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Understanding the penetration resistance and geotechnical properties of beach sands is important for erosion modeling and performance-based design; however, data for beach sand penetration resistance with depth is sparse, and particularly temporal and spatial investigations are lacking. This study presents the results of a series of instrumented dynamic cone penetrometer (DCP) tests that were performed in the intertidal zone of the Atlantic-side sandy beach in Duck, North Carolina, over a tidal cycle. Spatial (cross-shore) and temporal (tidal) changes in soil stiffness in the upper 2 m of the beach surface were investigated. In total, 13 DCP soundings that measured the sediment resistance at two cross-shore locations were approximately 3 m apart. The soundings were performed every 30 min, which alternated between the two locations and started with the ebb tide, followed by the low tide and flood tide. The results showed changes in the soil penetration resistance that were related to the tidal cycle. Location A, which was closer to the dune, had overall lower penetration resistance values compared with Location B, which was closer to the water. Near low tide, the differences between the penetration resistance diminished, and differences between the penetration resistance values increased during the ebb and flood tides. Therefore, the observed changes in penetration resistance could be related to groundwater dynamics that follow the tidal water elevations. [ABSTRACT FROM AUTHOR]

Recent research has shown that full mobilization of foundation bearing capacity may be beneficial in terms of structural integrity—especially in the case of seismic motions that exceed the design limits. Full mobilization of foundation bearing capacity may serve as seismic isolation because it limits the inertia loading transmitted to the superstructure. Although most research has focused on rocking shallow or embedded foundations, a rocking pile group has attracted much less attention. A potential reason is the probability of structural damage below the ground level (at the piles), which may be difficult to repair or even detect. To shed more light on the problem, the present study investigates the seismic performance of a rocking pile group in clay, aiming to assess its efficiency as a seismic isolation alternative. Employing the finite-element (FE) method, an idealized yet realistic example of a single bridge pier supported by a pile group foundation is analyzed. A carefully calibrated and thoroughly validated kinematic hardening constitutive model is employed for the soil, and the concrete damage plasticity model is applied for the structural members. Using a suite of records as seismic excitation, the response of an intentionally underdesigned rocking pile group is compared with that of a conventionally (capacity) designed system. Similarly to what has been shown for shallow foundations, the comparison reveals that the rocking pile group can be beneficial for the seismic performance of the bridge, reducing the flexural demand on the pier at the expense of increased settlement. Interestingly, the rocking pile group exhibits a genuinely ductile response, such that none of the studied ground motions could lead to full mobilization of the bending moment capacity of the piles. Thus, pile structural damage is avoided. The findings of the present study reveal the advantages of exploiting nonlinear soil–foundation response and indicate that there is a great potential to optimize the contemporary seismic foundation design, which conventionally culminates in massive pile group foundations. The rocking pile group concept may be of particular interest for the retrofit of existing bridges that do not meet the requirements of the current seismic design provision because it can reduce or even completely avoid strengthening the foundation. Ultimately the presented findings call for a shift toward performance-based design, with due consideration of geotechnical failure modes. [ABSTRACT FROM AUTHOR]

This paper proposes a performance-based microstructure design methodology specifically tailored for gas diffusion layers (GDLs). The generative machine learning denoising diffusion probabilistic model (DDPM) is trained and used for performance-based microstructure design. This study demonstrates significant progress in performance-based design by incorporating DDPM into the microstructure design process, offering a promising approach for GDL microstructure design. This methodology provides the advantage of generating 2D microstructures with desired permeability and volume fractions. Moreover, it is not limited to a specific performance criterion, making it adaptable to target other metrics. To train the DDPM, a 2D GDL microstructure dataset is constructed using the Lattice Boltzmann Method (LBM) for permeability estimation. Subsequently, we employ the DDPM with U-net architecture, which leverages positional encoding to learn the microstructure's volume fraction and permeability effectively. The input label pair of permeability and volume fraction is generated considering the inherent relationship between these two parameters to ensure the generation of meaningful microstructures. This relationship is supposed to ensure that the resulting microstructures align with realistic and physically meaningful characteristics. The simulated performance results obtained from the generated microstructures using the proposed methodology demonstrate a strong consistency with the targeted performance objectives. [ABSTRACT FROM AUTHOR]

Lightweight double leaf walls have been extensively employed in assembly and large-space buildings. Due to the complex and varied stud configurations in double leaf walls, accurately and efficiently predicting the sound transmission loss (STL) of such structures poses a significant challenge. To support performance-based design workflows, this paper presents an analytical model based on sound transmission path decoupling, enabling architects to quickly predict the STL of commonly used lightweight double leaf wall types, including wooden, steel, and acoustical stud constructions. The paper systematically discusses the impact of different stud configurations on sound insulation performance and reveals the underlying mechanisms of sound bridge effects. Results show that the sound bridge effect arises from the structural sound transmission path introduced by various types of studs in the wall, and optimizing stud configurations is essential for decoupling the two leaves of the wall acoustically. Traditional wooden studs, considered as rigid frames, contribute more to the sound bridge effect compared to steel studs of the same structure. A promising approach involving acoustical studs with rubber sound isolation inserts is proposed, which achieves high-level sound insulation performance while offering significant spatial and construction efficiency advantages. This study provides valuable insights into advancing high-performance, lightweight building partitions and contributes to enhancing indoor soundscapes. [ABSTRACT FROM AUTHOR]

This paper suggests a novel lateral load-resisting solution for RC (high-rise reinforced concrete) frames using superelastic SMA wires as friction dampers. The suggested SMA-friction damper has some advantages, such as an easy-to-configure and affordable application, in addition to being able to control the frictional energy dissipation components mechanism in line with the design procedure based on the suggested effectiveness thanks to its self-centering SMA wires. With the least amount of SMA use, it may produce hysteretic behavior and an intense tendency for self-centering. The research used two distinct design modes--common and with the recommended damper--to construct two tall, 18- and 22-story RC frames. Ten far-field earthquakes were studied using OpenSees software in a nonlinear time history fashion. Eighteen and twenty-two-story reinforced concrete frame high-rises were designed in two distinct ways: normally and with the recommended damper. Aside from the major advancement in ductility, the lateral strength and stiffness gave an exceptional capacity for self-centering, resulting in a substantial decrease in most drift and persistent distortions in the structure. The study's findings showed that the suggested damper may improve the RC frame's structural performance while using the fewest bracing spans and money. [ABSTRACT FROM AUTHOR]

A limiting factor in the drive to deliver performance-based design is the lack of knowledge regarding the constitutive behaviour of soil–structure interfaces, particularly in the case of cyclic loading. A series of experiments was undertaken using both a traditional interface shear apparatus (shearing a large body of soil grains over a structural interface) and a novel single-particle interface shear apparatus (involving shearing a single grain over a structural interface). In both cases the soil was sheared across the interface in a cyclical manner (more than 1500 cycles per test). For the traditional apparatus, a clear change in soil particle size distribution and abrasive wear of the structural interface occurs after many cycles. This change results in a significant increase of the interface friction ratio, which is the main parameter used in traditional design – increasing from approximately 0·2 (11°) to 0·7 (35°). The single-particle apparatus validated the results – where a significant increase in the friction ratio after many cycles was also observed. The novel interface behaviour presented in this paper may lead to improved interface constitutive models and consequently more economic and safer geotechnical designs. [ABSTRACT FROM AUTHOR]

In the past decade, there has been an increasing recognition of the role of computational design optimization in early-stage performance-based architectural design exploration. However, it remains challenging for designers to apply such optimization-based design explorations in practice. To address this issue, this paper introduces a design tool, called EvoMass, and an associated design method that facilitates design exploration for building massing typologies in performance-based design tasks. EvoMass is capable of offering architects design options reflecting performance-related building massing typologies for the design task, without necessitating advanced computational design skills. More importantly, it can provide architects with insights into the underlying performance implications, thereby enhancing early-stage performance-based design exploration. EvoMass and its associated design method overcome the limitation in the conventional typology-first-optimization-second design procedure adopted by most existing tools, and it promotes a typology-oriented design exploration method of using computational optimization in performance-based architectural design. To demonstrate the efficacy of EvoMass, case studies derived from architectural design studio tasks, incorporating daylighting, solar exposure, and subjective design intents, and the result of a user survey are presented, which highlights how EvoMass and the performance-based design optimization and exploration can enable architects to achieve a more performance-aware design. [ABSTRACT FROM AUTHOR]

Various parameters can be integrated in material-based computational design in architecture. Materials are the main driver of these processes and evaluated with the constraints related to the form, performance, and fabrication techniques. However, current methodologies mostly involve investigating already existing materials. Studies on computational material design, in which new materials are developed by designing their microstructures in response to the performative issues, are generally undertaken at the material scale, and not adopted to the architectural design process yet. To resolve this issue, the methodology titled Interscalable Material Microstructure Organization in Performance-based Computational Design (I2MO_PCD) is developed and presented in three stages, including (1) identification of different types of material microstructures, (2) computational material design, and (3) prototyping. Data-based material modelling and visualization, and algorithmic modelling techniques are utilized, followed by various performance simulations as a part of an iterative process. New microstructure organizations are designed computationally, organized under three main groups as linear-curvilinear, crystal and metaball-voronoi. The outcomes of different performance analyses, including structure, radiation, direct sun hours, acoustics and thermal bridge were compared. Thus, the role of geometrical organization of microstructures, scales and material types in different performance computations were identified, by designing and fabricating synthetic materials. [ABSTRACT FROM AUTHOR]

A circular reinforced concrete (RC) bridge column with two layers of longitudinal and spiral reinforcements is becoming a common structural form in high-seismic regions because they are expected to have improved seismic performance compared to conventional bridge piers. In seismic hazard zones, a large amount of transverse reinforcement is commonly required to satisfy the so-called antibuckling requirements. Accordingly, the double-confined steel (DCS) RC bridge pier is a simple and effective way to achieve high ductility levels and postyield stiffness for bridge piers in seismic regions. In DCS, the longitudinal steel rebars are well distributed inside the cross section; at the same time, the two layers of transverse reinforcement outline different levels of confinement for concrete, including unconfined (cover), singly confined (positioned between two spiral layers), and doubly confined (found inside the inner spiral layer or the core). The adopted reinforcement details, layout, and scale were unprecedented for lateral testing of large-scale DCS. Therefore, this experimental program investigated the effectiveness of DCS as an alternative to typical RC bridge piers. The behavior of large-scale DCS was compared with the performance of conventional RC bridge pier. During the quasi-static cyclic lateral displacement-controlled loading, the onset of cracking, concrete cover spalling, damage progression, plastic hinge length development, lateral load–displacement relationship, and strain in the steel reinforcements were observed. Overall, the curvature, stiffness degradation, and energy dissipation capacity all revealed that the DCS could significantly enhance the seismic performance of a bridge pier. A fiber-based finite-element model was generated to predict the experimental response of the piers under cyclic loading. Charts depicting the relationship between the ratio of elastic stiffness and axial load were developed to serve as a valuable design resource for bridge piers. The charts were created by conducting moment–curvature (M−Φ) analyses on DCS sections. These analyses involved varying the longitudinal reinforcement ratios, reinforcement layouts, and other parameters while also considering different axial load ratios. Subsequently, the performance-based design (PBD) approach was employed to assess the extent of damage relative to engineering demand parameters. Furthermore, a comprehensive example was provided to showcase the design of DCS within the framework of PBD. The findings revealed that DCS successfully met the performance objectives outlined in the PBD guidelines, making it an attractive design option for conventional RC bridge piers. [ABSTRACT FROM AUTHOR]

This paper validates a simplified approach for evaluating the seismic performance of concentrically braced frames (CBFs). The method, based on a performance-based design, defines a structure's capacity curve through elastic and rigid plastic analyses. It is validated by comparing the results with those from 420 pushover analyses. Additionally, the method is applied to two case studies designed according to older code provisions, and its accuracy is verified through Incremental dynamic analyses (IDA). The results demonstrate that the simplified method is reliable and provides an accurate evaluation of the structure's capacity compared to code-based tools. [ABSTRACT FROM AUTHOR]

Alkali-activated materials (AAMs) are promising alternatives to ordinary Portland cement (OPC), but standardized mix design approaches are limited. This study introduces a machine learning-based framework for inverse mix design of AAMs, predicting optimal mixes based on target properties and sustainability. The model considers eight key factors, including precursor reactivity, activator properties, and liquid-to-binder ratio. It operates in four steps: (i) constructing forward prediction models, (ii) generating new mix designs, (iii) evaluating workability and strength, and (iv) filtering for performance and sustainability. Experiments validated the model, targeting fluidity >100% and compressive strengths of 40 MPa (A40) and 50 MPa (A50). The A40 and A50 mixes achieved fluidities of 147.7% and 170.0%, and 28-day compressive strengths of 41.5 and 57.5 MPa. Both had lower environmental impacts (GWP, AP, and EP) compared to OPC-based mortars. This framework enhances AAM design efficiency and sustainability for broader applications. [ABSTRACT FROM AUTHOR]

In performance-based design and assessment, there are prescriptive limits based not only on element-based performance evaluation but also on comparing story drifts with limit values. The process of determining performance levels at the element level involves obtaining the required data through numerous calculation steps, followed by evaluation, which makes it a time-consuming process. The iterative nature of this process emphasizes the importance of selecting the structural system, element dimensions, and target performance levels during the preliminary design stage to ensure they are consistent with the final analysis results. For this purpose, the determination of story drifts, which is widely accepted in the literature, is a critical aspect of performance evaluation studies, particularly for high-rise buildings, within the framework of deformation-based calculation assumptions. The continuum model is a practical approach for the approximate analysis of high-rise buildings including moment-resisting frames and shear wall-frame systems. In the continuum model, discrete buildings are simplified such that their overall behavior is described through the contributions of flexural and shear stiffnesses at the story levels. In this study, the aim is to enhance the Miranda and Taghavi (2005) model, which is classified among the approximate methods in the literature for determining story drifts and is developed within the framework of continuum model approaches. [ABSTRACT FROM AUTHOR]

The use of geogrid reinforcement has proven to be an effective measure to improve the anchor uplift capacity. However, previous studies are limited to analyzing the axial pullout capacity of plate anchors. In comparison, the anchor foundations employed in field are compelled to resist both uplift and lateral forces. In most cases, the foundation's safety against lateral forces dictates the design criteria for tall structures. Therefore, improving the foundation's lateral load-bearing capacity is of utmost importance. This paper presents a three-dimensional numerical analysis of anchor foundations in geogrid-reinforced sand under uplift and lateral forces. The results highlight the benefits of geogrid reinforcement on the anchor's response to uplift and lateral loads. The geogrid reinforcement is modelled using cable elements capturing the actual apertures responsible for tensile force mobilization along the geogrid ribs. A significant reduction in the displacements of the anchor foundation is observed in geogrid-reinforced sand, both in horizontal and vertical directions, when combined loads are applied on the anchor. However, the maximum reduction is found in the case of vertical uplift forces for higher values of the applied load. The practical implication of this study is demonstrated using a performance-based design example of transmission tower foundations in geogrid-reinforced sand. [ABSTRACT FROM AUTHOR]

A simple relationship is proposed to construct constant-damage energy factor (γDI) spectra of single-degree-of-freedom (SDOF) oscillators with different levels of damage, expressed by the Park-Ang damage index. γDI is computed for SDOF oscillators with four hysteretic models when subjected to 80 pulse-like ground motions. The statistical dependence of γDI on initial period, damage index, postyield stiffness ratio, and ultimate ductility factor is investigated. In comparison with the non-pulse-type ground motions, the near-fault pulse-type ground motions can significantly increase the γDI of structures, and the magnitude of the increase can reach about 200%. Conservative estimates of mean γDI of SDOF oscillators are proposed taking into account the combined effect of period, damage level, and ultimate ductility factor. [ABSTRACT FROM AUTHOR]

In this work, the seismic response of a multi-story, multi-bay special truss moment frame (STMF) with Ni-Ti shape memory alloys (SMAs) incorporated in the form of X-diagonal braces in the special segment is investigated. The diameter of the SMAs per diagonal in each floor was initially determined, considering the expected ultimate strength of the special segment, developed when the frame reaches its target drift and the desirable collapse mechanism, i.e., the formation of plastic hinges, according to the performance-based plastic design procedure. To further investigate the response of the structure with the SMAs incorporated, half the calculated SMA diameters were introduced. Continuing, three more cases were investigated: the mean value of the SMA diameter was introduced at each floor (case DC1), half the SMA diameter of case DC1 (case DC2), and twice the SMA diameter of case DC1 (case CD3). Dynamic time history analyses under seven benchmark earthquakes were conducted using commercial nonlinear Finite Element software (SeismoStruct 2024). Results were presented in the form of top-displacement time histories, the SMAs force–displacement curves, and maximum inter-story drifts, calculating also maximum SMA displacements. The analysis outcomes highlight the potential of the SMAs to be considered as a novel material in the seismic retrofit of steel structures. Both design approaches presented exhibit a certain amount of effectiveness, depending on the distribution, with the placement of the SMA bars and the seismic excitation considered. Further research is suggested to fully understand the capabilities of the use of SMAs as dissipation devices in steel structures. [ABSTRACT FROM AUTHOR]

The Performance-Based Seismic Design (PBSD) is an advanced approach to designing earthquake-resistant structures, ensuring that a building meets specific performance objectives under seismic impacts. Unlike traditional design codes, PBSD aims to predict and control the damage to structures based on defined earthquake levels, minimizing damage and repair costs after an earthquake. The PBSD process includes defining performance objectives, selecting appropriate analysis models, conducting nonlinear analyses, and evaluating damage levels. Analytical methods such as nonlinear static pushover analysis and dynamic time history analysis are commonly applied in this process. Due to the need for in-depth knowledge and complex calculations, implementing PBSD can present significant challenges. This paper aims to present the details of PBSD based on seismic design codes and applies this approach to seismic design for bridges under earthquakes. [ABSTRACT FROM AUTHOR]

This study presents the development and analysis of high damping rubber bearings (HDRBs) with enhanced stiffness properties to improve seismic isolation performance. The proposed HDRBs exhibit displacement-dependent nonlinear stiffness and significant damping effects, especially under large deformations caused by various seismic events. A deformation history integral model, calibrated with experimental data, is employed to accurately simulate the mechanical behavior and stiffness-damping characteristics of the HDRBs. The numerical simulations are validated through experimental tests, providing a solid basis for parameter design and performance assessment. The results show that the equivalent stiffness coefficient of the HDRBs increases with deformation amplitude, effectively limiting extreme deformations. Parametric analyses and case studies across a wide range of earthquake scenarios demonstrate that the enhanced stiffness and high damping effects of HDRBs significantly improve seismic isolation efficiency while controlling isolation layer displacement. The performance-based design methodology developed in this research effectively limits bearing deformation, thereby preventing potential superstructure failures. Moreover, the adaptive characteristics of the HDRBs allow for the adjustment of deformation levels according to seismic intensity, ensuring the structural safety of buildings under varying earthquake conditions. [ABSTRACT FROM AUTHOR]

A performance-based seismic design method using the elastic displacement design spectrum based on equal displacement approximation is proposed for the Hinged Wall with BRBs at Base (HWBB) structural system. HWBB is simplified as an Equivalent Single Degree of Freedom (ESDOF) system. Design flowcharts are given. The proposed design approach aims to limit the lateral displacements to an allowable target displacement. Design examples are presented and target displacements are compared with numerical results. The results indicate that the plastic response of the HWBB structural system is accurately predicted by the elastic displacement spectrum, which verified that the performance-based design method of HWBB is accurate. [ABSTRACT FROM AUTHOR]

In this paper, three-dimensional nonlinear dynamic finite-element analyses are conducted to examine the effect of soil property variability on the lateral displacement (D) of liquefiable ground reinforced by granular columns. A suite of 20 ground motions is selected from the NGA-West2 database as input. A soil-granular column ground system consisting of an intermediate liquefiable layer is modeled in OpenSees. Both the random variable (RV) and random filed (RF) methods are adopted to model the variability of soil property parameters. Dynamic analyses are then conducted to estimate the earthquake-induced deformation of the soil-granular column system. It is found that modeling the variability of soil parameters based on the RV method generally increases the geometric mean and standard deviation (σlnD) of D for the soil-granular column system. Enlarging the spatial correlation of soil parameters in the RF model brings in a slight increase of the mean D and comparable σlnD values, respectively. Hence, incorporating the spatially correlated soil property parameters may not be necessarily increase the variation of D for the soil-granular column system. Specifically, the statistical distribution of D is more sensitive to the vertical scale of fluctuation rather than the horizontal one. The results presented could aid in addressing the variability issue for performance-based design of granular column-reinforced liquefiable ground in engineering applications. [ABSTRACT FROM AUTHOR]

This paper examines the shaft resistance mobilisation ratio as a predictor of cumulative displacement of small-scale floating and end-bearing energy pile foundations subjected to vertical compressive loads embedded in dry sandy soils. A reduced friction model pile was subjected to different mechanical loads and two long-duration, cyclic heating/recovery temperature changes. The pile, soil and container temperatures, pile strains, and vertical displacements are monitored, analysed, and discussed. The results further validate numerical analyses that propose the shaft resistance mobilisation ratio as a variable to identify thresholds above which permanent cyclic thermo-induced deformations may occur. Overall, the experimentally observed responses indicate incremental deformations as the shaft resistance mobilisation ratio increased. The results also suggest that a mobilisation ratio of 66% could be a potential conservative lower-bound limit that could control the increment of thermal-induced vertical displacements in the long term under free pile head conditions. This suggests that a performance-based design would be a reasonable approach for energy piles, and monitoring programs should be set in the field before loading and thermo-activation. [ABSTRACT FROM AUTHOR]

This study aimed to develop optimized alkali-activated concrete using ferronickel slag for high-temperature applications, focusing on minimizing environmental impact while maintaining high compressive strength and slump. A response surface methodology, specifically the mixture design of experiments, was employed to optimize five components: water, FNS-based alkali-activated binder, and three aggregate sizes. Twenty concrete mixes were tested for slump and compressive strength before and after exposure to 600 °C for two hours. The optimal mix achieved 88 MPa compressive strength before heat exposure and 34 MPa after, with a slump of 140 mm. An upscaled version with improved workability (210 mm slump) maintained similar unheated strength but showed reduced post-heating strength (23.5 MPa). Replacing limestone with olivine aggregates in the upscaled mix resulted in 65 MPa unheated and 32 MPa post-heating strengths. Life Cycle Analysis revealed that the optimized ferronickel slag alkali-activated concrete's CO2 emissions were 77% lower than those of ordinary Portland cement concrete of equivalent strength. This approach demonstrated the applicability of mixture design of experiments as an alternative design methodology for alkali activated concrete, providing a valuable performance-based design tool to advance the application of alkali-activated concrete in the construction industry, where no prescriptive standards for alkali-activated ferronickel concrete mix design exist. The study concluded that the developed ferronickel slag alkali-activated concrete, obtained through a performance-based mixture design methodology, offers a promising, environmentally friendly alternative for high-strength, high-temperature applications in construction. [ABSTRACT FROM AUTHOR]

Reinforced concrete bridge bents with double columns in bridge substructures are commonly used, but it has suffered severe damage during strong earthquakes. The seismic retrofit with structural fuses is used to effectively mitigate seismic damage of bridge bents. To obtain the displacement ductility demand for dual systems including the primary structure (PS) and structural fuses (SF), the corresponding ductility demand factor spectra were developed. The interaction between the PS and SF is described by defining two parameters of dual systems: the yield displacement ratio (α) and the initial stiffness ratio (β), and the influence of α, β, and strength reduction factor on the ductility demand factor spectra are also analyzed. For seismic retrofitting in bridge bents, buckling-restrained braces (BRBs) are used as energy dissipation fuses, and the steel core lengath of BRBs with three configurations forms, including diagonal, inverted-V, and toggle systems, are also explored. Then, based on the structural fuses concept and ductility demand factor spectra of dual systems, a performance-based seismic design procedure is proposed for bridge bents retrofitted with BRBs to ensure that the bridge bents maintain the target ductility under design-level earthquakes. Finally, the procedure was utilized to design the bridge bents with BRBs, and the procedure's feasibility was verified by nonlinear time-history analysis. [ABSTRACT FROM AUTHOR]

Many design regulations around the globe rely on member deflection as a governing criterion for resistance assessment in fire. The deflection evaluation in fire is generally achieved by conducting expensive experiments or computationally expensive finite-element analyses. This often restricts practicing engineers from using robust performance-based design philosophy for typical structures. Instead, they rely on objective design guidelines, often resulting in inefficient sizes of reinforced concrete (RC) members. Therefore, semiempirical relations are derived in the current study to determine the maximum deflection of the RC beam and RC column in a fire. Three separate end conditions are considered within the beam category: fixed-fixed beam, propped cantilever beam, and simply supported beam. Plausible variables are first identified that could affect the overall deflection of the member, and their proportionality is subsequently determined by performing one-on-one regression analysis. Furthermore, these relations are developed in terms of the most suitable fire intensity measures derived from the literature, which makes them applicable irrespective of the type of fire framework. The credibility of the deflection equations is validated through visual analysis followed by the three popular error indicator parameters, namely, Pearson's correlation coefficient, relative root-mean squared error (RRMSE), and performance index. Results indicated that all deflection equations accurately predict the RC member behavior under fire. [ABSTRACT FROM AUTHOR]

Eccentrically Braced Frames (EBFs) equipped with steel shear links primarily sustain large deformation demands through inelastic actions in the links, including yielding, bucking, and fracture of the steel plates or weld parts. This failure mode becomes more complex and results in highly nonlinear behavior using Low-Yield-Point (LYP) steels for the construction of the links due to their high strain hardening capacities. The existing analytical models have been presented for links made of normal steel grades, and thus there is a substantial research need for developing an analytical model to capture the actual behavior of links made of LYP steels. To fill this gap, this paper developed both shear-hinge and shear-spring-based models for performance-based evaluation of EBFs equipped with LYP steel shear links, which are more practical models in general-purpose structural analysis programs. The accuracy of the proposed model was assessed by comparing it with existing experimental tests and analytical models. As a result, there is good agreement between the proposed model and test results in terms of initial stiffness, post-yielding stiffness, and strength, which shows significant improvement over existing analytical models. [ABSTRACT FROM AUTHOR]

To incorporate the advantages of inelastic behaviour in design of civil engineering structures under seismic excitations, contemporary seismic design codes adopt a factor, termed as response reduction (or modification) factor ( R ). This factor is considered to calculate the seismic demand of a structure by estimating the inelastic base shear from its linear counterpart. This study first evaluates the adequacy of R values provided in Indian seismic codes by performing numerical studies on different reinforced concrete (RC) frame buildings, which are designed following the provisions of contemporary Indian seismic codes. In particular, to assess the values of R for multi-storey RC frames, the present work utilises rigorous incremental dynamic analysis (IDA). Next, in order to understand the influence of flexible base conditions on R values, elastic and inelastic soil-structure interactions (SSI) are incorporated in the analysis. In flexible base condition, Type II (medium) and Type III (soft) soil conditions (as per Indian seismic code) are considered to characterise the base soil and for designing the isolated footings of the frame structures considered in this study. It has been observed from this study that for both fixed and flexible base conditions, the code specified R value may not be conservative in some cases. [ABSTRACT FROM AUTHOR]

This study analyzes the impact of the standards determined within the Turkish "Regulation on Fire Protection of Buildings" scope on evacuation time. The evacuation performance of assembly-purpose structures was measured within the limitations imposed by the regulation. Three classes of assembly-purpose structures were analyzed, including the definition of the highest user load in the regulation. Scenarios A, B, and C, consisting of 230 sub-scenarios with varying user numbers, were created, resulting in a total of 690 different sub-scenarios being analyzed. The scenarios were analyzed using the Pathfinder program. The findings indicate that the user load is a decisive factor in evacuation time. Additionally, the exit width per person specified in the regulation was observed to be larger than necessary to maintain the same conditions. Minimum Required Safe Egress Time (RSET) values were determined for the three different assembly structures with the highest user load definition in the regulation within a fire regulation-compliant building. It was concluded that the exit capacity should exceed the limits set by the regulation to achieve shorter evacuation times. The study's findings demonstrate the need to include performance-based definitions in future amendments to the regulation. This study emphasizes the significance of performance-based analyses to underscore that overreliance on prescriptive definitions can impose limitations during the design process, negatively affecting efficiency. [ABSTRACT FROM AUTHOR]

Functional recovery is a new, nonstandardized building design objective, intended to improve a building's capacity to maintain or rapidly restore basic intended functions after a natural hazard event. Current building seismic design standards, which target life-safety performance objectives, provide limited requirements to ensure buildings maintain, or rapidly recover, function after earthquakes. Therefore, the expected functional recovery performance that is provided by current building codes is unclear. To provide clear and systematic insights to inform the development of prescriptive and performance-based design standards, this study documents the functional recovery performance for a set of 60 reinforced concrete archetype buildings. The results indicate that the estimated functional recovery time for reinforced concrete buildings designed to life-safety standards may approach 1 year, on average, for design-level earthquakes. Additionally, while increased strength and stiffness requirements significantly reduce the likelihood of a building being marked as unsafe due to structural damage, additional design provisions for nonstructural components are required to ensure a high confidence of rapid recovery. The findings from this study clarify the expected post-earthquake recovery of modern reinforced concrete buildings and identify key trends in underlying damage and response mechanisms required to improve future building performance. [ABSTRACT FROM AUTHOR]

Connecting infrastructures such as steel bridges are important for sustainable and economic development of society. Understanding the risks to these infrastructures associated with wind is crucial to ensure their resilience, particularly with the evident threat of climate change. The authors will discuss the benefits of early‐stage consulting in delivering climate aware performance‐based design for steel bridges. A holistic approach comprising bridge monitoring, aerodynamic consultation coupled with wind tunnel testing and numerical simulations enables us to understand the structural response of bridges, from an aerodynamic perspective. By combining this knowledge with a local climate model, the bridge response to current and future expected wind conditions, can be predicted and assessed. The outcomes of such an approach enable us to refine design wind loads optimizing material usage and ensuring safe and cost‐effective construction processes, thereby reducing embodied carbon. [ABSTRACT FROM AUTHOR]

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This paper presents the physics based ground motion synthetics and its earthquake engineering consequences in the National Capital Territory (NCT) Delhi, India due to the Mw8.2 scenario earthquake on the Nahan segment of the western Himalaya. In order to fulfill the aim, a state-of-the-art pseudo-dynamic rupture is implemented in a 3D fourth-order staggered-grid viscoelastic time-domain finite-difference code. The ground motion is simulated in a frequency bandwidth of 0–2.5 Hz at the basement level at 158 locations of the NCT Delhi. The computed transverse component of velocity time series at the basement level is numerically transferred to the free surface taking into account the rheological parameters of the sediment deposit. Upon first inspection, the estimated range of peak ground acceleration, between 0.017–0.12 g, indicates that all the buildings in the NCT Delhi will remain safe in the event of an Mw8.2 Nahan earthquake, provided they are constructed in accordance with Indian building codes. But, the computed acceleration response spectra (Sa) depicts that some of the high-rise buildings of the NCT Delhi may suffer minor damage to collapse under partial or complete double resonance condition due to Sa exceeding the DBE and MCE levels. The obtained range of pseudo-spectral displacements (Sd) reveals the need of performance-based design for high-rise buildings in the NCT Delhi, so that they can withstand under partial or complete double resonance condition during the occurrence of Nahan earthquakes. The developed contour maps of Sa and Sd at different periods can be used for the retrofitting and forced-based and displacement-based designs of the high-rise buildings. [ABSTRACT FROM AUTHOR]

The majority of fatalities in building fires are attributed to asphyxiation caused by toxic gases. Hydrogen cyanide (HCN) is one of the toxic gases that can be released during a fire, posing a lethal risk to humans even at low concentrations. However, analysis of the risk posed by HCN in fire risk assessments using fire simulations is relatively rare. This study conducted fire simulations to examine the potential risks of HCN to occupants during a fire. The simulations considered various fire conditions in residential buildings by varying fuel types, fire growth rates, and HCN yields. The relative risk score (RRS) was derived based on the time to reach the threshold values of parameters considered critical for life safety. The results of the fire simulations indicated that the RRS for HCN was approximately 20–40 points higher than that of O2, CO, and CO2, reaching a maximum of 92 points. However, the risk posed by HCN was found to be limited in comparison to the risks associated with temperature and visibility. Nevertheless, considering that the primary cause of fatalities in fires is asphyxiation due to toxic gases, HCN must be regarded as a critical factor in fire risk assessments. Additionally, since HCN yield values can increase up to nine times depending on temperature and ventilation conditions, the risk posed by HCN could be significantly higher. [ABSTRACT FROM AUTHOR]