Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Study of the effect of various scenarios of the sediment control on banks in the vicinity of lateral intake entrance Study of the effect of various scenarios of the sediment control on banks in the vicinity of lateral intake entrance 4055 4076 4889 10.22060/ceej.2022.19130.7080 FA Ali Attarzadeh Assistant professor of Hydraulic Engineering, Department of Civil Engineering, Qom University &lrm;of Technology, Qom, Iran &lrm; Babakhani Ali Civil Department, Engineering Faculty, Zanjan University, Zanjan, Iran Journal Article 2020 10 14 One of the main goals in diverting water flowing in rivers is to provide the required water (for different purposes) with a minimum of sediments, which is usually met through the installation of sediment control structures with different arrangements to significantly decrease the sediment that enters the intake. In addition to sediment control, serious attention should also be paid to the impact of these structures and sediment control scenarios on the riverbank and other relevant facilities located in the vicinity of the intake entrance. Using a laboratory scale canal, equipped with recirculating sediment and included a 90◦ lateral intake and a bed moving because of dunes movement, the effects of these structures including sill, spur dike, and submerged vanes on the banks in the vicinity of intake entrance experimentally investigated at four different sediment control scenarios and different discharge ratio. In order to accurately evaluate the scour near the banks, after dynamic equilibrium was achieved at the bed due to continuous changes of its elevation in these conditions, scour time series analysis was performed at upstream and downstream points near the intake, along the banks on either side of the main canal. The results show that different behaviors are observed near the intake due to various factors influencing the flow. While in the range of discharge ratios studied, the spur dike increases the depth and length of scour zone at the intake downstream by an average of about 72% and 34%, respectively, the submerged vanes reduce the length of scour zone by 37% and at the discharge ratio of 0.12, an increase of about 66% in the depth of scour zone is observed, while at the discharge ratio of 0.18, a decrease of about 24% in the depth of scour zone occurs. One of the main goals in diverting water flowing in rivers is to provide the required water (for different purposes) with a minimum of sediments, which is usually met through the installation of sediment control structures with different arrangements to significantly decrease the sediment that enters the intake. In addition to sediment control, serious attention should also be paid to the impact of these structures and sediment control scenarios on the riverbank and other relevant facilities located in the vicinity of the intake entrance. Using a laboratory scale canal, equipped with recirculating sediment and included a 90◦ lateral intake and a bed moving because of dunes movement, the effects of these structures including sill, spur dike, and submerged vanes on the banks in the vicinity of intake entrance experimentally investigated at four different sediment control scenarios and different discharge ratio. In order to accurately evaluate the scour near the banks, after dynamic equilibrium was achieved at the bed due to continuous changes of its elevation in these conditions, scour time series analysis was performed at upstream and downstream points near the intake, along the banks on either side of the main canal. The results show that different behaviors are observed near the intake due to various factors influencing the flow. While in the range of discharge ratios studied, the spur dike increases the depth and length of scour zone at the intake downstream by an average of about 72% and 34%, respectively, the submerged vanes reduce the length of scour zone by 37% and at the discharge ratio of 0.12, an increase of about 66% in the depth of scour zone is observed, while at the discharge ratio of 0.18, a decrease of about 24% in the depth of scour zone occurs.

https://ceej.aut.ac.ir/article_4889_cf63547fadc1aa6e897a62291e0cb124.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Evaluation of the adequacy of the response spectrum analysis for the seismic analysis of moment-resisting and concentrically-braced buildings according to the seismic design codes Evaluation of the adequacy of the response spectrum analysis for the seismic analysis of moment-resisting and concentrically-braced buildings according to the seismic design codes 4077 4100 4892 10.22060/ceej.2022.19329.7156 FA Ahmadreza Fatahi sahand university Mehdi Poursha Journal Article 2020 12 14 According to the seismic design codes, the response spectrum analysis (RSA) method can be used for the seismic analysis of tall buildings since it can consider the effect of higher modes. In addition, the nonlinear time history analysis is the most accurate method of evaluating the seismic responses of structures. Consequently, the present study investigates the accuracy of the RSA method by comparing the seismic responses computed by the RSA with the nonlinear time history analysis. To this end, six 3D structures with 4-, 10- and 20-story heights are investigated in this paper. The lateral load-resisting systems of the structures include special steel moment-resisting frames (MRFs) and concentrically braced frames (CBFs). To conduct the nonlinear time history analyses, four sets of ground motion records including three groups of near-fault records with different characteristics and one set of far-fault records are used. The near-fault ground motion sets include forward directivity, fling step and no pulse characteristics. All sets comprise seven seismic ground motion records. The results indicate that the seismic responses obtained by the RSA, are mostly underestimated and non-conservative in comparison with those from the nonlinear time history analysis. In general, the more the height of the structure, the larger the error in the seismic responses derived from the RSA. Also, the largest error in the RSA relative to the rigorous time history analysis occurs in the case of the near-fault ground motions with the fling-step effect. According to the seismic design codes, the response spectrum analysis (RSA) method can be used for the seismic analysis of tall buildings since it can consider the effect of higher modes. In addition, the nonlinear time history analysis is the most accurate method of evaluating the seismic responses of structures. Consequently, the present study investigates the accuracy of the RSA method by comparing the seismic responses computed by the RSA with the nonlinear time history analysis. To this end, six 3D structures with 4-, 10- and 20-story heights are investigated in this paper. The lateral load-resisting systems of the structures include special steel moment-resisting frames (MRFs) and concentrically braced frames (CBFs). To conduct the nonlinear time history analyses, four sets of ground motion records including three groups of near-fault records with different characteristics and one set of far-fault records are used. The near-fault ground motion sets include forward directivity, fling step and no pulse characteristics. All sets comprise seven seismic ground motion records. The results indicate that the seismic responses obtained by the RSA, are mostly underestimated and non-conservative in comparison with those from the nonlinear time history analysis. In general, the more the height of the structure, the larger the error in the seismic responses derived from the RSA. Also, the largest error in the RSA relative to the rigorous time history analysis occurs in the case of the near-fault ground motions with the fling-step effect.

https://ceej.aut.ac.ir/article_4892_b607aa5b2fd58dd860bfb55619389982.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Identification of some sources of heterogeneity in value of travel time of Tehran LEZ users Identification of some sources of heterogeneity in value of travel time of Tehran LEZ users 4101 4118 4872 10.22060/ceej.2022.19624.7213 FA Sogol Kanaani Maman Transportation Planning, Institute for Management and Planning Studies, Tehran, Iran. AmirReza Mamdoohi Transportation Planning Department, Faculty of Civil &amp; Environmental Engineering, Tarbiat Modares University 0000-0002-5339-9807 Journal Article 2021 02 11 Value of travel time (VOTT) plays a key role in the choices of travelers. Empirical studies have shown significant differences in VOTT estimates, which researchers attribute to several factors, including demographic, alternatives, trips, and regional economic characteristics. One of the policies reducing the use of the private car is congestion pricing of the low emission zone (LEZ). This study aims to estimate VOTT and analyze its heterogeneity among users of Tehran LEZ. We use stated preference (SP) data to calibrate mixed logit models, based on which, travelers' value of time is evaluated. The mean value of travel time is calculated 5788 Rials per hour. Results of the mixed logit model indicate a cost coefficient with triangle distribution (mean -0.00036) and a travel time coefficient with normal distribution (mean -0.20838). To investigate the source of VOTT heterogeneity, random coefficients analysis is used for the interaction between coefficients of time and cost and other variables revealing that only cost as a factor with three variables: number of the entrance to LEZ, number of household cars, and high education are significant. Value of travel time (VOTT) plays a key role in the choices of travelers. Empirical studies have shown significant differences in VOTT estimates, which researchers attribute to several factors, including demographic, alternatives, trips, and regional economic characteristics. One of the policies reducing the use of the private car is congestion pricing of the low emission zone (LEZ). This study aims to estimate VOTT and analyze its heterogeneity among users of Tehran LEZ. We use stated preference (SP) data to calibrate mixed logit models, based on which, travelers' value of time is evaluated. The mean value of travel time is calculated 5788 Rials per hour. Results of the mixed logit model indicate a cost coefficient with triangle distribution (mean -0.00036) and a travel time coefficient with normal distribution (mean -0.20838). To investigate the source of VOTT heterogeneity, random coefficients analysis is used for the interaction between coefficients of time and cost and other variables revealing that only cost as a factor with three variables: number of the entrance to LEZ, number of household cars, and high education are significant.

https://ceej.aut.ac.ir/article_4872_02b5b45ce743bc3f285ec4d39b5968c3.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Study of variations in discharge coefficients for broad-crested weirs with sloped upstream and downstream faces using numerical simulation Study of variations in discharge coefficients for broad-crested weirs with sloped upstream and downstream faces using numerical simulation 4119 4138 4902 10.22060/ceej.2022.19870.7279 FA Faezeh Malekzadeh Department of Water Engineering, Faculty of Agriculture, University of Tabriz Salmasi F. 0000-0002-1627-8598 Hadi Arvanaghi Department of Water Engineering, Faculty of Agriculture, University of Tabriz Journal Article 2021 04 16 Weirs are structures that are important for measuring flow and controlling water levels. Research has shown that the discharge coefficient is not constant and depends on the crest length, the height of the weir, the upstream head, and the upstream and downstream slopes. In this study, the effect of these parameters on the discharge coefficient (Cd) is investigated by numerical simulation. The current study presents numerical simulation using the ANSYS FLUENT software. The total number of simulations is 432 which includes: 4 upstream slopes, 4 downstream slopes, 3 weir heights, 3 upstream heads (h1) and 3 weir crest lengths. It was found that the downstream face slope has little effect on Cd. For 0.1<H1/w<0.4 by decreasing the upstream slope, Cd increases, where H1 is the water head on the weir crest and w is the length of the crest. Also, for the same range, by decreasing the height of the weir (p), the Cd increases. For 0.16<H1/p<2, as the length of the crest decreases, the Cd increases. By comparing the numerical simulation results to physical measurements, multi-variable regression equations for estimating Cd are presented. In addition to Cd, extraction of other more detailed information such as water level profiles and velocity profiles at different locations are provided. Weirs are structures that are important for measuring flow and controlling water levels. Research has shown that the discharge coefficient is not constant and depends on the crest length, the height of the weir, the upstream head, and the upstream and downstream slopes. In this study, the effect of these parameters on the discharge coefficient (Cd) is investigated by numerical simulation. The current study presents numerical simulation using the ANSYS FLUENT software. The total number of simulations is 432 which includes: 4 upstream slopes, 4 downstream slopes, 3 weir heights, 3 upstream heads (h1) and 3 weir crest lengths. It was found that the downstream face slope has little effect on Cd. For 0.1<H1/w<0.4 by decreasing the upstream slope, Cd increases, where H1 is the water head on the weir crest and w is the length of the crest. Also, for the same range, by decreasing the height of the weir (p), the Cd increases. For 0.16<H1/p<2, as the length of the crest decreases, the Cd increases. By comparing the numerical simulation results to physical measurements, multi-variable regression equations for estimating Cd are presented. In addition to Cd, extraction of other more detailed information such as water level profiles and velocity profiles at different locations are provided.

https://ceej.aut.ac.ir/article_4902_e7a425c6ece20cbc9056f98699b53c6f.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 DEM investigation of the effect of arrangement of grains on the behavior of brittle granular materials subjected to one dimensional compression DEM investigation of the effect of arrangement of grains on the behavior of brittle granular materials subjected to one dimensional compression 4139 4162 4862 10.22060/ceej.2022.20011.7314 FA Vahid Gorbanpoor Civil Engineering Faculty, Sahand University of Technology Mehrdad EMAMI Tabrizi Civil Engineering Faculty, Sahand University of Technology, Tabriz Journal Article 2021 05 07 Granular materials are used in many projects such as dams, railways and breakwaters. Because the size of granular materials in these projects starts from a few centimeters and sometimes reaches one meter, conducting laboratory experiments would be very expensive, time-consuming and even impossible. For this purpose, the use of numerical modeling to investigate the effect of different parameters on the mechanical behavior of this type of material is very important. Among the effective factors, grain arrangement is investigated in this study. Thus, cylindrical and cubic grains are modeled as representative of rounded and angular grains, in two regular and irregular arrangement based on the discrete element method and stress-strain behavior, applied energy and breakage values after loading are investigated. Using the non-linear Hertz model and determining its parameters based on laboratory experiments, controlling the uniformity of grain distribution based on the number of contact points along with the dip and direction of grains, defining the breakage criterion based on Von-Mises criterion and applying the breakage pattern based on particle splitting are among the features of the model used. In order to validate the numerical model, similar laboratory experiments were performed and their results were compared with each other. The results showed that the numerical model can study the effect of the arrangement of grains on the behavior of materials with high accuracy. Also, due to the existence of different shapes in granular materials, the effect of mixed arrangement was investigated on the results. Granular materials are used in many projects such as dams, railways and breakwaters. Because the size of granular materials in these projects starts from a few centimeters and sometimes reaches one meter, conducting laboratory experiments would be very expensive, time-consuming and even impossible. For this purpose, the use of numerical modeling to investigate the effect of different parameters on the mechanical behavior of this type of material is very important. Among the effective factors, grain arrangement is investigated in this study. Thus, cylindrical and cubic grains are modeled as representative of rounded and angular grains, in two regular and irregular arrangement based on the discrete element method and stress-strain behavior, applied energy and breakage values after loading are investigated. Using the non-linear Hertz model and determining its parameters based on laboratory experiments, controlling the uniformity of grain distribution based on the number of contact points along with the dip and direction of grains, defining the breakage criterion based on Von-Mises criterion and applying the breakage pattern based on particle splitting are among the features of the model used. In order to validate the numerical model, similar laboratory experiments were performed and their results were compared with each other. The results showed that the numerical model can study the effect of the arrangement of grains on the behavior of materials with high accuracy. Also, due to the existence of different shapes in granular materials, the effect of mixed arrangement was investigated on the results.

https://ceej.aut.ac.ir/article_4862_3713bdda7149579475f3734e8bd0e14a.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Solution of 3D elasticity problems using meshless local equilibrated basis functions Solution of 3D elasticity problems using meshless local equilibrated basis functions 4163 4188 4909 10.22060/ceej.2022.20119.7345 FA Danial Afifi Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran Nima Noormohammadi Department of civil engineering, Isfahan university of technology, Isfahan, Iran Bijan Boroomand Department of Civil Engineering,, Isfahan University of Technology, Isfahan, Iran Journal Article 2021 06 03 A mesh-free method is presented for 3D elasto-static problems in homogenous media using Equilibrated Basic functions. The method treats satisfaction of the Partial Differential Equation independent of the boundary conditions, using a weak weighted residual integration over a cubic fictitious domain embedding the main domain. All 3D integrals break into the combination of 1D library integrals, resulting in the omission of the numerical integration. Chebyshev polynomials of the first kind are used to approximate the solution function, and exponential functions combined with polynomials are used as weight functions. The weights vanish over the boundaries of the cubic fictitious domain, removing the boundary integrals. The meshless method considers some nodes for the definition of the Degrees of Freedom throughout the domain. Each node corresponds to a local sub-domain called cloud, including 98 other nodes than the main central one. The overlap between adjacent clouds ensures the continuity of both the displacement as well as stress components, an advantage with respect to the formulations. The approximation order within each cloud is 4. Boundary conditions are applied over a set of boundary points independent of the domain nodes, granting the method the ability of application for arbitrarily shaped domains without the drawback of irregularity in the nodal grid. The definition of curved boundary surfaces is easily done by inserting the coordinates of some boundary points located on them. Three numerical examples with various geometries and boundaries are presented to challenge the method. The results are compared with either the available exact solutions or the FEM. A mesh-free method is presented for 3D elasto-static problems in homogenous media using Equilibrated Basic functions. The method treats satisfaction of the Partial Differential Equation independent of the boundary conditions, using a weak weighted residual integration over a cubic fictitious domain embedding the main domain. All 3D integrals break into the combination of 1D library integrals, resulting in the omission of the numerical integration. Chebyshev polynomials of the first kind are used to approximate the solution function, and exponential functions combined with polynomials are used as weight functions. The weights vanish over the boundaries of the cubic fictitious domain, removing the boundary integrals. The meshless method considers some nodes for the definition of the Degrees of Freedom throughout the domain. Each node corresponds to a local sub-domain called cloud, including 98 other nodes than the main central one. The overlap between adjacent clouds ensures the continuity of both the displacement as well as stress components, an advantage with respect to the formulations. The approximation order within each cloud is 4. Boundary conditions are applied over a set of boundary points independent of the domain nodes, granting the method the ability of application for arbitrarily shaped domains without the drawback of irregularity in the nodal grid. The definition of curved boundary surfaces is easily done by inserting the coordinates of some boundary points located on them. Three numerical examples with various geometries and boundaries are presented to challenge the method. The results are compared with either the available exact solutions or the FEM.

https://ceej.aut.ac.ir/article_4909_457ded6f20b28feb21b9bca73c498671.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Effect of uncertainty of soil parameters on the dynamic response of soil using random field theory Effect of uncertainty of soil parameters on the dynamic response of soil using random field theory 4189 4204 4850 10.22060/ceej.2022.20229.7372 FA Hasan Nikpoor MSc student, Department of Civil Engineering, Shahrood University of Technology, Shahrood, Iran Amir Bazrafshan Moghaddam Assistant professor, Department of Civil Engineering, Shahrood University of Technology Journal Article 2021 07 03 Seismic waves caused by earthquakes undergo many changes when passing through different layers of soil. For this reason, the effects of soil parameters on the dynamic response of the ground should be considered. The parameters in a heterogeneous soil layer are affected by a set of uncertainties, which in this research is the inherent variability of the soil shear modulus parameter. In this research, using random field theory and finite difference method in the framework of Monte Carlo simulations, the effect of two-dimensional spatial variability of the soil shear modulus parameter on the magnification factor of the maximum ground acceleration and the surface acceleration response spectrum has been investigated. In the conventional deterministic analysis, only a constant value of the average shear modulus is considered in the dynamic model, but in the stochastic analysis, the parameter of the soil shear modulus is considered as a random variable. The results obtained from the analysis show that with the increase of heterogeneity and changes in the shear modulus of the soil, the values of the magnification factor of the maximum ground acceleration decrease. Also, with the increase in the coefficient of variation of the soil shear modulus and as a result of the increase in the heterogeneity of the soil profile, the acceleration response spectrum of the surface of the soil profile obtained from random analyzes decreases. Seismic waves caused by earthquakes undergo many changes when passing through different layers of soil. For this reason, the effects of soil parameters on the dynamic response of the ground should be considered. The parameters in a heterogeneous soil layer are affected by a set of uncertainties, which in this research is the inherent variability of the soil shear modulus parameter. In this research, using random field theory and finite difference method in the framework of Monte Carlo simulations, the effect of two-dimensional spatial variability of the soil shear modulus parameter on the magnification factor of the maximum ground acceleration and the surface acceleration response spectrum has been investigated. In the conventional deterministic analysis, only a constant value of the average shear modulus is considered in the dynamic model, but in the stochastic analysis, the parameter of the soil shear modulus is considered as a random variable. The results obtained from the analysis show that with the increase of heterogeneity and changes in the shear modulus of the soil, the values of the magnification factor of the maximum ground acceleration decrease. Also, with the increase in the coefficient of variation of the soil shear modulus and as a result of the increase in the heterogeneity of the soil profile, the acceleration response spectrum of the surface of the soil profile obtained from random analyzes decreases.

https://ceej.aut.ac.ir/article_4850_549406198764950208345d143aa67c7d.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Investigation of rhenium adsorption isotherm from two-component solutions by Dowex 21K and desorption tests using alkaline solutions Investigation of rhenium adsorption isotherm from two-component solutions by Dowex 21K and desorption tests using alkaline solutions 4205 4214 4908 10.22060/ceej.2022.20269.7384 FA Mohammadbagher Fahi Mining Department, Engineering Faculty, Urmia, University Bahram Rezai Mining Eng. Faculty, Amirkabir University Amirreza Azadmehr Mining Eng. Faculty, Amirkabir University Journal Article 2021 07 15 Nowadays, solutions and effluents resulting from the activities of mineral processing plants and related industries can be considered one of the most important resources for the production of valuable elements. Examining the extraction method and improving it, in addition to reducing the needs of modern industries, can be considered one of the effective methods in controlling wastes and reducing environmental concerns. In this study, in the presence of molybdenum the adsorption behavior of rhenium on the Dowex 21K resin from pregnant solutions, in conditions very close to copper-containing solutions resulting from heap leaching, was investigated by Freundlich, Temkin, Dubinin – Radushkevich and Langmuir isothermal equations. The results showed that in the case of one-component solutions, the fit of the data obtained from static experiments on the mentioned equations is most consistent with the Friendlich equation and in the case of two-component conditions with its expanded form. Examination of resin capacity changes in the two conditions showed that due to the presence of the second component, competition between the existing ions, the resin capacity is reduced by about 47%. Also, the examination of ammonium acetate (0.5 M) on desorption of adsorbed ions from seven resin samples loaded showed that after 7 hours, more than 92% of molybdenum was released from the resin, while during this period, the amount of rhenium desorption no more than 13% was obtained. Nowadays, solutions and effluents resulting from the activities of mineral processing plants and related industries can be considered one of the most important resources for the production of valuable elements. Examining the extraction method and improving it, in addition to reducing the needs of modern industries, can be considered one of the effective methods in controlling wastes and reducing environmental concerns. In this study, in the presence of molybdenum the adsorption behavior of rhenium on the Dowex 21K resin from pregnant solutions, in conditions very close to copper-containing solutions resulting from heap leaching, was investigated by Freundlich, Temkin, Dubinin – Radushkevich and Langmuir isothermal equations. The results showed that in the case of one-component solutions, the fit of the data obtained from static experiments on the mentioned equations is most consistent with the Friendlich equation and in the case of two-component conditions with its expanded form. Examination of resin capacity changes in the two conditions showed that due to the presence of the second component, competition between the existing ions, the resin capacity is reduced by about 47%. Also, the examination of ammonium acetate (0.5 M) on desorption of adsorbed ions from seven resin samples loaded showed that after 7 hours, more than 92% of molybdenum was released from the resin, while during this period, the amount of rhenium desorption no more than 13% was obtained.

https://ceej.aut.ac.ir/article_4908_1b33d16fc562464579b7199ca3114982.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Theoretical and numerical analyses of squeezing rock mass around a spherical opening considering the existence of a damaged zone Theoretical and numerical analyses of squeezing rock mass around a spherical opening considering the existence of a damaged zone 4215 4238 4871 10.22060/ceej.2022.20529.7452 FA Milad Zaheri Department of geotechnical Engineering, Faculty of civil engineering, University of Tabriz, 29 Bahman Blvd, Tabriz, Iran 0000-0002-9619-9397 Masoud Ranjbarnia Department of geotechnical Engineering, Faculty of civil engineering, University of Tabriz, 29 Bahman Blvd, Tabriz, Iran 0000-0003-3995-3258 Journal Article 2021 09 11 If an underground opening is excavated using the drill and blast method, an excavation damaged zone (EDZ) will appear around the opening in which it's mechanical and creep properties can be very different from the initial rock mass. The existence of such a zone in squeezing rock masses can lead the time-dependent displacements to increase. Therefore, in this paper, a closed-formed analytical solution is proposed to determine the long-term performance of a spherical opening surrounded by an EDZ. To consider the time-dependent behavior, the viscoelastic Burgers model is assigned to the rock mass. After verifying the proposed method, a parametric study is performed and the influence of various factors such as the radii of the opening and EDZ, the shear modulus, and the viscosity of rock mass are investigated. It is found that if the EDZ radius is considered constant, the displacement of the cavity with 7 meters radius, immediately and after 10 years, is respectively 1.42 and 1.57 times greater than the case in which the cavity radius is 4.57 meters. On the other hand, if the cavity radius is equal to 4.57 meters, immediately and after 10 years, the displacement of the cavity wall in which the EDZ radius is 8 meters is respectively 50% and 70% greater than the case in which this radius is equal to 6 meters. When the radii of the cavity and the EDZ are constant, if the Kelvin viscosity becomes one-twentieth, the cavity displacement increases by 115% and 173% after 1 year, respectively. However, if 20 times of the initial Maxwell viscosity of the EDZ is used in the calculations, this displacement decreases by about 14%, after 50 years. If an underground opening is excavated using the drill and blast method, an excavation damaged zone (EDZ) will appear around the opening in which it's mechanical and creep properties can be very different from the initial rock mass. The existence of such a zone in squeezing rock masses can lead the time-dependent displacements to increase. Therefore, in this paper, a closed-formed analytical solution is proposed to determine the long-term performance of a spherical opening surrounded by an EDZ. To consider the time-dependent behavior, the viscoelastic Burgers model is assigned to the rock mass. After verifying the proposed method, a parametric study is performed and the influence of various factors such as the radii of the opening and EDZ, the shear modulus, and the viscosity of rock mass are investigated. It is found that if the EDZ radius is considered constant, the displacement of the cavity with 7 meters radius, immediately and after 10 years, is respectively 1.42 and 1.57 times greater than the case in which the cavity radius is 4.57 meters. On the other hand, if the cavity radius is equal to 4.57 meters, immediately and after 10 years, the displacement of the cavity wall in which the EDZ radius is 8 meters is respectively 50% and 70% greater than the case in which this radius is equal to 6 meters. When the radii of the cavity and the EDZ are constant, if the Kelvin viscosity becomes one-twentieth, the cavity displacement increases by 115% and 173% after 1 year, respectively. However, if 20 times of the initial Maxwell viscosity of the EDZ is used in the calculations, this displacement decreases by about 14%, after 50 years.

https://ceej.aut.ac.ir/article_4871_a9c397afa342c368ba24e7620ee41a94.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Rural Road Safety Monitoring Using Crash Severity Predictive Models: A Case Study of Khorasan Razavi Province in Iran Rural Road Safety Monitoring Using Crash Severity Predictive Models: A Case Study of Khorasan Razavi Province in Iran 4239 4252 4916 10.22060/ceej.2022.20546.7457 FA Amirhossein Taheri MSc of transportation planning, Tarbiat Modares University, Tehran, Iran Arash Rasaizadi Transportation Planning, Civil engineering department, Tarbiat Modares University, Tehran, Iran Seyedehsan Seyedabrishami Associate Professor of Transportation Engineering, Tarbiat Modares University, Tehran, Iran, 0000-0002-9301-5417 Journal Article 2021 09 13 The high severity of crashes caused by high-speed vehicles is one of the drawbacks of intercity transportation. Heavy costs are linked to severe crashes, including death, injuries, and damage to the road, road equipment, and vehicles, as well as major psychological effects. This study uses predictable traffic characteristics to forecast the severity of crashes on suburban highways using logit family models. As a result, the traffic data from the traffic detectors on the roadways is integrated with the crash data in the first stage before being evaluated and modeled. Spatial-temporal scenarios are combined with these two datasets. In this investigation, the ordered logit (OL) and multinominal logit (MNL) models were used. The data, which refers to the roads in Iran's north-eastern province of Khorasan Razavi, was collected over a four-year period. Results indicate that the MNL model performs better than the OL model with more significant traffic parameters. The high severity of crashes caused by high-speed vehicles is one of the drawbacks of intercity transportation. Heavy costs are linked to severe crashes, including death, injuries, and damage to the road, road equipment, and vehicles, as well as major psychological effects. This study uses predictable traffic characteristics to forecast the severity of crashes on suburban highways using logit family models. As a result, the traffic data from the traffic detectors on the roadways is integrated with the crash data in the first stage before being evaluated and modeled. Spatial-temporal scenarios are combined with these two datasets. In this investigation, the ordered logit (OL) and multinominal logit (MNL) models were used. The data, which refers to the roads in Iran's north-eastern province of Khorasan Razavi, was collected over a four-year period. Results indicate that the MNL model performs better than the OL model with more significant traffic parameters.

https://ceej.aut.ac.ir/article_4916_f5e62af885293cf4d511ceef31e61c80.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Evaluation of the effect of micro-parameters on the macroscopic properties of cemented granular soils Evaluation of the effect of micro-parameters on the macroscopic properties of cemented granular soils 4253 4270 4870 10.22060/ceej.2022.20556.7462 FA Nazanin Mahbubi Motlagh Geotechnic-civil engineering-Shahid Beheshti university-Tehran-Iran Mahboubi Ardakani A. R. 0000-0002-7468-5140 Ali Noorzad P.O. 16765-1719 Tehran, Iran Journal Article 2021 09 14 One of the bonded contact models that is used to simulate the cemented bonds formed between soil particles in a cemented sample in the discrete element method is the "flat joint" model. There are numerous micro-parameters required to define this contact model between particles in the modeling and the effects of each of these parameters on the material response are not clear. In this research, after performing large-scale static and dynamic triaxial tests on cemented gravel in the laboratory, they were simulated as a granular assembly in which the flat joint contact model exists at all grain-grain contacts. Then, a sensitivity analysis was conducted to determine the effect of each micro-parameter on the macroscopic response of cemented samples and to specify the most impressive micro-parameters in order to simplify the calibration process. A regression analysis of the numerical results was performed to quantify the relationships between the micro-parameters and the mechanical properties of the sample. The results show that the maximum and residual shear strength of a sample are mainly dependent on the flat joint cohesion and stiffness ratio. The effects of elastic modulus and stiffness ratio on the initial tangential modulus and shear modulus are significant. The Poisson ratio is affected by the flat join cohesion and stiffness ratio. The damping ratio depends more on the elastic modulus. These results can be used as a guide for modeling the behavior of brittle materials in the discrete element method. A comparison between numerical and experimental test results of cemented granular specimens revealed that the model was able to capture the softening behavior of these materials with good accuracy. One of the bonded contact models that is used to simulate the cemented bonds formed between soil particles in a cemented sample in the discrete element method is the "flat joint" model. There are numerous micro-parameters required to define this contact model between particles in the modeling and the effects of each of these parameters on the material response are not clear. In this research, after performing large-scale static and dynamic triaxial tests on cemented gravel in the laboratory, they were simulated as a granular assembly in which the flat joint contact model exists at all grain-grain contacts. Then, a sensitivity analysis was conducted to determine the effect of each micro-parameter on the macroscopic response of cemented samples and to specify the most impressive micro-parameters in order to simplify the calibration process. A regression analysis of the numerical results was performed to quantify the relationships between the micro-parameters and the mechanical properties of the sample. The results show that the maximum and residual shear strength of a sample are mainly dependent on the flat joint cohesion and stiffness ratio. The effects of elastic modulus and stiffness ratio on the initial tangential modulus and shear modulus are significant. The Poisson ratio is affected by the flat join cohesion and stiffness ratio. The damping ratio depends more on the elastic modulus. These results can be used as a guide for modeling the behavior of brittle materials in the discrete element method. A comparison between numerical and experimental test results of cemented granular specimens revealed that the model was able to capture the softening behavior of these materials with good accuracy.

https://ceej.aut.ac.ir/article_4870_3c565485bbd2c54bb0ebe05c7ec741fc.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Dynamic coupled analysis of large-diameter steel piles located in liquefiable soil layers Dynamic coupled analysis of large-diameter steel piles located in liquefiable soil layers 4271 4286 4881 10.22060/ceej.2022.20610.7479 FA Amin Ghotbi Postgraduate student, Faculty of Civil & Environmental Engineering, Tarbiat Modares University, Iran Mohammad Oliaei Assistant Professor, Faculty of Civil & Environmental Engineering, Tarbiat Modares University 0000-0002-7672-5660 Heisam Heidarzadeh Assistant Professor of Civil Engineering, Faculty of Engineering, Sharekord University, Iran 0000-0002-9271-8313 Journal Article 2021 09 29 Many shores in Iran are at risk of earthquakes, and due to the dynamic loading of the earthquake, these saturated soils are prone to liquefaction. In this study, the behavior of two-layered saturated sand with different relative densities and the interaction effects of soil and pile under dynamic loads has been considered. For this purpose, a constitutive model presented in the multi-surface framework has been applied. In addition, the equations governing the saturated environment have been solved in a completely coupled way based on the finite element method. According to the obtained results, liquefaction will occur in the upper layers no matter the loading frequency when their liquefaction potential is high. Nevertheless, at depths and layers where the liquefaction potential is low, the pore pressure is strongly dependent on the loading frequency, so with an increase in the frequency of the dynamic loads, the water pore pressure increases less. Also, based on the analyses performed under different frequencies, it is observed that at a dynamic loading frequency, increasing the pile length has little effect on the displacement of the pile head but can significantly affect the displacement of the buried parts. Therefore, the larger the ratio of the pile length in the liquefiable soil to the total length of the pile, the greater the possibility of more displacement in the buried end of the pile; and as a result, it can lead to instability of the structure. Many shores in Iran are at risk of earthquakes, and due to the dynamic loading of the earthquake, these saturated soils are prone to liquefaction. In this study, the behavior of two-layered saturated sand with different relative densities and the interaction effects of soil and pile under dynamic loads has been considered. For this purpose, a constitutive model presented in the multi-surface framework has been applied. In addition, the equations governing the saturated environment have been solved in a completely coupled way based on the finite element method. According to the obtained results, liquefaction will occur in the upper layers no matter the loading frequency when their liquefaction potential is high. Nevertheless, at depths and layers where the liquefaction potential is low, the pore pressure is strongly dependent on the loading frequency, so with an increase in the frequency of the dynamic loads, the water pore pressure increases less. Also, based on the analyses performed under different frequencies, it is observed that at a dynamic loading frequency, increasing the pile length has little effect on the displacement of the pile head but can significantly affect the displacement of the buried parts. Therefore, the larger the ratio of the pile length in the liquefiable soil to the total length of the pile, the greater the possibility of more displacement in the buried end of the pile; and as a result, it can lead to instability of the structure.

https://ceej.aut.ac.ir/article_4881_c6ede20e6f597abf4b3f6bb30cee16c7.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Environmental Effect of Adding Zeolite and Sawdust on the Unconfined Strength of Stabilized Soil by Cement Environmental Effect of Adding Zeolite and Sawdust on the Unconfined Strength of Stabilized Soil by Cement 4287 4306 4917 10.22060/ceej.2022.20693.7502 FA Reza Yousefi Department of Civil Engineering, Faculty of Engineering, Qom University of Technology, Qom, Iran Amir Abbas Amooei Qom University of Technology (QUT) Abdolreza Karimi Member of Civil Engineering/ Qom University of Technology (QUT) Masoud Amelsakhi Civil Engineering department, Faculty of Engineering, Qom University of Technology 0000-0002-5894-0404 Journal Article 2021 10 20 Nowadays unlike decades ago, the environment plays a decisive role in using materials in construction. For example, one considerable part of a project is exploring environmental aspects as a preparatory topic. Chemicals such as cement have been used for decades in construction projects, however chemicals will lead to health catastrophes for both environment and humans consequently. One considerable hitch in human life is waste materials such as sawdust which will jeopardize the environment. One solution to alleviate these problems is using wastes in construction projects as substitution for cement. In this research, sawdust and zeolite were used to decrease cement use on sandy soil's improvement. The amount of materials are as follows: 4% cement (based on main soil weight), 0,1,3 and 5 % sawdust with two different sizes including powder and fibers (as supersede by cement) and 0, 10, 30 and 50 % zeolite as a supersede by cement. Results showed that zeolite and sawdust increase OMC but decrease MDD. Zeolite meets its optimum in 30% and powdered and fibrous sawdust in 3 and 1% subsequently. Finally, rupture strain will experience a sharp increase by enhancing the amount of sawdust. Overall it can be concluded that longer sawdust is more effective than short one. Nowadays unlike decades ago, the environment plays a decisive role in using materials in construction. For example, one considerable part of a project is exploring environmental aspects as a preparatory topic. Chemicals such as cement have been used for decades in construction projects, however chemicals will lead to health catastrophes for both environment and humans consequently. One considerable hitch in human life is waste materials such as sawdust which will jeopardize the environment. One solution to alleviate these problems is using wastes in construction projects as substitution for cement. In this research, sawdust and zeolite were used to decrease cement use on sandy soil's improvement. The amount of materials are as follows: 4% cement (based on main soil weight), 0,1,3 and 5 % sawdust with two different sizes including powder and fibers (as supersede by cement) and 0, 10, 30 and 50 % zeolite as a supersede by cement. Results showed that zeolite and sawdust increase OMC but decrease MDD. Zeolite meets its optimum in 30% and powdered and fibrous sawdust in 3 and 1% subsequently. Finally, rupture strain will experience a sharp increase by enhancing the amount of sawdust. Overall it can be concluded that longer sawdust is more effective than short one.

https://ceej.aut.ac.ir/article_4917_cf8d8c66b1212720e569b0bd67695451.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Determination of Tuned Mass Damper Parameters and its performance in a Four-Span Integral Bridge Determination of Tuned Mass Damper Parameters and its performance in a Four-Span Integral Bridge 4307 4326 4888 10.22060/ceej.2022.20692.7509 FA Seyyedeh Fatemeh Labbafi Department of Civil Engineering, Ferdowsi University of Mashhad , Mashhad, Iran Ahmad Shooshtari Department of Civil Engineering, Ferdowsi University of Mashhad , Mashhad, Iran Ehsan Mohtashami Department of Civil Engineering, University of Birjand, Khorasan, Iran Journal Article 2021 10 27 In this paper, the performance of the Tuned Mass Damper (TMD) control system in seismic response reduction of a four-span integral bridge is investigated. Two classic analytical methods and one optimization method are then employed to calculate TMD parameters. Then, the effect of selecting each of the three methods for calculating TMD parameters on the seismic response of the bridge is studied. Three objective functions are considered for the optimization procedure in MATLAB. After calculating TMD parameters, nonlinear dynamic analysis of the bridge in a transverse direction is carried out in OpenSees. The purpose of this study is to compare different methods for obtaining damper parameters and to introduce a method that calculates damper parameters in such a way that the damper has a better performance on the bridge. Numerical results indicate the performance of the damper is affected by its parameters and selecting the objective function. It is recommended to use the optimization method to calculate the damper parameters with maximum lateral displacement of the deck midpoint objective function. Also, the results show that the reduction of the response is related to the response corresponding to the objective function. For the studied bridge, the maximum values of reduction of displacement and acceleration of the middle deck are equal to 22.4 and 17.7%, respectively, and for the base, shear is 4.3%. Therefore, the lateral displacement of the deck midpoint objective function is introduced as the best cost function. In this paper, the performance of the Tuned Mass Damper (TMD) control system in seismic response reduction of a four-span integral bridge is investigated. Two classic analytical methods and one optimization method are then employed to calculate TMD parameters. Then, the effect of selecting each of the three methods for calculating TMD parameters on the seismic response of the bridge is studied. Three objective functions are considered for the optimization procedure in MATLAB. After calculating TMD parameters, nonlinear dynamic analysis of the bridge in a transverse direction is carried out in OpenSees. The purpose of this study is to compare different methods for obtaining damper parameters and to introduce a method that calculates damper parameters in such a way that the damper has a better performance on the bridge. Numerical results indicate the performance of the damper is affected by its parameters and selecting the objective function. It is recommended to use the optimization method to calculate the damper parameters with maximum lateral displacement of the deck midpoint objective function. Also, the results show that the reduction of the response is related to the response corresponding to the objective function. For the studied bridge, the maximum values of reduction of displacement and acceleration of the middle deck are equal to 22.4 and 17.7%, respectively, and for the base, shear is 4.3%. Therefore, the lateral displacement of the deck midpoint objective function is introduced as the best cost function.

https://ceej.aut.ac.ir/article_4888_0b846c55b4bde6baae8c12a2e53ae8c7.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 A strategy in developing standards for the liner of municipal solid waste landfills in Iran A strategy in developing standards for the liner of municipal solid waste landfills in Iran 4327 4342 4894 10.22060/ceej.2022.20944.7575 FA Nafise Jamialahmadi Environmental research center, Razi University, Kermanshah, Iran 0000-0002-2419-3527 Mohammad Hashemi Padena Zista Fan consulting engineers,, Tehran, Iran Mehran Karimpour-Fard Iran University of Science and Technology 0000-0001-5313-6444 Journal Article 2022 01 02 The difference in climatic conditions across the country and low investment capacity in waste management systems makes it unrealistic to establish the same prescribed design for the bottom liner of municipal solid waste landfills. In this paper, a semi-performance-based approach for the proper design of liners in these landfills has been proposed. This approach has been used in the development of technical evaluation guidelines and environmental criteria for municipal and hazardous waste landfills. Therefore, different climatic and hydrogeological conditions were considered. The rate of leachate infiltration into the leachate collection system in different climates corresponding to high, medium and low precipitation was calculated using the HELP model and considered as a representative parameter of climatic conditions. The rate of waste deposition, which indicates the size of the landfill, was introduced as the length of the landfill along the groundwater direction. Groundwater velocity, hydraulic conductivity and thickness of the aquitard were used as hydrogeological parameters. The resulting scenarios (324 scenarios) were defined in POLLUTE v7 and the chloride migration in five liner options were modeled. The results show that as the landfill is larger and the hydraulic conductivity of the aquitard is higher, the maximum contaminant concentration in the aquifer and the required time period to reach the maximum concentration will increase and decrease, respectively, by reducing the different layers of the liner system and decreasing groundwater velocity. Finally, the optimum liner for all climatic and hydrogeological conditions is proposed based on modeling results. The difference in climatic conditions across the country and low investment capacity in waste management systems makes it unrealistic to establish the same prescribed design for the bottom liner of municipal solid waste landfills. In this paper, a semi-performance-based approach for the proper design of liners in these landfills has been proposed. This approach has been used in the development of technical evaluation guidelines and environmental criteria for municipal and hazardous waste landfills. Therefore, different climatic and hydrogeological conditions were considered. The rate of leachate infiltration into the leachate collection system in different climates corresponding to high, medium and low precipitation was calculated using the HELP model and considered as a representative parameter of climatic conditions. The rate of waste deposition, which indicates the size of the landfill, was introduced as the length of the landfill along the groundwater direction. Groundwater velocity, hydraulic conductivity and thickness of the aquitard were used as hydrogeological parameters. The resulting scenarios (324 scenarios) were defined in POLLUTE v7 and the chloride migration in five liner options were modeled. The results show that as the landfill is larger and the hydraulic conductivity of the aquitard is higher, the maximum contaminant concentration in the aquifer and the required time period to reach the maximum concentration will increase and decrease, respectively, by reducing the different layers of the liner system and decreasing groundwater velocity. Finally, the optimum liner for all climatic and hydrogeological conditions is proposed based on modeling results.

https://ceej.aut.ac.ir/article_4894_723dadb8c699bf14f74503dbcb6e09c1.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 The Use Of Aluminum Oxide Nanoparticles In Improving Some Mechanical Properties And Increasing The Abrasion Resistance Of Concrete The Use Of Aluminum Oxide Nanoparticles In Improving Some Mechanical Properties And Increasing The Abrasion Resistance Of Concrete 4343 4364 4910 10.22060/ceej.2022.21040.7603 FA Hamed Yousefinezhad Faculty of Engineering, Islamic Azad University, Shiraz Unit, Shiraz, Iran Mohammad Mahdi Jabbari Faculty of Engineering, Islamic Azad University, Shiraz Unit, Shiraz, Iran 0000-0003-0284-033X Journal Article 2022 01 28 Today, with the development of nanotechnology, the application of this material is very important in achieving some desired properties in construction materials, especially concrete. In this regard, the use of nano aluminum oxide can cause changes in some physical characteristics and mechanical properties of concrete. Due to the high hardness of aluminum, it is expected to increase the abrasion resistance of concrete with the help of this nanoscale material. In this research, by examining the effect of nano aluminum oxide on the characteristics of concrete, while optimizing the amount of use of these materials, the possibility of using them in special applications, especially concrete coatings and flooring, has been evaluated. The amounts of nano oxide aluminum used in the concrete mixing plan of this research, in weight ratios of 0.25, 0.5 and 0.75%, replace part of the cement. Also, with the aim of reducing the cost and making it easier to implement, the spraying of a diluted nano-aluminum oxide solution in one to four layers on the concrete surface was also tested. The results of this research showed that the addition of 0.5% aluminum oxide nanopowder in concrete can increase the abrasion resistance of concrete up to 77% while partially improving some of the tested mechanical properties. Also, the results of the abrasion test showed that creating a layer of nano-aluminum oxide on the surface of the concrete, despite the improvement of effectiveness by increasing the number of coating layers, is less effective compared to the mixed design. Today, with the development of nanotechnology, the application of this material is very important in achieving some desired properties in construction materials, especially concrete. In this regard, the use of nano aluminum oxide can cause changes in some physical characteristics and mechanical properties of concrete. Due to the high hardness of aluminum, it is expected to increase the abrasion resistance of concrete with the help of this nanoscale material. In this research, by examining the effect of nano aluminum oxide on the characteristics of concrete, while optimizing the amount of use of these materials, the possibility of using them in special applications, especially concrete coatings and flooring, has been evaluated. The amounts of nano oxide aluminum used in the concrete mixing plan of this research, in weight ratios of 0.25, 0.5 and 0.75%, replace part of the cement. Also, with the aim of reducing the cost and making it easier to implement, the spraying of a diluted nano-aluminum oxide solution in one to four layers on the concrete surface was also tested. The results of this research showed that the addition of 0.5% aluminum oxide nanopowder in concrete can increase the abrasion resistance of concrete up to 77% while partially improving some of the tested mechanical properties. Also, the results of the abrasion test showed that creating a layer of nano-aluminum oxide on the surface of the concrete, despite the improvement of effectiveness by increasing the number of coating layers, is less effective compared to the mixed design.

https://ceej.aut.ac.ir/article_4910_43975bc2dfc84641a2a8c4d3fe653176.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Investigation on Deflection Amplification Factor for Special Moment Resisting Frames with Soft Story Investigation on Deflection Amplification Factor for Special Moment Resisting Frames with Soft Story 4365 4382 4901 10.22060/ceej.2022.21159.7652 FA Mohammad Amin Mirza Alian Department of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran Masood Yakhchalian aDepartment of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran 0000-0003-2672-6187 Journal Article 2022 03 11 One of the most common irregularities in structures is the irregularity in height and lateral stiffness. Due to the commonness of the use of irregular structures and also the different seismic responses of this type of structures, in comparison with regular structures, investigating the seismic response of irregular structures has always been the subject of several research studies. The structures designed for the reduced base shear, under the design earthquake, have inelastic response. To calculate the real (inelastic) displacements of structures under the design earthquake, the displacements obtained from the reduced base shear, are amplified by the deflection amplification factor (Cd). Seismic codes have dedicated a Cd for each structural system. But different studies have shown that the dedicated Cd by the codes cannot accurately estimate the real displacements. The main purpose of this research is to propose the Cd values for more accurately estimating the maximum inter-story drift ratio (MIDR) and maximum roof drift ratio (MRDR) in steel special moment resisting frames (SMRFs) with the soft story. The number of stories and the location of the soft story are the variables considered in this research. The results show that the use of Cd = 5.5, recommended by the 2800 standard and ASCE 7-16 for steel SMRFs, underestimates the real MIDR and also MRDR, under the design earthquake. It is shown that by increasing the number of stories, the mean Cd obtained from the analyses increases. The reason for this issue is the P-Δ effects that increase by increasing the number of stories. In addition, it is shown that a specified trend cannot be found between the location of the soft story and the mean Cd values in the stories of the structures. Thus, for more accurately estimating MIDR in the considered structures, under the design earthquake, Cd = 8.5 is proposed. Furthermore, for more accurately estimating MRDR, Cd roof = 8.0 is proposed. One of the most common irregularities in structures is the irregularity in height and lateral stiffness. Due to the commonness of the use of irregular structures and also the different seismic responses of this type of structures, in comparison with regular structures, investigating the seismic response of irregular structures has always been the subject of several research studies. The structures designed for the reduced base shear, under the design earthquake, have inelastic response. To calculate the real (inelastic) displacements of structures under the design earthquake, the displacements obtained from the reduced base shear, are amplified by the deflection amplification factor (Cd). Seismic codes have dedicated a Cd for each structural system. But different studies have shown that the dedicated Cd by the codes cannot accurately estimate the real displacements. The main purpose of this research is to propose the Cd values for more accurately estimating the maximum inter-story drift ratio (MIDR) and maximum roof drift ratio (MRDR) in steel special moment resisting frames (SMRFs) with the soft story. The number of stories and the location of the soft story are the variables considered in this research. The results show that the use of Cd = 5.5, recommended by the 2800 standard and ASCE 7-16 for steel SMRFs, underestimates the real MIDR and also MRDR, under the design earthquake. It is shown that by increasing the number of stories, the mean Cd obtained from the analyses increases. The reason for this issue is the P-Δ effects that increase by increasing the number of stories. In addition, it is shown that a specified trend cannot be found between the location of the soft story and the mean Cd values in the stories of the structures. Thus, for more accurately estimating MIDR in the considered structures, under the design earthquake, Cd = 8.5 is proposed. Furthermore, for more accurately estimating MRDR, Cd roof = 8.0 is proposed.

https://ceej.aut.ac.ir/article_4901_a08e32d2f9a8b78894d964ec7fd4172e.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Uncertainty Analysis of Artificial Intelligence Models in Forecasting River Flow (Case Study: Karun River) Uncertainty Analysis of Artificial Intelligence Models in Forecasting River Flow (Case Study: Karun River) 4383 4396 4882 10.22060/ceej.2022.21208.7653 FA Yaser Mehdizadeh Zare Anari Graduate Student, Water Engineering Department, Faculty of Civil and Surveying Engineering, Graduate University of Advanced Technology, Kerman, Iran Mohammad Najafzadeh Department of Water Engineering, Faculty of Civil and Survey Engineering, Graduate University of Advanced Technology, Kerman 0000-0002-4100-9699 Sedigheh Anvari Assistant Professor, Department of Ecology, Institute of Science and High Technology and Environmental Science, Graduate University of Advanced Technology, Kerman, Iran 0000-0002-3739-2947 Journal Article 2022 03 12 An accurate estimation of the discharge flow of natural streams plays a key role in irrigation planning, the design of bridges embedded in waterways, the management of reservoirs and dams, and the design of flood-warning systems. In recent decades, several studies have been conducted using artificial intelligence (AI) to accurately estimate the flow. Despite the proven accuracy level of AI methods, in many cases, there are uncertainties that occur for a variety of reasons. Insufficient knowledge of these uncertainties in the flow modeling process can have irreversible effects. In this research, monthly flow data, measured from Armand hydrometric station, located in Karun River basin, during a-28 year period (from 1980 to 2008) were used. First, the Thomas and Fiering method was used to generate flow series data and consider them as input variables. Then, flow forecast modeling was performed by three AI methods, namely Model Tree (MT), Gene Expression Programming (GEP), and Multivariate Adaptive Regression Spline (MARS). Statistical indicators such as correlation coefficient (R) and Root Mean Square Error (RMSE) were used to evaluate the accuracy of the models. In terms of the training stage, the MARS model with R=0.839 and RMSE=28.624 m3/s performed better than the other two models. Additionally, in the testing stage, the MT model with R=0.784 and RMSE=34.441 m3/s showed a more appropriate performance than other models. The Monte Carlo simulation method was used to calculate the uncertainty of the models, so the results showed that the r-factor parameter, which was the average width of the confidence band in the MT model, was equal to 1.67, indicating a lower and more optimal number compared to MARS (1.92) and GEP (2.025) models. Moreover, the usability of the statistical criterion for quantifying uncertainty, (known as 95PPU) indicated that the GEP model with 95PPU of 64% was selected as a more appropriate percentage than MARS (61%) and MT-M5 (55%). An accurate estimation of the discharge flow of natural streams plays a key role in irrigation planning, the design of bridges embedded in waterways, the management of reservoirs and dams, and the design of flood-warning systems. In recent decades, several studies have been conducted using artificial intelligence (AI) to accurately estimate the flow. Despite the proven accuracy level of AI methods, in many cases, there are uncertainties that occur for a variety of reasons. Insufficient knowledge of these uncertainties in the flow modeling process can have irreversible effects. In this research, monthly flow data, measured from Armand hydrometric station, located in Karun River basin, during a-28 year period (from 1980 to 2008) were used. First, the Thomas and Fiering method was used to generate flow series data and consider them as input variables. Then, flow forecast modeling was performed by three AI methods, namely Model Tree (MT), Gene Expression Programming (GEP), and Multivariate Adaptive Regression Spline (MARS). Statistical indicators such as correlation coefficient (R) and Root Mean Square Error (RMSE) were used to evaluate the accuracy of the models. In terms of the training stage, the MARS model with R=0.839 and RMSE=28.624 m3/s performed better than the other two models. Additionally, in the testing stage, the MT model with R=0.784 and RMSE=34.441 m3/s showed a more appropriate performance than other models. The Monte Carlo simulation method was used to calculate the uncertainty of the models, so the results showed that the r-factor parameter, which was the average width of the confidence band in the MT model, was equal to 1.67, indicating a lower and more optimal number compared to MARS (1.92) and GEP (2.025) models. Moreover, the usability of the statistical criterion for quantifying uncertainty, (known as 95PPU) indicated that the GEP model with 95PPU of 64% was selected as a more appropriate percentage than MARS (61%) and MT-M5 (55%).

https://ceej.aut.ac.ir/article_4882_c348616cd8a86ee661c7c98800678fad.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Optimization of photocatalytic degradation of rhodamine B dye using graphite carbon nitride nanocomposite in visible light and analyzing its experimental validation in kinetics under optimal conditions Optimization of photocatalytic degradation of rhodamine B dye using graphite carbon nitride nanocomposite in visible light and analyzing its experimental validation in kinetics under optimal conditions 4397 4416 4921 10.22060/ceej.2022.21241.7665 FA Ahmadreza Zeynali Ph.D. student of Environmental pollution, Faculty of Environmental and Natural Resources, University of Birjand, Birjand, Iran Afsaneh Shahbazi Associate Professor of Environmental Pollution, Environmental Sciences Research Institute, Shahid Beheshti University, 1983969411, Tehran, Iran Alireza Pourkhabbaz Associate Professor of Environmental, Faculty of Environmental and Natural Resources, University of Birjand, Birjand, Iran Journal Article 2022 03 24 In this paper, graphite carbon nitride nanocomposite was synthesized by stabilization of graphitic carbon nitride nanoparticles during the hydrothermal process onto periodic mesoporous organosilica based, and its efficiency was studied in photocatalytic degradation of rhodamine B in LED photoreactor using optimizing the parameters affecting the process in response surface methodology by Box-Benken method in three variables, time (10-50 min), photocatalyst dosage (0.3-0.7 g/l) and light wavelength (472-618 nm). The accuracy and validity of the quadratic model were confirmed with a high F-value, the significance of p-value (less than 0.0001), a small percentage of coefficient of variation, high correlation coefficients (0.98), non-significance of lack of fit and lack of autocorrelation based on D-W test results. The highest efficiency of photocatalytic degradation was observed in the wavelength variable and the wavelength-dose interactive variable. The optimal conditions in this analysis were defined as the time of 50 minutes, dose of nanocomposite 0.7 g/L, and wavelength 472 nm. The predicted mean value of photocatalytic degradation based on this model was 92.2% and its experimental value in validation kinetics under optimal conditions was 90.04%. The difference between the predicted mean value and experimental value in photocatalytic is within the prediction interval of 95% and finally, the model was approved. In this paper, graphite carbon nitride nanocomposite was synthesized by stabilization of graphitic carbon nitride nanoparticles during the hydrothermal process onto periodic mesoporous organosilica based, and its efficiency was studied in photocatalytic degradation of rhodamine B in LED photoreactor using optimizing the parameters affecting the process in response surface methodology by Box-Benken method in three variables, time (10-50 min), photocatalyst dosage (0.3-0.7 g/l) and light wavelength (472-618 nm). The accuracy and validity of the quadratic model were confirmed with a high F-value, the significance of p-value (less than 0.0001), a small percentage of coefficient of variation, high correlation coefficients (0.98), non-significance of lack of fit and lack of autocorrelation based on D-W test results. The highest efficiency of photocatalytic degradation was observed in the wavelength variable and the wavelength-dose interactive variable. The optimal conditions in this analysis were defined as the time of 50 minutes, dose of nanocomposite 0.7 g/L, and wavelength 472 nm. The predicted mean value of photocatalytic degradation based on this model was 92.2% and its experimental value in validation kinetics under optimal conditions was 90.04%. The difference between the predicted mean value and experimental value in photocatalytic is within the prediction interval of 95% and finally, the model was approved.

https://ceej.aut.ac.ir/article_4921_b64a70760bb75e3ecfd1ad86d8f10c88.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 11 2023 01 21 Experimental investigation of flexible pile behavior under lateral cyclic and post cyclic loading in sandy soil Experimental investigation of flexible pile behavior under lateral cyclic and post cyclic loading in sandy soil 4417 4432 4883 10.22060/ceej.2022.21312.7685 FA Roozbeh Owji School of Engineering, Shiraz University, Shiraz, Iran Ghassem Habibagahi School of Engineering, Shiraz University, Shiraz, Iran Mehdi Veiskarami School of Engineering, Shiraz University, Shiraz, Iran Journal Article 2022 04 19 Lateral behavior of piles is one of the most challenging design issues. While previous studies have mainly focused on rigid piles, a little attention has been paid to flexible ones. In this study, the behavior of flexible piles under lateral cyclic loading is investigated by experimental tests. For this purpose, a device was designed and commissioned for cyclic loading tests which can generate different types of sinusoidal loads. Measurement was made on the load and displacements during the cyclic loading with a loadcell and Linear Variable Differential Transducer (LVDT). The role of key parameters in cyclic loading including such as the frequency, loading interval, number of cycles, cyclic loading direction and also soil density were investigated. Moreover, post-cyclic loading tests were performed to evaluate piles lateral bearing capacity. Experimental observations showed that under one-way and two-way loadings, the stiffness gradually increases during 100 cycles of loading while under one-way without a complete unloading process, the stiffness starts to decrease and then remains constant. Increasing the frequency from 0.1Hz to 0.2Hz has shown a significant effect in increasing the lateral cyclic resistance. Under one-way loading, the residual force at the pile head increases with increasing the cyclic loading interval. Lateral behavior of piles is one of the most challenging design issues. While previous studies have mainly focused on rigid piles, a little attention has been paid to flexible ones. In this study, the behavior of flexible piles under lateral cyclic loading is investigated by experimental tests. For this purpose, a device was designed and commissioned for cyclic loading tests which can generate different types of sinusoidal loads. Measurement was made on the load and displacements during the cyclic loading with a loadcell and Linear Variable Differential Transducer (LVDT). The role of key parameters in cyclic loading including such as the frequency, loading interval, number of cycles, cyclic loading direction and also soil density were investigated. Moreover, post-cyclic loading tests were performed to evaluate piles lateral bearing capacity. Experimental observations showed that under one-way and two-way loadings, the stiffness gradually increases during 100 cycles of loading while under one-way without a complete unloading process, the stiffness starts to decrease and then remains constant. Increasing the frequency from 0.1Hz to 0.2Hz has shown a significant effect in increasing the lateral cyclic resistance. Under one-way loading, the residual force at the pile head increases with increasing the cyclic loading interval.

https://ceej.aut.ac.ir/article_4883_1f2b325dcdaf12a68ed498273206d263.pdf