@article{ author = {Naderpajouh, N. and Afshar, A. and Mirmohammadsadeghi, S.A.}, title = {Fuzzy Decision Support System for Application of Value Engineering in Construction Industry}, abstract ={The use of Value Engineering (VE) methodology in construction industry has grown significantly, mainly in view of its extensive benefits. The main task in evaluation phase of VE workshop is to assess alternative ideas, proposed for each function. This phase of VE, hence, could be deemed as a Multi Criteria Decision Making (MCDM) problem. This paper presents a fuzzy decision support system (DSS) to be employed in evaluation phase of VE. The proposed multi alternative decision model may be recommended where alternatives’ preferences ratios are different, and scores assigned to each alternative idea are uncertain. As use of VE has greater payoffs at the earlier stages of the construction projects, in which most of the criteria are still vague and not precisely defined, exploiting this DSS may result in more tangible model of decision making process and satisfactory outlook of VE studies in construction projects. A ranking methodology in a spreadsheet template is also provided to facilitate the ranking process. Performance of the proposed methodology is tested using a case example in the tunneling industry.}, Keywords = {Value Engineering – Fuzzy Set Theory – Evaluation Phase – Multi Criteria Decision Making - Tunneling}, volume = {4}, Number = {4}, pages = {261-273}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-334-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-334-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Afshar, M.H. and Ketabchi, H. and Rasa, E.}, title = {Elitist Continuous Ant Colony Optimization Algorithm: Application to Reservoir Operation Problems}, abstract ={In this paper, a new Continuous Ant Colony Optimization (CACO) algorithm is proposed for optimal reservoir operation. The paper presents a new method of determining and setting a complete set of control parameters for any given problem, saving the user from a tedious trial and error based approach to determine them. The paper also proposes an elitist strategy for CACO algorithm where best solution of each iteration is directly copied to the next iteration to improve performance of the method. The performance of the CACO algorithm is demonstrated against some benchmark test functions and compared with some other popular heuristic algorithms. The results indicated good performance of the proposed method for global minimization of continuous test functions. The method was also used to find the optimal operation of the Dez reservoir in southern Iran, a problem in the reservoir operation discipline. A normalized squared deviation of the releases from the required demands is considered as the fitness function and the results are presented and compared with the solution obtained by Non Linear Programming (NLP) and Discrete Ant Colony Optimization (DACO) models. It is observed that the results obtained from CACO algorithm are superior to those obtained from NLP and DACO models.}, Keywords = {Continuous Ant Colony Optimization (CACO) Algorithm, Global Minimization, Reservoir Operation}, volume = {4}, Number = {4}, pages = {274-285}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-335-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-335-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Wegian, F.M. and Alkhamis, M.T. and SabbaghYazdi, S.R.}, title = {Experimental Studies on GFRP Repaired Hollow-Block Concrete Sections}, abstract ={This study evaluates two different types of techniques for concrete hollow-block sections reinforced with traditional steel rebars and wire meshes, and compares their structural behaviour to that of an ordinary reinforced concrete beam section. The comparisons are based on the responses both before and after they were repaired with glass fibre reinforced polymers (GFRP). The specimens were subjected to concentrated loading up to initial failure. After failure, the specimens were repaired and loaded once again until ultimate failure. It was shown that the success of the repair by GFRP depended on the mode of failure of the hollow-block concrete beams.}, Keywords = {Masonry, reinforced, concrete beam, hollow-block, GFRP}, volume = {4}, Number = {4}, pages = {286-295}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-336-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-336-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Sadrnejad, S.A. and Labibzadeh, M.}, title = {A Continuum/Discontinuum Micro Plane Damage Model for Concrete}, abstract ={Analysis and prediction of structural response to static or dynamic loading requires prediction of concrete response tovariable load histories. The constitutive equations for the mechanical behavior of concrete capable of seeing damage effects or crack growth procedure under loading/unloading/reloading was developed upon micro-plane framework. The proposed damage formulation has been built on the basis of five fundamental types of stress/strain combinations, which essentially may occur on any of micro-planes. Model verification under different loading/unloading/reloading stress/strain paths has been examined. The proposed model is capable of presenting pre-failure history of stress/strain progress on different predefined sampling planes through material. Many of mechanical behavior aspects happen during plasticity such as induced anisotropy, rotation of principal stress/strain axes, localization of stress/strain, and even failure mechanism are predicted upon a simple rational way and can be presented.}, Keywords = {}, volume = {4}, Number = {4}, pages = {296-313}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-337-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-337-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Mohammadi, S. and Bebamzadeh, A.}, title = {Simulation of Explosion by a Coupled FE/DE Gas-Solid Interaction Model}, abstract ={Explosion has always been regarded as one of the most complicated engineering problems. As a result, many engineers have preferred rather simplified empirical approaches in comparison to extremely complex deterministic analyses. In this paper, however, a numerical simulation based on the combined finite/discrete element methodology is presented for analyzing the dynamic behavior of fracturing rock masses in blasting. A finite element discretization of discrete elements allows for complex shapes of fully deformable discrete elements with geometric and material nonlinearities to be considered. Only a Rankine strain softening plasticity model is employed, which is suitable for rock and other brittle materials. Creation of new lines/edges/bodies from fracturing and fragmentation of original objects is systematically considered in the proposed gas-solid interaction flow model. An equation of state is adopted to inexpensively calculate the pressure of the detonation gas in closed form. The model employed for the flow of detonation gas has resulted in a logical algorithmic procedure for the evaluation of spatial distribution of the pressure of detonation gas, work done by the expanding gas and the total mass of the detonation gas as functions of time indicating the ability of model to respond to changes in both the mass of explosive charge and the size of the solid block undergoing fracture. Rock blasting and demolition problems are amongst the engineering applications that are expected to benefit directly from the present development. The results of this study may also be used to provide some numerical based reliable solutions for the complex analysis of structures subjected to explosive loadings.}, Keywords = {Explosion, rock blasting, gas solid interaction, combined finite/discrete element method.}, volume = {4}, Number = {4}, pages = {314-329}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-338-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-338-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Mazloom, M. and Mehrabian, A.A.}, title = {A New Method for Reducing Earthquake Casualties in Poor Performance}, abstract ={The objective of this paper is to present a new method for protecting the lives of residents in catastrophic earthquake failures of unreinforced masonry buildings by introducing some safe rooms within the buildings. The main idea is that occupants can seek refuge within the safe rooms as soon as the earthquake ground motions are felt. The information obtained from the historical ground motions happened in seismic zones around the globe expresses the lack of enough safety of masonry buildings against earthquake. For this potentially important reason, an attempt has been made to create some cost-effective seismic-resistant areas in some parts of the existing masonry buildings, which are called safe rooms. The practical method for creating these areas and increasing the occupant safety of the buildings is to install some prefabricated steel frames in some of their rooms or in their halls. These frames do not carry any service loads before earthquake. However, if a near field seismic event happens and the load bearing walls of the building destroy, some parts of its floors, which are in the safe areas, will fall on the roof of the installed frames consequently, the occupants who have sheltered in the safe rooms will survive. This paper expresses the experimental and theoretical work executed on the steel structures of the safe rooms for bearing the shock and impact loads. Finally, it was concluded that both the strength and displacement capacity of the steel frames were adequate to accommodate the distortions generated by seismic loads and aftershocks properly.}, Keywords = {earthquake, masonry building, casualties, safe room, steel frame, vibration.}, volume = {4}, Number = {4}, pages = {330-341}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-339-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-339-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Kaveh, A. and RahimiBondarabady, H.A. and Shahryari, L.}, title = {Buckling Load of Symmetric Planar Frames with Semi-rigid Joints Using Graph Theory}, abstract ={The main aim of this paper is to extend the recently developed methods for calculating the buckling loads of planar symmetric frames to include the effect of semi-rigidity of the joints. This is achieved by decomposing a symmetric model into two submodels and then healing them in such a manner that the :::union::: of the eigenvalues of the healed submodels result in the eigenvalues of the entire model. Thus the critical load of the frame is obtained using the eigenvalues of its submodels.}, Keywords = {symmetry, buckling load, semi-rigid frame, decomposition, healing, graph theory}, volume = {4}, Number = {3}, pages = {157-175}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-340-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-340-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Khoei, A.R. and Yadegari, S. and Anahid, M.}, title = {Three-dimensional modeling of strain localization in Cosserat continuum theory}, abstract ={In this paper, a higher order continuum model is presented based on the Cosserat continuum theory in 3D numerical simulation of shear band localization. As the classical continuum models suffer from the pathological mesh-dependence in strain softening models, the governing equations are regularized by adding the rotational degrees-of-freedom to conventional degrees-of-freedom. The fundamental relations in three-dimensional Cosserat continuum are presented and the internal length parameters are introduced in the elasto-plastic constitutive matrix to control the shear bandwidth. Finally, the efficiency of proposed model and computational algorithm is demonstrated by a 3D strip in tensile. A comparison is performed between the classical and Cosserat theories and the effect of internal length parameter is demonstrated. Clearly, a finite shear bandwidth is achieved and the load-displacement curves are uniformly converged upon different mesh sizes.}, Keywords = {Localization, Displacement discontinuity, Cosserat theory, 3D FEM, Return mapping algorithm}, volume = {4}, Number = {3}, pages = {176-191}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-341-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-341-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Baziar, M.H. and Salemi, Sh. and Heidari, T.}, title = {Analysis of Earthquake Response of an Asphalt Concrete Core Embankment Dam}, abstract ={Seismic behavior of a rockfill dam with asphalt-concrete core has been studied utilizing numerical models with material parameters determined by laboratory tests. The case study selected for these analyses, is the Meyjaran asphalt core dam, recently constructed in Northern Iran, with 60 m height and 180 m crest length. The numerical analyses have been performed using a nonlinear three dimensional finite difference software and various hazard levels of earthquakes. This study shows that due to the elasto-plastic characteristics of the asphalt concrete, rockfill dams with asphalt concrete core behave satisfactorily during earthquake loading. The induced shear strains in the asphalt core, for the case presented in this research, are less than 1% during an earthquake with amax=0.25g and the asphalt core remains watertight. Due to large shear deformations caused by a more severe earthquake with amax=0.60g, some cracking may occur towards the top of the core (down to 5-6 m), and the core permeability may increase in the top part, but the dam is safe.}, Keywords = {Asphalt concrete core, Dynamic analyses, Laboratory tests, Three dimensional numerical models.}, volume = {4}, Number = {3}, pages = {192-210}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-342-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-342-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {R.Rofooei, F. and K.Attari, N. and Rasekh, A. and Shodja, A.H.}, title = {Comparison of Static and Dynamic Pushover Analysis in Assessment of the Target Displacement}, abstract ={Pushover analysis is a simplified nonlinear analysis technique that can be used to estimate the dynamic demands imposed on a structure under earthquake excitations. One of the first steps taken in this approximate solution is to assess the maximum roof displacement, known as target displacement, using the base shear versus roof displacement diagram. That could be done by the so-called dynamic pushover analysis, i.e. a dynamic time history analysis of an equivalent single degree of freedom model of the original system, as well as other available approximate static methods. In this paper, a number of load patterns, including a new approach, are considered to construct the related pushover curves. In a so-called dynamic pushover analysis, the bi-linear and tri-linear approximations of these pushover curves were used to assess the target displacements by performing dynamic nonlinear time history analyses. The results obtained for five different special moment resisting steel frames, using five earthquake records were compared with those resulted from the time history analysis of the original system. It is shown that the dynamic pushover analysis approach, specially, with the tri-linear approximation of the pushover curves, proves to have a better accuracy in assessing the target displacements. On the other hand, when nonlinear static procedure seems adequate, no specific preference is observed in using more complicated static procedures (proposed by codes) compared to the simple first mode target displacement assessment.}, Keywords = {seismic nonlinear analysis; pushover analysis; FEMA 356; load pattern; target displacement}, volume = {4}, Number = {3}, pages = {212-225}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-343-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-343-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Soltani-Jigheh, H. and Soroush, A.}, title = {Post-cyclic Behavior of Compacted Clay-sand Mixtures}, abstract ={This paper presents the results of a series of monotonic and post-cyclic triaxial tests carried out on a clay specimen and three types of clay-sand mixed specimens. The focus of the paper is on the post-cyclic mechanical behavior of the mixed specimens, as compared to their monotonic behavior. Analyses of the tests results show that cyclic loading degrade undrained shear strength and deformation modulus of the specimens during the post-cyclic monotonic loading. The degradation depends on the sand content, the cyclic strain level and to some degrees to the consolidation pressure.}, Keywords = {mixed clayey soils, undrained behavior, triaxial testing, post-cyclic loading, pore water pressure}, volume = {4}, Number = {3}, pages = {226-243}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-344-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-344-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {AfandizadehZargari, Sh. and Taromi, R.}, title = {Selecting an Optimum Configuration of Urban One-Way and Two-Way Streets Using Genetic Algorithms}, abstract ={Optimization is an important methodology for activities in planning and design. The transportation designers are able to introduce better projects when they can save time and cost of travel for project by optimization methods. Most of the optimization problems in engineering are more complicated than they can be solved by custom optimization methods. The most common and available methods are heuristic methods. In these methods, the answer will be close to the optimum answer but it isn’t the exact one. For achieving more accuracy, more time has been spent. In fact, the accuracy of response will vary based on the time spent. In this research, using the generic algorithms, one of the most effective heuristic algorithms, a method of optimization for urban streets direction will be introduced. Therefore model of decision making in considered one way – two way streets is developed. The efficiency of model in Qazvin network is shown and the results compared whit the current situation as case study. The objective function of the research is to minimize the total travel time for all users, which is one of the most used in urban networks objectives.}, Keywords = {Genetic Algorithms, Network, One-way & Two-way Streets}, volume = {4}, Number = {3}, pages = {244-259}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-345-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-345-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Oucief, H. and Habita, M.F. and Redjel, B.}, title = {Hybrid fiber reinforced self-compacting concrete: hardened properties}, abstract ={In most cases, fiber reinforced self-compacting concrete (FRSCC) contains only one type of fiber. The use of two or more types of fibers in a suitable combination may potentially not only improve the overal properties of self-compacting concrete, but may also result in performance synergie. The combining of fibers, often called hybridization, is investigated in this paper for a cimentetious matrix. Control, single, two fibers hybrid composites were cast using different fiber type steel and polypropylene with different sizes. Flexural toughness tests were performed and results were extensively analysed to identify synergy, if any, associated with various fiber combinations. Based on various analysis schemes, the paper identifies fiber combinations that demonstrate maximum synergy in terms of flexural toughness.}, Keywords = {self-compacting, concrete , hybrid , fibers , toughness , energy}, volume = {4}, Number = {2}, pages = {77-85}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-346-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-346-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Moharrami, H. and Alavinasab, S.A.}, title = {An Optimization Procedure for Automated Design of Seismic-Resistant Steel Frames}, abstract ={In this paper a general procedure for automated minimum weight design of twodimensional steel frames under seismic loading is proposed. The proposal comprises two parts: a) Formulation of automated design of frames under seismic loading and b) introduction of an optimization engine and the improvement made on it for the solution of optimal design. Seismic loading, that depends on dynamic characteristics of structure, is determined using "Equivalent static loading" scheme. The design automation is sought via formulation of the design problem in the form of a standard optimization problem in which the design requirements is treated as optimization constraints. The Optimality Criteria (OC) method has been modified/improved and used for solution of the optimization problem. The improvement in (OC) algorithm relates to simultaneous identification of active set of constraints and calculation of corresponding Lagrange multipliers. The modification has resulted in rapid convergence of the algorithm, which is promising for highly nonlinear optimal design problems. Two examples have been provided to show the procedure of automated design and optimization of seismic-resistant frames and the performance and capability of the proposed algorithm.}, Keywords = {optimization, weight minimization, earthquake resistant, seismic resistant, seismic analysis, equivalent static loading, Optimality Criteria, steel frames, sensitivity analysis}, volume = {4}, Number = {2}, pages = {86-105}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-347-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-347-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Baziar, M.H. and Ziaie_Moayed, R.}, title = {Evaluation of Cone Penetration Resistance in Loose Silty Sand Using Calibration Chamber}, abstract ={This paper highlights the effect of silt content on cone tip resistance in loose silty sand. In this study, twenty-seven cone penetration tests are performed in saturated silty sand samples with several different silt contents ranging from 10 to 50 percent. The samples are consolidated at three overburden stresses including 100, 200 and 300 kPa. It is shown that, as the silt content increases, the cone tip resistance decreases. In high percent of silt (30-50%), the cone tip resistance decreases more gently compared with low percent of silt (0-30%). It is also concluded that the method proposed by Olsen (1997) for stress normalization of cone tip resistance compared with the Robertson and Wride (1998) method has better agreement with the obtained results. To evaluate liquefaction potential of loose silty sand, the method presented by Robertson and Wride (1998) is also studied. The results showed that the use of Robertson and Wride (1998) method to estimate the fine content from CPT data causes some uncertainty especially for high silt content (FC>30%).}, Keywords = {Cone tip resistance, Silty sand, Stress normalization, Liquefaction}, volume = {4}, Number = {2}, pages = {106-119}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-348-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-348-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Sadrnejad, S.A.}, title = {Numerical Evaluation of Non-homogeneity and Anisotropy due to Joints in Rock Media}, abstract ={An important concern in rock mechanics is non-homogeneity as joints or fault. Adopting the joints as fractures, fractures are well known for their effects on the mechanical and transport properties of rock. It has been postulated that through fractured/jointed rock, mainly, the polygons turned to the shear vector (ti) are involved in the mobilization of shear resistance. Consequently, in order to locate the contact areas implicated into the shear-test it was firstly necessary to fix the shear direction. Moreover, since laboratory observations clearly show that only the steepest polygon surfaces touch the other sample, the identification of the potential sliding areas only requires the determination of the polygons which are faced to the shear direction and which, among them, are steep enough to be involved. The methodology to be discussed here is modeling of slip on the local and global levels due to the distribution of deformation procedure of the rock joint. Upon the presented methodology, more attention has been given to slip initiation and propagation through rock joint. In particular, softening in non-linear behaviour of joint in going from the peak to residual strengths imparts a behaviour often associated with progressive failure. A multi-plane based model is developed and used to compute plastic strain distribution and failure mechanism of rock joints. Validity of the presented model was examined by comparing numerical and test results showing the behavior of both homogeneous and jointed rock samples under general stress conditions.}, Keywords = {anisotropy, jointed rock, multi-axial stress state, plasticity, hardening/softening law.}, volume = {4}, Number = {2}, pages = {120-135}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-349-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-349-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Behnam, B. and Sebt, M.H. and Vosoughifar, H.M.}, title = {Evaluating Quality Seismic Damage Index for Urban Residential Buildings}, abstract ={By identifying the damage index of a structure, in addition to a correct understanding from real behavior of the structure, the required criterion for strengthening would be given. Researchers have given many relations for determination of damage index but such relations have been based upon laboratory methods which challenge their usage in a broad term. In this paper two new methods are given for calculation of damage index. Surveying the first crack limit and total structure failure is based upon the formation of plastic joints in the first column and basic floor columns. To give a qualitative simple and functional damage index, the functional method was given in the form of a qualitative method with statistical analysis and collection of different views. Using this method is very simple and meantime offers suitable accuracy. With a numerical study on three models it was made clear that the difference of new method with amended method of Papadopolos in approximate 3%. This shows that given qualitative method is suitable to be used in a broad terms.}, Keywords = {Quality Damage Index, Earthquake, Urban Building, Reformed Method}, volume = {4}, Number = {2}, pages = {136-145}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-350-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-350-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Naderi, M.}, title = {Assessing the in situ strength of concrete, using new twist-off method}, abstract ={This paper introduces an innovative partially destructive method, called “Twist-off”, for the assessment of in situ concrete strength. In this method a 40mm diameter metal probe is bonded to a concrete surface by means of a high strength epoxy resin adhesive. To measure the concrete compressive strength, a torque is applied using an ordinary torque-meter and the maximum shear stress at failure is used to estimate the cube compressive strength by means of a calibration graph. The relationship between the results of this new method and compressive strengths of concrete cores is also presented in this paper. The average coefficient of variation of the results of this method was seen to be of the order of 8 percent and the correlation coefficients of its comparative results with concrete cube and core compressive strengths were found to be 0.97 and 0.90 respectively. In order to assess the performance of this method on site, tests were undertaken on a number of buildings. Although the method was found to perform well but with some of the structures tested, the differences between the strengths of sample cubes and estimated in situ compressive strength of concrete were seen to be significant.}, Keywords = {Concrete strength; In situ testing; Twist-off method}, volume = {4}, Number = {2}, pages = {146-155}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-351-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-351-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Afshar, A. and Abbasi, H. and Jalali, M. R.}, title = {Optimum Design of Water Conveyance Systems by Ant Colony Optimization Algorithms}, abstract ={Water conveyance systems (WCSs) are costly infrastructures in terms of materials, construction, maintenance and energy requirements. Much attention has been given to the application of optimization methods to minimize the costs associated with such infrastructures. Historically, traditional optimization techniques have been used, such as linear and non-linear programming. In this paper, application of ant colony optimization (ACO) algorithm in the design of a water supply pipeline system is presented. Ant colony optimization algorithms, which are based on foraging behavior of ants, is successfully applied to optimize this problem. A computer model is developed that can receive pumping stations at any possible or predefined locations and optimize their specifications. As any direct search method, the mothel is highly sensitive to setup parameters, hence fine tuning of the parameters is recommended.}, Keywords = {Ant colony optimization, Design, Optimum, Conveyance System}, volume = {4}, Number = {1}, pages = {1-13}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-352-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-352-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Shamsai, A. and Soleymanzadeh, R.}, title = {Numerical simulation of Air-Water flow in bottom outlet}, abstract ={Flow regime in dam's bottom outlet is divided in pressurized flow and free surface flow by the gate located for discharge control. Down stream tunnel involves high velocity Multi component Air –water flow studied by mathematical model. In this research work, we used Finite volume mixture two phase flow model. Because of high Reynolds number, standard two equations k-e turbulence model was used. Model was verified by backward-facing step flow and results have been compared with experiments founded by Durst and Schmitt. Air demand ratio has been determined as function of Froude number at contracted section. Flow patterns have been compared at two categories of slug & stratified flows, Air mean concentration profile has been obtained at down stream tunnel. Comparison of flow pattern at two case with and without of aeration was investigated. Pressure drop behind of the gate and formation of vortex flow after the gate section have been discussed. Measurement of flow discharge and determination of contraction coefficient of the gate was outlined.}, Keywords = {Two phase flow, Bottom outlet, CFD, Aeration, Cavitation}, volume = {4}, Number = {1}, pages = {14-33}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-353-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-353-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Saghafian, B. and Shokoohi, A.R.}, title = {A Corrected Time-Area Technique for One-dimensional Flow}, abstract ={Time–Area method is one of the most widely applied techniques of watershed routing, and can be potentially used as a distributed model. In this paper, a fundamental flaw in the arrangement of subareas in the original time-area histogram is identified for one-dimensional flow. This is conducted on the basis of comparing time-area hydrograph with that of the kinematic wave theorem. Accordingly, a revised time-area algorithm is developed as a substitute for the original time-area. It is proved that in the revised approach, subareas must be reversely arranged. It is also shown that the revised time-area hydrograph is in perfect agreement with the hydrograph derived by the kinematics wave theory.}, Keywords = {Time–Area, Kinematic Wave, One-dimensional flow, Isochrone.}, volume = {4}, Number = {1}, pages = {34-41}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-354-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-354-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Zahabiyoun, B.}, title = {Impact Assessment of Climate Change on Rainfall over a Small Catchment}, abstract ={A methodology is presented for the stochastic generation of daily rainfall which accounts for changes to the climatic inputs. The focus of the study is an example catchment in Iran. The methodology addresses the inability of GCMs to provide suitable future scenarios for the time and space scales required for a water resource impact assessment for a small catchment. One stochastic model for rainfall (Neyman-Scott Rectangular Pulses, NSRP, model) is used to generate daily rainfall sequences and then validated using historic records. For present climate conditions, the NSRP model is fitted to observed rainfall statistics. GCM outputs are then downscaled using regressions between atmospheric circulation indices (ACIs) and rainfall statistics. The relationships are then used to predict the rainfall statistics for future conditions using GCM outputs. In this respect, climate change impacts are studied and assessed in this paper. Generated rainfall scenario can then be used as inputs to a rainfall-runoff model in order to generate daily streamflow data which is not investigated here.}, Keywords = {Climate change, downscaling, impact assessment, rainfall model.}, volume = {4}, Number = {1}, pages = {42-53}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-355-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-355-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Salehzadeh, H. and Procter, D.C. and Merrifield, C.M.}, title = {MEDIUM DENSE NON-CEMENTED CARBONATE SAND UNDER REVERSED CYCLIC LOADING}, abstract ={Carbonate materials are mostly found in tropical areas, where exploiting gas and oil resources are of high concern. Their unique behavior under shear loading first was recognised during oil resources investigations in the Persian Gulf. Off-shore structures have been placed on carbonate soils which are highly crushable.During storms cyclic loading imposes on the bases of structures lied down on seabed. Cyclic loading, therefore, may trigger liquefaction phenomenon which leads to soil collapse and a catostrophic event. Therefore, stability of these expensive structures need to be investigated. To this aim carbonate sand in medium dense to medium dense state was considered and its response under varied cyclic shear stress ratio was studied.}, Keywords = {}, volume = {4}, Number = {1}, pages = {54-63}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-356-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-356-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} } @article{ author = {Behbahani, H. and Elahi, S.M.}, title = {An Investigation to Determine the Minimum Acceptable Roadway Condition for Iran’s Highways}, abstract ={To properly plan for construction, repair, maintenance, and reconstruction of highways the minimum acceptable roadway condition is needed information. This, along with other pavement management tools, will help select the most desirable roadway alternatives. In this research the minimum acceptable conditions are developed based on an opinion survey of non-technical but high-level decision makers. Roadway roughness, expressed as international roughness index (IRI), is used as the measurement criteria. Because IRI is a widely known, acceptable, and a uniformly measurable index, it is used for the purpose of this research. The minimum IRI values developed here will help managers, planners, and engineers in prioritizing their plans and projects. Iran has a central planning system, hence having a minimum acceptable IRI will help in producing homogeneity in decision making. A questionnaire is sent to top level and influential managementlevel officials who have a decisive input in highway matters. The officials are asked to choose the minimum acceptable service level of different types of roadways and classifications. Naturally, roadways with higher levels of importance would require higher service levels. The answers to the survey questionnaires are investigated to determine a preferred minimum acceptable roadway condition. The IRI is computed using a mechanical device enabling a more uniform data collection. The IRI was first proposed by The World Bank as a standard roughness statistic. Extensive research has proven that the IRI can be related to pavement condition. The result of the opinion survey is investigated to determine the minimum levels acceptable for each category. The responses show distinct preference patterns for most of the roadway types. Survey results are investigated by plotting and analyzing them. Based on road user’s perception of roadway condition using guidelines from AASHTO, the Corp of Engineers, and related research work. The appropriate IRI limits and ranges are determined for Iran’s highways. These values are adjusted to obtain final values for Iran. The result, shown in a table, gives upper and lower IRI values accepted and recommended for Iran’s highways. The result of this research work is specifically useful in developing specifications for new pavement design, accepting new pavement from contractors, pavement management, highway planning, and in roadway life cycle cost analysis decision making. The results are subject to refinement over time.}, Keywords = {pavement condition, highway planning, pavement management, IRI, minimum acceptable, LCCA, decision making, pavement service level, roadway roughness, management tool, Iran’s highways.}, volume = {4}, Number = {1}, pages = {64-76}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-357-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-357-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2006} }