Semnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Numerical Investigation of Geometric Parameters Effect of the Labyrinth Weir on the Discharge Coefficient19257910.22075/jrce.2017.11428.1188ENSomayehEmamiWater Engineering Department, Faculty of Agriculture, University of Tabriz, Tabriz, IranHadiArvanaghiWater Engineering Department, Faculty of Agriculture, University of Tabriz, Tabriz, IranJavadParsaWater Engineering Department, Faculty of Agriculture, University of Tabriz, Tabriz, IranJournal Article20170523Weirs, as overflow structures, are extensively applied for the measurement of flow, its diversion, and control in the open canals. Labyrinth weir as a result of more effective length than conventional weirs allows passing more discharge in narrow canals. Determination of the design criteria for the practical application of these weirs needs more examination. Weir angle and its position relative to the flow direction are the most effective parameters on the discharge coefficient. In this article, Fluent software was applied as a virtual laboratory, and extensive experiments were carried out to survey the effect of geometry on the labyrinth weir discharge coefficient. The variables were the height of weir, the angle of the weir, and the discharge. The discharge coefficients acquired from these experiments were then compared with the corresponding values obtained from the usual rectangular sharp-crested weir experiments. Comparison of the results indicated that in all cases with different vertex angle, flow discharge coefficients are in a satisfactory range for relative effective head less than 0.3. The discharge coefficient is reduced for relative effective head more than 0.3 due to the collision of water napes. It revealed that the higher the weir, the more discharge capacity. As a result, the labyrinth weirs have a better performance in comparison with the common sharp-crested.https://civiljournal.semnan.ac.ir/article_2579_44e04779de252a02e833e69730750422.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Internal Structure Features of Asphalt Mixture for Field Samples1020261310.22075/jrce.2017.11579.1194ENMahmood RezaKeymaneshAssociate Professor, North Tehran Branch, Payam Noor UniversityAliNasrollahtabarDepartment of Civil, Payame Noor University, P.O. Box 19395-3697, Tehran, IranNooshinShahryariM.Sc. Graguated, Faculty of Engineering, Payam Noor UniversityJournal Article20170608Asphalt mixture is heterogeneous in nature; consequently, macroscopic parameters alone cannot describe the mechanical behavior of the mixture. In recent years, the arrangement of the aggregate particles in terms of spatial and directional distributions, and contact points are contemplated as the internal structure of asphalt. The main purpose of this article is to examine the microstructural characteristics of asphalt cores applying 2-D images. Comparison between the internal structure features in the laboratory samples and the Field samples is indicated in this paper. The results reveal that the survey of microstructural characteristics of asphalt cores by image processing provides new and functional information. This finding indicates that the number of contact points in cores is close to the lab samples that have been made at 45 to 65 blows on each end of the sample.https://civiljournal.semnan.ac.ir/article_2613_e91fa9cda975778e759492098fcb5cd6.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Seismic Vulnerability Assessment of Jacket Type Offshore Platforms2133263610.22075/jrce.2017.3047.1164ENSomayyehKarimiyanDepartment of Civil Engineering, Islamshahr Branch, Islamic Azad University, Islamshahr, IranJournal Article20170115Most of oil and gas offshore platforms are located in the seismic regains. Therefore, Seismic vulnerability evaluation of the offshore platforms is one of the essential vital issues in the structural systems. In this article, jacket type offshore platforms are examined by incorporating the pushover analyses and nonlinear time history analyses, in such a way that, first some push over analyses are performed to detect the more critical members of the jacket platform in consonance with the range of their plastic deformations. Subsequently, nonlinear time history analyses are performed, concentrating on the critical members, to examine the vulnerability of the jacket platform under intensive earthquake loads. Pursuant to the numerical results, the combination of the push over analyses and nonlinear time history analyses proposes a reliable and swift seismic assessment procedure to evaluate the seismic vulnerability of the offshore platforms. Moreover, seismic vulnerability of the offshore structures is dependent on the critical member locations and their load bearing situations in the offshore structures.https://civiljournal.semnan.ac.ir/article_2636_27dfc3c165beed9f924469a80e58ab6f.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Analysis of Flow Pattern with Low Reynolds Number around Different Shapes of Bridge Piers, and Determination of Hydrodynamic Forces, applying Open Foam Software3448246610.22075/jrce.2017.1517.1142ENHojatKaramiAssistant Professor, Faculty of Civil Engineering, Semnan University, Semnan, IranSaeedFarzinAssistant Professor, Faculty of Civil Engineering, Semnan University, Semnan, IranMohammadBadeliGraduated MSc. student, Faculty of Civil Engineering, Semnan University, Semnan, IranSayed-FarhadMousaviProfessor, Faculty of Civil Engineering, Semnan University, Semnan, IranJournal Article20160717In many cases, a set of obstacles, such as bridge piers and abutments, are located in the river waterway. Bridge piers disrupt the river’s normal flow, and the created turbulence and disturbance causes diversion of flow lines and creates rotational flow. Geometric shape and position of the piers with respect to flow direction and also the number of piers and their spacing are effective in changing the river-flow conditions, such as the formation of vortices, their breakdown and hydrodynamic forces exerted on the piers. This article has been performed by applying the two-dimensional, open-source, OpenFOAM software. For this purpose, after selecting the grid size in GAMBIT software, different pier shapes were examined , considering different Reynolds numbers, and formation of the flow pattern, Strouhal number, vortex magnitude, and drag and lift coefficients for each pier shape were specified. Results for three different pier shapes indicated that in Reynolds number of 200, the highest drag coefficient (1.82) and maximum flow velocity (1.55 m/s) correlated to the square pier. The lowest drag coefficient (0.46) was calculated for the rectangular pier (having a semi-circular edge on one side and a sharp-nose edge on the other side) when the flow collides with the semi-circular edge. The least drag and lift forces are exerted to the rectangular pier, as compared to other pier shapes. The lowest lift coefficient (0.012) was obtained for a rectangular pier. On the other hand, the position of the sharp-nosed edge in the wake region caused the vortex shedding to occur at a greater distance from the pier.https://civiljournal.semnan.ac.ir/article_2466_df3c20fba1cce9412aa818da51cbbf44.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Influence of Nano-Silica and Silica Fume in the Steel Corrosion Embedded in Concrete4957263910.22075/jrce.2017.1254.1126ENHosseinBakhshiDepartment of Engineering, Hakim Sabzevari University, Sabzevar, IranRezaAhmadiDepartment of Engineering, Hakim Sabzevari University, Sabzevar, IranJournal Article20160309Corrosion of steel is one of the essential potential dangers and threats in concrete structures. Corrosion of steel embedded in reinforced concrete plays a key role in reducing the strength and durability of reinforced concrete. Several studies have proposed that alternative approaches to enhancing the performance of reinforced concrete and its resistance to corrosion. In this article, the results of steel corrosion embedded in reinforced concrete with silica fume and Nano-silica particles are presented. In the testing phase, samples with a mixture of these particles ranging from 0 to 133 grams were generated, and their performance was compared applying Corrosion Potential (OCP), Electrochemical Impedance Spectroscopy (EIS), Linear Polarization (LPR), and TOEFL polarization tests. The results demonstrate that silica fume is effective in reducing the permeability of the concrete against malicious (adverse) ions, but nano-silica had far satisfying performance in reducing the corrosion rate of steel embedded in concrete.https://civiljournal.semnan.ac.ir/article_2639_f4896fb5113190e9dd2c71dcec0e5103.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Effects of Ground Motion Directionality on the Seismic Behavior of Mid-rise Concrete Buildings with Considering Unequal Live-Load Distribution in Height5869263710.22075/jrce.2017.11679.1198ENHamidrezaNooriM.Sc. of Earthquake Engineering, Department of Civil Engineering, Faculty of Engineering & Technology, Imam Khomeini International University, Qazvin, IranMohammad MahdiMemarpourAssistant Professor, Department of Civil Engineering, Faculty of Engineering & Technology, Imam Khomeini International University, Qazvin, IranJournal Article20170618The incident angle of ground motion is one of the sources of uncertainty in the seismic response of buildings. Moreover, understanding the structural response to the impose ground motion may cause significant changes in the maximum response of buildings. In order to investigate the influence of the spatial distribution of orthogonal components of earthquake strong motion on the structural responses, three 15-story buildings were analyzed in this study using the time-history method. A significant live load (750 kg/m<sup>2</sup>) is imposed at different vertical levels of the structures. The imposed load was combined with ground motion excitations in the range of 0 to 90 degrees. The response of structure was investigated using roof drift index and inter-story drift ratio. Results demonstrate the orientation of seismic excitation and considering the maximum values of roof drift index, which correspond to the critical direction increase roof drift index between 8 to 12 percent. Furthermore, the inter-story drift ratio increased between 30 to 33 percent due to the orientation of excitation and considering the maximum values of the inter-story drift ratio, which correspond to the critical direction.https://civiljournal.semnan.ac.ir/article_2637_011dd78c9cdcc50f5208b4a21b392bf8.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Hybrid Improved Dolphin Echolocation and Ant Colony Optimization for Optimal Discrete Sizing of Truss Structures7087264210.22075/jrce.2017.11367.1186ENMohammadArjmandDepartment of Civil Engineering, Bozorgmehr University of Qaenat, Qaen, IranMojtabaSheikhi AzqandiDepartment of Mechanical Engineering, Bozorgmehr University of Qaenat, Qaen, IranMahdiDelavarDepartment of Civil Engineering, Birjand University, Birjand, IranJournal Article20170517This paper presents a robust hybrid improved dolphin echolocation and ant colony optimization algorithm (IDEACO) for optimizing the truss structures with discrete sizing variables. The dolphin echolocation (DE) is inspired by the navigation and hunting behavior of dolphins. An improved version of dolphin echolocation (IDE), as the main engine, is proposed and uses the positive attributes of ant colony optimization (ACO) to increase the efficiency of the IDE. Here, ACO is employed to improve the precision of the global optimization solution. In the proposed hybrid optimization method, the balance between exploration and exploitation process was the main factor to control the performance of the algorithm. IDEACO algorithm performance is tested on several problems of benchmarks discrete truss structure optimization. The results indicate the excellent performance of the proposed algorithm in optimum design and rate of convergence in comparison with other metaheuristic optimization methods, so IDEACO offers a good degree of competitiveness against other existing metaheuristic methods.https://civiljournal.semnan.ac.ir/article_2642_0ae86de513fcf611c41d7693cd255a9d.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201An Artificial Neural Network Model for Estimating the Shear Contribution of RC Beams Strengthened by Externally Bonded FRP88103350910.22075/jrce.2018.376.1072ENEhsanMoradiM.Sc. Student, Faculty of Civil Engineering, Semnan University, Semnan, IranHoseinNaderpourAssociate Professor, Faculty of Civil Engineering, Semnan University, Semnan, IranAliKheyroddinProfessor, Faculty of Civil Engineering, Semnan University, Semnan, Iran0000-0001-7802-2013Journal Article20140128This paper provides an artificial neural network model for predicting the shear contribution of FRP in reinforced concrete (RC) beams strengthened in shear with externally bonded FRP. Although there are some models and equations for estimating the contribution of FRP, these models, in some cases, have a significant error in the calculation of FRP contribution. One of the reasons for these errors is neglecting the effect of shear span (a) to the effective depth of beam (d) ratio in FRP performance. In this model, mechanical and dimensional properties of RC beams strengthened and strengthening materials, and also the shear span to the effective depth of beam ratio (a/d) are taken as input parameters, and the shear contribution of FRP is the target of the network. After a comprehensive review in existing literature, 96 strengthened RC beams which all of them have FRP rupture failure mode were selected which 92 of them were used for training, validation and testing the network and four of them were used for controlling the generalization of the network. Finally, the outputs of the model have compared with ACI 440.2R, fib 14 and CIDAR guidelines, and the result indicated that the ANN model is more accurate than the existing guideline equations based on experimental result.https://civiljournal.semnan.ac.ir/article_3509_ccc275c8033a58ff2327d0a89cf582a7.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Leak Detection in Water Collection and Transmission Networks Using the Minimum Nodal Pressure Measurement104115272710.22075/jrce.2017.12353.1212ENHamid RezaAsgariDepartment of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranMahmoud FMaghrebiCivil Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, P. O. Box 91755-1111, Mashhad, Iran.Journal Article20170829<span>Leak has always been one of the problems in water distribution networks, whose preventing not only results in the saving of water sources but also has profound effects on the maintenance cost of networks. In the present paper, a new method is applied for leak detection in water collection and transmission network. In this method, detection of leak location is performed by pressure difference analysis at junctions and by the help of the relative index of the leak. The pressure measurements should be performed at least at two nodes for two cases of with and without the presence of leak. The minimum number of pressure measurements to form a relative leak index is two. However, in this case, two nodal pressure measurements are too few, and the number of pressure measurement should be increased. Therefore the next option for the number of measurements is three. The investigated network in this research includes 7 wells with an approximate length of 7800 m located in the northwestern city of Mashhad. A real leak with a rate of 7.57 l/s is created at one of the network nodes whose amount is measurable by a volume counter. The real leak is a hypothetical leak which is known in advance, and its magnitude is not necessarily a round number in term of a liter per second. Finally, this leak is identified by the proposed method via 3 nodal pressure measurements</span><span>.</span>https://civiljournal.semnan.ac.ir/article_2727_581f8dcdfcc25b8f54573b2038f95b77.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Comparative Study on Water Permeability of Concrete Using Cylindrical Chamber Method and British Standard and Its Relation with Compressive Strength116131403310.22075/jrce.2018.13489.1247ENMahmoodNaderiCivil Engineering,Faculty of Engineering, Imam Khomeini International University, Qazvin, IranAlirezaKaboudanCivil Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, IranAminAkhavan SadighiCivil Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, IranJournal Article20171224Since the penetration of fluids (water, oil and chemicals) into concrete, plays a major role in the durability of concrete, this paper describes the effect of compressive strength of concrete on its permeability. Having revised the existing methods developed so far, the results of investigations into the permeability of different mixtures of concrete are presented. The results of the new method (cylindrical chamber method) used for the estimation of the permeability of 5 different strength grades concrete samples after different curing periods were compared with the comparative results obtained using British standard method (BS EN 12390-8:2009). These experiments tend to indicate a very good correlation between the two sets of results. Based on the test results, higher water/cement ratio and shorter curing period result in decreased compressive strength and increased permeability. The correlations between compressive strength and permeability parameters (penetration depth, average penetration flow velocity, permeability coefficient and penetration volume) are also investigated using a regression approach. It is concluded that power and second-order polynomial approximations can predict these correlations with a desirable accuracy.https://civiljournal.semnan.ac.ir/article_4033_781d43580be64e12f4673c79e0cb6ace.pdfSemnan University PressJournal of Rehabilitation in Civil Engineering2345-44156120180201Modeling of Resilient Modulus of Asphalt Concrete Containing Reclaimed Asphalt Pavement Using Feed-Forward and Generalized Regression Neural Networks132147263810.22075/jrce.2017.10876.1177ENAhmadMansourianBitumen and Asphalt Department, Road, Building and Urban development research center, Tehran, IranAli RezaGhanizadehDepartment of Civil Engineering, Sirjan University of Technology, Sirjan, IranBabakGolchinDepartment of Civil Engineering, Ahar Branch, Islamic Azad University, Ahar, IranJournal Article20170316Reclaimed asphalt pavement (RAP) is one of the waste materials that highway agencies promote to use in new construction or rehabilitation of highways pavement. Since the use of RAP can affect the resilient modulus and other structural properties of flexible pavement layers, this paper aims to employ two different artificial neural network (ANN) models for modeling and evaluating the effects of different percentages of RAP on resilient modulus of hot-mix asphalt (HMA). In this research, 216 resilient modulus tests were conducted for establishing the experimental dataset. Input variables for predicting resilient modulus were temperature, penetration grade of asphalt binder, loading frequency, change of asphalt binder content compared to optimum asphalt binder content and percentage of RAP. Results of modeling using feed-forward neural network (FFNN) and generalized regression neural network (GRNN) model were compared with the measured resilient modulus using two statistical indicators. Results showed that for FFNN model, the coefficient of determination between observed and predicted values of resilient modulus for training and testing sets were 0.993 and 0.981, respectively. These two values were 0.999 and 0.967 in case of GRNN. So, according to comparison of R2 for testing set, the accuracy of FFNN method was superior to GRNN method. Tests results and artificial neural network analysis showed that the temperature was the most effective parameter on the resilient modulus of HMA containing RAP materials. In addition by increasing RAP content, the resilient modulus of HMA increased.https://civiljournal.semnan.ac.ir/article_2638_bd9ea11a6f0954519f4f781901f7ae8b.pdf