The Effect of Capacity Uncertainty on the Seismic Hazard Demand Curve Estimation of Steel-Moment Resisting Frames
Behzad
Shokrollahi-Yancheshmeh
Malayer University, Malayer, Hamedan, Iran
author
Amin
Mohebkhah
Malayer University, Malayer, Hamedan, Iran
author
Mehdi
Mahdavi Adeli
Department of Civil Engineering, Shoushtar Branch, Islamic Azad University, Shoushtar, Iran
author
text
article
2022
per
Probabilistic seismic demand assessment of steel moment-resisting frames is associated with uncertainty. The most important factors of uncertainty include the inherent uncertainty caused by the record-to-record variability, as well as the epistemic capacity uncertainty due to the model parameters. The first uncertainty can be applied in the form of using an acceptable number of different ground motion records. Capacity uncertainty arises due to the approximate nature of the parameters used to define the structural model behavior which is based on the experimental relationships derived from laboratory results. In the present study, a 20-story steel moment-resisting frame in two cases of uncertain and base model has been investigated with and without considering the capacity uncertainty, respectively. The method of applying such uncertainty has been done by generating random variables in the defined range by Monte Carlo simulation. Based on the results of the incremental dynamic analysis performed for both base and uncertain models, the seismic hazard demand curves for the entire range of demand parameters including limit states of immediate occupancy and collapse prevention has been extracted and compared. Also, in order to evaluate the influence of the fragility and seismic hazard curves parameters on the variation of the mean annual frequency of limit state of the uncertain model, sensitivity analysis based on the above-mentioned quantities has been done. The results indicate the significant effect of capacity uncertainty on increasing the mean annual frequency at the collapse prevention limit state.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5055
5082
https://ceej.aut.ac.ir/article_4129_1de9d14cdaf627f4db261d176b370d25.pdf
dx.doi.org/10.22060/ceej.2020.18577.6903
Investigation of Effects of Different Environmental Conditions on Balance Time of Bleeding and Evaporation in Plastic Shrinkage of Concrete Pavements
hassan
ziari
school of civil engineering.IUST
author
Seyed Javad
Vaziri Kang Oleyaei
Transportation, school of civil engineering, Iran University Of science and Technology, Tehran,Iran
author
Hassan
Fazaeli
School of civil engineering, Islamic Azad University,Tehran North Branch, Tehran, Iran
author
text
article
2022
per
One of the causes of early-age cracking in concrete pavements is plastic shrinkage. This shrinkage occurs after the balance of bleeding and evaporation and the formation of negative capillary pressures at the pavement surface. Different environmental conditions cause the rate of evaporation to change, resulting in a change in time of balance and subsequent cracking. This study, using the standard ASTM C 1579 method, examined the relationship between time of balance of bleeding and evaporation and cracking area in concrete in 27 different environmental conditions, including a combination of three ambient temperatures, three wind speeds, and three relative humidities with using a continuous video recording system and digital image analysis. The results showed that there is a significant relationship between time of balance and cracking area. By reducing the time of balance to 69 minutes, the cracking area increased more than four times. It has been shown that the combination of all three environmental factors has a more significant effect on the severity of cracking than the criticality of only one factor. Relative humidity also has the most excellent effect on the time of balance and cracking area, and the effect of ambient temperature and wind speed is close to each other. According to the results, it was stated that the time of balance might be used as a good factor to investigate the effect of different environmental conditions on the severity of plastic shrinkage cracking in concrete pavements.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5083
5102
https://ceej.aut.ac.ir/article_4067_75c7326fdc4bc6af7b85320a65612876.pdf
dx.doi.org/10.22060/ceej.2020.18686.6927
A Study on Soil-Structure Interaction on Seismic Response of Coupled Steel Plate Shear Wall subjected to Near and Far-Field Earthquakes
ehsan
yourtchi
MSc Student in structure Engineering, Faculty of Civil Engineering of Semnan University, Semnan, Iran.
author
Majid
Gholhaki
Associate Professor, Faculty of Civil Engineering of Semnan University, Semnan, Iran.
author
omid
rezayfar
Associate Professor, Faculty of Civil Engineering of Semnan University, Semnan, Iran.
author
text
article
2022
per
Coupled steel plate shear wall (C-SPSW) is a relatively new system that has received less attention from research centers. This system benefits from high ductility and stiffness, which are the two advantages that make this system superior to the other lateral load-resisting systems. This paper aims to study the seismic response of the CSPSWs under near and far-field earthquakes, resting on soil types II and IV considering soil-structure interaction (SSI) effects using the 5, 10 and 15-storey frames in which the length of link beams and frame bays is equal to 1.25, 2.5 and 3.75 as well as 2.4, 3.2 and 4.8m, respectively. Based on the analysis results, maximum roof displacement of the 5, 10 and 20-storey frames located on stiff soils (soil type II), does not experience remarkable changes under near and far-field earthquakes but, to the contrary, in the case of soil type IV, changes are considerable. Roof acceleration of the structure located on stiff soil, is less than that of the structure on soft soil. In this paper, the ratio of base shear to the effective weight of the structure was taken into account and it was found that incorporation of SSI effects influences the base shear. Moreover, regarding behavioral modes of the coupling beam and coupling degree of the SPSW, the results indicated that this degree has a meaningful correlation with the fundamental period of the structure and the short coupling beams that yield in shear, have a better performance.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5103
5138
https://ceej.aut.ac.ir/article_4142_7743db27fe3d061be55577731f7fb212.pdf
dx.doi.org/10.22060/ceej.2020.18696.6930
Experimental static data based Embedded Crack Identification of beam-column structures under axial load
MIRSAYYAD
HASHEMI
M.Sc., Department of Civil Engineering, Faculty of Engineering, Imam Khomeini International University, Qazvin, Iran,
author
RAMEZAN ALI
IZADIFARD
Civil Eng. Dep., Engineering Faculty, Imam Khomeini Int. Un., Qazvin, Iran
author
text
article
2022
per
Identification of damage to structures in order to prevent their expansion or improvement is an important issue that has received much attention from researchers. In this experimental study, a triangular model was used to apply the embedded cracks using CNC on the laboratory beam-columns. The size of the elements is such that the effective length of the crack is located inside the element and from it has not been removed. To identify embedded cracks, a static data index was used for Euler-Bernoulli beam-columns under axial load. In this laboratory study, two simple beams models with single, multiple damages and different loading scenarios were used. In the first step, the laboratory horizontal displacements are recorded and then included in the index. Finally, a comparison of the laboratory and the numerical results have shown the performance accuracy of the static database index.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5139
5154
https://ceej.aut.ac.ir/article_4242_437d67a4325008180dbe18d6fa435f6e.pdf
dx.doi.org/10.22060/ceej.2021.18662.6935
Numerical Study of using Diaphragm Wall to Mitigate Mechanized Tunneling Induced Settlements
Mojtaba
Shirzehhagh
Tarbiat Modares University, Tehran, Iran
author
Mohammad
Oliaei
Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran.
author
text
article
2022
per
Tunneling-induced displacements could be dangerous for surface structures and urban infrastructure, if not controlled. Accordingly, different techniques are carried out to mitigate tunneling-induced displacements. In this regard, using a diaphragm wall is a practical technique. In this study, the effect of using a diaphragm wall for mitigating the Madrid metro tunneling-induced displacements was investigated. Despite mechanized tunneling of the Madrid metro extension, there is considerable settlement due to a thick layer of made soil ground. In this regard, TBM-EPB tunneling of the Madrid metro tunnel has been modeled step by step and three-dimensional in the finite element code of ABAQUS. The main construction aspects of a TBM are modeled, such as the face pressure, the injection of grout behind the segments, the overcut produced by the gap between the diameters of the cutter-head and the shield. The diaphragm wall is also modeled three-dimensional. For the parametric study, the elastic modulus of the wall, length of the wall, friction between the wall and soil, the distance of the wall from the tunnel axis and density of the wall are assumed to be variable. The results show the elastic modulus of the wall and the distance of the wall from the tunnel axis are the most effective parameters in mitigating the tunneling induced surface settlements and horizontal displacements. In the distance of 0.7D between the wall and tunnel axis, a wall of 0.5D or C+1D length could be the optimum option to mitigate the settlements.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5155
5174
https://ceej.aut.ac.ir/article_4254_252bf149d9ceadf34f1b9f8e76a5677e.pdf
dx.doi.org/10.22060/ceej.2021.18674.6936
Usage of Particle Filter for Exact Estimation of Constant Head Boundaries in Unconfined Aquifer
Ali
Mohtashami
Department of civil engineering
author
Seyed Arman
Hashemi Monfared
Associate Professor of Civil Engineering Department, University of Sistan and Baluchestan
author
G.
Azizyan
Associate Professor in Hydraulic Structure, University of Sistan and Baluchestan
Zahedan, Iran
author
Abolfazl
Akbarpour
Faculty of Engineering, University of Birjand
author
text
article
2022
per
Having the exact values of boundary conditions is one of the effective ways to develop precise groundwater models. In the present study, the exact value of constant head boundaries in the Birjand aquifer is specified using particle filter linked to meshless groundwater model. Particle filter, known as one of the common data assimilation methods, applies to dynamic systems in order to improve performance. Meshless model, one of the numerical models that do not mesh the problem domain, enforces the governed equation to the nodes. Birjand aquifer, with an almost 269 km2 area, has 190 extraction and 10 observation wells. There are also nine inflow and one outflow regions with constant head boundary conditions, including 105 boundary nodes. In this research, after determining the lower and upper bounds of groundwater head for each node, the exact values of this parameter are computed. Finally, the simulated groundwater head was compared with observation data. The closeness of the achieved results to the observation data showed the performance of the engaged method, as the results indicated a significant decrease in RMSE occurs just with the usage of particle filter linked to the meshless model. RMSE value reduced to 0.386 m as its previous value was around 0.757 m. Results also showed that the model was more accurate when the number of particles in the particle filter was increased. The RMSE value for 500, 700 and 1000 particles were 0.484, 0.401 and 0.386m respectively.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5175
5194
https://ceej.aut.ac.ir/article_4203_1adef58b491ce8eca79e048b743ff328.pdf
dx.doi.org/10.22060/ceej.2020.18708.6937
Experimental and Analytical Study of connected and non-connected piled raft foundations
Mohammad Jamal
Malekkhani
Civil Engineering Department, Ferdowsi University of Mashhad, Mashhad, Iran
author
جعفر
بلوری بزاز
دانشگاه فردوسی مشهد دانشکده مهندسی گروه مهندسی عمران
author
text
article
2022
per
In the piled raft foundation, in contrast to the pile group, both raft and piles transfer the imposed load to the foundation soil. The concentration of shear stresses and bending moments at the connection point of the pile and raft in the piled raft may cause a structural collapse in the pile while the geotechnical bearing capacity of the pile has not fully mobilized. This problem may be solved by disconnecting the piles from raft and inserting a soil layer between the piles and the raft. This layer in non-connected piled rafts is called cushion. In a non-connected piled raft, the cushion plays an important role to mobilize the bearing capacity of the foundation soil, adjusting the load transfer mechanism, and changing the system stiffness. The behavior of a connected and non-connected piled raft is too complicated to easily estimate the load sharing ratio and stiffness for the preliminary design. In the present research, based on the test results of the pile group and the unpiled raft, an analytical approach is introduced to calculate the load sharing ratio and the stiffness of the connected and non-connected piled rafts. To verify the proposed analytical model accuracy, 21 small scale tests on the unpiled raft, pile group, connected and non-connected piled rafts were conducted. According to the results increasing the number and length of piles, increases the bearing capacity. In a non-connected piled raft, increasing the cushion thickness decreases the load sharing ratio of piles, stiffness, and bearing capacity of the system.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5195
5218
https://ceej.aut.ac.ir/article_4262_2c66780b9422d8a19f8716c626528f90.pdf
dx.doi.org/10.22060/ceej.2021.18726.6942
Numerical Modeling of Phosphorus Advection and Diffusion in Water Bodies (Case study: Sefidrood River)
Shervin
Faghihirad
Hydro- Environment Department ,Water Research Institute - Ministry of Energy, Tehran, Iran
author
Mahsa
Khodayary
MSc., Facaulty of Engineering, Imam Khomeini International University, Qazvin, Iran
author
Fouad
Kilanehei
Assistant Professor, Civil Engineering Department, Faculty of Engineering, Imam Khomeini International University
author
text
article
2022
per
Phosphorus is one of the vital nutrients for plants and algae growth. The low solubility of phosphorus compared to other nutrients has caused phosphorus to play a key role in algae growth and its often limiting nutrient in most freshwater. So that excessive phosphorus level in water can produce more algae that cannot be consumed by water body creatures and can cause eutrophication, water quality reduction and harmful condition for the aquatic ecosystem. Therefore, it is important to identify the main sources of entering into rivers, recognizing the mechanism of transport and its distribution as well as the conditions created in rivers due to the advection and diffusion of phosphorus. For this purpose, in this research, after identifying the main sources of phosphorus entry into the river, it investigates and simulates the advection and dispersion of phosphorus in the Qezel-Ozan, Shahrood and Sefidrood Rivers based on field measuring data and using HEC-RAS software. Five scenarios were designed based on statistics and engineering studies to predict the phosphorus concentration of rivers due to rising temperatures, changes in river discharge due to drought and wet season, human population growth and development of irrigation networks in the region for the future. Then, by numerical simulating using HEC-RAS software, the impacts of phosphorus dispersion have been investigated in the region research area. The result presented that controlling human activities that entering phosphorus to Qezel-Ozan and Shahrood rivers can reduce total phosphorus concentration of Sefidrood river, but the mass of algae has been increased only by increasing air temperature and discharge of rivers and decreasing by reduced river discharge. Besides, the results showed that the maximum total phosphorus concentration of Sefidrood River (downstream river) predicted by the numerical simulation related to the developed scenarios was higher than the maximum desired total phosphorus concentration for warm and cold-water fish. For this reason, paying more attention to limit entering phosphorus sources have to be considered for development program in the upstream rivers (Shahroood and Qezel-Ozan) in the region.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5219
5238
https://ceej.aut.ac.ir/article_4219_a91080952c926000cc2c3ad3b95e1e71.pdf
dx.doi.org/10.22060/ceej.2020.18745.6947
Social Impacts Assessment of Water Demand Management Policies on Wastewater System by Using SLCA Method
Haniye
Safarpour
M.Sc. student, School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran.
author
Massoud
Tabesh
Professor, Center of Excellence for Management and Engineering of Civil Infrastructure School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran.
author
Seyyed Ahmadreza
Shahangian
Ph.D. Candidate, School of Civil Engineering, College of Engineering, University of Tehran
author
text
article
2022
per
Urban water demand management policies (UWDMPs) are being proposed as a solution to deal with water scarcity. Applying any UWDMPs can lead to positive/ negative impacts on several aspects, including the urban infrastructure (e.g., water distribution networks or wastewater systems). Besides, studies on the effects of these policies on urban infrastructures have often focused on the water sector, and there is scant evidence in the wastewater section. Hence, in the current study, the impacts of the implementation of UWDMPs on sewage systems (consisting of the wastewater collection system and the wastewater treatment plant) from a social viewpoint have been evaluated during different scenarios of demand reduction. For this purpose, the Social Life Cycle Assessment (SLCA) method, as a subset of life cycle thinking, has been applied. In this regard, Baharestan city (located in Isfahan province) is selected. The groups (stakeholders) related to wastewater systems that are affected by the social impacts of UWDMPs have been identified and their characteristics have been determined. Stakeholders contain the social and local community, workers, and consumers (stakeholders that use wastewater or its other products for a specific activity). Then, by compiling a questionnaire and using the experts' opinions, the Analytic Hierarchy Process (AHP) method has been used in order to evaluate scenarios. In this procedure, (1) indicators are scored by the survey from experts, (2) the intensity of the effects of indicators in each scenario is specified, and (3) the social score of all scenarios is obtained. The results showed that social and local community had the biggest weight among stakeholders (weight of 0.45), and safe and healthy living condition was the most important indicator for this stakeholder. Moreover, the scenario that had the least decline in water consumption and sewage production was socially better than the others.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5239
5258
https://ceej.aut.ac.ir/article_4218_39a29af13222c57fd973d9d9c3c049e4.pdf
dx.doi.org/10.22060/ceej.2020.18756.6952
Experimental Study on Finding Reliable Connectors for Infill-frame Connection in Infilled Steel Frame
Saheb Ali
Asadzadeh
PhD candidate, Department of Civil Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran; ORCID: 0000-0002-9730-1090
author
Alireza
Zareei
PhD, Department of Civil Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
author
Majid
Mohammadi
PhD, Structural Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES)
author
Nader
Khaje ahmad atari
PhD, Department of Structural Engineering, Road, Housing & Urban Development Research Center, Tehran, Iran
author
text
article
2022
per
During earthquakes, infill walls are imposed to in-plane (IP) and out-of-plane (OOP) seismic loads. After some in-plane seismic vibrations, the worst case for out-of-plane stability of the infill appears when there is the least integrity in the frame-to-wall connections. Using some kind of reliable connectors for frame-to-wall connection is an innovative method to improve their IP and OOP seismic behavior. Noting that the literature on infilled frames has not focused on this subject yet, the present research was carried out with the purpose of introducing a kind of reliable and efficient frame-to-wall connector and to study its effects on IP and OOP behavior of the infilled frames and the infills. Four half-scale single-story single-bay specimens, including one bare frame, an infill wall and two infilled steel frames having walls of autoclave-cured aerated concrete (AAC) blocks, were tested under IP and OOP cyclic displacement controlled loading. The specimens were tested to investigate their failure modes, strength, stiffness degradation, damage evolution in frame and infill, cracking patterns of infill, energy dissipation capacity and out-of-plane displacement of infills. The experimental results revealed that the V-type connectors showed good and reliable interaction as far as the safety issues were concerned. Therefore, such types of fasteners can be used as kinds of promising reliable frame-to-wall connectors for AAC infill panels.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5259
5280
https://ceej.aut.ac.ir/article_4255_e4ac38ce30943ca84393bf82f520536c.pdf
dx.doi.org/10.22060/ceej.2021.18761.6953
An investigation of meso-scale crack propagation process in concrete beams using topology optimization
ali
permanoon
Razi University
author
Amir Hoshang
Akhaveissy
Department of Civil Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran
author
text
article
2022
per
The current research seeks to investigate a novel method for reducing the computational costs of concrete modeling in the meso-scale. Two separate scales, macro and meso, were used to evaluate concrete behavior. As the stress distribution at the macro scale can be a good indicator to determine the crack critical zones (onset and growth of crack), the numerical model is analyzed at the macro scale using the extended finite element method (XFEM), and then, critical zones are specified in each step using macro-optimization. Afterward, the sum of the zones is modeled in the main model at the meso-scale. At the meso-scale, the three parts of aggregate are modeled with linear behavior, and cement mortar and transfer zone with nonlinear behavior. Aggregates are distributed in cement mortar by a random algorithm and Fuller curve in a circular shape. For meso-scale discretization, the piecemeal discretization method was used, considering the adhesive zone for all elements. Using this method, crack onset and growth are properly modeled. To validate this method, two numerical examples were examined in 2D. The numerical analysis results were in perfect agreement with the laboratory results, and the volume of the calculations was reduced by an average of 35% while maintaining accuracy.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5281
5306
https://ceej.aut.ac.ir/article_4289_f24f0a76390ef1a91358bd17deecf882.pdf
dx.doi.org/10.22060/ceej.2021.18771.6958
Subspace based identification of structural parameters of the base isolation level
Kaveh
Karami
Assistant Professor of Structural Engineering.
Department of Civil Engineering, University of Kurdistan
author
Pejman
Fatehi
Department of Civil Engineering, University of Kurdistan, Sanandaj, Iran
author
Asra
Hoseini
Department of Civil Engineering, University of Kurdistan
author
text
article
2022
per
One of the common methods in controlling the seismic response of structures is the use of seismic isolators. Base isolations reduce the base shear as well as the relative displacement of the floors by increasing the period of the structure. Typically, extreme deformation of the base isolation level occurs due to severe environmental factors, which can lead to damage to the base isolations; As a result, there is a possibility of permanent deformation in the base isolation and also the collision of the structure with adjacent buildings. Therefore, to prevent damage to buildings equipped with base isolations due to severe ground motions, it is important to identify damage at the base isolations. In this study, assuming the linear behavior of the main structure, a proposed subspace-based method for identifying the stiffness of the base isolation with a limited number of sensors is presented. For this purpose, using the compression technique, the structure equipped with a separator with a large number of degrees of freedom (DOFs) is transformed into a two DOF structure; So that the stiffness associated with the first DOF in the reduced system corresponds to the stiffness of the Base isolation level in the original structure. Then, using the identified Markov parameters of the system, the reduced structural stiffness is identified. Numerical examples are used to evaluate and compare the performance of the proposed method. The results show that even in the presence of noises in the measured responses, the proposed method detects the amount of damage at the base isolation level with acceptable accuracy.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5307
5324
https://ceej.aut.ac.ir/article_4127_8048c4bb83900a7b205ff5edc1d00ef3.pdf
dx.doi.org/10.22060/ceej.2020.18784.6961
Numerical Solution of Steady Incompressible Turbulent Navier–Stokes Equations using Multiquadric Radial Basis Function (MQ-RBF) Method
Mohammad Hossein
Mirabi
University of Qom
author
Ehsan
Jabbari
University of Qom
author
Taher
Rajaee
University of Qom
author
text
article
2022
per
The inconveniences of introducing and modifying the mesh grids in mesh-based numerical methods lead the researchers to meshfree methods, among which the RBF methods are probably the most interesting and powerful ones. In this research, the numerical solution of the steady-state incompressible continuity and Navier–Stokes equations, and the standard k-Ɛ turbulence model was investigated in a 2D domain. The computational domain consisting of a 0.5 m×0.5 m square lid-driven cavity was analyzed for five Reynolds numbers of 2.5×105, 5×105, 10×105, 2×106, and 5.5×106. The Multiquadric Radial Basis Function (MQ-RBF), as the most successful RBF, was employed with 36 and 121 domain computational nodes to solve the PDEs. The velocity fields in two directions, the static pressure, the turbulent kinetic energy and the turbulent energy dissipation, were computed. A try–and–error algorithm was used for solving a set of non-linear equations, and the optimal values of the shape parameter c and the λ set coefficients were evaluated and discussed for each flow field. According to the results, assuming the independence of the values of the shape parameter c for each flow field at different Reynolds numbers, a predictable pattern can be obtained for the λ set for different Reynolds’ numbers in the studied range. These patterns with the predictor functions of the flow fields were compared to existing benchmark results of the finite volume method (ANSYS Fluent). The Nash-Sutcliffe coefficients of 93-99% and RRSME of about %1 obtained from this comparison indicated the reasonable accuracy of the assumption concerning the independence of the shape parameter c of the Reynolds’ numbers, the repeatable patterns of the normalized λ set, and polynomial predictor functions in the MQRBF method for each flow field.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5225
5356
https://ceej.aut.ac.ir/article_4326_191834802419a9104d1d11c1d6601aee.pdf
dx.doi.org/10.22060/ceej.2021.18788.6964
Effect of different adsorbents in shear resistance of lead heavy metal contaminated soil
mohmmad
hossein zade
Civil Engineering Department, Imam Khomeini International University, Iran.
author
Mahmuod
Hassanlou Rad
Civil Engineering department, Imam Khomeini International University, Iran.
author
Seyed abolhasan
Naeini
Department of geotechnical engineering, Engineering faculty, Imam khomeini international university, Qazvin, Iran
author
text
article
2022
per
In the past few decades, the expansion of industrial areas and increasing the effluents has led to an increase in the contamination of heavy metals in soil and groundwater resources. Adsorption is one of the most important processes that affecting in the leakage of contamination. In this study, with triaxial tests, the behavior of mixed sandy clay (base composition) with 10% of different low plasticity (kaolinite and zeolite) and high plasticity (bentonite) adsorbents is studied in both contaminated and uncontaminated states. As the type of adsorbent mineral changed, the resistance parameters of contaminated soil show different trend. Increasing the concentration of lead in the soil with bentonite adsorbent, has led to form the flocculation structure and it causes shear strength and internal friction angle to increase about 18% than the uncontaminated state. Also, cohesion in compositions with low and high adsorbent increases and decreases by about 30% and 19%, respectively.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5357
5376
https://ceej.aut.ac.ir/article_4207_7ecbb86afa4138e4fbd859fb515d33da.pdf
dx.doi.org/10.22060/ceej.2020.18801.6965
Investigation of Vulnerability of Concrete Filled Steel Column Connections under Different Blast Scenarios
Amir
Aliakbary
Ph.D Student, Zanjan Islamic Azad Univrsity
author
seyedamirhossein
Hashemi
Department of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
author
Yahya
Nasira
Assistant professor, Zanjan Islamic Azad univeristy
author
Masoud
Ziaei
Assistant Professor, Garmsar University
author
text
article
2022
per
Considering the increasing hostile and terroristic threats in the country, it is important to consider the passive defence criteria in structures. The desirable properties of steel and concrete can be used simultaneously to increase the strength of structural members. Concrete-filled steel tube columns (CFSTs) have been proposed as an efficient system in previous years. The main problem with using this type of column is how to connect the beam to such a column and extensive research has been done for seismic load scenarios. Despite the excellent resistance of these types of columns to the blast load, no comprehensive investigation has yet been conducted on the performance of beam-to-column joints under blast load. In this paper, the behavior of three types of beam-to-column connections under 5 blast scenarios is investigated. ABAQUS software was used to conduct the research. Verification was first performed using the results of an experimental study and a good agreement was observed. The behavior of beam-to-column blast-loaded connections was investigated using 16 different models using explicit nonlinear dynamic analysis. The results were compared in terms of stress, strain and damage contour as well as force, energy absorption, displacement, rotation and torsion diagrams. It was observed that the optimal connection where the connection was carried out as an extension of the beam inside the column, all parts of the column contributed to the load carrying and energy absorption and very good behavior was observed. In this case, the plastic joint in the beam is formed away from the column face.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5377
5406
https://ceej.aut.ac.ir/article_4275_8c98f3a91a0d6fab478df613d1e84bff.pdf
dx.doi.org/10.22060/ceej.2021.18821.6971
The Probabilistic Analysis of Steel Moment-Resisting Frame Structures Performance under Vehicles Impact
Abbasali
Sadeghi
Department of Civil Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran
author
Hamid
Kazemi
Department of Civil Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran
author
Maysam
Samadi
Department of Civil Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran
author
text
article
2022
per
Over the recent decades, with spreading unusual events such as fire, blast, and vehicles collision, studying the behavior of structures subjected to abnormal loadings has been attracted the attention of researchers and structural engineers. Among the various scenarios of impact loads, the collision of light and heavy vehicles to the external column of steel buildings accidentally and or intentionally is important as a research and an applied topic. The impact loads caused by vehicle collisions to the column of buildings are usually not considered in the design, so it's necessary that the effect of these loads should be studied on the nonlinear performance of structures. In this study, the steel moment-resisting frame structures 2, 5, 8 and 12-story with intermediate ductility are designed for gravity and seismic loads and then nonlinear dynamic analyses are conducted under the impact induced by Light and heavy vehicles collision to corner column of side axis by OpenSees software and fragility curves are proposed based on the different damage levels. Finally, structural responses of studied frames are investigated and compared due to the collision impact with different velocities until the occurrence of dynamic instability. The results showed that the impact induced by light vehicle collision at velocities 80, 100, 140 and 130 km/h and impact induced by the heavy vehicle at velocities 50, 60, 80 and 70 km/h has been caused dynamic instability in the desired frames 2, 5, 8 and 12-story, respectively.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5407
5440
https://ceej.aut.ac.ir/article_4220_97dba762b70e9ec1daaaf098399e464f.pdf
dx.doi.org/10.22060/ceej.2020.18828.6975
Experimental investigation of cyclic behavior of zeolite cemented sand
Meysam
Saadati
PhD student, Islamic Azad University Science and Research branch Tehran, IRAN, ISLAMIC REPUBLIC OF
author
Mehdi
Derakhshandi
Assistant, Professor, Department of Civil Engineering, Science and Research Branch, Islamic Azad University
author
Amin
Bahmanpour
Assistant Professor of Department of Civil Engineering, Islamic Azad University Science and Research branch Tehran, IRAN, ISLAMIC REPUBLIC OF
author
Navid
Ganjian
Assistant Professor of Science and Research branch of Azad University
author
text
article
2022
per
The shear module is of the most crucial soil dynamic properties in seismic geotechnical engineering. The replacement of a part of cement, the production of which is one of the most important sources of CO2 emission in the world, with natural materials such as zeolite is of great importance. In the present study, the cyclic behaviour of pure sand is compared with the cyclic behaviour of sand grouted with cement and zeolite. The sand used in this research was taken from Babolsar, which is classified as a poorly graded sand based on the Unified soil classification system. The effects of the confining pressure, the shear strain and the replacement of cement by zeolite on the shear modulus are studied. All the specimens were prepared by the wet tamping method and cyclic triaxial tests were performed with three different confining pressures of 100, 200, and 300 kPa in the moderate shear strain range. The results show that Shear modulus values of the cemented sand specimens with a water-to-cement ratio of 1 are greater than that of the pure sand specimens in all ranges of shear strains. The shear modulus values increased with the replacement of cement by zeolite of cemented samples. Therefore, the replacement of cement with zeolite can be considered from an environmental point of view. By increasing the confining pressure, the shear modulus values of the pure sand, cemented sand, zeolite cemented sand specimens increased. This increase is significant for cemented and cemented zeolite specimens at a larger confining pressure range.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5441
5456
https://ceej.aut.ac.ir/article_4279_e9fcbbfa69dba4b0f6f28897cca5bc37.pdf
dx.doi.org/10.22060/ceej.2021.18843.6978
Seismic Assessment of Three Generations of Isfahan Bridges Using Fragility Curves
Saeed
Pourebrahim Abadi
Department of Mechanical, Civil and Architecture Engineering, Khomeinishar Azad University
author
seyed behzad
talaeetaba
Department of Mechanical, Civil and Architecture Engineering, Khomeinishar Azad University, Isfahan, Iran
author
text
article
2022
per
Highway Bridges are a major part of the transportation network and an important part of a country's national economy. Despite numerous studies on their seismicity and fragility, very little research has comprehensively addressed all of their dimensions. In this regard, the purpose of this study is to consider the unique details of the design period of these bridges in Isfahan City. To do so, the bridges of the last 50 years in Isfahan were examined through fragility curves. Considering uncertainties and changes in loading in this study is one of the most important surveys conducted through the non-linear history-time analysis method. The 1971 San Fernando and 1989 Loma Prieta earthquakes revolutionized the philosophy of bridge design. Therefore, the study of the three bridges that were designed and built in the three periods before the San Fernando earthquake, after that and after the Loma Prieta earthquake has been done. The results of this study showed that due to the significant improvements in different seismic codes, the possibility of damage to bridges at different times, under the influence of different earthquake intensities is likely. Also, according to the results of this study, column failure is not the sole criterion of bridge failure and the involvement of different components of a bridge in the probabilistic seismic evaluation of that bridge will lead to greater fragility. Therefore, in order to evaluate the probabilistic seismicity properly, in addition to the column, the involvement of all bridge members must be considered.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5457
5482
https://ceej.aut.ac.ir/article_4243_984c88cbfddf14ded2098e99bfd19127.pdf
dx.doi.org/10.22060/ceej.2021.18847.6980
Ranking Iranian provinces in terms of the environmental performance of industries with a developed decision-making approach
rahim
Dabbagh
Urmia University of Technology
author
saber
agapoor
Master of Industrial Engineering, Urmia University of Technology, Urmia, Iran.
author
Ashkan
nokhodchi
Master, Faculty of Civil Engineering, Khajeh Nasir al-Din al-Tusi University, Tehran, Iran
author
text
article
2022
per
Nowadays, environmental management with the aim of preserving the environment has become a crucial matter to industries. Rising global concerns about the negative effects of industrial activities have led to a variety of changes in governments' policies and strategies to improve environmental performance. Hence, studying the environmental performance of industries is an important task. This study evaluates and ranks the Iranian provinces in terms of environmental performance of industries, in various dimensions. This research defines a multidimensional set of environmentally friendly manufacturing criteria by examining the various aspects of industrial activities impacts on the environment and also with the assistance of experts’ guidance for evaluating the industries at the provincial level. Then, we use a combined approach based on decision-making trial and evaluation laboratory technique and analytic network process (DANP) method to calculate the interactions between the research criteria and sub-criteria along with their influential weights. In the end, we utilize the additive ratio assessment (ARAS) technique to obtain relative utility coefficients (closeness coefficients) and ranking the provinces. Generally, this study concludes that industries in northwestern and southwestern provinces of Iran are more environmentally friendly than other provinces. In this evaluation, Bushehr, North Khorasan and Khuzestan provinces were ranked first to third with their relative utility coefficients of 0.488, 0.412 and 0.401, respectively.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5483
5502
https://ceej.aut.ac.ir/article_4300_58ff571f594bc3f9c2acddea71b12669.pdf
dx.doi.org/10.22060/ceej.2021.18852.6984
Investigating the effect of aeration on reducing food moisture by biological drying method
Steve
MARKARIAN
Faculty of Civil, Water, and Environment, Shahid Beheshti University
author
Maryam
Abbasi
Faculty of Civil, Water, and Environment, Shahid Beheshti University
author
Mehi
Jalilighazizadeh
EnvironmentResearch Center,, Shahid Beheshti University
author
text
article
2022
per
Biological drying is one of the pre-processing methods of waste to reduce its moisture. Municipal waste in developing countries, especially Iran, has high humidity due to separation from the source of dry waste and high volume of organic waste. The high humidity of municipal waste makes it difficult to manage this type of waste, reduce the thermal value, produce leachate and complicate disposal and recycling methods. Biological drying is an automated thermal process in which the rate of drying with the biological heat released during the decomposition of organic matter in situ increases and reduces moisture while retaining calories. Therefore, this method can be used as a method of pre-processing organic waste to produce heat and convert it into a fuel with high calorific value. The aim of this study was to investigate the effect of aeration on reducing the moisture content of food waste by biological drying of perishable organic waste. Hence, a new pilot-scale biological drying system was designed for municipal solid waste processing. Also, important and influential factors on biological drying including mixing rate, moisture, particle size, aeration time, aeration amount and bulking factor were investigated. Finally, the pilot performance on perishable food waste prepared from the central self-service of the main campus of Shahid Beheshti University was evaluated with two aeration rates. The results showed that the weight, volume and moisture content of the waste was significantly reduced and the ph value of the waste leachate was stabilized at 8.35. Moisture is also greatly reduced so that at the end of the first phase is equal to 25.10 and the second phase is equal to 21.80 and volatile solids are increased. The final weight of the waste reached 6.86 kg and as a result, aeration in reducing the moisture content of perishable food waste by biological drying method is a sustainable method to reduce the moisture content of the waste.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5503
5516
https://ceej.aut.ac.ir/article_4228_467c36d8331332dd90e5ba6c9c7caf19.pdf
dx.doi.org/10.22060/ceej.2020.18861.6986
Lace Design Optimization for Hard Rock TBMs
Ebrahim
Farrokh
Mining Engineering, Amirkabir University, Tehran, Iran
author
text
article
2022
per
Optimization in TBM cutterhead design is essential for increasing its performance. Lace design for the cutters, buckets, and manholes, is one of the major considerations in the design of the cutterheads. An optimum lace design is necessary to avoid cutterhead deviation, vibration, stress concentration, etc., during its operation. TBM manufacturers usually utilize two common lace designs of radial and spiral configurations. Each of these designs has its own disadvantages, which may cause difficulties in achieving an efficient design of the cutterhead. This paper presents the basis of the lace design of the hard rock TBMs. With the consideration of the problems of the radial and spiral configurations, a new method of “evenly distributed lace design” is introduced and the steps of achieving the final layout of the cutterhead are explained with its required parameters. The parameters are obtained from statistical analyses conducted on the gathered design information of many TBM cutterheads from around the world. The results show that the new method is very efficient in both evenly distributing the cutters on the cutterhead surface as well as in minimizing the unbalanced forces and moments.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5517
5534
https://ceej.aut.ac.ir/article_4229_b7edf304c82bdcb0d933deaca444dcdf.pdf
dx.doi.org/10.22060/ceej.2020.18890.6992
Effect of leachate and freeze-thaw on the hydraulic conductivity of clayey barriers
Mehdi
Gholikhany
Ph.D. Student, Department of Civil Engineering, Urmia University
author
Kazem
Badv
Department of Civil Engineering, Urmia University
author
text
article
2022
per
The effect of freeze-thaw cycles on the hydraulic conductivity (HC) of clayey barriers in water retaining structures and municipal solid waste landfills is a key issue in designing barrier systems in those structures. The effect of freeze-thaw cycles on the hydraulic conductivity of compacted clayey soil from Nazlou Region of Urmia City and a geosynthetic clay liner (GCL), and the effect of effective stress on the hydraulic conductivity change of clayey soil in freeze-thaw cycles were investigated for water and leachate. The flexible-wall triaxial hydraulic conductivity apparatus was used to measure the HC of specimens subjected to freeze-thaw. During the freezing process, ice lenses grow in the soil sample and when the ice lenses melt, a network of cracks is left and thus, the HC increases. Increasing the effective stress reduces the increased hydraulic conductivity due to freeze-thaw. The results show that on the contrary to compacted clayey soil, the application of freeze-thaw cycles do not significantly affect the HC of GCL. Interaction of clayey soil with leachate leads to a decrease in thickness of the diffuse double layer and thus, the hydraulic conductivity of clayey soil increases. Increase in hydraulic conductivity of clayey soil and GCL subjected to freeze-thaw and permeated with leachate is lower than that for water.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5535
5548
https://ceej.aut.ac.ir/article_4278_da4f2975b9b75ed8fe6005146f4f53e0.pdf
dx.doi.org/10.22060/ceej.2021.18909.6994
Hybrid fuzzy linguistic method for Construction project manager selection
Ali Reza
Afshari
Department of Industrial Engineering, Shirvan Branch, Islamic Azad University, Shirvan, Iran
author
text
article
2022
per
Selecting a construction project manager is one of the most important processes in human resource management in the construction industry. Deciding on the issue of hiring a project manager will be a complex and multivariate issue. The purpose of this study is to provide a hybrid model that optimally solves the issue of ranking and selection of a construction project manager by using decision-making techniques. The proposed model is based on fuzzy linguistic decision criteria to solve the construction manager selection based on criteria derived from the Delphi method based on previous studies. In this research, two methods of group decision making in ranking and selecting the construction project manager are presented. The Delphi method extracts the criteria, while the fuzzy TOPSIS method selects the optimal candidate. The results show that the use of multi-criteria decision-making methods in the Construction manager selection increases the efficiency of the process and because it considers various criteria, in the end, efficient managers in accordance with the needs of the project-based organization is a candidate in the recruitment process. One of the features of the proposed approach is to minimize the involvement of subjective judgments in the selection of the construction project manager. This approach can also help decision-makers of project-based organizations in identifying and determining the basic criteria before selecting a construction project manager and facilitate the decision to select the best construction project manager based on multiple criteria and options.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5549
5568
https://ceej.aut.ac.ir/article_4308_0cf773dd31c7b43b25308af25055d45a.pdf
dx.doi.org/10.22060/ceej.2021.18922.7000
Seismic performance of asymmetric isolated steel structures with different bracing systems
Seyedmohammadreza
Hsseini
Faculty of Engineering, Kharazmi University, Tehran, Iran
author
غلامرضا
نوری
گروه عمران، دانشکده فنی و مهندسی دانشگاه خوارزمی تهران ایران
author
text
article
2022
per
In this paper, the seismic performance of asymmetric isolated structures with different bracing systems under near-fault strong ground motions is investigated. Non-linear dynamic analyses are performed under the simultaneous application of horizontal and vertical components of seismic acceleration. For this purpose, three types of chevron, cross and zipper bracing systems in 5 and 10-story structures with 0%, 10% and 20% mass eccentricity have been studied. Non-linear time history analysis is performed by seven selected accelerograms. First, the symmetrical structure was analyzed in fixed and isolated base states. Then, the asymmetric effect on two eccentricity cases 10% and 20% in the target structures, was compared. The parameters studied in this paper are the average shear force, drift and rotation of floors, and input energy to the structure. With an increasing eccentricity of the structure, the energy absorption by the isolator is reduced and the base shear is increased. Among the different bracing systems, the energy absorbed by the isolation system in the structure with zipper bracing increased by 53% and the base shear rate decreased by 80%. Based on the analysis results, base-isolation in the structure with cross-bracing in symmetrical and asymmetric has caused a reduction of more than 70% of the floor rotation compared to other bracing systems.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5569
5588
https://ceej.aut.ac.ir/article_4263_cc08b3960e0d2227baf8400ee911e98e.pdf
dx.doi.org/10.22060/ceej.2021.18911.7001
Seismic behavior of coupled steel plate shear wall
A. R.
Rahai
Department of Civil Engineering, Amirkabir University of Technology, Tehran, Iran.
author
N.
Valizadeh
Department of Civil Engineering, Amirkabir University of Technology, Tehran, Iran.
author
A.
Shokoohfar
Department of civil engineering, Azad University of Qazvin, Qazvin, Iran.
author
text
article
2022
per
Coupled steel plate shear wall (CSPSW) is an efficient system to withstand lateral forces, especially in regions with high risk of earthquakes. This system consists of two steel plate shear walls which are linked together with coupling beams at the floor levels. In this article to study the CSPSW behavior, two parameters have been investigated. One is the degree of coupling, which represents the level of interaction between the two piers and the other is the plastic strength of the coupled steel plate shear wall. 12 CSPSW models have been selected which differ in terms of the length and the characteristics of the coupled beam and the height of CSPSW. These models have been analyzed using nonlinear static method. To verify the results, Borello & Fahnestock verified numerical model has been used. The results from the numerical modeling shows that changing the length of the coupled beams, with the same stiffness has a significant impact on the degree of coupling, while it has little effect on the plastic strength of the CSPSW. Additionally, increasing the stiffness of the coupled beams results in an increase of the degree of coupling, as well as an increase of the base shear of CSPSW.
Amirkabir Journal of Civil Engineering
Amirkabir University of Technology
2588-297X
53
v.
12
no.
2022
5589
5602
https://ceej.aut.ac.ir/article_4792_78f8b313991b73dd295e08cc420b481c.pdf
dx.doi.org/10.22060/ceej.2019.8504.4183