sing
Wong
College of Graduate Studies, Universiti Tenaga Nasional, IKRAMUNITEN Road, 43000 Kajang, Selangor, Malaysia
College of Graduate Studies, Universiti Tenaga
Malaysia
wongls2011@gmail.com
Falling Head
One Dimensional Consolidation
Peat Ash
Permeability
Silica Sand
[Abdi, M.R. and Parsa Pajouh, A. (2009). "Use of bentonite and lime for decreasing the permeability of liner and cover in landfills", Civil Engineering Infrastructures Journal, 43(1), 6170.##ASTM D508403. (2003), Standard test methods for measurement of hydraulic conductivity of saturated porous materials, American Society of Testing and Materials, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA.##ASTM D2435. (2003), ASTM D2435, Standard test method for onedimensional consolidation properties of soils using incremental loading, American Society of Testing and Materials, Annual Book of ASTM Standards, Philadelphia, 04.08, pp. 110.##ASTM C20411. (2014),Standard test methods for fineness of hydraulic cement by air permeability apparatus,American Society of Testing and Materials, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA.##ASTM D698. (2012), Standard test methods for laboratory compaction characteristics of soil using standard effort, American Society of Testing and Materials, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA.##ASTM D297414. (2014), Standard test methods for moisture, ash, and organic matter of peat and other organic soils, American Society of Testing and Materials, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA.##Bujang, B.K.H., Kazemian, S., Prasad, A. and Barghchi, M. (2011). "State of an art review of peat: General perspective", International Journal of the Physical Sciences, 6(8), 19881996.##Bazargan, J. and Shoaei, S.M. (2010). "Analysis of nondarcy flow in rock fill materials using gradually varied flow method", Civil Engineering Infrastructures Journal, 44(2), 131139.##Bahar, R., Benazzoug, M. and Kenai, S. (2004). "Performance of compacted cementstabilised soil", Cement and Concrete Composites, 26(7), 811820.##Das, B.M. (1989). Soil mechanic laboratory manual, 6th Edition, Hardcover, Oxford.##Ghasemzadeh, H. and Abounouri, A.A. (2013). "The effect of dynamic permeability on velocity and intrinsic attenuation of compressional waves in sand", Civil Engineering Infrastructures Journal, 46(2), 221231.##Goodary, R., LecomteNana, G.L., Petit, C. and Smith., D.S. (2012). "Investigation of the strength development in cementstabilised soils of volcanic origin", Construction and Building Materials, 28(1), 592598.##Hossain, K.M.A. and Mol, L. (2011). "Some engineering properties of stabilized clayey soils incorporating natural pozzolans and industrial wastes", Construction and Building Materials, 25(8), 34953501.##Horpibulusk, S., Rachan, R., Chinkulkijniwat, A., Raksachon, Y. and Suddeepong, A. (2010). "Analysis of strength development in cementstabilized silty clay from micro structural considerations", Construction and Building Materials, 24(10), 20112021.##Horpibulsuk, S., Phojan, W., Suddeepong, A., Chinkulkijniwat, A. and Liu Martin, D. (2012). "Strength development in blended cement admixed saline clay", Applied Clay Science, 55, 4452.##Horpibulsuk, S., Rachan, R. and Suddeepong, A. (2011). "Compressibility and permeability of Bangkok clay compared with kaolinite and bentonite", Applied Clay Science, 52(12), 150159.##Kowalski, T.E., Dale, W. and Starry, Jr. (2007). "Modern soil stabilization techniques", Annual Conference of the Transportation Association of Canada, Saskatoon, Saskatchewan, October, pp. 1417.##Mahasenan, N., Steve, S., Kenneth, H. and Kaya, Y. (2003). "The cement industry and global climate change: Current and potential future cement industry CO2 emissions", Greenhouse Gas Control Technologies, 6th International Conference, Oxford, Pergamon, pp. 9951000.##Mousavi, S.E. and Wong, L.S. (2015). "Performance of compacted and stabilized clay with cement, peat ash and silica sand", Jordan Journal of Civil Engineering, 9(1), 2032.##Wong, L.S., Hashim, R. and Ali, F. (2013). "Utilization of sodium bentonite to maximize the filler and pozzolanic effects of stabilized peat", Engineering Geology, 152(1), 5666.##Yilmaz, Y. and Ozaydin, V. (2013). "Compaction and shear strength characteristics of colemanite ore waste modified active belite cement stabilized high plasticity soils", Engineering Geology,155, 4553.##]
Damage Detection of Axially Loaded Beam: A FrequencyBased Method
2
2
The present study utilizes an analytical method to formulate the three lowest modal frequencies of axiallyloaded notched beam through both crack location and load level in a specific format that can be used in existing frequencybased crackidentification methods. The proposed formula provides a basis to shift into two states, one with axial loading and the other without any loading whatsoever. When any two natural frequencies in simplysupported beam with an open crack, subjected to axial load, are measured, crack position and extent can be determined, using a characteristic equation, which is a function of crack location, sectional flexibility, and eigenvalue (natural frequency). Theoretical results show high accuracy for service axial loads. In this range, errors for crack location and extent are less than 12% and 10%, respectively.
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165
172


Omid
Rezaifar
Assistant Professor of Civil Engineering Department, Research Institute of Advanced Technology in Civil Engineering, Semnan University, Semnan, Iran.
Assistant Professor of Civil Engineering
Iran
rezayfar@yahoo.com


Mohammad Reza
Doostmohammadi
M.Sc, Research Institute of Advanced Technology in Civil Engineering, Semnan University, Semnan, Iran.
M.Sc, Research Institute of Advanced Technology
Iran
m_doostmohamadi@semnan.ac.ir
Axial Load
Characteristic Equation
Damage Detection
Eigen Frequency
Notched Beam
[Attar, M. (2012). "A transfer matrix method for free vibration analysis and crack identification of stepped beams with multiple edge cracks and different boundary conditions", International Journal of Mechanical Sciences, 57(1), 1933.##BakhtiariNejad, F, Khorram, A. and Rezaeian, M. (2014). "Analytical estimation of natural frequencies and mode shapes of a beam having two cracks", International Journal of Mechanical Sciences, 78, 193202.##Binici, B. (2005). "Vibration of beams with multiple open cracks subjected to axial force", Journal of Sound and Vibration, 287(12), 277295.##Caddemi, S. and Calio, I. (2009). "Exact closedform solution for the vibration modes of the EulerBernouli beam with multiple open cracks", Journal of Sound and Vibration, 327(35), 473489.##Cicirello, A. and Palmeri, A. (2014). "Static analysis of Euler–Bernoulli beams with multiple unilateral cracks under combined axial and transverse loads",International Journal of Solids and Structures, 51(5), 10201029.##Gomes, H.M. and Almeida, F.J.J. (2014). "An analytical dynamic model for singlecracked beams including bending, axial stiffness, rotational inertia, shear deformation and coupling effects", Applied Mathematical Modelling, 38(3), 938948.##Jassim, Z.A., Ali, N.N., Mustapha, F. and AbdulJalil, N.A. (2013). "A review on the vibration analysis for a damage occurrence of a cantilever beam", Engineering Failure Analysis, 31, 442461.##Khiem, N.T. (2006). "Damage detection of beam by natural frequencies: General theory and procedure", Vietnam Journal of Mechanics, VAST, 28(2), 120132.##Khiem, N.T. and Toan, L.K. (2014). "A novel method for crack detection in beamlike structures by measurements of natural frequencies", Journal of Sound and Vibration, 333(18), 40844103.##Kisa, M. and Gurel, M.A. (2007). "Free vibration analysis of uniform and stepped cracked beams with circular cross sections", International Journal of Engineering Science, 45(28), 364380.##Labib, A., Kennedy, D. and Featherston, C. (2014). "Free vibration analysis of beams and frames with multiple cracks for damage detection", Journal of Sound and Vibration, 333(20), 49915003.##Lele, S.P. and Maiti, S.K. (2002). "Modeling of transverse vibration of short beams for crack detection and measurement of crack extension", Journal of Sound and Vibration, 257(3), 559583.##Lin, H.P. (2004). "Direct and inverse methods on free vibration analysis of simply supported beams with a crack", Engineering Structures, 26(4), 427436.##Mazanoglu, M. and Sabuncu, M. (2012). "A frequency based algorithm for identification of single and double cracked beams via a statistical approach used in experiment", Mechanical Systems and Signal Processing, 30, 168185.##Mazanoglu, K., Yesilyurt, I. and Sabuncu, M. (2009). "Vibration analysis of multiplecracked nonuniform beams", Journal of Sound and Vibration, 320(45), 977989.##Mei, C., Karpenko, Y., Moody, S. and Allen, D. (2006). "Analytical approach to free and forced vibrations of axially loaded cracked Timoshenko beams", Journal of Sound and Vibration, 291(35), 10411060.##Moradi, S. and Jamshidi Moghadam, P. (2014). "Vibration analysis of cracked postbuckled beams", Applied Mathematical Modelling, 38(13), 32813294.##Orhan, S. (2007). "Analysis of free and forced vibration of a cracked cantilever beam", NDT and E International, 40(6), 443450.##Rizos, P.F., Aspragathos, N. and Dimarogonas, A.D. (1990). "Identification of crack location and magnitude in a cantilever beam from the vibrating mode", Journal of Sound and Vibration, 138(3), 381388.##Saavedra, P.N. and Cuitino, L.A. (2001). "Crack detection and vibration behavior of cracked beams", Computers and Structures, 79(16), 14511459.##Sinha, J.K. and Friswell, M.I. (2002). "Simulation of the dynamic response of a cracked beam", Computers and structures, 80(1819), 14731476.##Viola, E., Ricci, P. and Aliabadi, M.H. (2007). "Free vibration analysis of axially loaded Timoshenko beam structures using the dynamic stiffness method", Journal of Sound and Vibration, 304(12), 124153.##Zheng, D.Y. and Kessissoglou, N.J. (2004). "Free vibration analysis of a cracked beam by finite element method", Journal of Sound and Vibration, 273(3), 457475.##Zheng, T. and Ji, T. (2012). "An approximate method for determining the static deflection and natural frequency of a cracked beam", Journal of Sound and Vibration, 331(11), 26542670.##]