Seismic resilience (SR) has emerged as a critical focus in earthquake engineering to evaluate the ability of structures to endure, recover from, and adapt to seismic events. This study presents an entropy-based multi-criteria approach for selecting optimal intensity measures (IMs) to assess SR of structures. Eight representative IMs, derived from time histories and response spectrum are evaluated. Incremental dynamic analysis is conducted on a reinforced concrete structure, using engineering demand parameters such as the maximum inter-story drift and floor acceleration to generate fragility curves via a probabilistic seismic demand model. The optimal IMs are identified through a multi-criteria decision-making process, with scores calculated using the entropy weight method to incorporate factors such as efficiency, proficiency, and uncertainty based on information entropy. An effective SR framework is derived from fragility results. The findings indicate that peak ground velocity and spectral IMs are the most effective, while energy-related IMs underestimate SR. The study highlights the importance of optimizing IMs for more accurate seismic resilience assessments. The proposed entropy-based multi-criteria approach is shown to be both reliable and effective for selecting optimal IMs in this context.

The benefits of applying Tuned Mass Damping (TMD) may be significantly reduced by soil structure interaction (SSI) effects. The paper proposes a parameter to quantify the efficiency of such technique when SSI effects are considered. Efficiency is based on the development of analytical fragility curves. A case study of a 20-floor structures subjected to 4 soil conditions was herein considered by modeling the SSI effects with Opensees. Unlike previous studies based on simplified soil representations, this work employs advanced nonlinear SSI simulations in OpenSees to capture amplitude-dependent soil behavior, plastic deformation accumulation, and permanent foundation movements. The proposed efficiency parameter provides a practical quantitative tool for assessing TMD applicability on deformable soils and has direct potential for integration into performance-based design frameworks and seismic design codes. The findings demonstrate that TMD efficiency depends on soil deformability as shown by performing 10 input motions selected to represent far and near field cases. In particular, the parameter efficiency was calculated as the ratio between the mean values of the fragility curves respectively calculated for the TMD and the original configuration. The ultimate scope of the paper is to implement the proposed formulation inside international codes to be used by practitioners and engineers to design TMD by quantifying the reduction of the efficiency due to the non-linear effects of SSI.

Past earthquake events demonstrated that liquefaction may compromise the stability of structural systems with high nonlinear deformations, lateral spread, and settlements. This study investigates the use of geotechnical seismic isolation (GSI) as a mitigation technique for soil liquefaction effects. Three-dimensional (3D) advanced numerical simulations are performed using the state-of-the-art platform OpenSees (version 3.7.1) that captures efficiently soil deformability, as well as the nonlinear effects of liquefaction. The structure under consideration is a low-rise RC building sitting on a shallow foundation with a GSI layer surrounding the shallow foundation. This system is subjected to five selected ground motions to demonstrate the efficiency of the GSI system in reducing the excess pore-water pressure that is the fundamental cause of soil liquefaction. Several key response parameters are considered for the soil (shear strain, excess pore pressure, longitudinal displacement, and ground settlement) and the structure (base shear, roof acceleration, and interstory drift), in order to support the use of GSI as a mitigation technique and to illustrate the stability of the entire system.

Seismic fragility of buildings is significantly affected by soil-structure interaction (SSI), even if there are rare systematic incorporations of its effects into probabilistic vulnerability frameworks. This study presents a state-of-the-art review of seismic fragility assessment studies considering SSI effects, following PRISMA guidelines and synthesizing studies published between 2011 and 2025. The objectives of this study consist of 1) discussing the influence of the various variables, such as the structural parameters, foundation types, and soil properties on fragility assessments, 2) assessing the implications of SSI-influenced fragility outcomes for performance-based seismic design and code provisions, 3) identifying the key parameters such as; soil stiffness, structural height, and foundation type, building typology. This review consolidates the current knowledge by highlighting the need for improved validation and SSI-aware fragility frameworks in code provisions.

The coupling of base isolation (BI) techniques with the benefits that arise from the soil structure interaction (SSI) effects can be an effective approach for seismic hazard mitigation of civil structures. While the simultaneous consideration of the BI and SSI effects could offer an advanced seismic hazard mitigation approach, this has not been studied extensively and closed-form solutions have not been suggested yet. This study aims to address these benefits by presenting the current state-of-the-art and by proposing a novel closed-form approach to express the period elongation in terms of the characteristics of the BI system and the soil properties, which are required during the design process. It is shown that the isolation ratio can be chosen as the main parameter to represent the performance of the structural system. A benchmark building has been chosen, assessing four different soil conditions. The findings demonstrate that the BI efficiency depends on the earthquake ground motions, since the soil deformability generates large amplifications in correspondence with the fundamental periods of the isolated systems. Base shear forces and acceleration time histories are compared for the different soil conditions, assessing the role of soil deformability in the interaction between BI and SSI effects. However, the closed-form approach is applicable to low-rise, regular structures on uniform soil deposits and the findings cannot be generalized beyond this typology.

Soil-structure interaction (SSI) is an important component of the seismic behaviour of structures, especially those supported on soft soils, but its implementation in design practice is inconsistent and generally deficient. In this extensive review of SSI modelling approaches, we integrate recent developments in earthquake engineering based on the state-of-the art concept of seismic resilience. On this regard, the present paper aims to make an in-depth state-of-the-art of the current research on seismic resilience for SSI cases, in order to identify the research gap that consists of a wide heterogeneity of approaches and investigations. The novelties of the paper consist of making a recognition of the various contributions that apply seismic resilience for SSI studies, analysing the methodologies employed to model SSI and resilience into unique framework, discussing the implications of SSI effects for seismic resilience and risk management, and suggesting future research directions. The study first outlines the basic mechanisms of SSI such as kinematic and inertial interaction effects, period elongation, and damping modification, showing from historical earthquake data that SSI effects can either be beneficial or detrimental depending on the conditions. A comparative assessment of international design codes (ASCE/SEI 7–16, Eurocode 8, JSCE, IS 1893) shows that there are significant inconsistencies in the provisions of SSI and a general lack of guidance for practical implementation. The study shows the diverse impact of SSI on different structural systems, highlighting the need to consider system-specific responses in the design. The paper concludes by identifying key research gaps in resilience-based assessments and design implementations. Key recommendations are given for researchers, practitioners, and code developers.

This study examines how ground inclination and pile spacing govern the seismic response and resilience of pile groups subjected to liquefaction-induced lateral spreading. A suite of free-field and 5 & times; 5 pile-group models with different ground slopes (0 degrees-6 degrees) and pile spacings (S/D = 2-8) is analyzed. Resilience is quantified via a driftbased repair time and a linear recovery model. Mechanistic results indicate asymmetry in the ground acceleration response, reveal spatiotemporal evolution of excess porewater pressure during shaking, and irregular lateral soil-pressure profiles that concentrate demand at group edges. Embedding these responses within the resilience framework shows that slope dominates spacing in delaying recovery: for corner piles, repair time increases by more than sixfold from 0 degrees to 6 degrees for a given spacing, versus twofold from S/D = 2-8 at fixed slope. Perimeter piles consistently control group-level rapidity.

Site response analyses (SRA) are commonly employed to study the free field responses with various soil properties subject to earthquakes with different characteristics. This study conducted 3D nonlinear numerical simulations to examine how various earthquake characteristics influence the behavior of multi-layered liquefiable soils profile composed of a 4 m loose Nevada sand layer (Dr ≈ 50%) confined between dense Monterey and Nevada sand layers (Dr ≈ 85%). Eight historical earthquake records, representing both near-fault and far-fault conditions and covering a wide range of rupture distances, frequency contents, durations, and energy measures, were applied after scaling to a peak ground acceleration of 0.3 g. The analyses investigated excess pore pressure generation, acceleration amplification, lateral displacement, settlement, and post-earthquake pore-pressure redistribution. Results indicate that liquefaction causes a systematic shift of seismic energy toward frequencies below 2 Hz and significantly modifies the effective duration of ground motions. Near-fault earthquakes generated larger lateral deformations and affected a greater depth of liquefaction than far-fault events. Correlation analyses showed that PGV/PGA, energy flux, and Arias intensity are the strongest predictors of lateral displacement (ρ = 1.00, 0.98, and 0.83, respectively), whereas moment magnitude exhibited the highest correlation with settlement (ρ = 0.86). Furthermore, excess pore-pressure redistribution after strong shaking promoted localized seepage-induced liquefaction within dense underlying layers. The findings provide insight into the mechanisms linking ground-motion characteristics and liquefaction-induced site response and support improved seismic assessment of layered liquefiable deposits.

Previous studies on the optimal parameter selection of non-traditional tuned mass damper inerter (N-TMDI) system have predominantly adopted a fixed-base assumption. However, neglecting soil–structure interaction (SSI) in practical applications may lead to significant design inaccuracies and reduced control performance of the N-TMDI system. To overcome this limitation, a new design framework is proposed for the tuning of N-TMDI systems installed in primary structures subjected to ground motion by explicitly considering SSI effects. The novelty of the proposed approach consists of performing a hybrid GA-PSO optimization algorithm to study the efficiency of N-TMDI system under near- and far-field ground motions. This study investigates the influence of varying mass and inerter ratios on the system's dynamic response through frequency-domain analyses. The performance of the N-TMDI system is subsequently validated using real earthquake records, with a specific focus on the comparative effects of near-fault and far-fault ground motions under diverse soil conditions. The results demonstrate that the inerter mass ratio is the most dominant factor in enhancing seismic protection, significantly reducing structural displacement and acceleration compared to conventional TMD. Furthermore, the findings reveal that SSI and the distinct characteristics of ground motions significantly modify the system's control efficiency. This research confirms the robustness of the optimized N-TMDI design, providing a reliable and efficient strategy for seismic structural control under varied seismic scenarios.

Fully coupled three-dimensional dynamic nonlinear FE analysis was conducted to investigate the comprehensive behavior of the soil-foundation-structure (SFS) system resting on stratified liquefiable ground. Parametric models were developed using the TCL scripting language and executed within the OpenSeesSP framework. The numerical framework was initially validated against centrifuge test results for an SFS system founded in liquefiable sand, after which it was employed to examine the effects of several governing parameters on seismic performance under representative earthquake motions. These key parameters include the relative density of liquefiable layer (Dr), liquefiable layer depth (DL), groundwater table (Hw), ground inclination of soil layers (S), foundation depth (Df), peak ground acceleration (PGA), and frequency content of earthquake. In particular, the influences on the excess pore pressure, acceleration, settlement, maximum lateral displacement (MLD), structural shear force, and drift were evaluated. The results showed that foundation settlement and rotation decreased, while acceleration was amplified at the foundation level with the increased key parameters (except for DL). The structural MLD and shear force increased with Dr, Hw, and S; conversely, MLD decreased with an increase in DL and Df. Among the examined mitigation strategies, increasing the Df exhibited the strongest mechanical influence in reducing foundation settlement, MLD, rotational response, and overall structural drift. The liquefiable layer compaction and increasing Hw are recommended as the next priorities. The compaction strategy reduces settlement, lateral displacement, and foundation rotation but increases structural drift and shear force. Therefore, the trade-off between beneficial and detrimental responses should be considered in its design and practical implementation. Ignoring even a small ground inclination can lead to underestimation of MLD and drift, but its impact on foundation rotation and settlement is approximately low.

The seismic resilience of composite moment frames featuring slender concrete-filled tube (CFT) columns is herein assessed with a focus on the implications of bidirectional moment connections. As seismic design codes evolve, the need for resilient structural systems that can withstand significant seismic events becomes increasingly critical. This study employs advanced numerical modeling approaches to analyze the behavior of two three-dimensional models of office buildings designed according to Chilean seismic standards. The findings reveal that slender CFT columns exhibit satisfactory ductility and low pinching effects, even under substantial drift levels. The research underscores the importance of connection behavior, demonstrating that bidirectional moment connections enhance overall structural performance and reduce the risk of brittle failures. Additionally, the study highlights the necessity of appropriate beam-to-column stiffness ratios to ensure that beams achieve their plastic moment capacity, thereby improving ductility. Furthermore, the resilience of the slender model is confirmed through the resilience analysis, showcasing limited functionality loss post-event. Finally, the research advocates for sustainable construction practices by emphasizing the reduced environmental impact associated with the use of CFT columns. These findings contribute to the development of more effective seismic design strategies that prioritize both structural integrity and environmental sustainability.

Realistic assessment of the structural state due to ageing and consequent deterioration of infrastructure is fundamental in assessing its resilience. Yet current methods have not integrated deterioration due to ageing in such assessments. This paper proposes a new framework for the assessment of the effect of deterioration on the resilience of critical infrastructure, with a focus on bridges. The method introduces a three-step process. First, different fit-for purpose materials have been implemented for the calculation of the loss model when the material properties are known. The second step involves the development of hazard-specific fragility models to estimate loss in performance. In the third step, the restoration of the assets is performed to compare the different performance of the configurations which leads to different resilience quantifications. The main outcome of the paper is the quantification of resilience by considering that the speed of recovery is not being affected by the deterioration (Scenario 1). For more realistic resilience assessments, a further scenario (Scenario 2) analyses the role of deterioration in the recovery process, by implementing different capacity reduction rates. The main conclusion of the research is the impact of different levels of deterioration over the years of operation of the bridge. The framework is also applied to estimate the seismic resilience of a bridge with different deterioration scenarios.

In the last two decades, seismic resilience (SR) has been developed as a main concept for the assessment of the structural vulnerabilities of buildings and city centres. In particular, historical centers consist of adjacent buildings organized in blocks with common characteristics and similar typologies. The paper proposes a methodology to quantify SR for urban regions, by overcoming the state of the art studies that focus on assessing the SR for singular buildings. In this regard, the presented methodology may calculate the SR of blocks of buildings for the assessment of recovery investments of historical city centers. The main idea is to assess the level of vulnerability by accurate 3D surveys and visual inspections in order to select empirical fragility curves. The proposed methodology was herein applied to the city center of San Marino, designated by UNESCO as a world heritage site.

Resilience of residential buildings depends on the recovery process that follows the impact of natural hazards, such as tsunamis. In particular, the historical database from tsunamis that occurred in different Countries (Sri Lanka, Thailand, Indonesia, and Japan) have been considered. This study proposes a selection of the best-fitting models to assess the recovery process of tsunamis to derive a framework for resilience at geographical scales. Since the damage depends on the vulnerability of the buildings, several typologies have been considered. In addition, aggregations of different damage sources have been considered to propose comprehensive relationships. The definition of best-fitting recovery functions for different countries has been discussed to implement them in advanced platforms and calculate the resilience to tsunamis.

The seismic resilience (SR) of civil structures has become an important concept for structural engineering in the last two decades. Ageing and deterioration effects must be considered during SR assessments. This paper proposes a framework that implements deterioration inside the assessment of SR for structures by developing hazard-specific fragility models to estimate the loss. Deterioration affects the rapidity of the recovery process, and several levels of deterioration were considered by performing a probability-based assessment. The results in terms of maximum longitudinal drift ratio were developed with analytical fragility curves. These outcomes were applied to calculate the SR of the structures demonstrating that the impact of deterioration may significantly reduce the seismic resilience. The SR was calculated for a benchmark low-rise building performed with advanced numerical simulations with OpenSees. Deterioration was implemented on the losses of the building and on the recovery process by implementing two rates of recovery.

Abstract. Neural Radiance Field (NeRF) rendering methodologies provide 3D reconstructions which better represent features and characteristics common to built heritage, which are otherwise poorly represented by traditional structure from motion reconstruction and rendering techniques. It is currently limited in its ability to scale to large projects. This paper, through a case study involving large scale seismic vulnerability surveys in San Marino, investigates and proposes systems which can extend NERF rendering to large multiscalar datasets linked by geographic coordinates.

Soil–structure interaction can significantly affect the seismic vulnerability of systems through several mechanisms that depend on the mutual effects of the soil properties and the structural characteristics. In this work, a probabilistic-based approach was applied to evaluate such effects on the fragility of an isolated bridge representing a typical Californian highway bridge. Analytical fragility curves were developed using OpenSees, implementing hysteretic materials and advanced plasticity models to represent non-linearity. The mutual non-linear effects of soil deformability and isolation on the system (soil–foundation–structure) were assessed by considering several limit states for the column ductility and the deck displacement.

This paper quantified the seismic resilience (SR) of different bridge classes by performing three-dimensional advanced numerical simulations in Opensees. SR was calculated by performing the seismic resilience for recovery investments of bridge (SRRIB) methodology that is based on the quantification of the losses and the repair time. In particular, the probabilistic-based methodology developed by the Pacific Earthquake Engineering Research Center (PEER) was implemented to produce fragility curves by considering the longitudinal displacement of the deck as the reference parameter. The recovery process was modeled using a linear formulation due to the unavailability of information from past earthquakes. SR for the selected bridge classes was calculated in terms of the seismic intensities to be applied for decision-making procedures during pre- and postearthquake assessments.

Seismic vulnerability of urban regions depends on the infrastructure systems that need to remain operative during and after earthquakes. In modern societies, the increasing interdependence of the various infrastructures may significantly affect the community resilience because a damage or a failure on a system may propagate to other interconnected ones. In this regard, the original concept of seismic resilience needs to be expanded to a more general definition that may consider the dependence of multiple infrastructures. In particular, this paper aims to develop a formulation of the seismic resilience by proposing an algebraic matrix form for the calculation of the seismic resilience. The presented formulation has the main advantages to be easily implemented in numerical platforms and to calculate the degree of interdependency between infrastructure.

The pounding between two structures may cause severe damage, as demonstrated during historical seismic events. In particular, the effects of the continuity between the foundations below two structures have been investigated a few times in the past literature. Two different configurations (continue and non-continue foundations) have been investigated herein by considering several low-rise buildings. In order to consider the effects of Soil Structure Interaction (SSI) between the structures, the foundation, and the soil, a deformable soil below the foundations was considered. 3D Numerical simulations have been performed with Opensees by considering the SSI non-linear mechanisms of the complex system: soil-foundation-structure. A parametric study on the dynamic characteristics (fundamental periods) of the two structures was performed in order to assess the mutual effects of the soil and the considered low-rise buildings. It was demonstrated the role of continued foundations, whether for existing or new buildings, on reducing the pounding risk between structures. In particular, the collision between the two foundations may significantly increase the response of the building, depending on its flexibility. Also, the level of stress in the soil depends on the pounding forces causing significant increases in the structural deformations.