International Institute of Earthquake Engineering and SeismologyJournal of Seismology and Earthquake Engineering1735-166927220250401Tectonic Model-Based Critique on Conventional Seismic Hazard Evaluations; Implications for the Role of the South Caspian Basin on Seismicity of Northern Iran11471861010.48303/jsee.2024.2034254.1108ENZamanMalekzadeAssistant Professor, Department of Geology, Payam-e Noor University, Tehran, IranJournal Article20240630Reconnaissance, definition, mapping, and mechanism(s) of the earthquake sources are the preliminary earthquake hazard analysis strategies. Heterogeneity of the crust, change in stress, and diffuse and distributed nature of the present-day continental deformation are the features that may influence the seismic sources, which, in turn, determine the seismic hazard assessment policy. The mechanisms and geometry of the sources potentially relate to the physics of the crust and then the magnitude, duration, and depth of generated earthquakes, etc. Tectonics, on the other hand, deals with recovering the stress state, and consequent deformations represented by geostructures, including the faults and folds. Therefore, the tectonic investigations and modeling may lead to better definitions and characteristics of the seismic sources. This study introduces a new approach to defining earthquake sources and segmentation, providing a practical guideline for evaluating earthquake occurrences. This evaluation model is supported by geological evidence that forms a crucial component of Probabilistic Seismic Hazard Assessment (PSHA) and Deterministic Seismic Hazard Analysis (DSHA) programs. The tectonic model's key output is the segmentation of fault zones responsible for earthquakes, some of which could be blind faults or faults yet to be identified as active faults. These regions might be regarded as seismic areas in conventional seismic evaluations. The study recommends distinguishing between seismic hazard and seismic risk maps in regions where the potential for seismic activity is the same, but the population densities differ.International Institute of Earthquake Engineering and SeismologyJournal of Seismology and Earthquake Engineering1735-166927220250401Generating Design Spectrum-Compatible Artificial Accelerograms Utilizing Generative Adversarial Networks152472515310.48303/jsee.2025.2034252.1109ENMehrshadMatinfarM.Sc. in Structural Engineering, Tarbiat Modares University, Tehran, Iran0000-0002-4850-7682NaserKhajiProfessor of Civil Engineering, Hiroshima University, Hiroshima, Japan0000-0002-5701-7706Journal Article20240630Recent advancements in Deep Learning (DL) have significantly expanded its application to address myriad challenges in civil and earthquake engineering. However, a notable challenge persists: the scarcity of reliable data pertinent to earthquake engineering, which may compromise the accuracy of DL-derived results. In response to this challenge, Generative Adversarial Networks (GANs) have emerged as a promising solution. Initially conceptualized to improve the training of generative models, GANs have exhibited exceptional performance and adaptability, particularly in image generation, gaining substantial recognition within the academic community. In structural engineering, the generation of synthetic ground accelerograms that conform to a specified target response spectrum is essential for conducting nonlinear dynamic analyses. This paper introduces an effective algorithm for spectral matching, facilitating the generation of numerous artificial, spectrum-compatible earthquake accelerograms from a limited set of ground motion records. The proposed algorithm represents a significant advancement in the field, addressing the critical need for robust and accurate synthetic data in earthquake engineering. Consequently, the integration of GANs into this domain not only enhances the reliability of DL applications but also paves the way for more precise and comprehensive analyses, thereby contributing to the overall progress of civil and earthquake engineering disciplines.International Institute of Earthquake Engineering and SeismologyJournal of Seismology and Earthquake Engineering1735-166927220250401Seismic Performance of Mat and Grid Foundations on a Soft Fine-Grained soil underlying an Eight-Story Building253371734510.48303/jsee.2024.2042496.1126ENJavadJaliliAssistant Professor, Geotechnical Engineering Research Center, International Institute of Earthquake Engineering and Seismology
(IIEES), Tehran, Iran0000-0001-6840-5221MojtabaMoosaviAssistant Professor, Geotechnical Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran0009-0007-2411-8643FaradjollahAskariAssociate Professor, Geotechnical Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran0000-0001-9157-2693AzadehMarghaiezadehResearch Expert, Geotechnical Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, IranJournal Article20241002<span>In cases of large deformations of the ground underlying a structure, mat and grid foundations are two options to reduce probable differential settlements, due to their rigidity in the perpendicular directions and their relatively larger area compared with single spread foundations. A case study of large settlements of an 8-storey structure resting on soft saturated fine-grained soil due to seismic loading is numerically investigated herein. The foundations were matching in plan dimensions (10*18 m), and the grid foundation was 30 cm thicker than the 60-cm-thick mat, reaching nearly similar volume (110 m3 in the case of grid foundation and 108 m3 in the case of mat foundation). To decide on the more economical foundation type between mat and grid, the amount of reinforcing steel bars and the cost of construction, including concrete molding should be considered. Herein, based only on the amount of foundation settlement, it is shown that the performance of a grid foundation is better than or identical to mat foundations, which makes it an alternative with probably a more economical option to be preferred to mats in the design of foundations in areas of high seismicity. It is also shown that assessment of the frequency content of the input motions by applying the white Gaussian noise added to a sine sweep of frequencies to the model and inspecting the results, is useful in understanding the results.</span>International Institute of Earthquake Engineering and SeismologyJournal of Seismology and Earthquake Engineering1735-166927220250401Scenario-Based Evaluation of Earthquake Impacts on Gas Infrastructure in Tehran354873123710.48303/jsee.2025.2067103.1154ENMostafaSharifiPh.D. Candidate, Department of Civil Engineering, SR.C, Islamic Azad University, Tehran, Iran0009-0003-3959-0239FereshtehEmamiAssistant Professor, Department of Civil Engineering, SR.C, Islamic Azad University, Tehran, Iran0000-0002-5410-7992GholamrezaGhodrati AmiriProfessor, Iran University of Science and Technology, Tehran, IranErfanFiruziAssistant Professor, Risk Management Research Center, International Institute of Earthquake Engineering and Seismology (IIEES),
Tehran, IranJournal Article20250726Tehran, the capital of Iran, lies in a highly active seismic zone and is exposed to significant earthquake risk due to multiple nearby faults. Among critical urban infrastructure, the gas distribution network is especially vulnerable to earthquakes, but it has not been thoroughly studied in most current risk assessments. This study proposes a probabilistic framework to evaluate the seismic vulnerability of Tehran’s gas distribution network under four major earthquake scenarios (Mosha, North Tehran Fault, Eyvanakey, and Rey faults). The methodology incorporates both aleatory and epistemic uncertainties from hazard and damage assessments of buried pipelines and pressure reduction stations. The intra-event variability of ground motion values is considered in the analysis through random sampling from spatial-cross correlation model. Similarly, the aleatory uncertainty of damage types (leak and break) in pipelines is captured in the analysis through random sampling from a probabilistic distribution. Results from 1,000 Monte Carlo simulations reveal that the Eyvanakey scenario poses the highest risk, particularly in southeastern Tehran, while the Rey scenario results in minimum damage. The spatial distribution of risk underscores the importance of localized mitigation strategies. The proposed framework provides an appropriate tool for urban seismic risk assessment and resilience planning of gas utility systems in seismically active cities.International Institute of Earthquake Engineering and SeismologyJournal of Seismology and Earthquake Engineering1735-166927220250401Sustainable Seismic Design Guidelines of Steel Earthquake Resisting Structures71761710.48303/jsee.2024.2037265.1116ENRazieAnsari TarghiPh.D. Candidate, School of Civil Engineering, Iran University of Science and Technology, Tehran, Iran0000-0001-5710-8387MarzieAnsari TarghiPh.D. Candidate, Faculty of Civil, Water and Environmental Engineering, University of Shahi Beheshti, Tehran, Iran0000-0003-0987-4241MarkGrigorianD.Phil., MGA Structural Engineering Consultant Inc,Glendale, California, USA0000-0002-8508-1481VahidBroujerdianAssociate Professor of Civil Engineering, Iran University of Science and Technology, Tehran, IranJournal Article20240731Recently, a number of much-needed innovations have captured the attention of the earthquake engineering communities worldwide: the stiff braced rocking core, as part of conventional steel earthquake-resisting systems (ERS); the introduction of low-damage systems and components; the use of triple and mixed multiple seismic structures; and the sustainable seismic design (SSD) philosophy with a view to economy and environmental protection. SSD has been the most challenging issue confronting structural engineers for decades. Regardless of carbon footprint reductions, unless a structure is designed for seismic sustainability, it would be disposable with greater human discomfort, economic loss, and harm to the environment. In the present context, design<em> </em>implies planning for controlled seismic resistance, environmental protection, construction economy and Post-earthquake Realignment and Repairs (PERR). In SSD, the practicality of PERR is as important as the relevance of the theoretical assumptions; therefore, the non-lateral resisting items are carefully designed not to partake in seismic resistance. All Earthquake Resisting Structures (ERS) are designed for practical, residue-free recentering while their energy-dissipating components are detailed to remain repairable/replaceable after the event. In the interim, new categories of ERS and innovative ideas have also been introduced. The authors hope this and related articles will form the basis of SSD guidelines for earthquake-prone resilient cities.International Institute of Earthquake Engineering and SeismologyJournal of Seismology and Earthquake Engineering1735-166927220250401Determining the Effect of Seismic Response of Isolated Structures of Urban Infrastructure under Dynamic Loading (Case study: Urban Train)71606710.48303/jsee.2024.2029835.1092ENRasoolNodeh FarahaniPh.D. in Civil Engineering, Noshirvani University of Technology, Babol, Iran0000-0002-1174-6137Journal Article20240528This study takes the indoor substation adjacent to the elevated urban train line as the engineering background, investigates the structural vibration response law of the substation induced by the operation of the subway line through on-site vibration measurement, and proposes a novel nonlinear gas-spring quasi-zero stiffness isolator (NGS-QZSI) is proposed to reduce the structural vertical vibration and further reduce the safety distance. The software ABAQUS is used to establish a structure-equipment coupling numerical analysis model considering soil-structure interaction, and its effectiveness and accuracy are validated based on the measured results. The structural vibration response analysis is carried out under different vibration source distances, and a nonlinear gas-spring quasi-zero stiffness isolator is proposed to be employed for substation structural vibration isolation. The research results show that the substation structure under subway load excitation is dominated by vertical vibration, and its vibration response increases gradually with the increase of floor level. When the substation structure is less than 45 m from the subway line, the structural response exceeds the safety limit (12.5 μm/s) of the VC-C standard. With the vibration isolator attached, the structural vibration response is significantly reduced, with the peak and root mean square response controlled by more than 70%. Particularly, the safe distance of the substation from the subway line is reduced from 45 m to 20 m. Moreover, the frequency domain result analysis indicates that the proposed nonlinear vibration isolator can effectively control the low-frequency vibration of the structure.