Residual Capacity Research Articles

Progressive collapse mode induced by slab-column joint failure in RC flat plate substructures: A new perspective

Majority of progressive collapse incidents of concrete flat plate structures were caused by slab overloading in the form of punching shear failure at a slab-column joint, which exhibit distinctive resistance mechanism from those triggered by column losses. Relevant studies on the slab overloading scenario are scarce. To fill this gap in research and to broaden the perspective on different collapse modes, an experimental test was conducted on a 1/3-scale 2 × 2-bay flat plate substructure specimen by applying an increased downward uniform load on the slab, until the structure was completely damaged following the initial punching shear failure at the interior slab-column joint and was unable to take any further load. In addition, the flexural capacity of the specimen was evaluated using the yield line theory, and an analytical model was also proposed to estimate the post-punching peak load of the specimen. Finally, the experimental results obtained from this study were compared to those of a similar test under an interior column removal scenario. Comparisons indicate that the specimen under the slab overloading scenario displays better collapse resistance than that under the column removal scenario. Nevertheless, the residual resistant capacity of the overloaded specimen may not be adequate enough to prevent the collapse of the entire structure after the initial punching failure.

Experimental Study on the Structural Performance of Reinforced Truss Concrete Composite Slabs during and after Fire

Standard fire resistance tests and post-fire tests on residual mechanical properties were carried out on two four-edge simply supported reinforced truss concrete two-way composite slabs with wide seam splicing (“integral seam”) and close seam splicing (“separated seam”), and the effects of the different splicing forms on the mechanical properties of the reinforced truss concrete composite slabs during and after exposure to high temperatures were explored. The results indicate that there are significant differences in terms of crack developments, moisture loss times on the slab surface, spalling characteristics of the bottom of the slab and cross-section temperature gradients of concrete and steel reinforcement along the thickness direction between the wide seam spliced reinforced truss concrete composite two-way slab (referred to as “S1 composite slab”) and the close seam spliced reinforced truss concrete composite two-way slab (referred to as “S2 composite slab”) in the fire test. This is mainly due to differences in the splicing forms and structural measures of the prefabricated base slabs at joints, which led to changes in the heat transfer path at the joints. As the temperature at the close seam can be released quickly, the stiffness recovery of the S2 composite slab is significantly greater than the stiffness weakening due to the thermal hysteresis of the concrete, so the deflection of the S2 composite slab recovers immediately after the fire stops. Overall, both the S1 and S2 composite slabs exhibit two-way high temperature deformation characteristics. The post-fire residual static load tests show that the static load-carrying capacity of the S1 composite slab is 12.08% higher than that of the S2 composite slab and the ultimate displacement is 8.74% lower than that of the S2 composite slab. It is appropriate to calculate the residual load capacities of the S1 and S2 composite slabs after the fire as a one-way slab.

Sulfated Polysaccharide Regulates the Homing of HSPCs in a BMP-2-Triggered In Vivo Osteo-Organoid.

Hematopoietic stem cell transplantation (HSCT) is a well-established method for a variety of acquired and congenital diseases. However, the limited number and sources of therapeutic hematopoietic stem/progenitor cells (HSPCs) hinder the further application of HSCT. A BMP-2triggered in vivo osteo-organoid that is previously reported, serves as a kind of stem cell biogenerator, for obtaining therapeutic HSPCs via activating the residual regenerative capacity of mammals using bioactive biomaterials. Here, it is demonstrated that targeting the homing signaling of HSPCs elevates the proportions and biological functions of HSPCs in the in vivo osteo-organoid. Notably, it is identified that sulfonated chito-oligosaccharide, a degradation product of sulfonated chitosan, specifically elevates the expression of endothelial protein C receptor on HSPCs and vascular cell adhesion molecule-1 on macrophages in the in vivo osteo-organoid, ultimately leading to the production of adequate therapeutic HSPCs. This in vivo osteo-organoid approach has the potential to provide an alternative HSPCs source for HSCT and benefits more patients.

Controllable MOF-Derived Hierarchical Hollow CoNiSe2 with Enhanced Mechanics and Kinetics for Extraordinary Rate Performance and Durable Anode of Sodium-Ion Batteries

High rates and durable anodes are the eternal pursuits of sodium ion batteries (SIBs). Constructing bimetal selenide is an efficient strategy to improve Na+ storage. Herein, a hierarchical hollow CoNiSe2/carbon compound (CoNiSe2/C) was designed as an anode of SIBs via selenizing the modified MOFs precursor. During the high-rate test, CoNiSe2/C electrodes exhibited an outstanding specific capacity of 301.9 mA h g–1 even at 20 A g–1, while an impressive cycle life over 2000 at 5 A g–1 was achieved with a residual capacity of 368.9 mA h g–1. The high-rate capability is attributed to the significantly reduced energy barrier of reaction activation and the strong microstructure of the hierarchical hollow CoNiSe2/C. It indicates that the CoNiSe2/C synthesized in this work is highly desirable and promising as a SIB anode material and sheds light on the design and development of anode materials.

The Influence of damage to reinfrorced concrete beam on strength and Deformability: the review

In accordance with current conditions, it is necessary to change the aim of buildings and structures in which a large number of reinforced concrete elements that undergo complex stress-deformed states are used. The task for researchers is to determine the residual bearing capacity of the element with uneven damage, making it possible to choose the most optimal calculation option and select materials for optimization, preservation of strength, and durability. Also, a special role is played by the study of the impact of damage and defects, which cause a stressed - deformed state that cannot be predicted by calculation. Methods of determining the residual bearing capacity of reinforced concrete elements with various types of damage are considered. It also provides a detailed analysis of the most common defects and damages in reinforcement concrete structures, different types of corrosion.

Experimental residual capacity of steel-reinforced concrete-filled steel tubular stub columns after fire exposure

Technological advances in the development of steel–concrete composite structures have led to the introduction of novel types of sections in the sought of higher load-bearing capacities. Particularly for composite columns, the axial capacity of concrete-filled steel tubular (CFST) sections may be enhanced by the introduction of an open steel profile embedded within the concrete infill, forming the so-called steel-reinforced concrete-filled steel tubular (SR-CFST) columns. An important aspect that should be revised, in order to safely use these sections in design, is their performance after a fire. In this experimental program, six SR-CFST stub columns are tested in the post-fire situation. Two series of columns comprising three circular and three square sections with the same steel usage are tested for comparison purposes. The size of the inner steel profile is varied in order to investigate its effect over the post-fire capacity of the columns. The specimens were initially exposed to elevated temperatures inside an electric furnace, and then cooled to ambient temperature; afterwards compressive axial load was applied gradually until failure, to ascertain their residual capacity. The experimental results show the high ductility of the SR-CFST stub columns after heating, with the circular specimens reaching higher post-fire peak loads than their square counterparts. This load increases with the size of the embedded steel profile. The post-fire capacities of the columns are evaluated through the Residual Strength Index, showing similar values for both circular and square SR-CFST columns. Finally, a design equation is proposed to facilitate the evaluation of the post-fire compression resistance of SR-CFST columns, as an extension of the existing room temperature design equation in Eurocode 4 Part 1–2 for CFST columns, accounting for the degradation of the steel and concrete after fire exposure through the corresponding residual factors.

Creep properties and energy evolution characteristics of weakly cemented rock under step loading

The contact mode of particles in weakly cemented mudstone (WCM) and the persistence of cemented materials, as well as the cemented particulate matter composed of them, lead to different mechanical response characteristics from general soft rock during loading, that is, rheological failure occurs under low stress. In order to study the creep characteristics and energy evolution characteristics of weakly cemented rock (WCR) in the western mining area of China, based on the triaxial graded loading creep test of WCR, the creep deformation and failure law of WCM under graded loading was studied, and the energy evolution characteristics of WCR in each creep stage were revealed by energy dissipation theory. The results show that with the increase of confining pressure, the fracture angle decreases, but the failure strength and volume expansion point show the opposite trend. In addition, due to the strong heterogeneity of WCR samples, the contact force between particles is different after loading, which makes the slip between particles and cements and then produces a completely different fracture form from other rocks. The energy growth in the deceleration and steady creep stages is mainly affected by the confining pressure. With the increase of confining pressure, the growth rate of dissipation energy Ud and total energy U gradually tends to be constant, but the growth rate of strain energy Ue remains at a high level. In the accelerated creep stage, the growth rate of strain energy Ue decreases rapidly, and the residual energy storage capacity does not change significantly with the increase of confining pressure. These results revealed the unique creep properties and energy evolution characteristics of the WCR, providing a theoretical basis for long-term stability control of roadways that are built with WCR.

Study on Quasi-Static Axial Compression Performance and Energy Absorption of Aluminum Foam-Filled Steel Tubes.

To study the axial compression performance of aluminum foam-filled steel tube and empty steel tube as objects, such tubes are studied in this paper, which explores the carrying capacity and deformation behavior of aluminum foam-filled steel tube with different lengths under a quasi-static axial load through experimental research. The carrying capacity, deformation behavior, stress distribution, and energy absorption characteristics of empty steel tubes and foam-filled steel tubes are compared through finite element numerical simulation. The results indicate that, compared with the empty steel tube, the aluminum foam-filled steel tube still presents a large residual carrying capacity after the axial force exceeds the ultimate load, and the whole compression process reflects steady-state compression. In addition, the axial and lateral deformation amplitudes of the foam-filled steel tube decrease significantly during the whole compression process. After filling the foam metal, the large stress area decreases and the energy absorption capacity improves.

The coupling effect of silica fume and basalt fibers on workability and residual strength capacities of traditional concrete before and after freeze–thaw cycles

The coupling effect of silica fume and basalt fibers on workability and residual strength capacities of traditional concrete before and after freeze–thaw cycles

A Visual Data-Informed Fiber Beam-Column Model for the Analysis of Residual Hysteretic Behavior of Post-Earthquake Damaged RC Columns

ABSTRACT Seismic damage to components and structures may cause extensive degradation of the seismic capacities of the damaged buildings. The analysis of the residual hysteretic behavior of post-earthquake damaged components and structures is a critical step in the assessment of their residual seismic capacities. Whereas, the difficulty in quantifying the damage distribution of materials in post-earthquake damaged components leads to the challenge of quantitative analysis of their residual behavior (i.e. residual stiffness, strength, energy dissipation). In this study, a visual data-informed fiber beam-column model was developed to analyze the residual hysteretic behavior of post-earthquake damaged RC columns under cyclic loads. To begin with, the method for quantifying the damage strain fields of the columns according to their inspected visual data was proposed. Then, the stress-strain relations of the materials considering the effect of damage strain fields were constructed, and the visual data-informed fiber beam-column model was proposed for the analysis of the residual hysteretic behavior of post-earthquake damaged RC columns subjected to cyclic lateral loads. At last, the proposed model was validated by comparing model results with existing test data. The comparison shows that the proposed visual data-informed fiber beam-column model can accurately analyze the concrete crushing surfaces, the residual load-displacement responses, and the energy dissipation capacities of post-earthquake damaged RC columns, facilitating the evaluation of the residual seismic capacities of post-earthquake damaged RC columns.

Fragility curves for reinforced concrete (RC)/steel vertical hybrid frame structure under mainshock–aftershock sequences

ABSTRACT A reinforced concrete (RC)/steel vertical hybrid frame structure usually consists of a lower concrete structure and an upper steel structure connected in series. This study aims to derive fragility curves for RC/steel vertical hybrid frame structures under mainshock–aftershock sequences. For this purpose, a double incremental dynamic analysis (D-IDA) approach is performed to derive fragility curves for a five-story RC/steel vertical hybrid frame (a three‐story RC frame at the bottom + a two‐story steel frame at the top) under 14 real mainshock– aftershock earthquake ground motions. The fragility curves obtained for RC/steel frame are also compared with fragility curves for a five‐story purely RC frame. Also, residual capacity diagrams are provided for RC/steel and purely RC frames based on the D-IDA results. The results show that RC/steel frame structure has larger collapse capacity than that of the purely RC frame structure, and can diminish collapse probability by 33% compared to purely RC frame structure.

Взаємозв’язок різних триместрів вагітності і ризику COVID-19

у статті узагальнено питання в рамках наукової дискусії щодо взаємозв’язку різних триместрів вагітності і ризику COVID-19. Основна мета цього дослідження це оцінка впливу ризику COVID-19 від часу зараження, а саме від різних триместрів, зрозуміти ризики ускладнень на різних термінах вагітності, оцінити вплив триместру інфікування COVID-19 на прогресування захворювання, визначити чи збільшується частота прогресування захворювання COVID-19 зі збільшенням терміну вагітності. Завдяки детальному вивченню літературних джерел, їхній систематизації та підходів до вирішення проблеми, було виявлено, що спалах пандемії COVID-19 у США призвів до понад 97 мільйонів заражень і понад 1,06 мільйона смертей. Зареєстровано приблизно 182 000 випадків захворювання серед вагітних жінок, і 285 випадків материнської смерті. Нормальна вагітність в основному пов'язана зі зниженням функціональної залишкової ємності легень на 20-30 % і збільшенням споживання кисню на 20 %. В результаті інфекції нижніх дихальних шляхів погано переносяться, особливо в третьому триместрі. Актуальність дослідження даної патології полягає в тому, що вагітні мають вищий ризик інфікування коронавірусом 2 (SARS‑CoV‑2) у важкій або критичній формі порівняно з жінками того ж віку. Крім того, ця невідповідність посилилася під час сплеску варіанту Дельта. Підвищений ризик несприятливих наслідків для новонароджених і матерів пов’язаний із тяжким перебігом COVID-19 під час вагітності. Однак мало відомо про вплив часу зараження під час вагітності на такі ризики, тому це може призвести до помилок у лікуванні таких вагітних, що перешкоджає своєчасному, правильному лікуванню і профілактиці. У дослідженні використано методи бібліографічного та контент-аналізу літератури, порівняльного підходу та синтезу, а також семантичного групування відносно особливостей взаємозв’язку різних триместрів вагітності і ризику COVID-19. Усі документи, знайдені на різноманітних офіційних веб-сайтах були проаналізовані, а зібрану інформацію порівняли і згрупували. В статті наведено результати досліджень, які показали, що частота прогресування захворювання COVID-19 не відрізняється від триместру діагностики. Захворювання середнього, важкого або критичного ступеня розвивається майже у 10% вагітних, інфікованих вірусом SARS-CoV-2. Ці результати підкреслюють важливість профілактичних заходів, включаючи вакцинацію проти COVID-19 до або якомога раніше під час вагітності. Оскільки рівень вакцинації серед вагітних зростає, необхідні подальші дослідження, щоб зрозуміти прогресування захворювання. Подібним чином тяжкість захворювання та прогресування слід вивчати далі в умовах розвитку медичної терапії та еволюції нових варіантів SARS-CoV-2 і рецидивуючої інфекції. Тому необхідно й надалі досліджувати це питання, щоб отримати дані, орієнтовані на пацієнта та економічну ефективність. Результати даного дослідження можуть бути цікавими для лікарів первинної ланки, гінекологів та терапевтів

The damage mode and forced response characteristics of articulated lining structure: A case study of metro tunnel under a reverse fault action

With the continuous development of underground tunnel engineering, there have been a large number of engineering cases of tunnels crossing active faults, and the dislocation of active faults must have a greater impact on the structural safety of tunnels. Therefore, it is of great significance to study the stress characteristics and anti-dislocation design of tunnels crossing active faults. Based on the tunnel of Urumqi Metro Line 1 crossing the Wanyaogou reverse fault, a large-scale physical model test of shear dislocation of subway tunnel crossing the reverse fault is designed and carried out, and the mechanical behavior difference between conventional tunnel structure and articulated tunnel structure is compared and analyzed. The surface displacement, structural deformation, additional earth pressure, strain distribution, fracture distribution and other test results were monitored and recorded, and the forced response characteristics and failure mode of subway tunnel structure under the effect of stick–slip of reverse fault were studied in depth. The results show that the failure modes of conventional tunnel are mainly shear failure at the fault plane, while articulated tunnel is mainly large eccentric failure. Compared with the conventional tunnel, the deformation failure range, strain peak and total crack length of the articulated tunnel are obviously reduced. Besides, there is no spalling phenomenon similar to conventional tunnel. The structure still has a certain residual bearing capacity, that is, the articulated tunnel structure is more adaptable to the forced displacement of the fault, the stress state is better, and its rupture resistance is better. To sum up, the model test study reveals the forced response characteristics and rupture resistance of articulated tunnel structure under reverse fault conditions, which has guiding significance for similar tunnel engineering problems.

Axial Compression Performance of Reinforced Concrete Columns after Lateral Impact Load

Axial compression performance and bearing capacity of reinforced concrete column is crucial to concrete structure. Lateral Impact load could pose severe danger to the security and service life of reinforced concrete column. Impact dynamic response, axial compression performance and residual bearing capacity of reinforced concrete columns after lateral impact load were investigated in this paper. Investigation results indicated that with the increase of impact energy, residual displacement and crack width on column increased, impact damage on column exacerbated. It was proved that impact resistance performance of reinforced concrete column could be enhanced by preload axial force. Residual bearing capacity of reinforced concrete column degenerated obviously after subjected to lateral impact load. And RC column would be under elastic stage when impact energy was low. According to analysis results on the correlation between residual displacement and residual bearing capacity, prediction model on residual bearing capacity of reinforced concrete column after lateral impact load was proposed.

Numeric simulation of corroded steel bridge girder end region repairs

An extensive finite element (FE) modeling campaign focusing on different means of repairing corrosion-damage steel girder ends is presented. Significantly corroded end regions were repaired using three approaches: conventional bolted steel repair, encasement in ultra-high performance concrete (UHPC), and encasement in conventional reinforced concrete (RC). ABAQUS-based models were developed and validated based on a previously-reported experimental program (Mash et al. 2023). The modeling of the test specimens proved to be robust and captured observed behavior well. Once the test specimen modeling was “benchmarked” against the observed behavior, the models were expanded to archetypal plate girders to verify the validity of the repair methods. The models confirmed the validity of adopting AASHTO-prescribed equations for estimating residual capacity of damaged girder ends. The numerical analyses presented were able to capture tension field behavior and, therefore, illustrate the potential degree of conservativeness – under ultimate loading conditions – in actual repair designs in which relative stiff bearing stiffeners are used. Similarly, by encasing the web, the shear panel length is reduced and capacity may be increased. Based on the robustness of the models, the analyses presented in this work may be adopted as a benchmark for future studies.

Chronic kidney disease in the elderly and frail patient: perspectives with opinions and comments.

Chronic kidney disease is common in elderly and frail people. The importance of age in staging chronic kidney disease is discussed as well as the possible constraints of staging what is actually a 'continuum' of disease progression. Frailty is a biological state characterized by the decline of several physiological systems and strongly correlated with adverse health outcomes, including mortality. Frailty is measured by the Comprehensive Geriatric Assessment, which focuses on quantitative rating scales that determine not only the clinical profile and pathological risk of frail individuals, but also their residual capacities, functional status, and quality of life. There is circumstantial evidence that Comprehensive Geriatric Assessment can improve both survival and quality of life in elderly chronic kidney disease patients. Despite the long list of emerging risk factors and markers of chronic kidney disease progression, it is the authors' opinion that a single biochemical parameter can hardly cover the complexity of chronic kidney disease in elderly and frail patients. Among the numerous clinical scores proposed, the European Renal Best Practice guidelines recommend the Renal Epidemiology and Information Network score and the Kidney Failure Risk Equations. The former provides a reasonable estimate of short-term mortality risk, the latter provides the risk of chronic kidney disease progression. In conclusion, the elderly individual with advanced chronic kidney disease is often comorbid and frail with peculiarities in terms of disease grading, clinical assessment and monitoring. The time has come to reshape the care of this growing number of patients by focusing on multidisciplinary teams both in the hospital and in the community.

Wettability of water-H2-quartz and water-H2-calcite experiment and molecular dynamics simulations: Critical assessment

In sandstone and carbonate, H2-wettability is an essential factor that defines structural and residual trapping capacities and significantly influences multi-phase fluid dynamics in the rock. Several studies have assessed H2 wettability using contact angle measurements on quartz and calcite at different pressure and temperature conditions; however, the reported data is fraught with a high degree of uncertainty. In this study, atomistic molecular dynamics (MD) simulation was used to calculate the water-H2-silica and water-H2-calcite contact angles under different conditions (pressure up to 20 MPa; 300K and 323K temperatures; and zero, 60 000 and 213 000 ppm salinities) in order to figure out the source of discrepancies in the laboratory contact angle measurement due to surface roughness and possible surface contamination. Further, we have re-performed the experimental measurements of the contact angles for both minerals and confronted them with our MD results. This study observed that in the presence of hydrogen, the water contact angles on clean quartz and calcite substrates are zero in all conditions (i.e., different pressures, temperatures, and salinities) using the sessile drop method and Molecular Dynamics (MD). This means H2 gas is a completely non-wetting phase and can be easily withdrawn after underground storage; however, cushion gas is essential to overcome snap-off and H2 residual trapping. These results highlight the importance of adopting a suitable cleaning method before contact angle measurement.

Lung Volume Reduction in Patients with Severe Emphysema: Bronchoscopic Lobar versus Surgical Tailored Treatment

Abstract Background Bronchoscopic lung volume reduction (BLVR) with valves excludes one whole lobe while lung volume reduction surgery (LVRS) allows tailored treatment by resection of only heterogeneous, hardly perfused target areas. Aims We hypothesize that by (bilateral) LVRS, more areas of low attenuation (LAA, ≤ - 950 houndsfield units) can be resected more precisely, thus generating more functional improvement than BLVR. Methods Empysema patients treated with BLVR and LVRS at our institution between August 2019 and October 2020 were collected prospectively and analyzed retrospectively. LVRS responders were defined as patients with a postoperative improvement of at least 10% in FEV1 in combination with 10% delta in 6-minute-walking-distance (6MWD) or residual volume (RV) or diffusion capacity (DLCO), within the BLVR group additionally with a chest CT scan proven target lobe atelectasis. We performed LAA measurement in preoperative CT scan and 3 months (LVRS) or 1 month (BLVR) postoperatively. Functional improvement as well as LAA reduction was measured in each group and the groups compared with each other. Results 29 patients underwent LVRS, 19 were responders (5 bilateral LVRS, 14 unilateral), 3 were lost for follow up. Within the BLVR group (n=29), 18 were responders. In bilateral LVRS, improvement of 6MWD and FEV1 was significantly higher than in BLVR, accompanied by a significantly higher LAA-reduction (22.18 vs 9.54, p=0.009). In unilateral LVRS, LAA-reduction was not significantly higher (12.06 vs 9.54, p=0.267), while 6MWD and FEV1 still showed a higher postoperative improvement. RV reduction and DLCO improvement did not differ significantly between the groups. Conclusions LVRS might lead to significantly more functional improvement than BLVR with valves, maybe due to more resected LAA, especially in bilateral surgery. This concept may justify favoring primary bilateral LVRS over BLVR with valves in bilateral heterogeneous emphysema.

The Effect ofBody Armor onPulmonary Function Using Plethysmography.

Military tactical athletes face the unique task of performing physically demanding occupational duties, often while wearing body armor. Forced vital capacity and forced expiratory volume measured using spirometry have been shown to decrease, while wearing plate-carrier style body armor, little is known about the comprehensive effects of wearing body armor on pulmonary function, including lung capacities. Further, the effects of loaded body armor vs. unloaded on pulmonary function are also unknown. Therefore, this study examined how loaded and unloaded body armor affects pulmonary function. Twelve college-aged males performed spirometry and plethysmography under three conditions (basic athletic attire [CNTL], unloaded plate carrier [UNL], and loaded plate carrier [LOAD]). Compared to CNTL, LOAD and UNL conditions significantly reduced functional residual capacity by 14% and 17%, respectively. Compared with CNTL, LOAD condition also showed a small but statistically significant lowered forced vital capacity (P = .02, d = 0.3), a 6% lower total lung capacity (P < .01, d = 0.5), and lowered maximal voluntary ventilation (P = .04, d = 0.4). A loaded plate-carrier style body armor exerts a restrictive effect on total lung capacity, and both loaded and unloaded body armor affects functional residual capacity, which could impact breathing mechanics during exercise. Resulting endurance performance decreases may need to be factored based on the style and loading of body armor, especially for longer-duration operations.

Post-blast capacity evaluation of concrete-filled steel tubular (CFST) column based on machine learning technique

In the present study, the post-blast axial load-bearing capacity of the CFST column under the close-in explosion is investigated. Dynamic response and residual axial load capacity (RALBC) of 1599 circular CFST columns are numerically studied using a validated finite element model. The effects of column dimensions, material properties, blast loading, and axial load ratio are discussed. Based on the huge database, prediction models of RALBC are developed using three commonly used machine learning techniques including Extreme Gradient Boosting (known as XGBoost), Artificial Neutral Network (ANN), and Support Vector Regression (SVR). Comparison results show that the prediction model generated by the XGBoost performs the best among the three methods followed by the ANN and SVR methods. The RALBC of the CFST columns can be estimated rapidly and accurately with the prediction model developed in the present study. Finally, the feature importance of the input variables is analyzed using the additive feature attribution method SHAP (Shapley Additive ExPlanation). The results show that geometric parameters are the main factors impacting the RALBC of the CFST columns under close-in explosion.