en jalali 1387 3 1 gregorian 2008 6 1 6 2 online 1 fulltext

en In the present investigation, the cyclic load deformation behaviour of soil-fly ash layered system isstudied using different intensities of failure load (I = 25%, 50% and 75%) with varying number of cycles (N =10, 50 and 100). An attempt has been made to establish the use of fly ash as a fill material for embankments ofHighways and Railways and to examine the effect of cyclic loading on the layered samples of soil and fly ash.The number of cycles, confining pressures and the intensity of loads at which loading unloading has beenperformed were varied. The resilient modulus, permanent strain and cyclic strength factor are evaluated fromthe test results and compared to show their variation with varying stress levels. The nature of stress-strainrelationship is initially linear for low stress levels and then turns non-linear for high stress levels. The testresults reveal two types of failure mechanisms that demonstrate the dependency of consolidated undrainedshear strength tests of soil-fly ash matrix on the interface characteristics of the layered soils under cyclicloading conditions. Data trends indicate greater stability of layered samples of soil-fly ash matrix in terms offailure load (i) at higher number of loading-unloading cycles, performed at lower intensity of deviatoric stress,and (ii) at lower number of cycles but at higher intensity of deviatoric stress. Layered soils, cyclic loading, triaxial tests, fly ash, shear strength 73 89 http://ijce.iust.ac.ir/browse.php?a_code=A-10-3-146&slc_lang=en&sid=1 2009/05/11 1388/2/21 M.A. Khan 003194753284600419 003194753284600419 No A. Usmani 003194753284600420 003194753284600420 No S.S. Shah 003194753284600421 003194753284600421 No H. Abbas abbas_husain@hotmail.com 003194753284600422 003194753284600422 Yes

en Solute transport in unsaturated porous media can be viewed as a coupled phenomenon with waterand heat transport, together with mechanical behaviour of media. In this paper, solute transport is formulatedmathematically considering heat and water flow in deformable porous media. Advection, dispersion anddiffusion of chemical species in the liquid phase are considered. Convection and conduction for heat flow istaken into account. Water flow is considered in both vapour and liquid phases. Equilibrium equation, energyconservation, mass conservation and linear momentum for water, gas and solute are written and solvedsimultaneously using finite element method. The developed model is validated by solving some examples andcomparing results with the results of experimental observation. 90 107 http://ijce.iust.ac.ir/browse.php?a_code=A-10-107-4&slc_lang=en&sid=1 2009/05/112009/05/11 1388/2/21 Hasan Ghasemzadeh 0031947532846003155 0031947532846003155 Yes

en In this paper shear behavior of two calcareous sands having different physical properties areinvestigated using drained and undrained triaxial tests. The investigated sands are obtained from two differentzones located in Persian Gulf, Kish Island and Tonbak region. Analysis based on energy aspects show thatfriction angle in these soils, having crushable particles, is formed of three components: substantial internalfriction angle, dilation and particle breakage angle. Dilation component is available in the two investigatedsand. Particle breakage component is a function of grains hardness, structure and geometry shape. Particlesbreakage decreases the volume of sample during drained tests and creates positive pore water pressure duringundrained tests. Two investigated sands show different amount of dilation and particle breakage under similarconditions. Simultaneous dilation and particles crushing and different amount of them result in different shearbehavior of the two studied sands. Energy aspects are used to determine the effect of particle crushing on theshear strength. There is a suitable compatibility between relative breakage of grains and consumed energyratio for particle breakage. calcareous soil, triaxial test, dilation, particle breakage, energy 108 119 http://ijce.iust.ac.ir/browse.php?a_code=A-10-668-56&slc_lang=en&sid=1 2009/05/112009/05/112009/05/11 1388/2/21 2014/01/11 1392/10/21 Mahmoud Hassanlourad 0031947532846006007 0031947532846006007 No Hosein Salehzadeh 0031947532846006008 0031947532846006008 Yes Habib Shahnazari 0031947532846006009 0031947532846006009 No

en Presence of risks and uncertainties inherent in project development and implementation playssignificant role in poor project performance. Thus, there is a considerable need to have an effective riskanalysis approach in order to assess the impact of different risks on the project objectives. A powerful riskanalysis approach may consider dynamic nature of risks throughout the life cycle of the project, as well asaccounting for feedback loops affecting the overall risk impacts. This paper presents a new approach toconstruction risk analysis in which these major influences are considered and quantified explicitly. Theproposed methodology is a system dynamics based approach in which different risks may efficiently bemodeled, simulated and quantified in terms of time, cost and quality by the use of the implemented objectoriented simulation methodology. To evaluate the performance of the proposed methodology it has beenemployed in a bridge construction project. Due to the space limitations, the modeling and quantificationprocess for one of the identified risks namely “pressure to crash project duration” is explained in detail. System Dynamics, Construction Industry, Decision Making, Risk Analysis 120 131 http://ijce.iust.ac.ir/browse.php?a_code=A-10-393-34&slc_lang=en&sid=1 2009/05/112009/05/112009/05/112009/05/11 1388/2/21 2014/01/112014/01/11 1392/10/21 Farnad Nasirzadeh f.nasirzadeh@iust.ac.ir 0031947532846006010 0031947532846006010 No Abbas Afshar a_afshar@iust.ac.ir 0031947532846006011 0031947532846006011 Yes Mostafa Khanzadi khanzadi@iust.ac.ir 0031947532846006012 0031947532846006012 No

en Large capacity cylindrical tanks are used to store a variety of liquids. Their Satisfactoryperformance during earthquake is crucial for modern facilities. In present paper, the behavior of cylindricalconcrete tanks under harmonic excitation is studied using the finite element method. Liquid sloshing, liquidviscosity and wall flexibility are considered and additionally excitation frequency, liquid level and tankgeometry is investigated. The results show a value for wall thickness to tank diameter ratio which may be usedas a guide in the consideration of wall flexibility effects. cylindrical liquid storage tank, wall flexibility, liquid viscosity, harmonic excitation, numerical analysis 132 141 http://ijce.iust.ac.ir/browse.php?a_code=A-10-145-6&slc_lang=en&sid=1 2009/05/112009/05/112009/05/112009/05/112009/05/11 1388/2/21 2014/01/112014/01/112014/01/11 1392/10/21 Kourosh Shahverdiani 0031947532846006013 0031947532846006013 No Ali Reza Rahai 0031947532846006014 0031947532846006014 Yes Faramarz Khoshnoudian 0031947532846006015 0031947532846006015 No

en The nonlinear static pushover analysis technique is mostly used in the performance-based design of structures and it is favored over nonlinear response history analysis. However, the pushover analysis with FEMA load distributions losses its accuracy in estimating seismic responses of long period structures when higher mode effects are important. Some procedures have been offered to consider this effect. FEMA and Modal pushover analysis (MPA) are addressed in the current study and compared with inelastic response history analysis. These procedures are applied to medium high-rise (10 and 15 storey) and high-rise (20 and 30 storey) frames efficiency and limitations of them are elaborated. MPA procedure present significant advantage over FEMA load distributions in predicting storey drifts, but the both are thoroughly unsuccessful to predict hinge plastic rotations with acceptable accuracy. It is demonstrated that the seismic demands determined with MPA procedure will be unsatisfactory in nonlinear systems subjected to individual ground motions which inelastic SDF systems related to significant modes of the buildings respond beyond the elastic limit. Therefore, it’s inevitable to avoid evaluating seismic demands of the buildings based on individual ground motion with MPA procedure. Modal pushover analysis, FEMA load distributions, nonlinear response history analysis, high-rise buildings 142 157 http://ijce.iust.ac.ir/browse.php?a_code=A-10-151-4&slc_lang=en&sid=1 2009/05/112009/05/112009/05/112009/05/112009/05/112009/05/11 1388/2/21 2014/01/112014/01/112014/01/112014/01/11 1392/10/21 Mehdi Poursha 0031947532846006016 0031947532846006016 No Faramarz Khoshnoudian 0031947532846006017 0031947532846006017 Yes AbdoReza S. Moghadam 0031947532846006018 0031947532846006018 No