153 reads in the past 30 days
Seismic behaviour of Exterior RC beam-column joints repaired and strengthened using post-tensioned metal strapsMarch 2024
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751 Reads
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12 Citations
Published by Springer Nature and European Association for Earthquake Engineering
Online ISSN: 1573-1456
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Print ISSN: 1570-761X
Disciplines: Earthquake engineering
153 reads in the past 30 days
Seismic behaviour of Exterior RC beam-column joints repaired and strengthened using post-tensioned metal strapsMarch 2024
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751 Reads
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12 Citations
137 reads in the past 30 days
Seismic hazard zonation map and definition of seismic actions for Greece in the context of the ongoing revision of EC8May 2024
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700 Reads
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5 Citations
118 reads in the past 30 days
Experimental investigation on the seismic performance of reinforced concrete frames with decoupled masonry infills: considering in-plane and out-of-plane load interaction effectsNovember 2024
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315 Reads
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1 Citation
114 reads in the past 30 days
Observed damage and simplified risk assessment of Italian masonry bell towers struck by past seismic eventsMarch 2024
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1,655 Reads
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4 Citations
108 reads in the past 30 days
Geotechnical assessment of the 2023 Jajarkot Nepal Earthquake using field observations and remote sensingJanuary 2025
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109 Reads
The Bulletin of Earthquake Engineering is an open access, peer-reviewed journal that publishes original research on the broad spectrum of earthquake engineering. It serves as a forum for discussing European damaging earthquakes, new developments in earthquake regulations, and national policies post-seismic events. The journal covers topics like seismic hazard studies, risk mitigation methods, earthquake source mechanisms, and the behavior of soils under seismic conditions. It aligns with the UN sustainable development goals, particularly SDG 9 and SDG 11.
February 2025
Lewis J. Gooch
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Mark G. Stewart
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Mark J. Masia
February 2025
Giuseppe D’Arenzo
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Pietro Rigo
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Valentino Nicolussi
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[...]
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Daniele Casagrande
February 2025
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9 Reads
Iason Grigoratos
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Ryan Schultz
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Janneke van Ginkel
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[...]
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Annemarie G. Muntendam-Bos
Activities related to energy production have been linked with felt (and in some cases damaging) earthquakes. Notable examples include hydraulic fracturing, wastewater disposal, geothermal systems, coal mining, carbon storage and hydropower dams. As the demand for energy continues to grow, new frontiers in energy exploration will emerge - some with the potential for induced seismicity. Thus, there is a clear need for a source-agnostic seismic risk protocol that can be applied to any activity or region. This study outlines one such implementation that uses scenario earthquakes to produce a priori risk thresholds that can be referenced against current seismicity levels on an ongoing basis. Our framework is designed to inform regulatory decisions by considering the consequences of earthquake scenarios on the population and the built environment, together with simplified forecasts of the next largest magnitude. The proposed framework can tackle both the screening process needed for permitting purposes and serve as a risk management plan during operations.
February 2025
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11 Reads
On 21 August 2017, a Mw 3.9 earthquake struck the island of Ischia, causing two casualties and significant damage in the village of Casamicciola Terme and its surroundings. The earthquake was recorded by the local INGV-OV seismic network, and represents the first relevant instrumentally recorded earthquake on the island. However, it is not possible to perform a statistical analysis based on past recordings, which forms the basis of the Ground Motion Model at a local scale. The numerical simulations can help overcome this problem. Here, we first analysed the low magnitude seismicity of the island and focused on estimating the seismic attenuation and average static stress drop through spectral inversion analysis. We then used a stochastic finite-fault approach considering two source models to simulate the Casamicciola earthquake’s strong ground motion by also taking into account the site effect at the IOCA station. The numerical simulations were also extended to the localities for which observed macroseismic intensity values are available. The simulated peak ground motions, converted into intensities through empirical relationships, are somewhat higher than the observed values for both source configurations, suggesting that the regional dependence between intensity and peak ground motion cannot be overlooked. Future investigations should be undertaken to improve seismic hazard assessment at a local scale. Conversely, synthetic PGAs and PGVs show a satisfactory match with the values predicted by the generic GMM calibrated for volcanic areas in Italy. The results underscore the importance of region-specific GMMs for reliable seismic scenarios.
February 2025
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10 Reads
To study the axial-shear-flexure-interactive (ASFI) and shear strength behavior of reinforced concrete (RC) members with low-bond reinforcement, 20 high-strength fly ash concrete beams with low-bond high-strength SBPDN 1275/1420 rebars were fabricated for testing. The experimental results indicated that the degradation in the shear strength carried by the concrete (Vc) controlled the overall shear strength behavior of the test beams. The Vc of the test beams with shear span ratios greater than 1.5 eventually reduced to zero owing to the development of shear cracks. A calculation method for predicting the ASFI behavior of RC members was proposed to predict the lateral behavior without numerous mathematical iterations, which accounted for deformations due to flexure, steel-bond slip, and shear. An analytical model was derived to calculate the nominal shear strength using the shear friction mechanism and the Mohr–Coulomb failure criterion. Compared to the models currently proposed in design provisions, this model exhibited better alignment with the experimental results. A new model describing the degradation of shear strength due to shear cracks was also proposed, which incorporated the effect of the longitudinal rebar bond strength on the drift at which the nominal shear strength begins to deteriorate. Comparisons between the predicted and experimental results of RC members with different structural variables indicated that the ASFI calculation program and shear strength model accurately predicted the lateral behavior, shear failure, and post-failure behavior.
February 2025
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13 Reads
The fling step, a significant near-field effect, has an adverse impact on long-period engineering structures. Despite early recognition by pioneers, identifying and processing the ground motions containing the fling step remains challenging due to conventional data filtering methods that ignore low-frequency components. This study investigates the recovery of the fling step from near fault records and by modifying and/or adding processing steps to previous methods, proposes a robust processing scheme for strong ground motion recordings in capturing fling amplitude. The proposed scheme’s capability is verified through GNSS-derived displacements from global and Turkiye earthquakes. Subsequently, the method is applied to strong motion recording in the Turkish dataset (Mw ≥ 6 shallow crust earthquakes recorded at RJB≤50 km), resulting in a comprehensive inventory of fling amplitudes across multiple motion components. This inventory serves both engineering and earth sciences research by facilitating the evaluation of existing predictive models. In addition, a Türkiye-specific performance evaluation of existing predictive models is conducted using the presented database. Lastly, a refined fling amplitude prediction model, based on conformity with the presented fling inventory, is proposed. This work addresses critical gaps in strong ground motion analyses, promoting improved seismic resilience through accurate characterization of near-fault effects.
February 2025
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110 Reads
Earthquake causes severe impact in the social property, and its damage to the aged buildings is one of the most disastrous consequences. Thus, seismic upgrading techniques and advanced design approaches are continuously proposed for a better structural performance, of which the externally-attached sub-system is an effective strategy. The authors formerly proposed a high-performance external sub-system for seismic upgrading, namely, the self-centering precast bolt-connected steel-plate reinforced concrete (SC-PBSPC) buckling-restrained braced frame (BRBF), and experiments have been performed to validate its feasibility and superiority. In this paper, a novel design framework for the external SC-PBSPC BRBF sub-system considering combined demand-capacity uncertainties under nonstationary excitation is further investigated. The novel design framework is derived from the incremental dynamic analysis and capacity spectrum method (IDA-CSM), and it is an organic integration and an effective improvement for a better upgrading solution. The proposed stochastic IDA-CSM based design framework consists of three stages (i.e., the performance evaluation before upgrading, the component design of sub-systems, and the performance verification after upgrading) and two primary analyzing approaches [i.e., the stochastic pushover analysis (POA) for capacity-demand spectra curves, and the stochastic IDA for fragility curves]. During the procedure, the design factors are regarded to be stochastic variables and multiple uncertainties are incorporated for a probabilistic estimation, both before and after upgrading, respectively. An application example via a three-dimensional frame building is also implemented to verify the feasibility of the design framework, and multiple uncertainties provide a probabilistic prediction of the upgraded behavior in a more realistic way. The proposed research serves as a reference for the related design exploration and plays a key role for further probabilistic work from a macro perspective.
February 2025
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4 Reads
The elastic-plastic displacement response of structures under long-period ground motions including far-field long-period ground motions (FLGM) and near-fault pulse-like ground motions (NPGM), are significantly different from ordinary ground motions (OGM), and the post-yield stiffness ratio of structures is a crucial index that determines the residual displacements and repairability of structures after earthquakes. Studying the influence of the post-yield stiffness ratio on the maximum and residual displacements of structures under long-period ground motions is crucial for post-earthquake repairs. This paper selected 25 OGM, 25 FLGM, and 25 NPGM to calculate the elastic-plastic displacement response of single degree of freedom (SDOF) systems, analyzing the influence of ground motion types, post-yield stiffness ratio, natural periods, and strength reduction coefficients on normalized elastic-plastic displacement. And the influence of design parameters and loading paths on the post-yield stiffness ratio of components was analyzed by finite element analysis based on the method of calculating the post-yield stiffness ratio of components. The results show that the normalized maximum displacement decreases with the increase of the period, the increase of post-yield stiffness ratio and the decrease of strength reduction coefficient. Nevertheless, the variation degree of the normalized maximum displacement is distinguishing under different ground motions. The normalized residual displacement of SDOF system under the NPGM is the most significant and the variation of normalized residual displacement with post-yield stiffness ratio, strength reduction coefficient and natural period is different under different ground motions. Moreover, post-yield stiffness ratio of components is significantly influenced by design parameters and loading path.
February 2025
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95 Reads
The central Apennines are renowned for their active NW-SE striking and SW-dipping normal-fault systems responsible for significant seismic events. However, uncertainties persist in attributing some past destructive earthquakes to seismogenic sources, as in the case of the 1706 Maiella earthquake (Mw 6.8, Abruzzi region). This study comprehensively assesses competing source hypotheses derived from the literature and uses geological and geophysical data to constrain their possible fault geometry. Employing a 3D seismogenic source model approach, we rigorously analyze the earthquake-fault association, assessing the misfit between the simulated site intensities and the macroseismic values estimated from the historical accounts. Our findings highlight the complexities in determining a reliable source for the 1706 earthquake. Finally, the best-fit source model was adopted to produce ground motion predictions regarding Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), and macroseismic intensity, including site effects, coupling the ground motion model (GMM-ITA18; Lanzano et al. 2019) and the ground motion intensity conversion equation (GMICE; Gomez Capera et al., 2020). The presented outcomes possibly unveil the shaking scenario that occurred in the past and perhaps in the future. These results, shedding light on one of the most relevant unknowns of the Apennine seismicity, offer valuable insights to better constrain the seismic hazard of this region, with implications for seismic risk mitigation strategies.
February 2025
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488 Reads
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1 Citation
The southern Türkiye and northern Syria areas were hit on February 2023 by a large earthquake with Mw = 7.8, followed by another large aftershock with Mw = 7.5. The two-earthquake sequence, coupled with a series of smaller aftershocks, caused severe structural and geotechnical damage and fatalities. The objective of this study is to investigate the characteristics of near-fault ground motions observed in the earthquake sequence. To this end, the ground motion intensity measures are firstly compared with existing models; it is shown that PGA and spectral accelerations from both the non-pulse-like and the pulse-like motions are overall captured by the Zhao et al. (Bull Seismol Soc Am 96(3):898–913, 2006, https://doi.org/10.1785/0120050122) model. Subsequently, the velocity pulses in near-fault ground motions are not only quantitatively identified, but are also parameterized using the progressive iterative approach. The identified pulses are then empirically categorized into two groups of records with different causative effects according to the criterion of whether or not non-zero displacements could be visually inspected at the end of the integrated pulse displacement traces. Pulse-like ground motions containing baseline offset are also corrected, and final permanent displacements due to fling-step effects are accordingly derived. To determine the orientations at which the strongest pulses can be observed, two different approaches are employed. It is revealed that the indirect method by seeking the orientation of the maximum PGV appears to be not reliable if it is to find the strongest pulse, at least with respect to the 2023 Türkiye earthquake sequence.
February 2025
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27 Reads
Catastrophic earthquakes in Uganda have the potential for detrimental consequences on the socio-economic welfare and resilience of communities. Despite considerable efforts in predicting earthquake risk across Africa, a national comprehensive seismic risk study for Uganda does not exist. With increasing population, urbanisation and rapid construction, seismic risk is escalating fast and is compounded by the high vulnerability of buildings and scanty disaster prevention and mitigation strategies. This study uses the probabilistic event-based risk calculator of the OpenQuake-engine to assess potential risks resulting from future earthquakes. Although the building exposure model is largely inferred and projected from the national population and housing census of 2014, total replacement costs are obtained by performing series of interviews with local engineering practitioners. Analytical vulnerability curves are selected from Global Earthquake Model (GEM) database. Seismic hazard studies confirm that western Uganda is exposed to the highest level of seismicity where peak ground accelerations on rock ground can reach up to 0.27 g over a 475-year return period. Relative to Uganda’s gross domestic product, the associated seismic risk estimates indicate mean economic loss ratios of 0.36%, 2.72% and 4.94% over 10, 50 and 100-year return periods respectively; with mean annual economic loss of US$ 74.7 million (0.34% relative to the total replacement value) and annual deaths averaging 71 persons across the whole country. It is envisaged that the findings will inform strategic land use planning patterns, earthquake insurance pricing and foster the continuous improvement of Uganda’s National Policy for Disaster Preparedness and Management.
January 2025
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109 Reads
On November 3, 2023, at 23:47 local time, a MW 5.7 earthquake struck Barekot in northwest Nepal at a depth of approximately 12 km. Although the region has been predicted to experience a major earthquake, this moderate-sized earthquake was the most severe seismic event in 518 years. Despite its relatively low magnitude, the earthquake caused significant damage, resulting in 154 deaths and the collapse of over 26,557 houses. This underscores the critical need for post-earthquake reconnaissance to identify vulnerabilities and improve mitigation strategies before more severe events occur. Recognizing this importance, a detailed reconnaissance was conducted from November 6 to 9, 2023, focusing on the geotechnical impact of the earthquake. Based on the field observations, this paper discusses several geotechnical issues triggered by earthquakes in the region, including shallow landslides, rockfalls, and structure damage to flexible pavement and retaining walls. The study also explores the potential triggering mechanisms for the rock fall and discusses possible remedial techniques. Additionally, the influence of the local site effect on the extent of damage was examined. Remote sensing techniques were employed to detect post-earthquake ground patterns and land use changes using Sentinel-1 and Sentinel-2 images, respectively. The Sentinel-1 images were analyzed using the persistent scattering interferometric synthetic aperture radar (PS-InSAR)-based method, and the Sentinel-2 images were analyzed via the Google Earth Engine (GEE). By assessing these geotechnical impacts, this study aims to enhance earthquake preparedness in the future and provide valuable insights for engineers and policymakers to reduce risks and improve disaster resilience.
January 2025
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34 Reads
1160 framed reinforced concrete buildings, holding 3–13 stories, have been modelled in a probabilistic way. Capacity spectra have been calculated and characterized by means of 5 parameters: initial stiffness, ultimate capacity (Sdu, Sau), μ and σ. μ is related to ductility, and σ controls the way the building strength degrades. A strong correlation among these five parameters has been found. Moreover, the also high correlation between the initial stiffness and the number of stories allows to define median and percentile capacity spectra starting from the number of stories. Afterwards, for each number of stories, a fragility analysis is performed for the median capacity spectrum. The Barcelona city, in Spain, is used to depict the expected physical damage for a probabilistic and a deterministic seismic hazard scenario. Two procedures, based on the bilinear form of the capacity spectrum and on the Park and Ang damage index, are used to define damage states thresholds. The probabilistic scenario is more damaging than the deterministic one is and, damage states thresholds based on the capacity spectrum lead to more damages than the ones based on the Park and Ang damage index. Mean damage states close to 2.0 are obtained, being 25% and 6% the probabilities of Severe, and Complete, damage states, which would have significant impact on the number of homeless people and victims. Maps of expected damages depict the physical seismic risk of the probabilistic scenario. These scenarios are very useful for emergency planning and for earthquake protection.
January 2025
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65 Reads
Tuned Mass Dampers (TMDs) can be used for mitigating vibrations in structures caused by ground motion, with an effectiveness significantly increasing with the TMD mass. However, due to spatial constraints, the latter is usually limited to 2–3% of the structural mass. As a remedy, in a novel fashion the TMD can be regarded as a superelevation of the existing layout, potentially having a mass of 30–40% of the structural one. This approach, referred to as Large Mass ratio TMD (LM-TMD), can be particularly advantageous for retrofitting existing buildings. Conversely to earlier studies overlooking the soil compliance, this paper shows numerical evidence about the role of soil-structure interaction on the seismic effectiveness of LM-TMDs in an archetype building designed in accordance with old technical provisions. This is accomplished through the development of a coupled soil-building-LM-TMD model in OpenSees, simulating the nonlinear interactions between soil and structure under multi-directional seismic loading. The results of the nonlinear dynamic analyses shed light on the marked enhancement of the performance of the benchmark building produced by LM-TMDs compared to conventional dampers and, at the same time, the favourable or detrimental role of soil-structure interaction. The latter induces combined deformation modes of the structural system, further magnified by a pronounced nonlinear soil behaviour in case of severe scenarios, pointing out the necessity of a substantial LM-TMD mass for avoiding adverse effects on the superstructure response.
January 2025
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19 Reads
To assess the importance of bridges in road networks and achieve uniform traffic loss risk in seismic design, this paper introduces a novel bridge seismic design methodology incorporating the Seismic Importance Adjustment Factor (SIAF) and uniform traffic loss risk. The key technical contributions are as follows: (1) defining SIAF and developing an integrated framework that couples seismic design with traffic loss risk assessment; (2) proposing a calculation method for traffic loss risk that accounts for traffic demand variations during different periods of the day, uncertainties in post-earthquake bridge repair times, and dynamic traffic flow reassignment in post-earthquake road networks; (3) establishing design indicators for traffic loss risk and defining five seismic risk design levels based on historical disaster data; (4) validating the methodology through case studies on bridges and road networks, demonstrating how SIAF interconnects seismic design with risk-based design targets and adapt seismic design standards to varying network redundancies. The research demonstrates that SIAF can quantify bridge importance within complex road networks and provide a practical reference for the development of seismic design standards.
January 2025
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85 Reads
Reliable site-specific amplification information can be retrieved using earthquake-based methods that involve the deployment of a permanent (or temporary) network of seismic recording stations. Such an endeavour may need to operate for years, especially within regions of high risk but low recurrence rates in seismic activity. Hence, time- and cost-effective approaches using ambient vibrations are gaining popularity. Among such techniques, the canonical correlation approach (CC) collates measured empirical amplification with its indicator computed from ambient vibrations (i.e. horizontal-to-vertical spectral ratios) for a training set of seismic stations, to predict site response at locations without earthquake recordings. Another method, the hybrid standard spectral ratio method (SSRh) takes advantage of simultaneous recordings of ambient vibrations that are adjusted using earthquake ground motion data using a limited number of instrumented sites to estimate local seismic soil response. We apply both methods in the Lucerne area (Switzerland), which is located on a soft sedimentary basin, and obtain consistent results that are comparable to amplification estimates derived solely from earthquake ground motion data. These results show significant linear amplification factors (8–10 or more) at the fundamental frequency of resonance of the sediments (0.8–2 Hz). However, both techniques show systematic differences in the spatial and frequency domains. The CC method tends to underestimate the amplification at the fundamental frequency, while the SSRh technique predicts higher amplification in the centre of the basin and lower amplification at the basin edges in comparison to the CC approach. The study discusses the impact of the limitations in the completeness of the calibration dataset, and variability introduced by the choice of the shear wave velocity model of the shallow subsurface and inelastic behaviour treatment for the CC method, as well as the influence of the measurement setup for the SSRh method.
January 2025
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39 Reads
Recently, use of 6000 series aluminium alloys in braced frame structures has been increased due to their superior structural properties. Fracturing of braces as a result of low-cycle fatigue has a major impact on nonlinear behaviour of structures under earthquake loading. Therefore, modelling low-cycle fatigue life, i.e., number of reversals to failure, is important to understanding braced-frame structural performance. To date, there are no readily available methods for predicting the low-cycle fatigue behaviour of 6000 series aluminium alloys. This research study aims to provide structural engineers with a computationally efficient approach to assess aluminium alloy structures in the context of potential low cycle fatigue. For this purpose, 18 low-cycle high amplitude fatigue tests (up to ± 6% strain amplitude) were conducted to establish strain − life relationships for 6082-T6, 6063-T6 and 6060-T5 aluminium alloys. The obtained experimental results were then used to calibrate a low-cycle fatigue life model to capture the fracture behaviour of the studied materials. The comparison of experimental results and predicted fatigue behaviour shows the capability of the proposed model to predict to a high degree of precision the onset of fracture and the overall low-cycle fatigue behaviour of material.
January 2025
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28 Reads
To address the challenge of designing structures that can withstand seismic loads and simplify the design process, a novel optimization formulation considering performance targets is defined in this paper. Multiple ground motions are considered to optimize structures under earthquake excitations. Single and seven ground motions are employed to perform nonlinear time history analysis, and the resulting responses are utilized as the objective function for the optimization problem. Subsequently, a Kriging model is adopted to approximate the objective function. During the model construction process, an enhanced Latin hypercube sampling strategy with mutation and evolutionary operation is employed, conditional likelihood approach is used to update the kriging model, and genetic algorithm (GA) is employed to search for the optimal solution. Finally, the methodology is applied to three 2-dimensional (2D) examples and a 3-dimensional (3D) example to demonstrate its effectiveness. The results show the Kriging model-assisted methodology can significantly reduce the computational burden associated with function evaluations, while simultaneously identifying optimum designs that improve the dynamic responses of structures. This highlights the effectiveness of the proposed methodology in mitigating the effects of earthquakes and reducing dynamic responses, which is crucial for preventing structural damage and collapse. Furthermore, the results emphasize the importance of considering multiple ground motions when optimizing structures under earthquakes.
January 2025
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70 Reads
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1 Citation
The vulnerability of Reinforced Concrete (RC) structures against seismic events has prompted extensive research into retrofitting techniques aimed at enhancing their seismic performance. Among these, Fabric-Reinforced Cementitious Matrix/Mortar (FRCM) systems have gained prominence as promising solutions for strengthening RC-columns. This study presents a comprehensive investigation into the seismic strengthening of RC columns using FRCM, combining experimental and numerical approaches to assess their effectiveness. The experimental phase of this research involved the fabrication of scaled RC-column specimens representing real-world conditions. These columns were subjected to a series of cyclic loading tests to simulate seismic forces. Multiple FRCM configurations, including different fiber types and dosages, were applied to these specimens. The experimental results revealed a substantial increase in the ductility, stiffness, and ultimate strength of the strengthened RC-columns, indicating the potential of FRCM systems as effective seismic retrofit solutions. In parallel, a numerical analysis was conducted using Finite Element Modeling (FEM) to simulate the behavior of the strengthened RC-columns under seismic loading conditions. The FEM simulations were validated against the experimental data, demonstrating good agreement. This numerical investigation allowed for a more in-depth understanding of the stress distribution and deformation patterns within the strengthened columns, aiding in the optimization of FRCM reinforcement strategies. The integrated experimental and numerical investigation presented in this study contributes valuable insights into the seismic strengthening of RC-columns using FRCM systems. It provides a holistic understanding of their performance, including their enhanced load-carrying capacity, as well as improved ductility guiding the adoption of FRCM systems as a viable solution for mitigating seismic risk in existing RC-structures.
January 2025
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51 Reads
In recent years, researchers have taken advantage of the nonlinear characteristics of the underlying soil to mitigate the excessive seismic force demands on the superstructure under earthquake excitation. For this purpose, the conventionally designed foundation can be replaced with rocking foundation. This is achieved by under proportioning the shallow foundation. Although the mechanism of rocking foundations has been well documented, there remains a gap in developing a methodology for reduction of foundation sizes in multi storey Reinforced Concrete (RC) shear wall framed structure. Therefore, this study focuses on the seismic responses of a shallow foundations supporting a multistorey RC shear wall framed structure. The foundation for RC shear wall is proportioned by gradually reducing the earthquake load considered for the foundations to enhance the increased rocking effect and to mitigate seismic force demands. Thereafter, key parameters responsible for seismic behavior of sub-structure are being compared with conventionally designed foundation with increasing foundation rocking, by varying type of underlying soil and with increasing height. Seismic behavior obtained by implementing a series of nonlinear time history analyses indicates that the foundation rocking greatly influences the dynamic properties. With increasing degree of foundation rocking, natural fundamental period of the overall structure gets lengthened, with decreasing peak roof acceleration, thereby mitigating the peak base moment and base shear experienced at the shear wall compared to conventionally designed foundation. On the other hand, it is observed that there is an increase in roof displacement and shear wall settlement at the foundation level. It is found that the foundation of shear wall can be designed by considering 40%, 60% of earthquake loads for zone V and zone II structural designs, respectively without encountering excessive settlements. From the sensitivity analysis it is highlighted that the foundation size and design seismicity impact the base shear contribution ratios between shear wall and column members, fundamental natural period and foundation settlement.
January 2025
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73 Reads
This paper provides a comprehensive examination of post-earthquake structural damage assessment efforts following the Kahramanmaras, Turkey, earthquakes that occurred on February 6, 2023. Drawing on global damage assessment protocols, the study compares and analyzes the methods implemented in the aftermath of the earthquakes, offering insights into lessons learned and challenges faced. The analysis of objections raised regarding the assessment efforts reveals significant changes in structures with moderate and severe damage, emphasizing the need for continuous improvement in assessment strategies. The paper advocates for a realistic and two-stage application method, consideration of crack type and cause, and active involvement of local communities in the assessment process. Furthermore, the study identifies key issues in the current earthquake damage assessment methodology and proposes solutions, including a more precise classification system, regular volunteer training, consideration of secondary disaster risks, and effective communication methods. The paper concludes by underscoring the importance of effective damage assessment in disaster management, addressing objections from the affected population, and continual enhancement of strategies to improve resilience in earthquake-prone regions.
January 2025
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61 Reads
Our study focuses on predicting topographic amplification of ground motion in the near-source region, where seismic rays reach the free-surface at varying incidence angles. We rely on data from previous 3D numerical simulations conducted on a topographic relief with a homogeneous medium. First, using neural networks, we identify which key parameters, describing the geometric characteristics of the relief relative to the seismic source position, control ground motion amplification. Then, we determine the functional form that relates these parameters to the simulated amplifications. Subsequently, we conduct a regression study to develop a model of topographic amplification, referred to as the i-FSC proxy (Illuminated Frequency-Scaled Curvature). Our estimator depends on the frequency-scaled (1) curvature, a parameter that accounts for the occurrence of amplifications over convex topographies and de-amplification over concave ones; (2) normalized illumination angle, a newly defined parameter that quantifies the slope exposure to the incoming wavefield, accounting for high amplification on slopes oriented opposite to the seismic source. The illumination parameter reduces the uncertainties of the proxy by a factor of 2 compared to estimators that rely solely on curvature. The proxy does not require high computational resources. It uses a digital elevation map and a seismic source position to predict amplification factors (without lithological effects) for an S-wave at any site on the surface topography. It allows exploration of variations in topographic amplification near seismic sources, representing a significant breakthrough as areas closest to the fault typically sustain the highest damages. A MATLAB script performing the i-FSC calculations is provided.
January 2025
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1 Read
January 2025
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8 Reads
January 2025
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53 Reads
This study presents an integrated approach for the seismic assessment of the 13th-century San Michele Arcangelo Cathedral Bell Tower in Caserta Vecchia, Italy, utilizing a detailed photogrammetric survey and Finite Element (FE) modelling. The analysis focuses on the structural vulnerability and seismic response of the historical masonry tower to assess its response against earthquake-induced damage. By employing Ambient Vibration Tests (AVTs) present in literature and calibrating the FE model accordingly, the research identifies the principal vibrational modes and natural frequencies of the tower, enhancing the model's accuracy. Various earthquake intensities were inputted to the structural model to evaluate the bell tower's structural performance and potential collapse mechanisms. The findings reveal a significant susceptibility of damage under severe seismic conditions, emphasizing the critical need for tailored conservation strategies to preserve such irreplaceable cultural heritage. The study underscores the importance of integrating historical documentation, structural analysis, and modern engineering techniques to safeguard historical architecture in seismically active areas.
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