@article{ author = {Kaveh, A. and ShakouriMahmudAbadi, A.}, title = {Harmony search based algorithms for the optimum cost design of reinforced concrete cantilever retaining walls}, abstract ={Cost optimization of the reinforced concrete cantilever soil retaining wall of a given height satisfying some structural and geotechnical design constraints is performed utilizing harmony search and improved harmony search algorithms. The objective function considered is the cost of the structure, and design is based on ACI 318-05. This function is minimized subjected to design constraints. A numerical example of the cost optimization of a reinforced concrete cantilever retaining wall is presented to illustrate the performance of the presented algorithms and the necessary sensitivity analysis is performed.}, Keywords = { Structural optimization, Reinforced concrete, Cantilever retaining walls, Harmony search algorithm, Modified harmony search}, volume = {9}, Number = {1}, pages = {1-8}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-292-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-292-en.doc}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {An, Sung-hoon and Cho, Hunhee and Lee, Ung-Kyu}, title = {Reliabilty assessment of conceptual cost estimates for building construction projects}, abstract ={In the early stages of a construction project, the reliability and accuracy of conceptual cost estimates are major concerns for clients and cost engineers. Previous studies applied scoring methods and established common rules or mathematical methods to assess the quality of cost estimates. However, those approaches have some limitations in adapting to real-world projects or require understanding of sophisticated statistical techniques. We propose a Conceptual Cost Estimate Reliability Index (CCERI), a simple, easy-to-use, and easy-to-understand tool that incorporates weights for 20 factors influencing the quality of conceptual cost estimates. The weights were obtained by eliciting experts’ experience and knowledge. Cost data from 71 building projects were used in the analysis and validation of the CCERI. The analysis reveals that a conceptual cost estimate with a CCERI score of less than 3000 has a high probability of exceeding 10% error, and such conceptual cost estimates are unlikely to be reliable. With the CCERI score, a decision maker or a client can recognize the reliability of the conceptual cost estimates and the score can thus support decision making using conceptual cost estimates. In addition, with the CCERI and the relative importance weights of factors affecting the conceptual cost estimates, the estimator can find ways to modify a conceptual cost estimate and reestimate it. These alternatives can decrease the risk in the conceptual estimated cost and assist in the successful management of a construction project.}, Keywords = { Cost estimation, Reliability assessment, Reliability index, Decision making}, volume = {9}, Number = {1}, pages = {9-16}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-463-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-463-en.doc}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {Malaikrisanachalee, S. and Vathananukij, H.}, title = {Integration of Java-based BIM with spatial database}, abstract ={Java is an object-oriented program that has abundant open-source libraries for application development and 3D model rendering. Spatial database is the database that can efficiently store and manage geographic information data though various spatial data management techniques. This paper explores the rationale of coupling java with spatial database to develop an effective platform for future Building Information Modeling (BIM) application. The paper methodically presents the prototype system integration design to demonstrate how the system can be developed. The paper also meticulously presents the logical and physical data models in designing optimum BIM database for a reinforced concrete building. An 8-storey reinforced concrete building was used as an implementation case study to validate the proposed prototype system design and investigates the implementation issues. The outcome shows that not only the proposed prototype system offers technological advantages over the traditional BIM applications, its open-source solution can also overcome the financial constraint that currently inhibits the implementation of BIM especially for medium and small enterprises.}, Keywords = { BIM, spatial database, project management, construction database, 3D model}, volume = {9}, Number = {1}, pages = {17-22}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-439-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-439-en.doc}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {Sebt, M.H. and Yousefzadeh, A. and Tehranizadeh, M.}, title = {The optimal TADAS damper placement in moment resisting steel structures based on a cost-benefit analysis}, abstract ={In this paper, the optimal location and characteristics of TADAS dampers in moment resisting steel structures, considering the application of minimum number of TADAS dampers in a building as an objective function and the restriction for destruction of main members is studied. Genetic algorithm in first generation randomly produces different chromosomes representing unique TADAS dampers distributions in structure and the structure corresponding to each chromosome is time history analyzed. Then the damage index for each member and the average weighted damage index for all members are determined. Genetic algorithm evaluates the fitness of each chromosome then selection and crossover as logical operators and mutation as random operator effect the current generation;#39s chromosomes according to their fitness and new chromosomes are generated. Accordingly, successive generations are reproduced in the same way until the convergence condition is fulfilled in final generation and four distributions are suggested as better options. Since these proposed distributions are selected under the one earthquake, therefore, it is better that the four new structures are cost-benefit analyzed in different earthquakes. Finally, the optimal placement for dampers is compared and selected based on a benefit to cost ratio, drift stories and the number of different TADAS types of such structures. The increase in amount of energy dissipated via dampers located in different floors as well as the status of plastic hinges in main members of the structure strengthened with optimum option are the proof of the optimal placement and suitable characteristics for dampers.}, Keywords = {Optimal location, TADAS dampers, Destruction of main members, Genetic Algorithm, Cost-benefit analyze, Dissipation energy}, volume = {9}, Number = {1}, pages = {23-32}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-433-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-433-en.doc}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {Afandizadeh, Sh. and Yadak, M. and Kalantar, N.}, title = {Simultaneous determination of optimal toll locations and toll levels in cordon-based congestion pricing problem (case study of Mashhad city)}, abstract ={The congestion pricing has been discussed as a practical tool for traffic management on urban transport networks. The traffic congestion is defined as an external diseconomy on the network in transport economics. It has been proposed that the congestion pricing would be used to reduce the traffic on the network. This paper investigates the cordon-based second-best congestion-pricing problems on road networks, including optimal selection of both toll levels and toll locations. A road network is viewed as a directed graph and the cutest concept in graph theory is used to describe the mathematical properties of a toll cordon by examining the incidence matrix of the network. Maximization of social welfare is sought subject to the elastic-demand traffic equilibrium constraint. A mathematical programming model with mixed (integer and continuous) variables is formulated and solved by use of two genetic algorithms for simultaneous determination of the toll levels and cordon location on the networks. The model and algorithm are demonstrated in the road network of Mashhad CBD.}, Keywords = { Congestion pricing, Genetic algorithm, Network, Cutset, Cordon, Optimization}, volume = {9}, Number = {1}, pages = {33-40}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-256-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-256-en.doc}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {RezaieMoghaddam, F. and Afandizadeh, Sh. and Ziyadi, M.}, title = {Prediction of accident severity using artificial neural networks}, abstract ={In spite of significant advances in highways safety, a lot of crashes in high severities still occur in highways. Investigation of influential factors on crashes enables engineers to carry out calculations in order to reduce crash severity. Therefore, this paper deals with the models to illustrate the simultaneous influence of human factors, road, vehicle, weather conditions and traffic features including traffic volume and flow speed on the crash severity in urban highways. This study uses a series of artificial neural networks to model and estimate crash severity and to identify significant crash-related factors in urban highways. Applying artificial neural networks in engineering science has been proved in recent years. It is capable to predict and present desired results in spite of limited data sets, which is the remarkable feature of the artificial neural networks models. Obtained results illustrate that the variables such as highway width, head-on collision, type of vehicle at fault, ignoring lateral clearance, following distance, inability to control the vehicle, violating the permissible velocity and deviation to left by drivers are most significant factors that increase crash severity in urban highways.}, Keywords = { Crash Severity, Human Factors, Highway, Traffic Volume, Artificial Neural Networks}, volume = {9}, Number = {1}, pages = {41-48}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-544-en.html}, eprint = {}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {Vafaie, J. and Taghikhany, T. and Tehranizadeh, M.}, title = {Near field effect on horizontal equal-hazard spectrum of Tabriz city in north-west of Iran}, abstract ={The near field ground motions have a high amplitude pulse like at the beginning of the seismogram which are significantly influenced by the rupture mechanism and direction of rupture propagation. This type of ground motion cause higher demands for engineering structures and its response spectrum is dramatically different than far field spectra. Tabriz is one of the ancient cities in Azerbaijan province with many industrial factories, financial centers and historical monuments in North-West of Iran. In this region, North Tabriz Fault which has a well known history of intense seismic activity is passing through in close distance of urban area. In this regard investigation of near field ground motion effect on current practice seismic design spectrum in this region is necessary. Hence, probabilistic seismic hazard analysis is carried out using appropriate attenuation relationship to consider near field effect. The peak ground acceleration (PGA) and several spectral accelerations (SA) over bedrock are estimated for different return periods and maps of iso acceleration contour lines are provided to indicate the earthquake hazard in different points of Tabriz city. Afterward, the generated horizontal equal-hazard spectrums considering near field effect are compared with different spectrums developed base on simple pulses model for near field motion. Both types spectrum used to verify current practice seismic design spectrum of Iranian code (2005) and International Building Code (IBC 2000). The results reveal the long-period structures which are seismically designed based on current practice seismic codes are in high risk to be damaged during near fault ground motion.}, Keywords = { Equal-Hazard Spectrum, Near Field Effect, Tabriz City}, volume = {9}, Number = {1}, pages = {49-56}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-251-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-251-en.doc}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {Mahmoudi, M. and Zaree, M.}, title = {Evaluating the overstrength of concentrically braced steel frame systems considering members post-buckling strength}, abstract ={Inelastic deformation of structural components is generally acceptable in seismic design. In such behavior, the strength of structures increases while plastic hinges are formed in members frequently. The strength revealed during the formation of plastic hinges is called "overstrength". Overstrength is one of the important parameters in the seismic design of structures. The present study tries to evaluate the overstrength of the concentrically steel braced frames (CBFs), considering reserved strength, because of members post-buckling. As such, a static nonlinear (pushover) analysis has been performed on the model buildings with single and double bracing bays, different stories and brace configurations (chevron V, invert Vand X-bracing). It has been realized that the number of bracing bays and the height of buildings have a low effect on reserve strength due to brace post-buckling. However, these parameters have a profound effect on the overstrength factor. These results indicate that the overstrength values for CBFs, proposed in seismic design codes, need to be modified.}, Keywords = { Concentrically steel braced frames, Overstrength factor, Post-buckling strength, Response modification factor}, volume = {9}, Number = {1}, pages = {57-62}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-301-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-301-en.pdf}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {Poorazizi, M.E. and Alesheikh, A.A.}, title = {Monitoring real-time environmental information using Web 2.0 and GIServices technology}, abstract ={Air pollution is a serious challenge in densely populated cities. It poses a significant threat to human health, property and the environment throughout the developed and developing parts of the world. Real-time air quality monitoring and public access to related information are the key components of a successful environmental management. Mashups can be customized to adequately address the monitoring of such geographically oriented challenges. The growth of mashups has been accelerated by Web 2.0 technologies. The integration of Web 2.0 and GIS (Geographic Information System) has been highlighted by the second generation of Internet-based services that emphasizes on online information collaboration and sharing among users. The main objective of this paper is to assess, design and develop a Web 2.0 thin client application called Tehran Air Quality Reporter. The application uses Google Maps API (Application Programming Interface), Web GIServices (Geographic Information Services), and AJAX (Asynchronous JavaScript and XML) to disseminate real-time air quality information through internet. Such information can improve the decisions of the pertinent environmental organizations as well as urban settlers. The software also utilized DOM (Document Object Model) and JavaScript functionalities for handling the response events and providing flexibility and more interactivity. The developed Geo Mashup includes geospatial maps and features, standard business charts, node and link displays, as well as custom visual displays. All visualization components run in any web browsers and provide a user friendly environment.}, Keywords = { GIS, Data interoperability, Mashups, Google maps, Web service, Geospatial data interchange format}, volume = {9}, Number = {1}, pages = {63-70}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-274-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-274-en.docx}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} } @article{ author = {Hajivalie, F. and YeganehBakhtiary, A.}, title = {Numerical simulation of the interaction of a broken wave and a vertical breakwater}, abstract ={In this paper, a two-dimensional Reynolds Averaged Navier-Stokes (RANS) model is developed to simulate the shoaling, breaking and overtopping of a solitary wave over a vertical breakwater. Turbulence intensity is described by using a k turbulence closure model and the free surface configuration is tracked by Volume Of Fluid (VOF) technique. To validate the numerical model the simulation results is compared with the Xie (1981) experimental data and a very good agreement between them is observed. The results revealed that wave height and wave energy decrease considerably during the reflection from vertical wall, which illustrates a considerable energy lost during the impaction and wave overtopping process. The turbulence production during the broken wave interaction with vertical breakwater is very significant consequently the vertical breakwater undergoes sever turbulent and dynamic drag force.}, Keywords = { RANS model, shoaling, wave breaking, wave overtopping, k-ε turbulence closure model, VOF technique, solitary wave}, volume = {9}, Number = {1}, pages = {71-79}, publisher = {}, title_fa = {}, abstract_fa ={}, keywords_fa = {}, url = {http://ijce.iust.ac.ir/article-1-239-en.html}, eprint = {http://ijce.iust.ac.ir/article-1-239-en.doc}, journal = {International Journal of Civil Engineering}, issn = {1735-0522}, eissn = {2283-3874}, year = {2011} }