Structural Resilience Research Articles

Life-Cycle Performance Modeling for Sustainable and Resilient Structures under Structural Degradation: A Systematic Review

The performance of structures degrades during their service life due to deterioration and extreme events, compromising the social development and economic growth of structure and infrastructure systems. Buildings and bridges play a vital role in the socioeconomic development of the built environment. Hence, it is essential to understand existing tools and methodologies to efficiently model the performance of these structures during their life cycle. In this context, this paper aims to explore the existing literature on the life-cycle performance modeling, assessment, enhancement, and decision making of buildings and bridge infrastructure systems under deterioration and extreme events for a sustainable and resilient built environment. The main objectives are to (1) systematically review the existing literature on life-cycle performance modeling of buildings and bridges based on the PRISMA methodology, (2) provide a bibliometric analysis of the systematically assessed journal articles, (3) perform an analysis of the included articles based on the identified components of life-cycle performance modeling, and (4) provide a discussion on the utilized tools, techniques, methodologies, and frameworks for buildings and bridge infrastructure systems in the life-cycle context. The provided systematic literature review and subsequent discussions could provide an overview to the reader regarding the individual components and existing methodologies of life-cycle performance management under deterioration and extreme events.

Resilience of code compliant reinforced concrete buildings to progressive collapse: A numerical analysis investigation

This study investigates the resilience of dual-system reinforced concrete (RC) structures impacted by progressive collapse where the local failure of a primary structural component leads to the sequential collapse of adjoining elements. The study is conducted on buildings designed in the United Arab Emirates in the context of extreme events. Nonlinear dynamic analysis of twenty-seven different building models is performed to evaluate the impact of critical variables, building height, and column spacing on progressive collapse potential under the Unified Facilities Criteria (UFC) regulations. The research methodology aims to study impacts associated with sudden removal of critical columns (corner, edge, and internal) that replicate severe accident scenarios in buildings. The structural responses were assessed based on the ASCE 41 performance design criteria. The formation of plastic hinges was analyzed to determine the ductility and resilience of the structures. The study finds that buildings with removed corner columns exhibit more significant vertical displacements than those with edge or internal column removals. The results also indicate that columns adjacent to the removed ones generally remained elastic and within their structural capacities, showing structural resilience to localized damage. However, the flexural strength of RC flat slabs near removed or adjacent columns demonstrates insufficient flexural capacities. This study underscores the imperative for enhanced design strategies and emphasizes the critical importance of bolstering structural resilience against extreme events. Moreover, it intends to draw the attention of policymakers locally to the need to consider progressive collapse when designing reinforced concrete structures.

Impacts of Waste Rubber Products on the Structure and Properties of Modified Asphalt Binder: Part I—Crumb Rubber

The issue of forming a reliable and sustainable structure of crumb-rubber-modified binder is an important scientific and technical task. The quality of this task will increase the technical and economic efficiencies of road construction materials. This work is dedicated to developing a scientifically justified method of directed thermomechanical devulcanization, which ensures the solubility of the crumb rubber in the complex structure of a polydisperse composite material, preventing the formation of aggregates consisting of unsaturated crumb rubber particles, whose elastic aftereffect causes intensive cracking, especially during low-temperature road operations. The novelty in the first part of this article is due to the fact that, for the first time, the quantitative ratio of the polymer component in the crumb rubber was experimentally determined. The ratio of the polymer component to the total content of the other rubber components in the crumb rubber (CR) was determined to be, on average, 93.3 ± 1.8%. The stabilities of the compositions of crumb rubber from different batches were experimentally studied. The nature of the polymer component in the crumb rubber was determined. A hypothesis was formulated to obtain a thermodynamically stable and sustainable binder modified with crumb rubber. To evaluate the compatibility of hydrocarbon plasticizers with the studied CR samples, the following semi-empirical and thermodynamic compatibility parameters were calculated: Hildebrand solubility parameters based on evaporation energy and surface tension, Barstein’s compatibility parameter |X|, Traxler coefficient, and the mass ratio of paraffin naphthene:asphaltenes. It was shown that for the substances under study, it is advisable to justify the choice of plasticizer based on chemical compatibility criteria. It was established that a supramolecular plasticization mechanism occurs in the “hydrocarbon plasticizer–crumb rubber” systems under consideration. In the development of the crumb-rubber-modified binder, it was found that the use of activated crumb rubber (ACR) from large tires does not ensure the achievement of a stable and resilient structure of the crumb-rubber-modified bitumen.

Advances and challenges in friction pendulum bearings for seismic isolation systems

Friction pendulum bearings (FPBs) have emerged as critical structural isolation devices in the field of earthquake engineering. Extensive research and development efforts have led to the exploration and refinement of these bearings, resulting in the creation of various models with unique structural configurations and superior mechanical properties. This paper offers an in-depth review of the friction materials employed in FPBs, alongside an analysis of the mechanical performance and advancements in research regarding single-pendulum, double-pendulum, multiple-pendulum, and other types of friction bearings. Characterized by their low sensitivity and high stability, these bearings are adept at resisting seismic forces, thus providing dependable isolation protection for structures. This review also includes a succinct examination of the seismic performance and engineering applications of these isolation structures. With robust self-centering capabilities, excellent isolation, and energy dissipation mechanisms, FPBs are capable of quickly resuming normal operations post-seismic events. This reduces structural damage and maintenance expenses, significantly improving the seismic resilience of structures. Moreover, the paper outlines the current challenges in the research and development of FPBs and suggests future research directions, including optimizing friction materials, enhancing the design and performance of isolation structures, and improving the seismic performance and engineering application efficiency of FPBs. By identifying underexplored areas and synthesizing findings differently, this review provides a comprehensive and novel perspective that advances the field of earthquake engineering.

A framework for post-windstorm functional recovery of non-residential buildings applied to hospitals

This study introduces a framework for recovery-based design in wind engineering. Currently, research is well advanced to implement this approach in earthquake engineering, with the scope of improving the resilience of structures and critical infrastructure, to achieve a durable and re-occupiable built environment after the occurrence of a disaster, and estimating downtimes and quantifying service disruption. The concept of interdependencies between the nonstructural components (building envelope) and a building’s functions is realized using Fault-Tree Analysis (FTA). Using this method allows the construction of fragility curves of systems of components and services using information as weights to reduce epistemic uncertainties, and a hypothetical recovery curve for the functionality of building services based on exposure to the hazard’s impact on the building envelope. The recovery process established here highlights the fundamental importance of accurate estimation of service losses. The methodology is applied to 4 hospitals located in different climatic regions in the United States surveyed using the database of EYP Architecture & Engineering. The analysis showed the importance of building design factors; such as the location of services relative to the envelope, number of stories, and the Window-to-Wall Ratio as significant influences on the risk of service disruption and recovery.

Enhancing Power and Thermal Gradient of Solar Photovoltaic Panels with Torched Fly-Ash Tiles for Greener Buildings

Solar photovoltaic (PV) panels that use polycrystalline silicon cells are a promising technique for producing renewable energy, although research on the cells’ efficiency and thermal control is still ongoing. This experimental research aims to investigate a novel way to improve power output and thermal performance by combining solar PV panels with burned fly-ash tiles. Made from burning industrial waste, torched fly ash has special qualities that make it useful for architectural applications. These qualities include better thermal insulation, strengthened structural integrity, and high energy efficiency. Our test setup shows that when solar PV panels are combined with torched fly-ash tiles, power generation rises by 7% and surface temperature decreases by 3% when compared to standard panels. The enhanced PV efficiency is ascribed to the outstanding thermal insulation properties of fly ash tiles and their capacity to control panel temperature. To ensure longevity and safety in building applications, the tiles employed in this study had a water absorption rate of 5.37%, flexural strength of 2.95 N/mm2, and slip resistance at 38 km/h. Furthermore, we find improved structural resilience and lower cooling costs when up to 30% of the sand in floor tiles is replaced with torched fly ash, which makes this method especially appropriate for sustainable buildings. Key performance indicators that show how effective these tiles are in maximizing energy use in buildings include thermal emissivity (0.874), solar reflectance (0.8), and solar absorption (0.256). While supporting more ecofriendly building techniques, this study highlights the advantages of utilizing burned fly ash in solar PV systems: enhanced power generation and thermal comfort. The main results open a greater potential for fly ash use in different building materials. The use of torched fly ash in building materials enhances thermal insulation and structural integrity while lowering cooling costs, making it an ideal choice for eco-friendly construction and highlighting the potential for further research into environmentally responsible, energy-efficient solutions.

Characterizing the free-vibration response of a two-span rocking bridge with free-standing columns

For accelerated bridge construction (ABC), replacing traditional emulative connections of precast elements with simpler discontinuities may lead to more resilient structures with reduced expected damages after strong seismic events. This paper comprises novel free-vibration tests of a 1:10 scale two-span rocking bridge with free-standing columns with proper geometrical and dynamic similarity. The two spans induced in the model the interaction between frames with different tributary masses, as would be expected for a realistic bridge. To excite the bridge uniformly, the experimental protocol consisted of forty-nine incremental sinusoidal ground motions that were interrupted, letting the bridge vibrate freely to rest. The results were compared with six analytical models. The results showed that the structure remained undamaged for the free-vibration tests after drifts up to 6 % and did not wobble unrestricted. The results were used to obtain the dynamic properties of the system and their variation to displacement increments. Construction imperfections induced the model to rock for all excitations, including low-intensity excitations, and to vibrate with periods different from those of theoretical equations at low displacements. This behavior was critical in the comparison between experimental results and the estimates from analytical models. These findings demonstrate that rocking bridges are a suitable system to control structural damage during seismic events despite the apparent variability of the behavior under realistic conditions. However, the design of these structures must account for the effects of construction imperfections at the rocking surface. The experimental results are openly available for download in the DesignSafe Data Depot using this DOI https://doi.org/10.17603/ds2-znfv-8t55.

Urban Internal Network Structure and Resilience Characteristics from the Perspective of Population Mobility: A Case Study of Nanjing, China

In the face of diverse chronic pressures and increased factor mobility, the resilience of urban internal network structures has become a cutting-edge research topic. This study utilizes 2019 mobile signaling big data to construct employment and recreational flow networks among 101 townships and streets within Nanjing City. Based on the characteristics of these network structures, the resilience of the network structure is measured from the perspectives of density, symmetry, and transmissibility through interruption simulation techniques. The results show that the intensity of population mobility within Nanjing presents a general decay from the central urban area to the outer layers. In the employment scenario, cross-river population mobility is more frequent, while in the recreational scenario, the natural barrier effect of the Yangtze River is prominent. Due to the concentration of employment centers and high spatial heterogeneity, the employment flow network exhibits greater vulnerability to sudden shocks. Townships and streets with weighted degree values ranking around 60 and 80 are of great importance for maintaining the normal operation of both employment and recreational flow networks. Strengthening the construction of resilient parks and village planning within resilient cities can enhance the risk resistance of employment and recreational flow networks.

Analysis of high temperature and strain amplitude effects on low cycle fatigue behavior of pitting corroded killed E350 BR structural steel

High-tension structural steels are prone to accelerated fatigue damage from pitting corrosion and high-temperature. Despite adverse effects, research on their low cycle fatigue (LCF) behavior is limited. Specifically, studies analyzing temperature-dependent pit sensitivity effects, considering pit-related material’s susceptibility to surface topographic features variation and stress concentration are lacking. This study conducts LCF tests on pitting corroded killed E350 BR structural steel at multiple strain amplitudes and high temperatures. It develops temperature-dependent parameters, such as the cyclic softening pit sensitivity factor, suitable for integration into existing approaches like total cyclic plastic strain energy density (CPSED), power-law, average strain energy density (SED), Coffin-Manson, and pit stress intensity factor (pit-SIF). Further, it proposes multiple linear regression-based prediction models relating total CPSED and average SED with strain amplitude and temperature. Corroded specimens show higher plastic deformation and reduced peak stress, fatigue life, and total CPSED compared to uncorroded ones. The developed parameters, integrated with average SED approach, predicts LCF life within an error band of ±1.5, while power-law relationship reduces it to ±1.2. Moreover, pit-SIF approach estimates fatigue life within an error band of ±1.5. The findings provide critical knowledge for enhanced component design, leading to structural safety, performance, and fire resilience.

Development and testing of a thermal self-straining preloading test setup for reinforced concrete beams and slabs to perform thermomechanical action

PurposeAt this moment, there is substantial anxiety surrounding the fire safety of huge reinforced concrete (RC) constructions. The limitations enforced by test facilities, technology, and high costs have significantly limited both full-scale and scaled-down structural fire experiments. The behavior of an individual structural component can have an impact on the entire structural system when it is connected to it. This paper addresses the development and testing of a self-straining preloading setup that is used to perform thermomechanical action in RC beams and slabs.Design/methodology/approachThermomechanical action is a combination of both structural loads and a high-temperature effect. Buildings undergo thermomechanical action when it is exposed to fire. RC beams and slabs are one of the predominant structural members. The conventional method of testing the beams and slabs under high temperatures will be performed by heating the specimens separately under the desired temperature, and then mechanical loading will be performed. This gives the residual strength of the beams and slabs under high temperatures. This method does not show the real-time behavior of the element under fire. In real-time, a fire occurs simultaneously when the structure is subjected to desired loads and this condition is called thermomechanical action. To satisfy this condition, a unique self-training test setup was prepared. The setup is based on the concept of a prestressing condition where the load is applied through the bolts.FindingsTo validate the test setup, two RC beams and slabs were used. The test setup was tested in service load range and a temperature of 300 °C. One of the beams and slabs was tested conventionally with four-point bending and point loading on the slab, and another beam and slab were tested using the preloading setup. The results indicate the successful operation of the developed self-strain preloading setup under thermomechanical action.Research limitations/implicationsGaining insight into the unpredictable reaction of structural systems to fire is crucial for designing resilient structures that can withstand disasters. However, comprehending the instantaneous behavior might be a daunting undertaking as it necessitates extensive testing resources. Therefore, a thorough quantitative and qualitative numerical analysis could effectively evaluate the significance of this research.Originality/valueThe study was performed to validate the thermomechanical load setup for beams and slabs on a single-bay single-storey RC frame with and without slab under various fire possible scenarios. The thermomechanical load setup for RC members is found to be scarce.

Enhancing bird habitat networks in metropolitan areas: Resilience assessment and improvement strategies – A case study from Shanghai

Constructing bird habitat networks (BHNs) is crucial for maintaining the health and service equilibrium of urban ecosystems, especially in large metropolitan areas where the pressure of urbanization is intense. However, most existing BHNs fail to account for the dynamic changes and unique requirements of local species, leading to homogenized construction outcomes and ecological corridor objectives. This study employs a comprehensive approach to identify bird habitat patches using multiple high-quality sources, then utilize circuit theory and complex network theory to construct and assess the resilience of BHN. Our key findings showed: (1)93 bird habitat sources were identified, predominantly situated in the continuous green spaces of southern and southeastern Shanghai, whereas habitat sources in the city center and other densely built-up areas are more dispersed, highlighting them as prime targets for future ecological restoration efforts. (2) The distribution of bird habitat corridors exhibits significant spatial heterogeneity, with primary corridors predominantly spanning the southwestern and eastern parts of the study area, while secondary corridors are more abundant in the western and northern parts, forming a denser network, whereas the central area shows fewer and more isolated corridors. (3) The decline in structural and functional resilience was notably more rapid under targeted attacks than under random attacks, underscoring the need to prioritize crucial bird habitat sources on the city's periphery, especially near highly urbanized areas, in urban planning and biodiversity conservation efforts to sustain ecological balance and biodiversity. These insights provide a crucial scientific basis for urban planners, emphasizing the integration of biodiversity conservation into urban development strategies by optimizing ecological sources and corridors to balance development with ecological preservation.

Longitudinal structural resilience of shield tunnel: Characterization and field application

The longitudinal structural resilience performance of shield tunnels is an important concern given the dramatic development of underground systems and the increasing demand for maintenance work. In this paper, a new model using longitudinal relative differential settlement as the index of tunnel structural resilience performance is proposed. The resilience metric (Re) is defined as the ratio of the area integrated by the residual performance during environmental disruptions to the area integrated by the normal performance for the corresponding duration. Then, the proposed resilience analysis model is applied to a well-documented case in Shanghai, where the existing metro tunnel is disrupted by a newly constructed large-diameter shield tunnel undercrossing and subsequently repaired by soil grouting. The variations of tunnel settlement concerning construction parameters and driving distance of the shield machine are analyzed. The performance degradation characteristics of the tunnel during disruption and recovery are effectively captured. The results show that 32.3 % of the performance loss is attributed to the new tunnel undercrossing in the first 38 days. After the completion of the grouting reinforcement, the tunnel performance is improved from 0.677 to 0.868, accounting for approximately 59.1 % of the performance loss during the crossing period. Moreover, the resilience metric (Re) is calculated as 0.764, indicating a high level of resilience for the existing metro tunnel in this case. In addition, other performance indexes based on tunnel longitudinal settlement are discussed, demonstrating the good rationality and applicability of the proposed index.

Seismic assessment of glulam frames with dual-tube self-centering buckling-restrained braces

The development of resilient lateral load-resisting systems is essential for multi-story and high-rise timber buildings in earthquake-prone areas. In this paper, an attempt is made to integrate dual-tube self-centering buckling-restrained braces (DT-SCBRBs) to glulam frames, aiming to improve their structural resilience to earthquakes. To assess the seismic effectiveness of such a DT-SCBRB glulam frame, nonlinear time-history analyses (NLTHAs) were conducted on a series of prototype DT-SCBRB glulam frames with different building heights and design parameters of DT-SCBRBs. The seismic performance of these prototype structures was evaluated in terms of maximum inter-story drift ratios (MaxISDRs), residual inter-story drift ratios (ResISDRs), and inter-story drift uniformity. The results show that the frame with lower post-tensioning-to-yielding ratios of DT-SCBRBs tended to exhibit lower MaxISDRs but could sometimes lead to higher ResISDRs under major earthquakes. Low deformability of tendons could result in tendon fracture under major earthquakes. The ResISDRs of all the prototype frames were lower than 0.5 %, the drift limit for the “Repairable” performance level. Compared to minor and moderate earthquakes, the DT-SCBRB glulam frames deformed more uniformly during major earthquakes. Incremental dynamic analyses (IDAs) were also conducted on these prototype structures, developing a database to quantify performance levels of DT-SCBRB glulam frames. The MaxISDRs of 0.5 %, 0.7 %, and 2.6 % were recommended for immediate occupancy (IO), life safety (LS), and collapse prevention (CP) limit states of DT-SCBRB glulam frames.

Perceived structural empowerment, resilience, and intent to stay among midwives and registered nurses in Saudi Arabia: a convergent parallel mixed methods study

BackgroundRetaining midwives and registered nurses in the Obstetrics and Gynecology department/unit (OB/GYN) is not just a matter of organizational effectiveness and financial wellness. It’s a crucial aspect of ensuring quality healthcare delivery. This study aimed to discuss the degree to which midwives and nurses in OB/GYN departments are structurally empowered, resilient, and committed to remaining at the organizations and to examine whether nurses’ and midwives’sense of structural empowerment and resilience is a good predictor of their decision to stay with the organization.MethodsThis study employed a unique convergent parallel mixed methods approach. The research was conducted in two distinct phases. The first phase involved a cross-sectional quantitative survey with a convenience sample of 200 midwives and nurses in OB/GYN departments. The second phase was a qualitative study utilizing semi-structured, open-ended interviews. Eighteen nurses and midwives, specifically chosen as the target population, were invited to participate in individual interviews. The data collection took place at three major hospitals in Saudi Arabia, starting in January 2023 and concluding in February 2023.ResultsThe study results revealed that structural empowerment and resilience were statistically significant predictors of the intent to stay in the organization (F = 35.216, p < 0.001), with 26.3% variation, the structural empowerment is higher predictor (β = 0.486, p < 0.000) to intent to stay if compared to resilience (β = 0.215, p < 0.008). Five major themes emerged from the narratives of the nurses and midwives: the nurturing of the physical and physiological, the development of the psychological, the managing finances, the restructuring of the organization, and the enrichment of the professional and occupational.ConclusionThe study’s findings have significant implications for healthcare organizations. They highlight the importance of cultivating a culture of empowerment and resilience, which can serve as a powerful tool to encourage registered nurses and midwives to remain in their organizations. This insight empowers healthcare administrators, human resource managers, and obstetrics and gynecology professionals to take proactive steps toward improving retention rates.

Crosslinked polyetherimide based electrospun membrane: Effect of fibre morphology on hot oil sorption

Handling hot oil spillage, particularly from oil refineries, petrochemical industry and automobiles is challenging and there have been limited solutions to address the issue. Polyetherimide (PEI) electrospun fibrous membranes were developed in this study by leveraging PEI's high-temperature stability to serve as promising materials for hot oil sorption. The morphology of the membrane forming fibers varied from circular to dumbbell shaped, by judicious choice of solvents of varying boiling points, to study the effect of fiber morphology on oil sorption capacity. Crosslinking of PEI membranes was carried out using ethylenediamine (EDA) to impart structural integrity and resiliency to the membranes. The PEI membrane composed of dumbbell-shaped fibers demonstrated an oil-sorption capacity of 25.4 ±1.5 g/g for engine oil at 150°C within one hour, outperforming a commercial polypropylene (PP) nonwoven absorbent, which failed and collapsed under the same high-temperature conditions. Enhanced oil sorption in the dumbbell-shaped fibrous membrane was achieved due to its lower tortuosity, aligned inter-fiber channels, and higher capillary pressure. Usefulness and sorption capacity of PEI based electrospun membranes may further be explored for controlling the oil spillage through introduction of specific surface features and functionalization.

Role of women in the water–energy–food (WEF) nexus—challenges and opportunities

AbstractWater, food and energy are crucial for human survival and sustainable development, being interconnected through the water–energy–food (WEF) nexus. Despite extensive research, the significant roles women play in these sectors are often underappreciated. Women are vital in water management, enhancing resource management, water quality and access, particularly in rural areas. In agriculture, they make up a large proportion of the workforce, boosting productivity, promoting sustainable farming practices and ensuring food security. Their deep knowledge of traditional food systems, coupled with their caregiving roles, contributes to providing nutritious and culturally appropriate diets. In the energy sector, women are key advocates for sustainable solutions and grassroots adoption of renewable energy technologies. Recognizing gender equality and empowering women are essential for maximizing their potential in the WEF nexus. Implementing gender‐responsive policies, inclusive decision‐making processes, and investing in education and skills training can significantly enhance women's roles in sustainable management. Empowered women drive innovation and transformative change, leading to more resilient and inclusive governance structures. This article emphasizes the importance of recognizing and supporting women's contributions within the WEF nexus, as this leads to more sustainable and equitable outcomes for all.

Parametric Analysis of Critical Buckling in Composite Laminate Structures under Mechanical and Thermal Loads: A Finite Element and Machine Learning Approach.

This research focuses on investigating the buckling strength of thin-walled composite structures featuring various shapes of holes, laminates, and composite materials. A parametric study is conducted to optimize and identify the most suitable combination of material and structural parameters, ensuring the resilience of structure under both mechanical and thermal loads. Initially, a numerical approach employing the finite element method is used to design the C-section thin-walled composite structure. Later, various structural and material parameters like spacing ratio, opening ratio, hole shape, fiber orientation, and laminate sequence are systematically varied. Subsequently, simulation data from numerous cases are utilized to identify the best parameter combination using machine learning algorithms. Various ML techniques such as linear regression, lasso regression, decision tree, random forest, and gradient boosting are employed to assess their accuracy in comparison with finite element results. As a result, the simulation model showcases the variation in critical buckling load when altering the structural and material properties. Additionally, the machine learning models successfully predict the optimal critical buckling load under mechanical and thermal loading conditions. In summary, this paper delves into the study of the stability of C-section thin-walled composite structures with holes under mechanical and thermal loading conditions using finite element analysis and machine learning studies.

Failure analysis and structural resilience of a masonry arch Bridge subjected to blast loads: The Case study, Halilviran Bridge

This study investigates the dynamic response of masonry bridges under blast-induced shock waves, focusing on the structural integrity and safety of these critical infrastructure components under extreme conditions. The research employs theoretical approaches to analyze the effects of blast-induced shock waves on masonry bridge structures. A comprehensive numerical simulation framework is developed using finite element analysis (FEA) to model the dynamic interactions between blast waves and the masonry materials. Key parameters, including the blast load intensity, duration, and distance from the blast source, are varied to assess their impact on bridge performance. The results reveal significant insights into the deformation patterns, stress distribution, and potential failure modes of masonry bridges under blast loading scenarios. The findings underscore the importance of incorporating blast resistance measures in the design and retrofitting of masonry bridges to enhance their resilience against explosive events. This study contributes to the advancement of safety standards and design guidelines for masonry bridge structures in the context of blast loading, providing valuable information for engineers, policymakers, and infrastructure managers.

Development of Approaches for Strengthening and Retrofitting of Concrete Beams Using Structural Steel

In structural analysis, the term 'frame' typically refers to a robust structure comprising various elements such as slabs, beams, columns, and footings. These components are cast together to create a monolithic construction, effectively functioning as a single integral unit. The frame is subject to various forces, which are transferred through its different components. Additionally, changes in facility usage or the introduction of additional live loads can exert further stresses on the structure. Consequently, it is imperative that the elements of the frame possess sufficient strength to withstand these loads. In this study, we focus on the development of approaches for strengthening and retrofitting concrete beams using structural steel elements. Specifically, our investigation involves the analysis of beams under different load combinations to enhance their integrity performance. To achieve this, angles and steel plates are utilized for reinforcement. We conduct numerical analysis through finite element modeling using ANSYS Workbench. Multiple beam models are created within the ANSYS platform, allowing us to study and compare various outcomes, including total deformation. This comprehensive approach aims to contribute to the advancement of methods for enhancing the structural resilience of concrete beams in real-world applications.

Seismic performance investigation of new buckling-restrained steel plate for resilient rocking column foot joint

Seismic damage-controllable components and design approaches are crucial for achieving the seismic resilience and post-earthquake recovery of building structures. To improve the seismic resilience of reinforced concrete (RC) frame structures, this study proposed a novel assembled replaceable rocking column foot joint. The column foot joint is composed of a concrete foundation, short steel-tube concrete column in the center, and four new buckling-restrained steel plates (BRSPs) on the periphery. A detailed design method for the BRSPs was developed, and six BRSP specimens were designed with different core weakening forms and thicknesses. The specimens were cyclically tested and the failure mode and hysteresis behavior were examined. The test results confirmed that the proposed BRSPs exhibit satisfactory energy-dissipation capacity and achieve damage control. The refined numerical models were developed using ABAQUS and verified using the test results. Parametric analyses were conducted for the BRSPs to examine the influence of core plate thickness, gap size, and restraint plate thickness. A numerical analysis model of the column foot joint was established, and the influence of the axial compression ratio and BRSP bearing capacity on the seismic performance of the column foot was investigated. This study provides a reference for the construction of resilient RC frame structures.