Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201Structural Damage Control with Interval Type-2 Fuzzy Logic Controller125134297110.22060/ajce.2018.13827.5255ENM.AzadvarDepartment of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, IranH.HajkazemiDepartment of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, IranA.KaramoddinDepartment of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20171212<span>In this study, with designing of an Interval Type-2 Fuzzy Logic Controller (IT2FLC), the ability of this system to control the uncertainties governing the structure has been investigated. One of the main shortcomings of fuzzy systems is to consider the uncertainties in the fuzzy rule base. IT2FLS, which is in fact a development of fuzzy systems, has the ability to handle this problem and reducing the uncertainties surrounding it. In order to evaluate the performance of the proposed controller, building with the Magneto-rheological (MR) dampers have been used as benchmark. The results of the analysis of the structures in the proposed controller, with the uncontrolled structure, the controlled structures equipped with the type-1 fuzzy controller (FLC Type-1), as well as the controlled structures under the Genetic algorithm-Fuzzy Logic Controller (GA-FLC), have been compared and analyzed. </span><span>Numerical results showed that IT2FLC is more effective in reducing the uncertainties governing the structure compared to other controllers, and the structural response will be optimized in different loading conditions. Using the proposed controller will reduce damage in the structure by 5 to 15 percent more than other controllers. In addition, the use of IT2FLC has reduced the displacement and acceleration time history responses of the structure compared with FLC-Type-1. The proposed controller has been able to reduce the maximum response of the different floors of structure by 10 to 30 percent compared to other controllers. Dynamic analysis of IDA method shows that at different load levels, the performance of IT2FLC will be more optimal than FLC-Type-1.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201Effects of Silica Fume and Nano-silica on the Engineering Properties of Kaolinite Clay135142297310.22060/ajce.2018.14203.5462ENS.GhavamiSchool of Civil Engineering, Iran University of Science and Technology, Tehran, Iran0000-0001-5102-7658B.FarahaniSchool of Civil Engineering, Alaodoleh Semnani Institute of Higher Education, Garmsar, IranH.JahanbakhshDepartment of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, IranF.Moghadas NejadDepartment of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran0000-0003-3830-4555Journal Article20180311<span>The improvement of geotechnical properties of weak soils is of interest through the resources shortage. Therefore, this study focused on the effect of silica fume as industrial waste products and nano-silica on geotechnical characteristics and micro-structural properties of kaolinite clay as a soft soil with poor strength properties. Silica fume was added to the kaolinite clay to enhance the strength with 5, 10 and 15%. Moreover stabilized soil with nano-silica were fabricated with 1, 2 and 3% by dry weight of the soil. Then, Atterberg limits, standard proctor, unconfined compressive strength, and California bearing ratio tests were conducted. In addition, the micro-structural changes of soil samples through the stabilization were examined using scanning electron microscope. The results indicated that silica fume and nano-silica increase the optimum water content and decrease the maximum dry density of the stabilized soils. Addition of 15% silica fume and 3% nano-silica to kaolinite clay improved the unconfined compressive strength at curing age of 28 days by up to 70% and 55%, respectively. Also, the results of soaked California bearing ratio test after 7 days of curing demonstrated that 15% of silica fume and 3% nano-silica increased the California bearing ratio values about two times more than the raw soil. Scanning electron microscope (SEM) images were then utilized to evaluate the effects of additives on the kaolinite clay soil. It was concluded that silica fume and nano-silica filled pore space between clay particles and a dense matrix were formed. This textural event caused an improvement in compressive strength of stabilized soils.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201Evaluation of Seismic Vulnerability of Masonry Buildings without Ties Using the RISK-UE Method, Case Study of Kermanshah City143152298510.22060/ajce.2018.14731.5493ENM.BiglariCivil Engineering Department, Razi University, Kermanshah, Iran0000-0002-1245-7740E.KamarizadehCivil Engineering Department, Razi University, Kermanshah, IranI.AshayeriCivil Engineering Department, Razi University, Kermanshah, IranJournal Article20180718Investigating the seismic vulnerability of masonry buildings without either horizontal or vertical ties, are important due to their number of usage more specifically in old parts of cities. Kermanshah, as a cultural center of west of Iran and 9th most populated city of Iran, hosts large number of masonry buildings. Besides, the city is located in the seismically active region of Zagros. Hence, it is crucial for urban planning of the city to study the seismic vulnerability of these buildings. Three major types of masonry buildings, which are brick walls with steel beam, brick walls with wooden beam, and adobe buildings are identified and their seismic vulnerabilities are evaluated using the RISK-UE method. The vulnerability of these buildings in terms of damage level as well as the human vulnerability rate estimated from the severity of the demolition of these buildings for each area of the city, assuming that 80% of the people are in the roofed places during the earthquake scenarios. The results show that under the earthquake scenario with return period of 475 years, more than 12% of brick walls with wooden beam, 11% of brick walls with steel beam, and 29% of adobe buildings, may experience severe structural damage or complete destruction. Furthermore, under the earthquake scenario with return period of 2475 years, the level of severe structural damage or complete destruction is expected for more than 42% of brick walls with wooden beam, 39% of brick walls with steel beam, and 66% of adobe buildings.Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201SWOT Analysis on Marine Transport Companies of Iran: a Case Study153160283810.22060/ajce.2018.12319.5167ENM. H.SebtCivil and Environmental Engineering Department, Amirkabir University of Technology, Tehran, IranA. H.KhalilianpoorCivil and Environmental Engineering Department, Amirkabir University of Technology, Tehran, IranQ.BagheriCivil and Environmental Engineering Department, Amirkabir University of Technology, Tehran, IranE.Riahi DehkordiCivil and Environmental Engineering Department, Amirkabir University of Technology, Tehran, IranJournal Article20161231<span>Strengths – weaknesses – opportunities – threats (SWOT) analysis is one of the well-known management tools for strategic planning. Although papers published in different journals have discussed different subject that used SWOT analysis, it is found that there are no researches which applied SWOT analysis in the marine transport companies in Iran. On the other hand the economic and social effect of the sea on its neighbours live is undeniable. Consequently, the objective of this paper is to analyse the internal and external environment of the marine transport company in Iran with SWOT analysis method and then to give a number of solutions and strategies for promoting the development of marine transport companies. Firstly, a general review of SWOT analysis is presented, next, the research method conducted through 5 steps; include research and data collection, questionnaire design and survey, brainstorming, SWOT analysis and strategy recommendations. Results indicated that Iranians government encourages the development of these companies and positively support them, but the sanctions in recent years, created a difficult and complex situation for these companies.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201Exterior Concrete Beam-column Connection Reinforced with Glass Fiber Reinforced Polymers (GFRP) bars under Cyclic Loading161176300010.22060/ajce.2018.14611.5487ENH.Rezaee AzarianiDepartment of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran0000-0002-7209-5550H.ShariatmadarDepartment of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.0000-0001-5966-3317M. RezaEsfahanirDepartment of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.Journal Article20180617<span>This paper is devoted to assess the behavior of the exterior concrete beam-column connections reinforced with Glass Fiber Reinforced Polymers (GFRP) bars under cyclic loading. For this purpose, 8 different beam-column connections were experimentally investigated. In these specimens, concrete with compressive strength of 30 and 45 MPa was employed. In four of these connections, GFRP bars were used while the others were reinforced with steel bars. The confinement of longitudinal bars was different in the connections. The GFRP-reinforced beam-column connection showed an elastic behavior with very low plasticity features under cyclic loading. This resulted in lower energy dissipation compared to the steel-reinforced beam-column connections. The GFRP-reinforced beam-column connections showed lower stiffness than that of the steel-reinforced beam-column connections. Load-story drift envelope for specimens with GFRP bars showed an acceptable drift capacity. These specimens had the essential requirements for acting as a member of a moment frame in seismic regions. In case of GFRP strengthened specimens with low and high strength concrete, increasing the cyclic loading results in flexural failure of the beam in the beam-column connection region. Increasing the confinement of concrete beams leads to the reduction of crack width. Furthermore, at higher drifts, spalling was not observed in concrete surface in beam-column connection region. In the analytical parts of the study, specimens were simulated using the SeismoStruct software. Experimental and analytical results showed a satisfactory correlation.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201Effect of Bentonite fine Content on the Triaxial Shear Behavior of Sandy Soils177182298910.22060/ajce.2018.14451.5476ENM.HasanlouradFaculty of Engineering, Imam Khomeini International University, Qazvin, IranS.M.H.KhatamiFaculty of Engineering, Imam Khomeini International University, Qazvin, IranM. M.AhmadiCivil Engineering Department, Sharif University of Technology, Tehran, IranJournal Article20180514<span>Addition of fine and plastic clays such as bentonite to sandy soils is one of the methods of reducing soil hydraulic conductivity and making it suitable for seepage barriers. Also, in nature, soil mixtures such as clayey sands, silty sand and clayey silts are found much more than pure soils such as clean sand, clay or silt. Thus, in this paper, the effects of adding bentonite particles on the shear behavior of a sandy soil were studied by performing series of consolidated un-drained triaxial tests. In these experiments, different amounts of weight contents of bentonite such as 0, 5 and 10% were added to a sandy soil named Firoozkooh sand. Generally, obtained results showed that addition of bentonite led to changes in the shear behavior and strength of sand. These changes depend on the relative density of soil, confining stress and bentonite content. As an example, in loose samples of sand, addition of bentonite reduced the maximum deviator stress of the soil; on the other hand, in dense samples, addition of 5% bentonite reduced the deviator stress. However, addition of 10% bentonite increased the deviator stress. Generally, addition of bentonite reduced the secant modulus of elasticity and increased the positive pore water pressure at phase transition point. It is worth noting that, in dense samples, the effectiveness of bentonite content was not as high as that in loose samples and, in some conditions, the results did not follow a specific trend.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201A Shear-based Adaptive Pushover Procedure for Moment-resisting Frames183194300810.22060/ajce.2018.14616.5489ENM.HadiDepartment of Civil Engineering, Isfahan University of Technology, Esfahan, IranF.BehnamfarDepartment of Civil Engineering, Isfahan University of Technology, Esfahan, IranS.ArmanDepartment of Civil Engineering, Isfahan University of Technology, Esfahan, IranJournal Article20180617<span>The effects of higher modes are neglected in conventional pushover analysis procedures. Among the improved pushover methods, the adaptive pushover procedures are attractive for their multi-mode capability. In such procedures, the dynamic characteristics of buildings are updated in each stage of analysis consistent with the extent of the non-linear action throughout the structure. In this paper an adaptive pushover procedure is introduced that works with inter-story shear forces. It is compared with the conventional adaptive pushover methods where story accelerations or displacements are the bases of analysis. In the proposed method, the inter-story shears are calculated and updated based on the current dynamic characteristics of structure at each analysis step. They are then converted to the equivalent lateral forces for pushover analysis. Through using a correction factor based on the fundamental period of the building, a procedure is also developed for modifying the story drifts. Comparison with the average results of exact nonlinear dynamic analysis of a number of buildings under several earthquakes shows accuracy similar to the most precise procedure within the available conventional adaptive pushover methods. For the comparative analysis, 5, 10 and 15-story buildings and seven ground motions are utilized. Moreover, the proposed method is practically more adaptable to the current commercial softwares.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201The Evaluation of Friction Demand Factor in Loop Ramps of Interchange Facilities195208301010.22060/ajce.2018.14330.5472ENM. H.Dehshiri PariziDepartment of Transportation Engineering, Isfahan University of Technology, Isfahan, IranM.TamannaeiDepartment of Transportation Engineering, Isfahan University of Technology, Isfahan, Iran0000-0001-5305-3825H.HaghshenasDepartment of Transportation Engineering, Isfahan University of Technology, Isfahan, IranJournal Article20180416<span>The aim of this study is to evaluate the side friction demand factor in the loop ramps of interchange facilities. The substantial exclusivity of these ramps is the existence of horizontal curves, combined with longitudinal grades. In this study, CarSim and TruckSim software packages, as simulation tools, are applied. Both passenger cars and heavy vehicles are used. The vehicles used in simulations were Hatchback and Sedan (as passenger cars) and Truck (as heavy vehicle). In addition, two various types of loop ramps, including Curve-Curve-Curve and Spiral-Curve-Spiral, in two different conditions (braking and no-braking) are examined. The results showed that the side friction demand factor values assumed by AASHTO Green book (as a main geometric design guideline) are uncertain. In the condition of no-braking, the differences between AASHTO values and the simulation results for uphill and downhill states are 24% and 18%, respectively. In braking condition, similar differences for uphill and downhill are 124% and 135%, respectively. Additionally, based on the regression analysis of the simulation results, the appropriate side friction demand factor models were achieved for different conditions. The findings of the study verify the necessity of revising the friction demand values, especially for the design of interchange loop ramps.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201A Geometrically Non-linear Stochastic Analysis of Two-dimensional Structures made of Neo-hookean Hyperelastic Materials Uusing MLPG Method: Considering Uncertainty in Mechanical Properties209218304510.22060/ajce.2018.14531.5483ENM.H.Ghadiri RadEngineering Department, Quchan University of Technology, Quchan, IranF.ShahabianCivil Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, IranS.M.HosseiniIndustrial Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20180530<span>In recent decades, analysis of structures considering variability of some parameters for more reliable design has attracted the attention of researchers. In this paper, the stochastic analysis of a cantilever deep beam made of large deformable neo-hookean material is carried out. For this purpose, the meshless local Petrov-Galerkin (MLPG) method is developed to obtain the geometrically non-linear equilibrium equations. The radial point interpolation method is used for generating the shape functions. The incremental iterative Newton-Raphson method with suitable load steps is used to solve the non-linear governing equations. The results of deterministic analysis obtained with proposed method are compared with the finite element results and good agreement is achieved. The initial elasticity modulus of neo-hookean material is considered to be uncertain variable. To generate random field of uncertain variable with normal, lognormal and uniform probability density functions (PDFs), the Monte Carlo Simulation (MCS) technique was employed. The sufficient number of simulations for convergence the results was determined experimentally. The effect of elasticity modulus, PDF and coefficients of variation (COV) on maximum vertical displacement, PDF and COV of results are studied in details. Comparing the stochastic and deterministic results shows that the uncertainty in mechanical properties has significant effect on results.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201The Performance of Integral and Semi-integral Pre-tensioned Concrete Bridges Under Seismic Loads in Comparison with Conventional Bridges219226290910.22060/ajce.2018.14338.5473ENS. S.Shid MoosaviDepartment of Civil Engineering, Amirkabir University of Technology, Tehran, IranA. R.RahaiDepartment of Civil Engineering, Amirkabir University of Technology, Tehran, IranJournal Article20180418<span>Bridges are divided into three categories of integral, semi-integral, and conventional (seat type) bridges, based on the connection of deck to abutment. The integral and semi-integral bridges have been widely used recently, while the interactions of soil with abutments and piles are important issue in designing them. However, limited studies have been carried out on the behaviors of integral and semi-integral bridges and, hence, a few specific and suitable designing indices for them can be found. In this study, a 3D finite element model for each type of bridges was developed and analyzed under seismic load. Due to the importance of soil-structure interaction, non-linear springs (links) were employed to simulate the effects of soil behind abutments and soil around piles on the structure. This study determined the effects of seismic loading on the abutment and its backfill soil in the conventional, integral and semi-integral bridge models, and also compared the equivalent exerted force from backfill soil to structure in these three types of bridge models.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201Analysis of Local Site Effects on Seismic Ground Response under Various Earthquakes227240302210.22060/ajce.2018.13696.5253ENA.AsakerehDepartment of civil engineering, Faculty of engineering, University of Hormozgan, Bandar Abbas, Iran0000-0003-4706-2957M.TajabadipourDepartment of civil engineering, Faculty of engineering, University of Hormozgan, Bandar Abbas, IranJournal Article20171110<span>By assessment of induced damages to structures and major infrastructures, seismic geotechnical researchers have concluded that the site conditions significantly influence on the failure distribution in urban and rural areas. Consequently, to determine the characteristics of seismic motions of the ground, it is essential to study the effective geotechnical factors. In this study influence of local site effects and soil conditions on the intensity of ground motion are investigated with two methods (non-linear and equivalent linear methods) based on one dimensional shear wave propagation in soil layer theory. In this regard, some series of site response analyses which consider various input motions, geotechnical parameters of site and non-linear properties were performed. The comparisons demonstrated that non-linear method provides a more accurate characterization of the true non-linear soil behavior compared to the equivalent-linear procedures. The earthquakes with Peak Ground Acceleration (PGA)less than 0.1 g have the most increase in horizontal acceleration at the surface in comparison with the earthquakes with greater peak accelerations.</span>Amirkabir University of TechnologyAUT Journal of Civil Engineering2588-28992220181201Prediction of Local Seismic Damage in Jacket-type Offshore Platforms241250306710.22060/ajce.2018.14738.5495ENMohammad.Aghajani DelavarSchool of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran0000-0002-4688-1224K.BargiSchool of Civil Engineering, College of Engineering, University of Tehran, Tehran, IranJournal Article20180722<span>Due to the severe environmental condition, steel jacket type offshore platforms are highly vulnerable to damage; so, ensuring its proper performance and detection of probable damage is very important and undeniable. The assessment of existing offshore platforms is relatively a new process and has not yet been standardized as the design has. To do so, seismic assessment of the existing 4-legged steel jacket type offshore platform placed in the Persian Gulf (SPD12) is presented in this paper. Based on an actual platform structure and its mechanical model, the parameters which may affect the rate of shock absorption are analyzed, such as the condition of the site where the platform is located. Assessment is done by finding the seismic damage spread in the structure. Therefore, by using some documents such as FEMA-356 and ATC-40 developed for seismic assessment of buildings, seismic damage of the jacket-type platform is predicted with pushover analysis, and damage spread in this structure is predicted. This method could be very simple and detect damage spread precisely. As a result, knowing the weaker points of the structure which will be the first and third levels of the platforms similar to SPD12 in structural system can help to detect the damaged places, and by improving the capacity of the structure locally, the structural damage spread will be delayed.</span>