Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Long-term flexural behavior of reinforced baked clay beams
877
883
EN
N.A.
Lakho
Department of Civil Engineering, Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah, Sindh, Pakistan.
M.
Auchar Zardari
Department of Civil Engineering, Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah, Sindh, Pakistan.
10.24200/sci.2017.4072
Clay is a low cost and environment-friendly material for construction. On firing, it gets hard and attains compressive strength as high as normal concrete. This paper presents the flexural behaviour of singly reinforced baked clay beams under longterm sustained loads. The loads applied at midspan of these beams were 30%, 40%, and 50% of their short-term failure load for a period of 360 days. The results show that the<br />rate of defection, formation of cracks, and their stabilization was completed in a certain period of time depending on the intensity of the long-term sustained loads. In the first and second loading conditions, this period of opening and stabilization of cracks was 100 and 77 days, respectively. Then, the defection increased with a decreasing rate. While in the case of 50% of loading condition, the period of formation and stabilization of cracks was reduced to only 50 days, and then these cracks became dormant and no new crack was developed with respect to time. After that, negligible midspan defection was observed with time. In addition to this, the defection in these beams was more compared to the estimated long-term defection according to ACI code.
Baked clay beams,Sustained loads,Ultimate loading capacity,Defection,Cracks
http://scientiairanica.sharif.edu/article_4072.html
http://scientiairanica.sharif.edu/article_4072_6606520a83469ebbfff03d67f95e7276.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Effect of record scaling on the behavior of reinforced concrete core-wall buildings subjected to near-fault and far-fault earthquakes
884
899
EN
H.
Beiraghi
Department of Civil Engineering, Mahdishahr Branch, Islamic Azad University, Mahdishahr, Iran
A.
Kheyroddin
Faculty of Civil Engineering, Semnan University, Semnan, Iran.
M.A.
Kafi
Faculty of Civil Engineering, Semnan University, Semnan, Iran
10.24200/sci.2017.4073
In this paper, two distinct record scaling methods, Spectrum-Matching (SM) and Amplitude Scaling (AS), were used to study the seismic behavior of reinforced concrete core-wall buildings subjected to Near-Fault (NF) and Far-Fault (FF) strong ground motions. First, the core-walls were designed based on seismic codes. Next, nonlinear fiber element models of the core-walls were prepared using the extended plastic hinge and the single-plastic hinge approaches. The SM and AS methods were used to obtain appropriate records for use in nonlinear time history analysis. Amplitude scaling procedure led to larger curvature ductility demand at the upper levels of the buildings, and this issue was more critical for the near-fault ground motions. On the other hand, SM procedure led to larger curvature ductility demand at the lower levels and less curvature ductility demand at the upper levels. The reason for this difference was the changes in the ground motion characteristics due to SM procedure. The changes in the ground motion characteristic were more severe for near-fault ground motions. For NF records, mean period of the SM records was 0.67 times that of the AS records, and shows that the frequency content of the SM-NF events was affected by SM process.
Reinforced concrete,core-wall,near-fault,Far-fault,Record scaling
http://scientiairanica.sharif.edu/article_4073.html
http://scientiairanica.sharif.edu/article_4073_0b45dd3a112a23d807162c9e8a8ab05f.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
State of the art on the maximum strength of masonry infilled frames
900
909
EN
M.
Mohammadi
International Institute of Earthquake Engineering and Seismology (IIEES), No. 21, Arghavan St., Tehran, Iran.
ccvttcco@scientiaunknown.non
10.24200/sci.2017.4074
For infill panels, the expected strength is very close to the cracking strength; however, experimental values of the cracking strength are very scattered, and there is no formula to estimate it accurately. That is why some new codes have been assumed to focus on determining the expected strengths of Infill panels by their maximum strengths. In this paper, an extensive statistical analysis is conducted on experimental data to<br />achieve a formula for the maximum (mostly referred as ultimate) strength of solid masonry infilled frames. For the ultimate strength, reliability of the existing empirical relations (9 formulas) is investigated, based on the available experimental data, categorized in accordance with their conning frames. The obtained results of 51 experimental specimens show that the formula, recommended by Maintone et al., is the best one; however, it mostly underestimates the ultimate strength and is more accurate for the inlls in concrete<br />frames. The formula is also improved to have a better correlation with the experimental data.
Strength,Masonry,Infill panel,Seismic design,Ultimate strength,Equivalent strut
http://scientiairanica.sharif.edu/article_4074.html
http://scientiairanica.sharif.edu/article_4074_a6114767bedc086dc02f63f65c5412c3.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Selection and scaling of spectrum-compatible ground motion records using hybrid coded genetic algorithms
910
925
EN
S.
Yaghmaei-Sabegh
Department of Civil Engineering, University of Tabriz, Tabriz, Iran.
S.
Karami
East Azarbaijan Science & Research Branch, Islamic Azad University, Tabriz, Iran.
M.
Hosseini-Moghadam
East Azarbaijan Science & Research Branch, Islamic Azad University, Tabriz, Iran.
10.24200/sci.2017.4075
This paper presents a new searching framework for optimal scaling of earthquake ground motion records as inputs for dynamics analysis. Two hybrid-coded Genetic Algorithms (GA), named real-permutation and binary-permutation GA, are effectively used to solve an applicable optimization problem in earthquake engineering field. Methodologies are outlined to choose a set of ground motions, with a good level of t to the design spectrum, and the corresponding scales simultaneously during a hybrid-coded process. The effects of dierent parameters used in design of algorithms are investigated through sensitivity analysis to suggest a set of proper input values. Analysis showed that the sensitivity of the binary-permutation GA results to input parameters variations is less than that of real-permutation GA. The paper also concludes that binary-permutation GA is slightly more reliable than real-permutation GA; accordingly, it is recommended as a<br />suitable algorithm to select and scale spectrum-compatible ground motion records.
Ground motion scaling,Time history analysis,Design spectrum,Genetic Algorithm,Hybrid-coded genetic algorithm
http://scientiairanica.sharif.edu/article_4075.html
http://scientiairanica.sharif.edu/article_4075_2326a94a34d95ae1460d8be83235f5db.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Wind turbines design corrections for next Galicia climatic conditions
926
932
EN
J.A.
Orosa
Departamento de Energa y P. M. Escuela Tecnica Superior de N. y M. Universidade da Coruna. M. Paseo de Ronda, 51, ~
15011. A Coruna.
A. M.
Costa
Departamento de Energa y P. M. Escuela Tecnica Superior de N. y M. Universidade da Coruna. M. Paseo de Ronda, 51, ~
15011. A Coruna.
G.
Roshan
Department of Geography, Golestan University, Shahid Beheshti, Gorgan, P.O. Box 49138-15759, Iran
E.J.
Garcia-Bustelo
Departamento de Energa y P. M. Escuela Tecnica Superior de N. y M. Universidade da Coruna. M. Paseo de Ronda, 51, ~
15011. A Coruna
10.24200/sci.2017.4076
Galicia, placed in northwest of Spain, is a clear example of global wind energy development as a consequence of its climate conditions. Despite this fact, previous research works have indicated a climate change in the next years that must be considered at the time of wind turbine design, selection, and placement. In this work, information about weather conditions and power output from twenty four wind turbines was sampled in a typical year, and a statistic study was done. Based on this information, a model that relates weather to power conversion in this particular region and wind turbines model was obtained. This particular procedure lets us define the effect of climate change over wind power on Galician wind farms. Results showed a 10% power output fall during spring and summer seasons. Therefore, future studies about new technologies that work out well under those conditions, such as low wind turbines, must be done. At the same time, results can be employed for future wind turbines placement optimization. Finally, nowadays, there is no standard or procedure to consider this highly complex situation, and so the present work aims to be the initial guide.
Wind energy,Climate change,Moist air,Power,Wind farm
http://scientiairanica.sharif.edu/article_4076.html
http://scientiairanica.sharif.edu/article_4076_d3b5afd16bf705ab59ecdf302f7c02c4.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Probabilistic seismic hazard analysis using reliability methods
933
941
EN
M.
Kia
Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, P.O. Box 15875-4413, Iran
M.
Banazadeh
Department of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, P.O. Box 15875-4413, Iran
mbanazadeh@aut.ac.ir
10.24200/sci.2017.4077
By considering uncertainties in the input parameters (e.g., magnitude, location, wave path, etc.), the Probabilistic Seismic Hazard Analysis (PSHA) aims to compute annual rate of various exceeding ground motions at a site or a map of sites of all anticipated given earthquakes. Uncertainties may be originated due to inherent randomness of the phenomena or variability in the mean values of dierent models parameters, mainly due to use of nite-sample size of observations. The rst, in literature reviews, is commonly named aleatory uncertainty; the second is known as epistemic uncertainty. The total probability numerical integration, generally employed to calculate PSHA, only considers aleatory uncertainties, and variability in the models' parameters is neglected to simplify calculation. In this paper, as an alternative to the total probability numerical integration, matured and standard reliability methods tailored to eortlessly consider both types of<br />uncertainties are put forward to compute site-specic PSHA. Then, as an application study, the peak ground acceleration hazard curve for the site, at which a historical bridge is located, is developed and compared with those obtained from the total probability numerical integration.
Probabilistic seismic hazard analysis,Reliability methods,Probabilistic model,Epistemic and aleatory uncertainties,Limit-state function
http://scientiairanica.sharif.edu/article_4077.html
http://scientiairanica.sharif.edu/article_4077_2f53979d36024454e031cafbdf49080a.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Strength and elastic moduli of a concrete bridge using advanced nondestructive techniques
942
952
EN
M.A.
Hadianfard
Department of Civil and Environmental Engineering, Shiraz University of Technology, Shiraz, P.O. Box 71555313, Iran
H.
Marzouk
Department of Civil Engineering, Faculty of Engineering and Architecture, Ryerson University, Toronto, ON, Canada
C.
Shafieyanb
Department of Civil Engineering, Faculty of Engineering and Architecture, Ryerson University, Toronto, ON, Canada
10.24200/sci.2017.4078
In this research, Non-Destructive Test (NDT) wave tomography techniques are used to estimate the strength and elastic moduli and to assess the health condition of the piers of an existing concrete bridge. There are various empirical relationships to evaluate concrete characteristics based on NDT techniques. However, it is not clear which empirical relationship matches the desired concrete better. Therefore, using only one empirical model can lead to inaccurate results. In the current investigation, the mean value of several appropriate relationships is considered as the desired value. Also, the use of only one NDT technique causes some errors. In order to accurately estimate the concrete characteristics, the combination of two or more nondestructive methods is very efficient. In this research, data of Ultrasonic Pulse Velocity (UPV) and shear wave velocity<br />tests are used simultaneously. The results show that the combination of the two criteria of strength and elasticity and using an average value of several empirical models give a relatively accurate scale for assessment of the concrete condition. The results show the ability and eciency of the combination of two different NDT methods to estimate the strength, elastic moduli, and health condition of the concrete structure.
Ultrasonic Pulse Velocity,Shear wave velocity,compressive strength,dynamic modulus of elasticity,Nondestructive test,Mira-3D
http://scientiairanica.sharif.edu/article_4078.html
http://scientiairanica.sharif.edu/article_4078_49c8c93de1371f2122a6d968c5b19a35.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Arc based ant colony optimization algorithm for solving sewer network design optimization problem
953
965
EN
R.
Moeini
Department of Civil Engineering, University of Isfahan, Postal Code: 81746-73441, Isfahan, Iran
rmoeini@iust.ac.ir
10.24200/sci.2017.4079
In this paper, Arc Based Ant Colony Optimization Algorithm (ABACOA) is used to solve sewer network design optimization problem with proposing two different formulations. In both of the proposed formulations, i.e. UABAC and CABAC, the cover depths of sewer network nodes are taken as decision variables of the problem. The constrained version of ABACOA (CABAC) is also proposed in the second formulation to optimally determine the cover depths of the sewer network nodes. The constrained version of ABACOA is proposed here to satisfy slope constraint explicitly leading to reduction of search space of the problem, which is compared with that by the unconstrained arc based ACOA (UABAC). The ABACOA has two signicant advantages of efficient implementation of the exploration and exploitation features along with an easy and straightforward denition of the heuristic information for the ants over the alternative usual point based formulation. Two benchmark test examples are solved here using the proposed formulations, and the results are presented and compared with those obtained by alternative point-based formulation and other existing methods. The results show the superiority of the proposed ABACOA formulation, especially the constrained version of it,<br />to optimally solve the sewer network design optimization.
Arc based ant colony optimization algorithm,Sewer network,Exploration,Exploitation,Heuristic information,Optimal design
http://scientiairanica.sharif.edu/article_4079.html
http://scientiairanica.sharif.edu/article_4079_d486bc42109518f864fcbd1e02135b5f.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Three-dimensional axisymmetric responses of exponentially graded transversely isotropic tri-materials under interfacial loading
966
978
EN
Y.
Zafari
School of Civil Engineering, College of Engineering, University of Tehran, Tehran, P.O. Box 11155-4563, Iran
M.
Shahmohamadi
School of Civil Engineering, College of Engineering, University of Tehran, Tehran, P.O. Box 11155-4563, Iran
A.
Khojasteh
School of Engineering Science, College of Engineering, University of Tehran, Tehran, P.O. Box 11155-4563, Iran.
M.
Rahimian
School of Civil Engineering, College of Engineering, University of Tehran, Tehran, P.O. Box 11155-4563, Iran
rahimian@ut.ac.irr
10.24200/sci.2017.4080
In this paper, an analytical formulation is presented to study an exponentially graded transversely isotropic tri-material under applied axisymmetric point-load and patchload with the aid of Hankel transform and use of a potential function. The given formulation is shown to be reducible to the special cases of (1) an inhomogeneous nite layer on a rigid base; (2) exponentially graded bi-material or half-space under applied buried loads; (3) homogeneous tri-material or bi-material solid. Several numerical solutions are presented<br />to explain inhomogeneity eect on the stress transfer process in the inhomogeneous threelayered medium by means of a fast and accurate numerical method.
Functionally graded material,Exponentially graded,Transversely isotropic,Displacement potential,Tri-material,Axisymmetric green's function
http://scientiairanica.sharif.edu/article_4080.html
http://scientiairanica.sharif.edu/article_4080_26175b101812b4f22012ffeaa811784d.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Influence of foundation flexibility on the seismic response of low-to-mid-rise moment-resisting frame buildings
979
992
EN
H.
Tahghighi
Department of Civil Engineering, University of Kashan, Kashan, P.O. Box 87317-51167, Iran
M.
Rabiee
Department of Civil Engineering, University of Kashan, Kashan, P.O. Box 87317-51167, Iran
meysam_rabiee@basu.ac.ir
10.24200/sci.2017.4081
Recent studies have shown that the effects of Soil-Structure Interaction (SSI) may be detrimental to the seismic response of structure, and the neglect of SSI in analysis may lead to an un-conservative design. The objective of this study is to simulate the performance of multi-storey building-foundation systems through a Winklerbased approach. Four typical steel Moment-Resisting Frame (MRF) buildings on three soil types with shear wave velocities of less than 600 m/s subjected to actual ground motion records of varied hazard levels are modeled with and without SSI. It is observed that the performance level of models supported by <br />flexible foundation, particularly in an intense earthquake event, may alter signicantly in comparison to fixed-based structures. Moreover, for MRFs on soft soil, the nonlinear foundation is found to have a signicant<br />effect on the force and displacement demands. This indicates the necessity for consideration of <br />flexible foundation behavior in the modern design codes in order to accomplish a more economic yet safe structural design.
seismic response,Soil-structure interaction,Moment-resisting frame,Nonlinear Analysis,Design code
http://scientiairanica.sharif.edu/article_4081.html
http://scientiairanica.sharif.edu/article_4081_584b5cb4fa10a69e40eb0bc2734e50a5.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Application of trend analysis and artificial neural networks methods: The case of Sakarya River
993
999
EN
G.
Ceribasi
Sakarya University, Technology Faculty, Department of Civil Engineering, Sakarya, Turkey.
E.
Dogan
Sakarya University, Faculty of Engineering, Department of Civil Engineering, Sakarya, Turkey.
U.
Akkaya
Sakarya University, Science Institute, Department of Civil Engineering, Bolu, Turkey
U.E.
Kocamaz
Uludag University, Vocational School of Karacabey, Department of Computer Technology, Bursa, Turkey
10.24200/sci.2017.4082
Various articial intelligence techniques are used in order to make prospective estimations with available data. The most common and applied method among these artificial intelligence techniques is Artificial Neural Networks (ANN). On the other hand,another method which is used in order to make prospective estimations with available data is Trend Analysis. When the relation of these two methods is analyzed, Artificial Neural Networks method can present the prospective estimation numerically, while there is no such a case in Trend Analysis. Trend Analysis method presents result of prospective estimation as a decrease or increase in data. Therefore, it is quite important to make a comparison between these methods which brings about prospective estimation with the available data, because these two methods are used in most of these studies. In this study, annual average stream flow and suspended load measured in Sakarya River along with average annual rainfall trend were analyzed with trend analysis method. Daily, weekly, and monthly average stream <br />flows and suspended loads measured in Sakarya River and average daily, weekly, and monthly rainfall data of Sakarya were all analyzed by ANN Model. Results of trend analysis method and ANN model were compared.
Trend analysis,Artificial Neural Networks,Sakarya river,Rainfall,Stream flow,Suspended load
http://scientiairanica.sharif.edu/article_4082.html
http://scientiairanica.sharif.edu/article_4082_7efaafcf4da6866f1b089304b1c78a32.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Development of group method of data handling based on genetic algorithm to predict incipient motion in rigid rectangular storm water channel
1000
1009
EN
I.
Ebtehaj
Department of Civil Engineering, Razi University, Kermanshah, Iran.
H.
Bonakdari
Department of Civil Engineering, Razi University, Kermanshah, Iran
F.
Khoshbin
Department of Civil Engineering, Razi University, Kermanshah, Iran
Ch. Hin Joo
Bong
Department of Civil Engineering, Faculty of Engineering, University Malaysia Sarawak, Malaysia
A.
Ab Ghani
River Engineering and Urban Drainage Research Centre (REDAC), University Sains Malaysia
10.24200/sci.2017.4083
Sediment transport is a revalent vital process in fluvial and coastal environments, and incipient motion" is an issue inseparably bound to this topic. This study utilizes a novel hybrid method based on Group Method of Data Handling (GMDH) and Genetic Algorithm (GA) to design GMDH structural (GMDH-GA). Also, Singular<br />Value Decomposition (SVD) was utilized to compute the linear coecient vectors. In order to predict the densimetric Froude number (Fr), the ratio of median diameter of particle size to hydraulic radius (d=R) and the ratio of sediment deposit thickness to hydraulic radius (ts=R) are utilized as eective parameters. Using three different sources of experimental data and GMDH-GA model, a new equation is proposed to predict incipient motion. The performance of development equation is compared using GMDH-GA and traditional equations . The results indicate that the presented equation is more accurate (RMSE = 0:18 and MAPE = 6:48%) than traditional methods. Also, a sensitivity analysis is presented to study the performance of each input combination in predicting incipient motion.
genetic algorithm (GA),Group Method of Data Handling (GMDH),Rigid rectangular channel,Incipient motion,Sediment transport,Storm water
http://scientiairanica.sharif.edu/article_4083.html
http://scientiairanica.sharif.edu/article_4083_f71e5aa91c3f919a4d3add7cb056cb59.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Fundamental period of vibration for seismic design of concrete shear wall buildings
1010
1016
EN
A.
Badkoubeh
Department of Civil Engineering, Faculty of Engineering, Kharazmi University, No. 43, Dr. Mofatteh Ave., Tehran, P.O. Box
15719-14911, Iran
A.
Massumi
Department of Civil Engineering, Faculty of Engineering, Kharazmi University, No. 43, Dr. Mofatteh Ave., Tehran, P.O. Box
15719-14911, Iran
10.24200/sci.2017.4084
simple expression is proposed to estimate the fundamental period of vibration for concrete Shear Wall (SW) buildings. Most seismic codes specify empirical period formulas for seismic design. In this study, fundamental period data for concrete SW buildings recorded during California earthquakes between 1971 and 1994 were compared with the current US code formulas. It is shown that these formulas are inadequate for estimation of the fundamental period of concrete SW buildings. A closed-form period solution based on Rayleigh's method using SW displacement as a parameter is proposed to estimate the fundamental period of concrete SW buildings in low, moderate, and high seismicity regions. The accuracy of the closed-form solution is veried using recorded periods, and it conrms that the proposed expression provides reasonable estimates of the<br />lower bound of a period. The results show that the fundamental period of concrete SW buildings depends signicantly on the displacement and mechanical properties of the SW.
Fundamental period,Concrete shear wall buildings,Code periods,Closed-form solution,Lower bound period
http://scientiairanica.sharif.edu/article_4084.html
http://scientiairanica.sharif.edu/article_4084_07d54c457ee9b05c303a31fe3e91c4b0.pdf
Sharif University of Technology
Scientia Iranica
1026-3098
2345-3605
24
3
2017
06
01
Effects of petrochemical wastes incinerator ash powder instead of Portland cement on the properties of concrete
1017
1026
EN
D.
Mostonejad
partment of Civil Engineering, Isfahan University of Technology, Isfahan, Iran
S.
Noorpour
Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran
M.
Noorpour
Young Researchers and Elite Club, Tabriz Branch, Islamic Azad University, Tabriz, Iran
R.
Karbati Asl
Young Researchers and Elite Club, Tabriz Branch, Islamic Azad University, Tabriz, Iran
V.
Sadeghi Balkanlou
Young Researchers and Elite Club, Tabriz Branch, Islamic Azad University, Tabriz, Iran
A.
Karbati Asl
Department of Project Management, Payame Noor University, Iran
10.24200/sci.2017.4085
Petrochemical wastes incinerator ash is generated from industries in which the landfill is the last step for their <br />flowing. This research was performed for waste management of ash and its possible large-scale utilization in making concrete. An experimental investigation carried out to evaluate the mechanical properties of concrete mixtures in which Portland cement type II was partially replaced with Petrochemical Complex Incinerator<br />Ash Powder (PCIAP). The cement was replaced with various amounts of PCIAP, i.e. 5%, 10%, 15%, 20%, and 25%. Tests were performed on the properties of fresh concrete as well as hardened concrete. Compressive, splitting tensile and flexural strengths, and modulus of elasticity were determined in 7, 28, and 90 days. Test results indicated that by using PCIAP as partial replacement of cement, stabilization, solidication, and neutralization treatment processes for the industrial wastes management were carried out, and the test<br />results of the mixture M-2 (5% PCIAP) indicated that it can be used to make concrete which is lighter than normal concrete and heavier than structural lightweight aggregate concrete.
concrete,Incinerator ash,compressive strength,Splitting-tensile strength,Flexural strengths,Elastic modulus
http://scientiairanica.sharif.edu/article_4085.html
http://scientiairanica.sharif.edu/article_4085_53a45a7524b5534e5b47c4289c09e57c.pdf