Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Numerical Investigation of the Failure Mechanism of Short and Very Short Shear Links Made from ASTM A992 Steel Numerical Investigation of the Failure Mechanism of Short and Very Short Shear Links Made from ASTM A992 Steel 3 15 24123 10.24200/j30.2025.65406.3375 FA Abbas Ghadami Baderloo Dept. of Civil Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran. Naser Zare Dept. of Civil Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran. Mohammad Payband Dept. of Civil Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran. Journal Article 2024 10 20 There are numerous uncertainties in determining the rotation capacity and overstrength factor of shear links, which have raised concerns among structural designers regarding the design provisions in the AISC 341 code for accurately characterizing the behavior of shear links in eccentrically braced frames. Researchers attribute these past ambiguities to the failure mode of the links, as the maximum force developed in the link is proportional to the rotation capacity and, consequently, its failure mechanism. To address some of these previous uncertainties, this study examined the failure mode of short and very short shear links made from ASTM A992 steel. For this purpose, a parametric study was conducted using the finite element software ABAQUS, considering the effects of local buckling, cumulative damage under cyclic loading, and the influence of crack initiation and propagation on the reduction of strength and stiffness. According to the results, the code provisions lead to conservative outcomes (by more than 40%) for the rotation capacity of shear links, especially very short shear links. Thus, one of the main reasons for the occurrence of a large overstrength factor in shear links is their rotation capacity exceeding 0.08, which leads to strain hardening in the steel material and the development of forces greater than the plastic shear strength of the section. Furthermore, examining the failure mode of the links showed that, with an increase in web slenderness, the location of damage initiation and tearing shifts away from the stiffener-to-web connection and moves towards the center of the web panel. Additionally, in short shear links, particularly in models with smaller link length ratios, failure typically begins with vertical cracks near the stiffener and then propagates at the end of the stiffener into the link web. However, in very short shear links with smaller length ratios, web tearing occurs at the intersection of the flange and web. There are numerous uncertainties in determining the rotation capacity and overstrength factor of shear links, which have raised concerns among structural designers regarding the design provisions in the AISC 341 code for accurately characterizing the behavior of shear links in eccentrically braced frames. Researchers attribute these past ambiguities to the failure mode of the links, as the maximum force developed in the link is proportional to the rotation capacity and, consequently, its failure mechanism. To address some of these previous uncertainties, this study examined the failure mode of short and very short shear links made from ASTM A992 steel. For this purpose, a parametric study was conducted using the finite element software ABAQUS, considering the effects of local buckling, cumulative damage under cyclic loading, and the influence of crack initiation and propagation on the reduction of strength and stiffness. According to the results, the code provisions lead to conservative outcomes (by more than 40%) for the rotation capacity of shear links, especially very short shear links. Thus, one of the main reasons for the occurrence of a large overstrength factor in shear links is their rotation capacity exceeding 0.08, which leads to strain hardening in the steel material and the development of forces greater than the plastic shear strength of the section. Furthermore, examining the failure mode of the links showed that, with an increase in web slenderness, the location of damage initiation and tearing shifts away from the stiffener-to-web connection and moves towards the center of the web panel. Additionally, in short shear links, particularly in models with smaller link length ratios, failure typically begins with vertical cracks near the stiffener and then propagates at the end of the stiffener into the link web. However, in very short shear links with smaller length ratios, web tearing occurs at the intersection of the flange and web.

https://sjce.journals.sharif.edu/article_24123_f75ebe37cb0944c11a492ed38269a0cf.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Evaluation of seismic performance of Special truss moment frames (STMF) with Vierendeel special segment Evaluation of seismic performance of Special truss moment frames (STMF) with Vierendeel special segment 17 29 24122 10.24200/j30.2025.65546.3383 FA Naimeh Sadeghi Faculty of Civil Engineering, K. N. Toosi University of Technology. 0000-0002-5079-3227 Farbod Farmani Rastgoo Faculty of Civil Engineering, K. N. Toosi University of Technology. Journal Article 2024 11 02 In designing structures subjected to seismic forces, selecting an appropriate system based on seismic performance and building height is essential. Special Truss Moment Frames (STMF) are an innovative structural system designed to provide adequate lateral stiffness and control deformations. This system, combining steel trusses and columns instead of traditional beams, is highly efficient in absorbing lateral seismic forces, making it suitable for tall buildings and large spans. This study investigates the influence of the number of stories and the number of Vierendeel special segment panels in the STMF system on its seismic performance parameters. The analyzed models include nine cases with two, five, and eight stories, each designed with one, two, and three special segment panels. These models were developed in the ETABS software for preliminary design, while nonlinear analyses, including pushover and time history, were conducted in OpenSees. The pushover analysis was performed following FEMA P695 guidelines, and the nonlinear dynamic time history analysis was conducted based on ASCE 7 standards with 11 pairs of far-field ground motion records. The results highlight the high ductility of the STMF system, which increases with the number of stories and special segment panels, along with average over-strength factors of 2.5, which are close to the ASCE 7 recommended value of 3. The average transient story drift remained below 2%, while the average residual drift was approximately 0.15%, both within the permissible limits outlined in the code. Moreover, the models exhibit desirable seismic performance without any indications of non-compliance under severe seismic demands. In terms of design, increasing the number of panels in the special segment reduces the amount of structural steel required. This occurs because longer special segments result in lower expected shear forces, leading to smaller cross-sections for members outside the special segment. Conversely, models with shorter special segments demonstrate higher lateral stiffness and greater base shear capacities. Overall, this research confirms that the STMF system with Vierendeel special segments offers excellent seismic performance and can serve as a suitable and cost-effective option for designing structures with large spans. In designing structures subjected to seismic forces, selecting an appropriate system based on seismic performance and building height is essential. Special Truss Moment Frames (STMF) are an innovative structural system designed to provide adequate lateral stiffness and control deformations. This system, combining steel trusses and columns instead of traditional beams, is highly efficient in absorbing lateral seismic forces, making it suitable for tall buildings and large spans. This study investigates the influence of the number of stories and the number of Vierendeel special segment panels in the STMF system on its seismic performance parameters. The analyzed models include nine cases with two, five, and eight stories, each designed with one, two, and three special segment panels. These models were developed in the ETABS software for preliminary design, while nonlinear analyses, including pushover and time history, were conducted in OpenSees. The pushover analysis was performed following FEMA P695 guidelines, and the nonlinear dynamic time history analysis was conducted based on ASCE 7 standards with 11 pairs of far-field ground motion records. The results highlight the high ductility of the STMF system, which increases with the number of stories and special segment panels, along with average over-strength factors of 2.5, which are close to the ASCE 7 recommended value of 3. The average transient story drift remained below 2%, while the average residual drift was approximately 0.15%, both within the permissible limits outlined in the code. Moreover, the models exhibit desirable seismic performance without any indications of non-compliance under severe seismic demands. In terms of design, increasing the number of panels in the special segment reduces the amount of structural steel required. This occurs because longer special segments result in lower expected shear forces, leading to smaller cross-sections for members outside the special segment. Conversely, models with shorter special segments demonstrate higher lateral stiffness and greater base shear capacities. Overall, this research confirms that the STMF system with Vierendeel special segments offers excellent seismic performance and can serve as a suitable and cost-effective option for designing structures with large spans.

https://sjce.journals.sharif.edu/article_24122_72e72abe69317ef746232215d04833ab.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Damage Detection in Structures Using Chaotic Excitation and Improved Generalized Interdependence Feature Damage Detection in Structures Using Chaotic Excitation and Improved Generalized Interdependence Feature 31 42 24114 10.24200/j30.2025.65638.3385 FA Alireza Bahrami Faculty of Civil Engineering of K. N. Toosi University of Technology, Tehran, Iran. Saeid Asil Gharebaghi Faculty of Civil Engineering of K. N. Toosi University of Technology, Tehran, Iran. Journal Article 2024 11 10 Damage detection methods are integral components of structural health monitoring systems. Identifying damage in structures using vibration-based methods has always been one of the most important and popular topics among researchers in structural health monitoring. Vibration-based damage identification includes extracting a feature that can be used to measure the minuscule changes caused by damage to the structure. In recent years, advances have been made in using chaotic excitation and representing damage-sensitive features based on the properties of the chaotic attractor. These types of damage-sensitive features try to measure the minuscule changes caused by structural damage by comparing the chaotic attractors obtained from the structural response. The high sensitivity of chaotic systems to small changes makes attractor-based features suitable for identifying structural damage. One of the most widely used attractor-based features is the Generalized Interdependence, which has a reasonable sensitivity to damage and relatively low computational complexity. Also, the comparative nature of this feature can help identify damage in the presence of environmental variables such as noise. However, this feature has limitations that make its use exclusive to particular instances. e.g., in structures where the exact location of the damage is known beforehand. In the damage identification method presented in this research, improvements like adding a damage sensitivity factor and applying controls over the operation have been made to this feature to remove these limitations while preserving its exceptional properties in detecting damage in structures. In the structure examined in this research, where the generalized interdependence feature does not show the slightest decrease in dependence due to damage, the improved feature detects damage by showing about 20% better performance in finding a reduction in the dependence between two points of the structure. Two points of the structure are selected to be located at different distances from the damage. In other words, the improved feature can measure the different impacts due to damage on these two points. Damage detection methods are integral components of structural health monitoring systems. Identifying damage in structures using vibration-based methods has always been one of the most important and popular topics among researchers in structural health monitoring. Vibration-based damage identification includes extracting a feature that can be used to measure the minuscule changes caused by damage to the structure. In recent years, advances have been made in using chaotic excitation and representing damage-sensitive features based on the properties of the chaotic attractor. These types of damage-sensitive features try to measure the minuscule changes caused by structural damage by comparing the chaotic attractors obtained from the structural response. The high sensitivity of chaotic systems to small changes makes attractor-based features suitable for identifying structural damage. One of the most widely used attractor-based features is the Generalized Interdependence, which has a reasonable sensitivity to damage and relatively low computational complexity. Also, the comparative nature of this feature can help identify damage in the presence of environmental variables such as noise. However, this feature has limitations that make its use exclusive to particular instances. e.g., in structures where the exact location of the damage is known beforehand. In the damage identification method presented in this research, improvements like adding a damage sensitivity factor and applying controls over the operation have been made to this feature to remove these limitations while preserving its exceptional properties in detecting damage in structures. In the structure examined in this research, where the generalized interdependence feature does not show the slightest decrease in dependence due to damage, the improved feature detects damage by showing about 20% better performance in finding a reduction in the dependence between two points of the structure. Two points of the structure are selected to be located at different distances from the damage. In other words, the improved feature can measure the different impacts due to damage on these two points.

https://sjce.journals.sharif.edu/article_24114_62c56b3c5d7645a8afc46b632d05f7fc.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Experimental Investigation of the Bearing Capacity of a Masonry Wall Strengthened with Cold Polyurea Coating Under Out-of-Plane Loading Experimental Investigation of the Bearing Capacity of a Masonry Wall Strengthened with Cold Polyurea Coating Under Out-of-Plane Loading 43 50 24118 10.24200/j30.2025.65130.3371 FA Mohammad Ghajar Department of Civil Engineering, Imam Khomeini International University, Qazvin, Iran. Ramezan Ali Izadifar Department of Civil Engineering, Imam Khomeini International University, Qazvin, Iran. Journal Article 2024 11 25 One of the most vulnerable parts of a building during an earthquake, which can severely impact its functionality, is the non-structural walls or separating masonry walls. The 2016 Kermanshah earthquake highlighted that in some newly constructed buildings, while the primary structural elements, such as columns and beams remained intact, non-structural components, specifically walls, suffered significant damage, creating hazardous living conditions. These damages not only pose serious safety risks to occupants but also lead to substantial repair and reconstruction costs. Following the earthquake, modifications were made to building bylaws to enhance the reinforcement of non-structural elements, such as separating walls, aiming to improve overall structural stability. However, these regulations primarily apply to newly constructed buildings, and a large number of older structures, built before the implementation of these bylaws, still lack sufficient resistance in their non-structural elements, particularly walls. Thus, the need for strengthening these walls is evident, and the application of polyurea coating is one viable solution. In this research, the effectiveness of polyurea coating in enhancing wall resistance was evaluated through four four-point bending tests conducted on four different masonry walls with various forms of cold-applied polyurea coating. The experimental results demonstrated that walls coated with polyurea exhibited significantly higher load-bearing capacity compared to uncoated walls. Furthermore, displacement at the midpoint of the coated walls was considerably lower than in uncoated samples, confirming the effectiveness of polyurea in strengthening masonry structures. Specifically, walls treated with full polyurea coating and cross-framed polyurea coating showed a 45% and 39% increase in bearing capacity, respectively, compared to uncoated walls. Additionally, displacement in these coated walls decreased by 50%. Considering the optimal balance between structural resilience and cost-effectiveness, the application of polyurea coating in the form of a cross-frame or full coating is highly recommended to improve the resistance of masonry walls against out-of-plane loads, such as earthquakes and explosions. This method not only enhances the overall safety of buildings but also significantly mitigates damage risks during seismic events. One of the most vulnerable parts of a building during an earthquake, which can severely impact its functionality, is the non-structural walls or separating masonry walls. The 2016 Kermanshah earthquake highlighted that in some newly constructed buildings, while the primary structural elements, such as columns and beams remained intact, non-structural components, specifically walls, suffered significant damage, creating hazardous living conditions. These damages not only pose serious safety risks to occupants but also lead to substantial repair and reconstruction costs. Following the earthquake, modifications were made to building bylaws to enhance the reinforcement of non-structural elements, such as separating walls, aiming to improve overall structural stability. However, these regulations primarily apply to newly constructed buildings, and a large number of older structures, built before the implementation of these bylaws, still lack sufficient resistance in their non-structural elements, particularly walls. Thus, the need for strengthening these walls is evident, and the application of polyurea coating is one viable solution. In this research, the effectiveness of polyurea coating in enhancing wall resistance was evaluated through four four-point bending tests conducted on four different masonry walls with various forms of cold-applied polyurea coating. The experimental results demonstrated that walls coated with polyurea exhibited significantly higher load-bearing capacity compared to uncoated walls. Furthermore, displacement at the midpoint of the coated walls was considerably lower than in uncoated samples, confirming the effectiveness of polyurea in strengthening masonry structures. Specifically, walls treated with full polyurea coating and cross-framed polyurea coating showed a 45% and 39% increase in bearing capacity, respectively, compared to uncoated walls. Additionally, displacement in these coated walls decreased by 50%. Considering the optimal balance between structural resilience and cost-effectiveness, the application of polyurea coating in the form of a cross-frame or full coating is highly recommended to improve the resistance of masonry walls against out-of-plane loads, such as earthquakes and explosions. This method not only enhances the overall safety of buildings but also significantly mitigates damage risks during seismic events.

https://sjce.journals.sharif.edu/article_24118_c77dc9d482ed58bfa6efb3c3d545fefc.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Winter Maintenance of Ultra-Thin Bonded Wearing Course (UTBWC): A Case Study in Minnesota Winter Maintenance of Ultra-Thin Bonded Wearing Course (UTBWC): A Case Study in Minnesota 51 58 24121 10.24200/j30.2025.65732.3390 FA Mohammadreza Sabouri Department of Civil Engineering, Sharif University of Technology, Tehran, Iran Ali Ruhi Department of Civil Engineering, Sharif University of Technology, Tehran, Iran Journal Article 2024 11 27 Ultra-Thin Bonded Wearing Course (UTBWC) is utilized as a preventive maintenance option to extend pavement life by postponing the need for rehabilitation or reconstruction operations. UTBWC usually consists of a thin open-graded asphalt mixture over a polymer-modified emulsion membrane, which is applied by special pavers. Regarding the open-graded structure and rough texture of UTBWC, their winter maintenance differs from conventional pavements, leading to some challenges in the maintenance process. In this regard, this study aims to investigate the winter maintenance of UTBWC overlays through a comprehensive literature review, case study evaluation of a UTBWC section in Minnesota (performance and economic assessments), and field survey on the experiences with the UTBWC winter maintenance from Department of Transportation (DOT) specialists of some US states that are located in cold regions. The results showed that the winter maintenance of UTBWC sections, due to their porous structure and open-graded aggregate texture, which promotes greater accumulation of snow and ice, requires more deicing materials and more frequent snow plowing, which results in higher winter maintenance costs. Also, to avoid the accumulation of blown snow on the UTBWC surface, it is recommended to avoid the use of UTBWC in rural windy environments where the roadway runs in a direction perpendicular to the common wind direction. Economic assessment of the UTBWC section shows that the winter maintenance of UTBWC was more costly than the conventional mixtures and overlays. On the other hand, the results of the case study showed that the performance of UTBWC, in terms of Ride Quality Index (RQI), was better than the conventional Hot Mix Asphalt (HMA) overlay, which can reduce the overall maintenance cost and make UTBWC an economical preventive maintenance option. Therefore, decision-making regarding the management and maintenance of these overlays can be facilitated by considering a multifaceted approach, including technical, economic, and environmental performance. Also, a better understanding of the behavior of UTBWC and its maintenance methods can help to make more effective and better decisions for the implementation of this type of wearing course in the cold regions. Ultra-Thin Bonded Wearing Course (UTBWC) is utilized as a preventive maintenance option to extend pavement life by postponing the need for rehabilitation or reconstruction operations. UTBWC usually consists of a thin open-graded asphalt mixture over a polymer-modified emulsion membrane, which is applied by special pavers. Regarding the open-graded structure and rough texture of UTBWC, their winter maintenance differs from conventional pavements, leading to some challenges in the maintenance process. In this regard, this study aims to investigate the winter maintenance of UTBWC overlays through a comprehensive literature review, case study evaluation of a UTBWC section in Minnesota (performance and economic assessments), and field survey on the experiences with the UTBWC winter maintenance from Department of Transportation (DOT) specialists of some US states that are located in cold regions. The results showed that the winter maintenance of UTBWC sections, due to their porous structure and open-graded aggregate texture, which promotes greater accumulation of snow and ice, requires more deicing materials and more frequent snow plowing, which results in higher winter maintenance costs. Also, to avoid the accumulation of blown snow on the UTBWC surface, it is recommended to avoid the use of UTBWC in rural windy environments where the roadway runs in a direction perpendicular to the common wind direction. Economic assessment of the UTBWC section shows that the winter maintenance of UTBWC was more costly than the conventional mixtures and overlays. On the other hand, the results of the case study showed that the performance of UTBWC, in terms of Ride Quality Index (RQI), was better than the conventional Hot Mix Asphalt (HMA) overlay, which can reduce the overall maintenance cost and make UTBWC an economical preventive maintenance option. Therefore, decision-making regarding the management and maintenance of these overlays can be facilitated by considering a multifaceted approach, including technical, economic, and environmental performance. Also, a better understanding of the behavior of UTBWC and its maintenance methods can help to make more effective and better decisions for the implementation of this type of wearing course in the cold regions.

https://sjce.journals.sharif.edu/article_24121_d8b7ec341b770a4eba53fa6649644c82.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Evaluation of seismic performance of Special truss moment frames (STMF) with Vierendeel special segment Evaluation of seismic performance of Special truss moment frames (STMF) with Vierendeel special segment 59 71 24147 10.24200/j30.2025.66262.3406 FA ََAlireza Mirzaei School of Civil Engineering, College of Engineering, University of Tehran, Iran‌. Abazar Asghari School of Civil Engineering, College of Engineering, University of Tehran, Iran‌. Amirreza Ghiami Azad School of Civil Engineering, College of Engineering, University of Tehran, Iran‌. Journal Article 2025 02 18 In designing structures subjected to seismic forces, selecting an appropriate system based on seismic performance and building height is essential. Special Truss Moment Frames (STMF) are an innovative structural system designed to provide adequate lateral stiffness and control deformations. This system, combining steel trusses and columns instead of traditional beams, is highly efficient in absorbing lateral seismic forces, making it suitable for tall buildings and large spans. This study investigates the influence of the number of stories and the number of Vierendeel special segment panels in the STMF system on its seismic performance parameters. The analyzed models include nine cases with two, five, and eight stories, each designed with one, two, and three special segment panels. These models were developed in the ETABS software for preliminary design, while nonlinear analyses, including pushover and time history, were conducted in OpenSees. The pushover analysis was performed following FEMA P695 guidelines, and the nonlinear dynamic time history analysis was conducted based on ASCE 7 standards with 11 pairs of far-field ground motion records. The results highlight the high ductility of the STMF system, which increases with the number of stories and special segment panels, along with average over-strength factors of 2.5, which are close to the ASCE 7 recommended value of 3. The average transient story drift remained below 2%, while the average residual drift was approximately 0.15%, both within the permissible limits outlined in the code. Moreover, the models exhibit desirable seismic performance without any indications of non-compliance under severe seismic demands. In terms of design, increasing the number of panels in the special segment reduces the amount of structural steel required. This occurs because longer special segments result in lower expected shear forces, leading to smaller cross-sections for members outside the special segment. Conversely, models with shorter special segments demonstrate higher lateral stiffness and greater base shear capacities. Overall, this research confirms that the STMF system with Vierendeel special segments offers excellent seismic performance and can serve as a suitable and cost-effective option for designing structures with large spans. In designing structures subjected to seismic forces, selecting an appropriate system based on seismic performance and building height is essential. Special Truss Moment Frames (STMF) are an innovative structural system designed to provide adequate lateral stiffness and control deformations. This system, combining steel trusses and columns instead of traditional beams, is highly efficient in absorbing lateral seismic forces, making it suitable for tall buildings and large spans. This study investigates the influence of the number of stories and the number of Vierendeel special segment panels in the STMF system on its seismic performance parameters. The analyzed models include nine cases with two, five, and eight stories, each designed with one, two, and three special segment panels. These models were developed in the ETABS software for preliminary design, while nonlinear analyses, including pushover and time history, were conducted in OpenSees. The pushover analysis was performed following FEMA P695 guidelines, and the nonlinear dynamic time history analysis was conducted based on ASCE 7 standards with 11 pairs of far-field ground motion records. The results highlight the high ductility of the STMF system, which increases with the number of stories and special segment panels, along with average over-strength factors of 2.5, which are close to the ASCE 7 recommended value of 3. The average transient story drift remained below 2%, while the average residual drift was approximately 0.15%, both within the permissible limits outlined in the code. Moreover, the models exhibit desirable seismic performance without any indications of non-compliance under severe seismic demands. In terms of design, increasing the number of panels in the special segment reduces the amount of structural steel required. This occurs because longer special segments result in lower expected shear forces, leading to smaller cross-sections for members outside the special segment. Conversely, models with shorter special segments demonstrate higher lateral stiffness and greater base shear capacities. Overall, this research confirms that the STMF system with Vierendeel special segments offers excellent seismic performance and can serve as a suitable and cost-effective option for designing structures with large spans.

https://sjce.journals.sharif.edu/article_24147_9636ead7f8350ad9bfa7efbc0fe3609c.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 A Review of Damages and Lessons Learnt from Major Incidents in Concrete Dams A Review of Damages and Lessons Learnt from Major Incidents in Concrete Dams 73 84 24146 10.24200/j30.2025.65521.3380 FA Mohammad Taghi Ahmadi Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran. Ehsan Valadkani Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran. Journal Article 2024 12 14 Large dams are structures considered national assets, and any incident involving them can be catastrophic in terms of loss of life, property, and social impact. Most large concrete dams have been gradually constructed over the past century. Many of these dams were built without sufficient understanding of the foundation and abutment conditions, without a proper grasp of load processes and probable environmental conditions in their design, or with incorrect assumptions about the behavior of materials and structural systems. Given that the weakness of unreinforced concrete used in the main body of dams under tensile and shear conditions leads to sudden and brittle cracks of large dimensions, a combination of various incidents can create a concerning scenario, either gradually or abruptly, posing a serious threat to the safety of the dam and reservoir system. Even modern knowledge and technology cannot entirely rule out the possibility of errors or unintended uncertainties in the behavior of these strategic structures. As a result, risk management practices, including the study of past events and minor and major incidents, have become crucial in the evaluation and assessment of large dam systems. Through systematic or case studies on the behavior and service life processes of these systems, there is hope for a deeper understanding of the dam-reservoir-foundation system's behavior, thereby enabling the prevention of similar incidents in the future. The objective of this study is to investigate the most significant historical damages sustained by large concrete dams and analyze the factors contributing to each incident and its various dimensions. In most cases of dam failure, it is impossible to attribute the damage to a single factor. Typically, major damage or failure in a concrete dam results from a combination of factors that interact with one another or form a chain of events leading to the primary failure. Overall, based on past incidents and research, it becomes clear that although factors such as overall foundation weakness, unforeseen mechanisms resulting from geological or geotechnical deficiencies within the foundation and abutment, issues arising from complex thermal loads, seepage, and unforeseen earthquake characteristics are recognized as the most common causes of severe incidents, in most cases, it is human error—stemming from a lack of sufficient knowledge about the system, ignorance of available knowledge, or non-technical managerial decisions—that enables these physical factors to take effect. Such errors during the design, construction, and operation phases provide the opportunity for the above-mentioned physical factors to exert their influence. Finally, it should be noted that most major incidents occur during the early years of the dam’s life, particularly during the initial reservoir filling, underscoring the absolute necessity of a gradual, step-by-step approach and the strict enforcement of monitoring regulations during this critical period. Large dams are structures considered national assets, and any incident involving them can be catastrophic in terms of loss of life, property, and social impact. Most large concrete dams have been gradually constructed over the past century. Many of these dams were built without sufficient understanding of the foundation and abutment conditions, without a proper grasp of load processes and probable environmental conditions in their design, or with incorrect assumptions about the behavior of materials and structural systems. Given that the weakness of unreinforced concrete used in the main body of dams under tensile and shear conditions leads to sudden and brittle cracks of large dimensions, a combination of various incidents can create a concerning scenario, either gradually or abruptly, posing a serious threat to the safety of the dam and reservoir system. Even modern knowledge and technology cannot entirely rule out the possibility of errors or unintended uncertainties in the behavior of these strategic structures. As a result, risk management practices, including the study of past events and minor and major incidents, have become crucial in the evaluation and assessment of large dam systems. Through systematic or case studies on the behavior and service life processes of these systems, there is hope for a deeper understanding of the dam-reservoir-foundation system's behavior, thereby enabling the prevention of similar incidents in the future. The objective of this study is to investigate the most significant historical damages sustained by large concrete dams and analyze the factors contributing to each incident and its various dimensions. In most cases of dam failure, it is impossible to attribute the damage to a single factor. Typically, major damage or failure in a concrete dam results from a combination of factors that interact with one another or form a chain of events leading to the primary failure. Overall, based on past incidents and research, it becomes clear that although factors such as overall foundation weakness, unforeseen mechanisms resulting from geological or geotechnical deficiencies within the foundation and abutment, issues arising from complex thermal loads, seepage, and unforeseen earthquake characteristics are recognized as the most common causes of severe incidents, in most cases, it is human error—stemming from a lack of sufficient knowledge about the system, ignorance of available knowledge, or non-technical managerial decisions—that enables these physical factors to take effect. Such errors during the design, construction, and operation phases provide the opportunity for the above-mentioned physical factors to exert their influence. Finally, it should be noted that most major incidents occur during the early years of the dam’s life, particularly during the initial reservoir filling, underscoring the absolute necessity of a gradual, step-by-step approach and the strict enforcement of monitoring regulations during this critical period.

https://sjce.journals.sharif.edu/article_24146_de687c06de474c0276920b53caef7e59.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Semi-Automated Lifecycle Safety Risk Assessment of Construction Projects: A Preventive Approach Based on Building Information Modeling Semi-Automated Lifecycle Safety Risk Assessment of Construction Projects: A Preventive Approach Based on Building Information Modeling 85 96 24115 10.24200/j30.2025.65673.3388 FA Amirhossein Ostovari School of Architecture, Department of Construction and Project Management, University of Tehran, Tehran, Iran Sayyed Vahid Faghihi School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran Seyed Hossein Hosseini Nourzad 1School of Architecture, Department of Construction and Project Management, University of Tehran, Tehran, Iran Journal Article 2024 12 23 Due to its complex and multifaceted nature, the construction industry has always faced many safety challenges. Safety management is critical in countries like Iran, which face limitations regarding training, equipment, and regulations. This article aims to provide a comprehensive review of safety management in the construction industry and provide new approaches to improve it. For this purpose, first, the existing literature in the field of safety management in construction projects is reviewed, and then the challenges in this field are identified and analyzed. In this research, using historical accident database data and in the framework of building information modeling, a semi-automatic approach to identify and evaluate safety risks in the design phase has been developed. To achieve this goal, a plugin was developed for Autodesk Revit, which, by analyzing building components in 3D models, identifies different risks and classifies them based on the severity of the results they create in varying levels of risk (high, medium, and low). Also, the plugin automatically suggests appropriate preventive measures by leveraging OSHA standards and helps users manage risks and prevent them from occurring. In this way, a comprehensive risk assessment process is implemented from the stage of identification and evaluation to the provision of control measures and documentation on these incidents. The results of this research show that by using new technologies, such as building information modeling and implementing preventive strategies in the design phase, it is possible to improve the safety level in construction projects significantly. Due to its complex and multifaceted nature, the construction industry has always faced many safety challenges. Safety management is critical in countries like Iran, which face limitations regarding training, equipment, and regulations. This article aims to provide a comprehensive review of safety management in the construction industry and provide new approaches to improve it. For this purpose, first, the existing literature in the field of safety management in construction projects is reviewed, and then the challenges in this field are identified and analyzed. In this research, using historical accident database data and in the framework of building information modeling, a semi-automatic approach to identify and evaluate safety risks in the design phase has been developed. To achieve this goal, a plugin was developed for Autodesk Revit, which, by analyzing building components in 3D models, identifies different risks and classifies them based on the severity of the results they create in varying levels of risk (high, medium, and low). Also, the plugin automatically suggests appropriate preventive measures by leveraging OSHA standards and helps users manage risks and prevent them from occurring. In this way, a comprehensive risk assessment process is implemented from the stage of identification and evaluation to the provision of control measures and documentation on these incidents. The results of this research show that by using new technologies, such as building information modeling and implementing preventive strategies in the design phase, it is possible to improve the safety level in construction projects significantly.

https://sjce.journals.sharif.edu/article_24115_fd7bc2f8e125f4c19e8ef2c539cba2d3.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Sensitivity Analysis of Energy Dissipation in a Yielding Damper with Cantilever Bars Sensitivity Analysis of Energy Dissipation in a Yielding Damper with Cantilever Bars 97 107 24124 10.24200/j30.2025.65775.3392 FA Saeed Reza Sabbagh Yazdi Faculty of Civil Engineering of K. N. Toosi University of Technology, Tehran, Iran. Mostafa Rezvani Sharif Civil Engineering Department, K. N. Toosi University of Technology, Tehran, Iran Reza Zakibakhsh Mohammadi Faculty of Civil Engineering of K. N. Toosi University of Technology, Tehran, Iran. Journal Article 2024 11 30 Seismic isolators serve a vital function in mitigating structural damage resulting from lateral loads and in diminishing the forces exerted upon the structure. In structures that are isolated, the displacement may experience a substantial increase, which, in the case of bridges, could potentially result in the collapse of the deck from its supports. In addition, isolator systems may have low energy absorption capacity. Controlling displacement and ensuring adequate energy dissipation in isolated structures under wind and earthquake loads proves the importance of incorporating devices like energy dampers alongside seismic isolators. Yielding dampers are a category of dampers recommended in previous research, which are produced in various types. These dampers utilize the inelastic deformation of ductile metals to dissipate the energy. One effective type of damper for energy dissipation in isolated structures is the bar-shaped damper with cantilever bars. In these dampers, the bars are positioned vertically, so that energy is dissipated regardless of the direction. The energy-absorbing elements in these dampers are the cantilever bars, with one end connected to the substructure and the other to the isolated structure. As relative displacement occurs between the substructure and isolated structure, the bars undergo bending and enter the plastic deformation range, so that dissipating earthquake energy occurs. The behavior of these dampers is influenced by parameters such as bar diameter, bar length, number of bars, and bar yield stress. Hence, determining the effect of each parameter on damper performance is crucial for selecting a suitable damper. In this study, after modeling a bar damper with a cantilever bar in the ABAQUS finite element software, the effect of changes in each of these parameters on the damper's energy dissipation was analyzed. The results demonstrate that energy dissipation in this damper is most sensitive to changes in bar diameter, followed by the number of bars, bar length, and bar yield stress. Seismic isolators serve a vital function in mitigating structural damage resulting from lateral loads and in diminishing the forces exerted upon the structure. In structures that are isolated, the displacement may experience a substantial increase, which, in the case of bridges, could potentially result in the collapse of the deck from its supports. In addition, isolator systems may have low energy absorption capacity. Controlling displacement and ensuring adequate energy dissipation in isolated structures under wind and earthquake loads proves the importance of incorporating devices like energy dampers alongside seismic isolators. Yielding dampers are a category of dampers recommended in previous research, which are produced in various types. These dampers utilize the inelastic deformation of ductile metals to dissipate the energy. One effective type of damper for energy dissipation in isolated structures is the bar-shaped damper with cantilever bars. In these dampers, the bars are positioned vertically, so that energy is dissipated regardless of the direction. The energy-absorbing elements in these dampers are the cantilever bars, with one end connected to the substructure and the other to the isolated structure. As relative displacement occurs between the substructure and isolated structure, the bars undergo bending and enter the plastic deformation range, so that dissipating earthquake energy occurs. The behavior of these dampers is influenced by parameters such as bar diameter, bar length, number of bars, and bar yield stress. Hence, determining the effect of each parameter on damper performance is crucial for selecting a suitable damper. In this study, after modeling a bar damper with a cantilever bar in the ABAQUS finite element software, the effect of changes in each of these parameters on the damper's energy dissipation was analyzed. The results demonstrate that energy dissipation in this damper is most sensitive to changes in bar diameter, followed by the number of bars, bar length, and bar yield stress.

https://sjce.journals.sharif.edu/article_24124_6fe24362f443161c8d5f1fc198e33a2c.pdf

Sharif University of Technology Sharif Journal of Civil Engineering 2676-4768 41 4 2026 03 20 Bearing Capacity of Strip Foundations on Shale Rock Masses with Rheological Behaviour: Probabilistic Based Approach Bearing Capacity of Strip Foundations on Shale Rock Masses with Rheological Behaviour: Probabilistic Based Approach 109 122 24166 10.24200/j30.2025.66634.3422 FA Faraz Motamedi Mamaghani Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran. Masoud Ranjbarnia Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran. Milad Zaheri Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran. Journal Article 2025 04 08 Predicting the bearing capacity of rock masses can be challenging when the values of rock mass properties have high uncertainty. This challenge becomes even greater when the rock mass exhibits time-dependent behavior. Therefore, in this paper, the bearing capacity of strip foundations located on rock masses with time-dependent behavior is investigated. For this purpose, FLAC software is used and the visco-elasto-plastic CVISC model is assigned to the rock mass. Also, the Hoek-Brown criterion constant, uniaxial compressive strength of rock mass, GSI (geological strength index of rock mass), Kelvin shear modulus, Maxwell viscosity, and Kelvin viscosity are selected as random parameters. Initially, using the results obtained from this software and using the response surface methodology, the relationship between these input parameters and the bearing capacity of the rhological rock mass is determined. Then, a normal distribution and mean and standard deviation values are assigned to each of these parameters. In the next step, using the Monte Carlo method, a large number of random numbers are generated and, considering the relationship between the above input random variables and the resulting output (bearing capacity of the rock mass with the time-dependent behaviour), probability distributions for the output of the problem are determined. The results of this research indicate that the Kelvin shear modulus of the rock mass is the most effective parameter in predicting of the value of the bearing capacity, and the resulting distributions follow the normal distribution. Besides, if the uncertainty of the rock mass parameters increases, the standard deviation of the results also increases. Also, the amount of positive skewness also increases. As a result, the probability that the bearing capacity of the rock mass is less than the average value is greater. Thus, in various construction projects, the bearing capacity of rock masses needs to be examined based on probabilistic methods. Predicting the bearing capacity of rock masses can be challenging when the values of rock mass properties have high uncertainty. This challenge becomes even greater when the rock mass exhibits time-dependent behavior. Therefore, in this paper, the bearing capacity of strip foundations located on rock masses with time-dependent behavior is investigated. For this purpose, FLAC software is used and the visco-elasto-plastic CVISC model is assigned to the rock mass. Also, the Hoek-Brown criterion constant, uniaxial compressive strength of rock mass, GSI (geological strength index of rock mass), Kelvin shear modulus, Maxwell viscosity, and Kelvin viscosity are selected as random parameters. Initially, using the results obtained from this software and using the response surface methodology, the relationship between these input parameters and the bearing capacity of the rhological rock mass is determined. Then, a normal distribution and mean and standard deviation values are assigned to each of these parameters. In the next step, using the Monte Carlo method, a large number of random numbers are generated and, considering the relationship between the above input random variables and the resulting output (bearing capacity of the rock mass with the time-dependent behaviour), probability distributions for the output of the problem are determined. The results of this research indicate that the Kelvin shear modulus of the rock mass is the most effective parameter in predicting of the value of the bearing capacity, and the resulting distributions follow the normal distribution. Besides, if the uncertainty of the rock mass parameters increases, the standard deviation of the results also increases. Also, the amount of positive skewness also increases. As a result, the probability that the bearing capacity of the rock mass is less than the average value is greater. Thus, in various construction projects, the bearing capacity of rock masses needs to be examined based on probabilistic methods.

https://sjce.journals.sharif.edu/article_24166_27a3b0eec153ba7006d590de314a5428.pdf