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Hybrid interference‐fit bolted‐bonded (HIBB) composite joint has a wide application prospect in improving bearing capacity of the hybrid structure. In order to deeply understand its load sharing mechanism, an analytical stiffness prediction model of HIBB composite joint was established, considering the influence of interference‐fit percentage, preload, friction coefficient, adhesive property, material performance, secondary bending moment and other parameters. Corresponding experiments were carried out to determine the experimental secondary bending moment coefficient, and the accuracy of the model was further verified. Research on HIBB composite joint shows that the hybrid form increases the adhesive failure displacement but has no effect on failure load. Before adhesive failure occurs, bolted joint stiffness is small and bolt load will increase suddenly to bear the load loss caused by the adhesive failure. It is further found that load‐sharing ratio of the bolt and total load of the structure increase with the increase of interference when adhesive failure occurs. Preload and friction coefficient have limited influence on total load of the structure at this moment, but have great influence on the bearing capacity of pure bolted structure after adhesive failure. The adhesive properties have great influence on the bearing capacity of bonded joint. Low modulus high strength adhesive can improve the load‐sharing ratio of bolt and enhance the bearing capacity by reducing the overall stiffness of the structure. Bearing mechanism of the two joint forms in the hybrid one was fully revealed, which provides a theoretical method for the application of HIBB composite joint. Highlights: An analytical stiffness prediction model of HIBB composite joint was established to deeply understand its load sharing mechanism.Load sharing mechanism analysis and parametric research for the two joint forms were carried out and influences on stiffness were obtained.Low modulus high strength adhesive can improve the load‐sharing ratio of bolt by reducing the overall structure stiffness.Bearing mechanism of the two joint forms in the hybrid one was revealed. [ABSTRACT FROM AUTHOR]

ABSTRACT The large diameter piles are widely used in structures such as offshore wind turbines due to their superior lateral load‐bearing capacity. To explore the lateral response of a large‐diameter pile under combined horizontal dynamic and axial static loads in nonhomogeneous soil, a simplified analytical model of the pile–soil interaction is developed. This model represents the pile as a Timoshenko beam resting on the Pasternak foundation, incorporating the double‐shear effect by considering both pile and soil shear. The governing matrix equations for the pile elements are derived from the principle of virtual work. Further, the pile's lateral deformations and internal forces are obtained using the modified finite beam element method (FBEM) and then validated through existing analytical solutions. Finally, the contribution of various properties of pile, soil, and applied load to the pile's lateral vibration response are performed. It is found that both pile and soil shear effects significantly impact the lateral dynamic response of a large‐diameter pile. Additionally, in nonhomogeneous soil, decreasing surface soil strength and dimensionless frequency lead to increased lateral displacements and bending moments of the pile, which are significantly affected by the P‐Δ effect under increasing axial load. [ABSTRACT FROM AUTHOR]

To study the bearing characteristics of rock-socketed single piles on the southeast coast of Fujian Province, we conducted similar material ratio tests and single pile model tests. Initially, based on the mechanical parameters of strongly weathered granite, 10 groups of similar material samples were prepared using iron concentrate powder, barite powder, and quartz sand as aggregates, with rosin and alcohol as the cementing agents and gypsum as the modulating agent. Through triaxial testing and range and variance analysis, it was determined that the binder concentration has the most significant impact on the material properties. Consequently, Specimen 1 was selected as the simulation material. In the model test, the strongly weathered granite stratum was simulated using the ratio of Specimen 1. A horizontal load was applied using a pulley weight system, and the displacement at the top of the pile was measured with a laser displacement meter, resulting in a horizontal load–displacement curve. The results indicated that the pile foundation remained in an elastic state until a displacement of 2.5 mm. Measurements of the horizontal displacement and bending moment of the pile revealed that the model pile behaves as a flexible pile; the bending moment initially increases along the pile length and then decreases, approaching zero at the pile's bottom. The vertical load test analyzed the relationship between vertical load and settlement of the single pile, as well as its variation patterns. This study provides an experimental basis for the design of single pile foundations in weathered granite formations on the southeast coast of Fujian Province and aids in optimizing offshore wind power engineering practices. [ABSTRACT FROM AUTHOR]

The batter rock-socketed pile (BRSP) groups have been gradually introduced in practice to support not only the vertical load caused by overlying infrastructures but also the horizontal loads caused by waves and wind. A series of laboratory model tests were conducted to investigate the bearing capacities of the BRSP groups installed with their batter piles ranging from 0° to 20° under combined vertical and horizontal loads. It is found that the vertical ultimate bearing capacities nonlinearly increase with the increase of the batter angle with its optimum batter angle of 10°. The normalized vertical loads and horizontal ultimate loads are nonlinearly related to their relationship in an ellipse function. The plumb rock-socketed pile groups develop primarily a pair of shear forces and secondary bending moments due to the clockwise rotation under the pure horizontal loads. The BRSP group may fail due to the pile fracture near the pile cap in the form of the plastic hinge or compression failure at the base of the front pile. The corresponding load-displacement curves mostly have no peak or sudden downward trend. [ABSTRACT FROM AUTHOR]

Monopiles are the economic choices in shallow water as the foundations of offshore wind turbines (OWTs). Maximum allowed rotation θ = 0.25° is set as the criterion in the serviceability limit state design. However, the allowed load combinations of monopiles in sand are not fully revealed and understood satisfying the criterion. In this paper, load envelop concept to ensure the allowed monopile rotation less than 0.25° was proposed to understand all possible load combinations on monopiles for the OWTs. Finite element models based on the sand hypoplastic model with inter-granular strain were established. After verification with the centrifuge results, different load–displacement curves were acquired by changing loading paths to acquire the envelope surfaces meeting the criterion. Finally, the most likely load combinations of the OWTs were particularly analysed. Under the condition with θ = 0.25°, the allowed horizontal loads and the bending moments are closely coupled. The calculated envelop curves composed of maximum allowed loads can be well fitted and described by the cubic function. This note provides a method to obtain load combinations with allowed inclinations, which is beneficial to understand the load states of monopile for OWTs. [ABSTRACT FROM AUTHOR]

Large deformation is a kind of geological hazard in the construction of soft rock tunnels, which hinders construction, threatens workers' safety, and raises project costs. Accurately obtaining the large deformation characteristics and patterns of tunnels is the prerequisite for taking targeted support measures. First, a viscoelastic–plastic model that can simulate both the short-term strain-softening effect and the long-term creep effect was proposed to investigate the large deformation features of soft rock tunnels. Then, a sophisticated model for creep parameter inversion was developed using the support vector machine, genetic algorithm, and particle swarm optimization. Finally, the deformation, stress, plastic zone, and internal forces in the lining of a large deformation tunnel were determined using the proposed constitutive model and the creep parameters obtained by inversion. As the creep displacement only makes up 14.4–23.2% of the total displacement, the results demonstrate that the elastic–plastic displacement is much more than the creep displacement. Notably, the connection between the top and middle benches has the most pronounced horizontal movement, accompanied by a significant strain-softening effect, which ultimately becomes the weak point in the support system. The excavation disturbs the surrounding rock, causing a high-stress zone and a low-stress zone, with the interface located around the junction of the elastic and plastic zones. The bending moment is positive at the wall waist and negative at the vault and arch waist. In addition, there is a progressive rise in the bending moment from negative to positive at the arch foot. [ABSTRACT FROM AUTHOR]

The effectiveness of load-reduction techniques often diminishes due to creep behavior observed in geomaterials, as loess backfill is used, the load reduction rate of high-filled cut-and-cover tunnels (HFCCTs) after creep will decrease by 10.83%, posing a threat to the long-term stability of deeply buried structures such as HFCCTs. Therefore, a geotechnical solution is crucial to ensuring sustained effectiveness in load-reduction strategies over time. This study utilizes a finite-difference method to examine three promising measures for mitigating creep effects. Our analysis focuses on the time-dependent changes in earth pressure atop the cut-and-cover tunnel (CCT) and the internal distribution of cross-sectional forces, including bending moment, shear force, axial force, and displacement. Results indicate that the creep behavior of load-reduction materials significantly influences the internal force distribution. Furthermore, sustained load reduction is achieved when utilizing low-creep materials like dry sandy gravel as backfill soil, which needs to be borrowed from other sites. Additionally, integrating concrete wedges with load-reduction techniques facilitates a more uniform stress distribution atop CCTs. [ABSTRACT FROM AUTHOR]

The procedure to estimate the amplitude of the special wind events according to IEC 61400‐1 as proposed by Larsen is reviewed. Corrections are specified that yield larger amplitudes for the extreme operating gust (EOG) and the extreme coherent gust with simultaneous direction change (ECD). For the ECD case, distributions for longitudinal and lateral gust amplitudes are derived and applied in simulations to derive the load distribution, from which the 50‐year extreme load can be found. Results are compared with the calculation with the conventional ECD: In the example calculation, the 50‐year values of both blade root bending moment and tip deflection are smaller than the conventional values. [ABSTRACT FROM AUTHOR]

Under earthquake excitations, reinforced concrete (RC) columns could be subjected to lateral drift reversals and a combination of axial forces, bending moments, and torsional effects. This paper investigates the behavior of glass fiber-reinforced polymer (GFRP)-RC columns under seismic-simulated loading, including torsion, which has not been studied previously. Seven large-scale circular GFRP-RC column-footing connections were cast and tested under various combined reversed cyclic loading configurations to examine the effects of torsion-bending moment ratio (tm), transverse reinforcement ratio, and concrete compressive strength. The test results revealed that increasing the tm reduced the lateral load capacity and deformability of the GFRP-RC column, but resulted in a more symmetric torque-twist relationship. Increasing the transverse reinforcement ratio mitigated core damage and provided additional support (for example, spiral turns) for torsion-induced tensile stresses. Moreover, increased concrete compressive strength bolstered torque capacity and torsional stiffness, while, under a tm of 0.4, it resulted in decreased twist capacity. When torsion was present, increasing the concrete compressive strength had an insignificant impact on the bending-shear response, differing from findings for GFRP-RC columns subjected to seismic loading without torsion. [ABSTRACT FROM AUTHOR]

The ultra‐high toughness cementitious composite (UHTCC) has the tensile strain‐hardening characteristic and an excellent ability to prevent tensile cracking. To enhance the seismic and durability performance of the conventional buckling‐restrained steel plate shear wall (BRSPSW), UHTCC‐enhanced BRSPSW (UBRSPSW) was proposed in this paper as a new type of lateral bearing system. The buckling of the inner steel plate is restrained by UHTCC‐normal concrete (NC) functionally graded panels, where the panels are composed of UHTCC and NC layers. In this study, experimental and numerical research was carried out on the UBRSPSWs. Six specimens were tested to investigate the seismic behavior of the UBRSPSW. Parameters including the number of stiffeners, the thickness of UHTCC‐NC functionally graded panels, the material of restraining panels, and the gap between the inner steel plate and restraining panels were considered in the test design. Mechanical response and failure modes of the structures under cyclic loads were analyzed. The obtained hysteretic curves and corresponding skeleton curves indicated that the proposed design had excellent seismic performance. Compared to the steel plate shear wall (SPSW), the load‐bearing capacity of UBRSPSW was improved by 13%, respectively. The appearance of macrocracks was delayed by a drift angle of 1.2%. In addition, a refined finite element (FE) model was developed and validated by the results obtained from experiments. The development and distribution of bending moments in the restraining panels were extracted based on the FE method. Then, the loading capacity design method of restraining panels and a theoretical model for controlling the crack width of restraining panels were proposed. The research results of this paper can provide useful suggestions for the seismic design of UBRSPSWs. [ABSTRACT FROM AUTHOR]

To predict the seismic response of column‐supported silos (CSSs), the granular–structure interaction (GSI) analysis method is proposed with considering the combined effect of the friction between the particles–particles and the particles–silo wall. Using free‐body dynamic equilibrium equations, we reconstruct the mutual interactions between different grain portions and between the grains and the silo wall to develop the ideal calculation model of the CSS structure. Based on the analysis model, additional dynamic overpressure and the effective mass caused by the stored content interacting with the silo wall is obtained with different slenderness ratios and peak accelerations. The additional bending moment caused by the friction between the particles and silo wall is further quantified. To verify the reliability of the proposed method, we discuss some applicative examples by comparing the GSI method with other theories, Eurocode 8, and experimental results. Moreover, the along‐the‐height acceleration profiles of the silo wall and the ensiled content are analyzed according to the shaking‐table tests. The results show that the GSI method can match Janssen's theory well in the case of static pressure at slenderness ratios exceeding 1.0. The overpressure profiles along the height of the silo wall follow a nonlinear distribution, different from Eurocode 8. The bending moment obtained by predictive formulas agrees well with the experimental results for the CSS, indicating that the GSI method is reasonable. Some design and construction recommendations, including the maximum overpressure position, the reference range of the dynamic overpressure coefficient, and the reduction factors of the ensiled content mass, are proposed to facilitate the engineering applications of CSSs, considering different slenderness ratios. [ABSTRACT FROM AUTHOR]

During strong earthquakes, the footing of a rockable bridge can temporarily and partially separate from the support. This rocking motion can activate rigid‐like motions, reducing the deformation along the height of bridge piers and leading to smaller bending moments. As a result, rockable footing has been considered as a possibility for low‐damage seismic design of structures. For bridges, the seismic‐induced interaction between girders and adjacent abutments can change the structural dynamics due to the impeded girder movements. Although bridges with rockable footing, for example, the South Rangitikei viaduct, have been constructed, research on rockable bridges mainly focused on a single‐segment case. Physical experiments on rockable bridges considering pounding are very limited. In this work, large‐scale shake table experiments were performed on a two‐segment bridge model with abutments. The cases without pounding and with girder‐girder pounding alone were considered as references to help interpret the results. To investigate the consequence of footing rocking, the results of the rockable bridge on a rigid base were compared to that of the fixed‐base bridge. The study reveals that compared to a fixed‐base segment, the girder of a rockable segment is easier to move laterally. This change in dynamics due to rocking leads to less maximum pounding forces and thus reduces the damage potential to girders and abutments. [ABSTRACT FROM AUTHOR]

The increasing degree of urbanization has resulted in traffic and space congestion. When there is no longer any aboveground space for development, the existing space underground is excavated, and the construction of underground buildings is expected to solve the above problems. In the excavation of an underground layer, it is necessary to drive supplementary and existing piles into the soil to form a double-layer pile-supported structure. Aiming at an existing–supplementary double-layer pile-supported structure and considering the pile spacing of the supplementary piles, use of crown beams, and other factors, this study performed a series of indoor model tests and an simulation analysis in combination with finite element analysis software to reveal the bearing characteristics of this structure. The results showed that the installation of supplementary piles could effectively inhibit soil slippage after pile driving, redistribute the soil pressure load of the existing piles, and reduce the number of soil cracks between the piles. With the increase in the supplementary pile spacing, the deformation of the existing–supplementary double-stacked piles gradually intensified, and the bending moment of the pile body and the horizontal displacement at the top of the piles increased. The installation of crown beams in the existing piles could strengthen the connection between the existing and supplementary piles, reduce the number of soil cracks between these piles, and change the force mode of the pile body. Considering the geological conditions and the influence of existing buildings, the deformation laws of the supporting structure and the soil around the foundation piles during the excavation of an underground layer of an L-shaped foundation pit were revealed. The research results are expected to provide a scientific and theoretical basis for the design and construction of downward additional support structures for existing buildings, along with socio-economic significance. [ABSTRACT FROM AUTHOR]

Monitoring forming forces in metal forming processes is essential for analyzing process behaviors, mechanisms, and defect detection. This is particularly relevant in aluminum tube bending processes, where the dimensional quality of the formed product is sensitive to multiple upstream and in-process variables. This research presents a method for real-time, in-process monitoring of forming forces in rotary draw bending (RDB). By developing a set of innovative forming tools (clamp die, bend die, pressure die, etc.) with directional force sensors embedded, key forming forces are measured. Through a series of experiments, the measurement method was validated by analyzing both measured forces and calculated moments, demonstrating high measurement consistency. The systematic examination of measurement variations provided insights into the reliability and robustness of the method. Moreover, comparison with FE results supported the accuracy of the measurements. Additionally, laser-based measurements showed a good correlation between the measured springback angle and the calculated moment during bending. These findings lay the groundwork for the industrial implementation of in-process force measurements in RDB, advancing the production of tube components. [ABSTRACT FROM AUTHOR]

The purpose of this work is to test the effectiveness of strengthening timber structures by means of composite bars. This article presents the results of preliminary tests carried out on solid beams made of fir wood. The test specimens, which are classified as strength class C24, had dimensions of 7 × 17 × 330 cm. Beams were reinforced with 8 mm diameter basalt fiber-reinforced polymer (BFRP) bars. The bars were glued into grooved channels along the bottom surface. Epoxy resin was used as an adhesive. The strength tests were conducted in accordance with the requirements of EN 408+A1:2012. The four-point bending scheme was adopted. The tests were conducted in the following two series: unreinforced beams (A) and beams reinforced with composites (B). Five elements were tested in each series. The reinforcement resulted in an average increase in the bending moment value of 8.41%. The deflection value at failure increased by 19.77%. The work also includes an analysis of the failure mode and a ductility analysis. Further tests should be carried out using a higher reinforcement ratio. A higher reinforcement ratio should make the presented reinforcement configuration more effective. [ABSTRACT FROM AUTHOR]

Voids behind tunnel linings can be formed either during or after the construction phase, occurring due to inadequate backfilling, substandard workmanship, water erosion, or gravitational forces. Investigations into numerous tunnels in which collapses occurred while in operation have indicated that voids behind the liner constitute the primary contributors to these failures. Consequently, it is imperative to devise lining reinforcement strategies tailored to the specific conditions encountered in the field. Fiber-reinforced plastic (FRP) represents a viable alternative construction material that has been widely utilized in the reinforcement of concrete structures. It is essential to quantitatively assess the reinforcing effect of FRP grids when they are employed in the restoration of deteriorated tunnel linings, thereby facilitating the development of effective maintenance designs. In this study, we aimed to enhance the sensitivity analysis of the reinforcement method by evaluating the impact of voids through the analysis of bending moments and axial forces within the tunnel lining. The effects of voids based on the different locations in which they occur were explored numerically through an Elastoplast finite element analysis. The study involved simulating tunnel linings that had been reinforced with FRP grids and assessing the effects of such reinforcement in tunnels afflicted with various structural problems. Based on the outcomes of these simulations, the internal forces within the lining are scrutinized, and the efficacy of the reinforcement is appraised. [ABSTRACT FROM AUTHOR]

In port dock engineering, high-piled wharves represent one of the primary structural forms. Damage to the foundation piles is a common issue, influenced by external loads such as impact forces during vessel berthing, slope deformations, and operational loads. This study focuses on the Jungong Road Wharf in Shanghai, utilizing FLAC 3D version 6.0 to conduct dynamic calculations under ship impact loading. The dynamic responses of the structure were analyzed, and various internal forces were extracted during the impact event. By combining concrete cracking failure criteria and fatigue damage theories, the effects of ship collisions on the cracking damage of high-piled wharf structures under different scenarios were assessed. Additionally, the applicability of modal flexibility in high-piled wharf scenarios was evaluated through finite element simulations. The results indicate that the dynamic amplification factor caused by dynamic loading is approximately 1.5, underscoring the necessity of considering this effect in the design and impact analysis of high-piled wharves. The impact loading significantly influences the bending moments of the piles, with inclined piles showing the greatest sensitivity. When a designed ship model collides with the high-piled wharf structure at a speed of 0.2 m/s, the tensile stress in the inclined piles reaches 87% of the ultimate tensile strength of the reinforcement. The impact loading has a relatively minor effect on the axial forces of the piles, a limited influence on the bending moments of the beams, but a considerable impact on the axial forces of the beams. Berthing by oversized vessels and unexpected incidents can lead to more severe damage to high-piled wharf structures. In the finite element simulations, modal flexibility effectively identified the locations of damage, with greater changes in modal flexibility correlating with increased damage severity. [ABSTRACT FROM AUTHOR]

Open ground story (OGS) buildings, prevalent in urban areas of countries like India, are structurally unique due to the absence of infill walls in the ground floor. This characteristic increases their seismic vulnerability. Traditional design practices often neglect the stiffness contribution of upper-story infill walls, leading to inadequate ground floor column design, which cannot withstand the amplified bending moments and shear forces during an earthquake. This study identifies the most vulnerable story in OGS buildings through a comprehensive seismic fragility analysis. The findings from the probabilistic seismic demand model (PSDM) log-log graph reveal that the ground floor is the most vulnerable, exhibiting significantly higher inter-story drift (ID), compared to upper levels, due to its reduced lateral stiffness from the absence of infill walls. ID, used as the demand variable in a power law model, captures this vulnerability, providing critical insights into the ground floor's heightened risk during seismic events. [ABSTRACT FROM AUTHOR]

This study examines the influence of the reinforced-concrete frame topology and crack opening effects on the structural behavior under a column removal scenario. For this purpose, a variant of discretization of the finite element model has been proposed, which takes into account additional rotations during the formation of discrete cracks. As a criterion of the bearing capacity of structures, the equilibrium point at the force-displacement curve was adopted. Verification of the proposed method has been performed using experimental data for a U-shaped frame. The paper provides a comparative analysis of the calculation results for 3-story, 5-story and 9-story reinforced-concrete frames using structural elements and the proposed method. It is found that accounting for the discrete nature of cracks had practically no effect on the magnitudes of axial forces in the elements. However, for bending moments, the proposed method showed a decrease compared to the traditional approach. The increase of axial tensile forces in the support sections of the beam above the zone of local failure has been detected for reinforced-concrete frames with 3 - 5 stories, which can lead to an increase in the influence of buckling for the columns to which such a beam is adjacent. [ABSTRACT FROM AUTHOR]

In combination with the field monitoring data, PLAXIS3D finite-element software was used to numerically model the pull-pile supporting structure in a deep foundation pit. This structure was compared to the single-row pile support structure in order to learn more about the pull-pile supporting structure's force and deformation characteristics and how it works. The study found that the cumulative horizontal displacement curves of the supporting piles are integrated into an "upward convex" shape. The bending-moment curve of the front-row piles presents an "inverted S" shape, and the bending-moment curve of the back-pull piles presents a "bow" shape. The "back-pull-pile effect" can improve the unbalanced distribution of positive and negative bending moments in single-row piles by changing the stress condition of the soil. In other words, the pull-pile supporting structure has good safety and serviceability and can well control the lateral displacement of the foundation pit. [ABSTRACT FROM AUTHOR]

The in-plane folding wing is one of the important research directions in the field of morphing or bionic aircraft, showing the unique application value of enhancing aircraft maneuverability and gust resistance. This article provides a structural realization of an in-plane folding wing and an aeroelasticity modeling method for the folding process of the wing. By approximating the change in structural properties in each time step, a method for calculating the structural transient response expressed in recursive form is obtained. On this basis, an aeroelasticity model of the wing is developed by coupling with the aerodynamic model using the unsteady panel/viscous vortex particle hybrid method. A wind-tunnel test is implemented to demonstrate the controllable morphing capability of the wing under aerodynamic loads and to validate the reliability of the wing loads predicted by the method in this paper. The results of the gust simulation show that the gust scale has a significant effect on the response of both the open- and closed-loop systems. When the gust alleviation controller is enabled, the peak bending moment at the wing root can be reduced by 5.5%∼47.3% according to different gust scales. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to capture the mechanical response of the support structure of deep excavation subject asymmetric load. A two-dimensional (2D) numerical analysis model was established by taking a pipe gallery deep excavation subject to asymmetric load as an example. The numerical analysis results were in good agreement with the measured data, thus verified the validity of the numerical model. On this basis, the stress and displacement of support structure caused by the change in foundation asymmetric load were studied. According to the numerical results, horizontal displacement of the diaphragm wall (DW) was dominant, and the maximum horizontal displacement of the DW was 7.54 mm when the deep excavation was completed. With the increase in asymmetric load, the left wall displacement continued to increase, while the displacement of the right DW continued to decrease, and the maximum horizontal wall displacement occurred near the excavation face. The DW was the main bending component, and the maximum wall bending moment when the deep excavation was completed was 173.5 kN·m. The maximum wall bending moment increased with the increase in asymmetric load, and the maximum wall bending moment on the left of the deep excavation was greater than that on the right. The inner support sustained the main component of axial force, with the axial force peaking at 1051.8 kN when the deep excavation was completed. The axial force of the inner support increased with increasing the asymmetric load, and the axial force of the second inner support was obviously greater than that of the first inner support. This research has a positive effect on the design and optimization of deep excavation support structure subject to asymmetric load on ground surface. [ABSTRACT FROM AUTHOR]

Hydroelastic effects are particularly pronounced in ultralarge container ships due to their substantial size and high velocity. The computation of combined torsional and bending moments presents a challenge, exacerbated by warping effects. This study focuses on the investigation of wave loads, encompassing vertical, horizontal, and torsional moments, through model tests on a 20,000 TEU container ship. A 1/77 scale model featuring an open U‐shaped backbone was crafted to simultaneously simulate and measure longitudinal, horizontal, and torsional stiffness, along with these loads. Wave loads on the hull, including those resulting from springing effects, were calculated in regular waves, employing hydroelastic theory and accounting for hydrodynamic forces. The study also delves into the characteristics and analysis of spring effects within the wave loads on the hull. The insights garnered from this research contribute to the fatigue analysis and safety assessments of ship structures. [ABSTRACT FROM AUTHOR]

This article presents a theoretical analysis on the multiple equilibria of pinned functionally graded porous graphene platelet reinforced composite (FGP-GPLRC) circular arches subjected to a half-span distributed radial load. The effective material properties of the arch with different porosity distribution modes are approximated via a modified Halpin–Tsai micromechanical model. The decoupled neutral-plane-based governing equations are then built in the framework of the principle of minimum potential energy, from which analytical solutions for the radial displacement at an arbitrary point on the arch axis are derived. Utilizing a perturbation method, the possible buckling modes are discussed. The complete buckling evolution process of bending moment and vertical displacement are followed, meanwhile the critical geometrical parameters that control buckling behaviors switching are identified. To validate the presented analytical solutions, Finite element (FE) analysis is carried out. An in-depth parameter analysis is performed subsequently to evaluate the fluences of porosity distributions, GPL weight fraction, and porosity coefficient on the multiple equilibria path of arches. It was found that the pinned FGP-GPLRC arches could buckle only in a limit point mode under a half-span distributed radial load. When λ ≥ 8.36 , the multiple equilibria phenomenon occurs and the external force corresponding to inflexion point vanishes. [ABSTRACT FROM AUTHOR]

The paper focuses on the identification of the 3D failure envelope of a shallow foundation on soft soil reinforced by rigid inclusions. A nonlinear 3D finite element model is first validated against literature results and novel centrifuge experimental data. The failure envelope, defined in the vertical force (V), bending moment (M) and horizontal force (H) space, is then constructed using numerical swipe tests. Analytical formulas are introduced to describe the 3D failure envelope shape and inclination, considering the influence of the coverage area, the thickness, and the friction angle of the load transfer platform. Finally, the efficiency of a rigid inclusion foundation is highlighted by comparing its failure envelope to that of the same foundation without rigid inclusions. The proposed analytical failure envelope can be used by engineers to quantify the bearing capacity of rigid inclusion foundations and by researchers to develop novel macroelements submitted to complex coupled loads. [ABSTRACT FROM AUTHOR]

In recent years, 3D printing technology has become very important in many fields of science, manufacturing, design, medicine, aviation, sports, etc. Furniture design and manufacturing are also not left out of this trend. In this study, the results of bending moments and stiffness of joints of thin structural elements connected by 3D printing with polylactic acid (PLA) connectors are given. The connectors are newly developed, and information on their strength characteristics is lacking in the literature. Ten joints were investigated, made with 9 and 12 mm plywood and 6 mm MDF. The tested joints constructed by 3D-printed connecting elements show a high strength under arm compression bending load, between 44.16 and 24.02 N·m. The stiffness coefficients of joints with 3D-printed connecting elements are between 348 and 145 N·m/rad and are higher than those of conventional detachable mitre joints but lower than those of glued ones. The type of filling of the hollow section of the connecting elements and the wall thickness influenced the joints' strength and stiffness. Reducing the width of the connecting elements from 40 to 30 mm and the inner radius between the arms from 2 to 1 mm does not significantly affect the joints' strength and stiffness coefficients. [ABSTRACT FROM AUTHOR]

The immediate functionality of bridges following severe earthquakes is vital for uninterrupted rescue operations. Regarding the significance of resiliency in bridges, post‐tensioned (PT) rocking piers with low residual displacements and minimal damages have developed over the past few decades. The rocking mechanism at two ends of the pier avoids bending moments and excessive flexural damage. The self‐centering (SC) capacity in this system is provided through post‐tensioning forces. Concerning optimum seismic design and retrofit purposes, it is essential to predict the actual degree of seismic damage and SC capacity of PT rocking systems after seismic hazards. In this case, a self‐centering index (SI) is proposed to evaluate the SC capacity when piers are subjected to cyclic and seismic loadings. This SI, when used in co‐operation with a viable damage prediction model, predicts whether or not the piers remain reparable under cyclic or seismic loading scenarios. After comparing a number of energy‐based damage indices, all of which consider the cumulative hysteresis energy, with the input energy‐based damage index (IEB‐DI), the latter was calibrated against observed damages under cyclic loading tests. This DI was chosen as the most suitable damage prediction model and was considered to be simply applicable after time history analysis. In this study, the seismic performance of a seismic‐resistant dual system, consisting of three RC bents along with an SC bent, was evaluated using the aforementioned damage limit states and the introduced SI. The damage predictions of the monolithic bridge, as the reference model, were compared with the estimated damage to the dual bridge. The results show that the joint application of the IEB‐DI and the proposed SI in predicting the performance level of SC rocking piers results in a comprehensive damage prediction model. [ABSTRACT FROM AUTHOR]

The end restraint strength of the reinforced concrete (RC) beams under the fire conditions may greatly influence the inner force redistribution and the structural behavior of the beams, even the stability of the whole structure. The structural fire behavior of two full‐scale frame beams with different end restraint strength under load were studied based on experiment and simulation. The temperature field, reinforcement strain, beam deflection, end axial displacement, and rotation angle of the structure during the whole heating and cooling process were measured. The influence of end restraint strength on the structural behavior was analyzed. The results show that the vertical displacement, axial force, end bending moment, and angular displacement first increase rapidly, then decrease gradually and become stable in the whole process; the lateral displacement increases first and then stabilizes; the change of axial and rotational deformations appeared to be non‐proportional with the corresponding restraining forces, reflecting that the axial and the rotational restraint strength at the ends of the beams decreased with the rise of temperature. The restraining strength of beams that submitted to fire globally decreased faster, and leading to a severe fire response and an earlier failure of the structure. The analysis results and the conclusions will supply scientific basis for the fire‐resistance design and safety evaluation on complex structures. [ABSTRACT FROM AUTHOR]

The response of tunnels subjected to seismic loading is a complex mechanism and depends not only on the seismic nature but also on tunnel structure and surrounding soil properties. The individual behavior of circular, rectangular, and sub-rectangular tunnels subjected to seismic loadings has already been studied in the literature. In the present research, two case scenarios of circular, rectangular tunnels and four sub-rectangular shaped tunnels, with similar cross-section areas, were adopted to perform a comprehensive numerical investigation. The purpose of the study was to determine the mechanical behavior of tunnels of different shapes, depending upon seismic conditions. Analyses were performed by considering the influence of soil-lining interaction, soil parameters, and lining thickness, as well as lining rigidity. Computations were performed for no-slip and full-slip conditions. The results indicate that the tunnel shape design is of great importance when regarding the mechanical behavior of the surrounding soil. This concerns no-slip as well as full-slip soil-lining interaction, especially when the lining is subjected to seismic loading. Moreover, it is shown that changes in incremental bending moments for circular, rectangular and sub-rectangular tunnels that depend upon the soil-lining interaction conditions differ significantly. [ABSTRACT FROM AUTHOR]

The in-plane stability of internally hinged, end-fixed shallow arches is in the spotlight. The non-linear model accounts for the coupled effect of the bending moment and axial force on the membrane strain. The model itself can handle homogeneous or non-homogeneous material distributions along the thickness of the uniform arch. Analytical findings reveal how the typical geometrical data, like arch length, radius of gyration, and arch angle, affect the lowest buckling loads. The typical non-linear behaviour of arches is also assessed including the equilibrium path and the internal force system. [ABSTRACT FROM AUTHOR]

A detailed study of the behaviour of concrete-filled rectangular tubular flange girders (CFRFGs) was undertaken. The CFRFGs were steel beams in which the top flange plate is replaced with a concrete-filled steel section, resulting in greater load-carrying capacity and lateral torsional buckling resistance compared with a regular steel beam of similar proportions. They are complex members and their behaviour is governed by several interrelated parameters, which were studied in this work. Using the Abaqus program, a three-dimensional finite-element (FE) model was developed to investigate the flexural behaviour of simply supported CFRFGs. Using available experimental results, the computational model was validated and then used to study the influence of the most salient properties on the overall response. Based on a fundamental assessment of the behaviour, a simplified analytical model was developed to predict the capacity of these types of section in a way that is suitable for designers. The results were compared with those from the FE analysis and it was found that the analytical model is capable of providing an accurate depiction of the behaviour and the bending moment capacity. [ABSTRACT FROM AUTHOR]

A full-scale, two-tiered steel buckling-restrained braced frame (BRBF) was tested to evaluate experimentally the seismic behavior of steel multitiered BRBFs, namely, column stability response, column seismic demands, and tier deformations under a loading protocol representing earthquake ground motions. The test specimen consisted of diagonal braces oriented in opposing directions in the two adjacent tiers to create the most critical multitier response. The test frame was designed in accordance with the 2010 AISC Seismic Provisions as a lateral load-resisting system of a single-story building. The frame was subjected to a three-phase loading protocol consisting of lateral displacement time histories corresponding to a far-field ground motion record and a near-field ground motion record applied sequentially achieving total frame drifts in excess of 3.5%, followed by a final monotonic lateral displacement corresponding to 4.5% story drift. The test frame exhibited a stable response despite a non-uniform distribution of frame inelastic deformation between the tiers, which induced significant in-plane bending moments in the columns. Flexural bending, combined with a large axial compression force, led to partial yielding in the columns. Large deformation demands were also observed in the BRB yielding in tension and attracting the majority of frame lateral deformation. On the basis of test results, a displacement-based analysis approach was proposed to relate column in-plane bending and flexural stiffness to relative inelastic tier deformations. [ABSTRACT FROM AUTHOR]

An experimental campaign is conducted on a 100g centrifuged monopile model, impact driven, into saturated dense sand, down to three embedding depths, corresponding to three slenderness ratios of 5, 4 and 3. These models are instrumented with optical fibres to measure the bending moment profile along the monopile. A new method is developed to determine the experimental soil reaction curves by considering the distributed moment part from the measured bending moment. This distributed moment is assessed by the one-dimensional finite-element (1D FE) model of the PISA (pile soil analysis) method. The key features of this study are: (a) the monopile behaves from pure rotation to combined rotation–flexure as the slenderness ratio is enhanced from 3 to 5, inducing a less pronounced linear rotation–deflection response at ground level; (b) although the distributed moment assessed in the PISA project is very low, the developed method is useful to explore the experimental local behaviour of laterally loaded monopiles; (c) the 1D FE PISA model captures reasonably well the overall behaviour of laterally loaded centrifuged driven monopiles, even if it is less accurate for the local behaviour. [ABSTRACT FROM AUTHOR]

Hydrothermal co-liquefaction (HTCL) is the prominent process for producing bio-products with a higher conversion rate. It is performed at high temperatures and pressure in the presence of water. Earlier, it was mostly conducted in batch reactors, but it has major limitations including operating volume, back mixing, and tedious process for high productivity. With that, the present investigation is performed on designing the screw shaft for the high-pressure HTCL process. The dimensional factors including flight length, pitch, helix angle, and depth were considered to design the optimal screw shaft. Likewise, principal stresses, shear stress, bending stress, bending moment, and total deformation were regarded as inevitable response variables to analyze the internal strength of the shaft. In this regard, the Taguchi approach provides the L9 (34) orthogonal array as an experimental design. Then, the numerical results from the transient structural analysis were analyzed with the assistance of statistical methods such as Grey Relational Grade (GRG), Grey Fuzzy Reasoning Grade, Analysis of Variance (ANOVA), and Taguchi method to find the most influential dimensions for minimizing the response variable. Consequently, the results from both GRG and Taguchi optimization were compared, and selected the most optimum parameters. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to propose and verify pile foundation underpinning technology for overlapping shield tunnels crossing pile groups and to predict and analyze the impact of overlapping tunnel excavation on the surrounding environment. Based on the pile foundation underpinning project of the Harbin Metro overlapping tunnel crossing the viaduct, a three-dimensional numerical model is first established to simulate the pile foundation underpinning process. Then, the rationality of the model is verified by comparing field monitoring data with numerical calculation data. The influence of the overlapping tunnel crossing the underpinning area is predicted and analyzed, and the mutual influence trend between the overlapping tunnels and the tunnel and underpinning area is explored. The results show that the trend of the settlement monitoring data of the cap and pier are consistent with that of the simulation results. Considering mutual coordination of the bridge structure, the rationality of the model is verified. In the underpinning process, the settlement of the underpinning pile is mainly caused by underpinning. The D52' pier and underpinning cap exhibit large settlement, but they still meet the safety requirements. During overlapping tunnel excavation, the vault settlement and segment bending moment in the underpinning area can be effectively controlled, while the surrounding environmental displacement also meets the requirements. Therefore, the pile foundation underpinning technology proposed in this study can be adopted to effectively solve the problem of overlapping tunnels crossing viaduct foundations, protect bridge structures and the surrounding environment, and provide a reference for similar projects. [ABSTRACT FROM AUTHOR]

This study examines stress distributions in adhesive joints under various loading and temperature conditions. Finite element analysis (FEA) was employed to compute the peel and shear stresses at the adhesive interface and bondline mid-section. Dependency analysis shows that mid-section peel stress significantly impacts the experimental shear strength of SLJs more than shear stress. This insight highlights the need to carefully analyze peel stress and bending moment factors. The analytical solutions proposed by Goland and Reissner were analyzed with modifications by Hart-Smith and Zhao. Hart-Smith's approach performed more effectively, especially when the adhesive layer thickness (ta) was 0.5 mm and the overlap length to thickness ratio (c/ta) was ≥20. FEA revealed stress distributions at the adhesive/adherend interface and bondline mid-section. DP490 adhesive joints exhibited lower stresses than EA9696. Temperature variations significantly affected joint behavior, particularly above the adhesive's glass transition temperature (Tg). Both EA9696 and DP490 adhesive joints displayed distinct responses to stress and temperature changes. The parabolic and biquadratic solutions for functionally graded adhesive (FGA) joints were compared. The biquadratic solution consistently yielded higher shear and peel stress values, with an increase ranging from 15% to 71% compared to the parabolic solution at various temperatures because of the larger gradient of the Young's modulus distribution near the overlap ends. The ratio of peak peel stress to peak shear stress suggests that selecting an adhesive with a superior peel strength or primarily reducing the peak peel stress by functionally grading is advisable, particularly if the adhesive is brittle. The comparison of stress distributions emphasizes the importance of selecting adhesives based on stress type, temperature, and solution methods in optimizing adhesive bonding applications. These findings provide valuable insights for thermomechanical applications where thermal stimuli may be used for controlled debonding. [ABSTRACT FROM AUTHOR]

This paper proposes a design framework to create individualised finger actuators that can be expanded to a generic hand. An actuator design is evaluated to help a finger achieve tendon-gliding exercises (TGEs). We consider musculoskeletal analysis for different finger sizes to determine joint forces while considering safety. The simulated Finite Element Analysis (FEA) response of a bi-directional Pneumatic Network Actuator (PNA) is mapped to a reduced-order model, creating a robust design tool to determine the bending angle and moment generated for actuator units. A reduced-order model is considered for both the 2D plane-strain formulation of the actuator and a full 3D model, providing a means to map between the results for a more accurate 3D model and the less computationally expensive 2D model. A setup considering a cascade of reduced-order actuator units interacting with a finger model determined to be able to achieve TGE was validated, and three exercises were successfully achieved. The FEA simulations were validated using the bending response of a manufactured actuator interacting with a dummy finger. The quality of the results shows that the simulated models can be used to predict the behaviour of the physical actuator in achieving TGE. [ABSTRACT FROM AUTHOR]

The suspended monorail is a new mode of rail transit with light weight, medium speed and low cost. It has a lightweight and aesthetically pleasing structure but has obvious limitations when spanning obstacles such as rivers and valleys. From the perspective of structural force and operational safety, this paper puts forward a new composite beam structure scheme, in which track piers and track beams are erected on the main beam of a cable-stayed bridge, overcoming the limitations of conventional suspended monorail spanning ability. To investigate the complex force situation and the load transfer path at the junction of the main beam of the cable-stayed bridge and the track beam piers, finite element models of steel box girder section and concrete box girder section were established using ANSYS software. The results showed that, in the steel box girder section, the pier load was mainly transferred to the diaphragm and the middle web directly connected to it. Among them, the diaphragm load experienced relatively uniform stress, while the middle web's stress was mainly concentrated within a 2-meter radius centered around the pier, which could be mostly transferred to the steel girder bottom plate. 58% of the pier's axial force was transferred to the directly connected diaphragm. During the transfer of the pier column's transverse bending moment, 58. 8% of the shear force was transferred to the directly connected diaphragm. During the transfer of the pier column's longitudinal bending moment, 53. 4% of the shear force was transferred to the middle web. In the concrete box girder section, the pier load was mainly transferred to the concrete web and diaphragm directly connected to it. The concrete stress was mainly concentrated within a 2-meter radius centered around the joint surface, and the pier load was basically transferred within about 0. 5 meters below the joint surface. 68. 8% of the pier's axial force was transferred to the directly connected diaphragm. During the transfer of the pier column's transverse bending moment, 86. 4% of shear force was transferred to the directly connected diaphragm. During the transfer of pier column's longitudinal bending moment, 44. 6% of shear force was transferred to the middle web. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiaotong University (Science) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The BlueDeck profiled steel sheeting system offers an innovative composite flooring solution, integrating high-strength steel sheets with reinforced concrete to form a unified structure. This study aimed to evaluate the development of full composite action, the ultimate bearing capacity, and the flexural stiffness of the system. A comprehensive experimental programme involving 18 four-point bending tests and 6 shear tests was conducted to quantify the mechanical interaction between the steel deck and concrete slab. This study specifically examined bending capacity and vertical deflection, comparing the results with predictions from AS/NZS 2327. It was found that the system consistently achieved full composite action, with composite specimens demonstrating higher flexural stiffness and load-bearing capacity as the concrete depth increased. For example, specimens with 200 mm slab depths exhibited a 60% improvement in ultimate capacity compared to those with 150 mm slabs, while those with 175 mm depths saw a 27% increase. Additionally, the BlueDeck system showed an 81% improvement in de-bonding resistance in thicker slabs. The experimental results exceeded the bending moment and deflection limits prescribed by AS/NZS 2327, confirming that the system is structurally sound for use in buildings. This study provides quantitative evidence supporting the system's compliance with Australian standards, highlighting its potential for improving construction efficiency through reduced material use, while maintaining structural integrity under imposed loads. [ABSTRACT FROM AUTHOR]

In this study, 3D-printed reinforced concrete beams were tested for flexural performance and compared with the analytical model based on the material test results. Two cementitious mixes (PSU and GCT) were designed for concrete printing and were mechanically tested and compared. Anisotropies in the compressive strength and modulus of elasticity of printed concrete were observed, applied to the analytical prediction of flexural bending behavior, and validated by actual test results. Significant differences between analytical predictions and experimental tests of the bending behaviors of the printed concrete beams were observed. Furthermore, higher compressive strengths and moduli of elasticity were observed when the loading direction was perpendicular to the printed layers or with the PSU mix. The effect of anisotropic mechanical properties on a reinforced beam was compared to the flexural bending tests for both mixes. The analytical model based on the material test results was compared to the flexural bending test results. The significant errors in the prediction of printed concrete's structural performance, from 10% to 50%, suggest that factors other than reduced compressive strengths may influence the structural behaviors of printed concrete beams. [ABSTRACT FROM AUTHOR]

The overall reinforcement of soft soil foundation has the disadvantages of large engineering quantity and high cost. When the pile foundation bears horizontal loads in the soil, the mechanical properties of the soil near the surface have a greater impact on it compared to the deep soil. Therefore, studying the influence of shallow soil reinforcement on the horizontal bearing capacity of pile foundations has important engineering significance. Studying the influence of shallow soft soil reinforcement around piles on the horizontal bearing performance of piles is of great significance for improving the economic efficiency of pile foundation reinforcement technology in soft soil areas. In this paper, seven pile-soil finite element models are established based on ABAQUS 2022 software to study the influence of shallow reinforcement on the horizontal bearing capacity of single pile. The models were established on the basis of a field test and its validity was verified. The influence of different reinforcement degrees on the horizontal bearing capacity of piles is analyzed by taking the reinforcement width and reinforcement depth as variables. The results indicate that shallow ground improvement significantly enhances the horizontal bearing capacity of the pile. The horizontal bearing capacity of the pile is increased by 83.0%, 104.3%, and 224.4%, respectively, corresponding to a reinforcement width of 2 times, 3 times, and 4 times the diameter of the pile, respectively. With the increase of the reinforcement width, the bending moment and deformation of the pile under the same horizontal load decrease significantly, while it has no significant effect on the location of the maximum bending moment of the pile. The bearing capacity of the pile foundation gradually increases with the increase of the reinforcement depth. Compared with the unreinforced situation, the horizontal bearing capacity of the pile body is increased by 224.4%, 361.3%, and 456.8%, respectively, corresponding to a reinforcement depth of 0.1 times, 0.2 times, and 0.3 times the pile length. As the reinforcement depth increases, the corresponding increase in bearing capacity does not increase linearly, but gradually decreases. This indicates that blindly carrying out deep soil reinforcement without comprehensive evaluation is not advisable. [ABSTRACT FROM AUTHOR]

To simulate the influence of rainfall on the internal forces of expansive soil slope retaining structures, an approximate calculation method for the humidity stress field of expansive soil is proposed in this study. Considering both rainy and non-rainy conditions, on a high expansive soil slope, a numerical model is constructed for a combining supporting structure, which is composed of upper and lower anti-sliding piles and anchor rods/cable frames. Furthermore, the distribution of internal forces in the retaining structure is studied, and design optimization is performed. The research findings reveal that the bending moment profile along the longitudinal axis of the lower anti-sliding pile demonstrates a distinctive "W" pattern, which is characterized by initial reduction, following augmentation, a subsequent reduction, and final amplification. In contrast, the upper anti-sliding pile experiences an ascending trend, followed by a descending trend, and then a subsequent ascending trend. Interestingly, the introduction of rainfall grants an escalation in both the shear force exerted along the entire length of the upper and lower anti-sliding piles and the bending moment encountered by the lower anti-sliding pile. The determination of the internal force distribution of the expansive soil slope retaining structures under different conditions, using the proposed calculation method, provides a further optimization in their design. [ABSTRACT FROM AUTHOR]

As basic structural components of the ship hull, stiffened plates suffer both thrust and shear loads while ships sail in rough sea environments. In order to guide the scaled model design effectively, the similarity law is investigated in this paper. The parameters that determine the nonlinear behaviour of the stiffened plate under compression and shear loading are defined and the nonlinear similarity method is improved. This method is applied to design a scaled model under combined bending and torsional moment, and the collapse test is conducted to research the collapse characteristics. The collapse behaviour of actual ship structures under combined loads predicted by the model test is compared with that obtained by the nonlinear finite element analysis. The good agreement represents the capability of the newly improved nonlinear similarity law. The present research provides a proper way to investigate the collapse characteristics of actual ship structures through a model test. [ABSTRACT FROM AUTHOR]

For the disaster prevention and control problems of down-gradient slopes, a pre-reinforcement structure of yielding anchor pile with a flexible material bedding layer between the soil body of the slope and the anchor cables as well as the anti-slip piles is used. The finite element numerical model is constructed to analyze the effects of the modulus of elasticity (E1) and thickness (D) of the let-shear layer and the modulus of elasticity (E2) and thickness (d) of the let-shear layer on the load-bearing capacity of the yielding anchor pile. The results show that the horizontal displacement, internal force and axial force of anchor cable of yielding anchor piles are significantly reduced compared with those of ordinary anchor piles, and the smaller E1 and E2 or the larger D and d are, the horizontal displacement, internal force and axial force of anchor cable are reduced, and the peaks of shear force and bending moment of the pile body are in the middle and lower parts of the pile body. The sensitivities of the factors affecting the load-bearing capacity of yielding anchor piles are D, E1, d, E2 in order. [ABSTRACT FROM AUTHOR]

To explore the long-term deformation performance of a large-span prestressed concrete continuous box-girder bridge after overload, a three-span prestressed concrete continuous box-girder bridge model with a length of 24.88 m was designed. The long-term deformation performance experiment was conducted for 558 days, and the prestress loss, deflection behavior, strain development, crack increase, and support reaction transformation of the bridge model were analyzed, which could indicate that the deformation of the bridge model developed rapidly in the first 3 months, reaching 60%–70% of the total deformation, and then tended to be stable. The midspan section appeared to reverse arch at the beginning, and with the extension of time, the negative bending moment at the two middle supports decreased owing to the redistribution of the bending moment, resulting in the disappearance of the camber phenomenon. Besides, considering the influence of cracking on the redistribution of the internal force of the structure, the moment modulation coefficient was modified by introducing a damage coefficient. Based on the bending performance test results of the bridge model, the bending moment amplitude modulation method and long-term deflection theory were used for analysis, and the long-term deflection calculation formula of the bridge model was established according to the conjugate beam method. The results showed that the theoretical calculation value of long-term deflection of each midspan section of the test girder was in good agreement with the test results, and the maximum error was less than 15%, which can provide a reference for the safety evaluation of the prestressed concrete continuous box-girder bridges. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Concrete shells, designed with near optimal shapes for uniform gravity loads, can be subjected to nonmembrane effects caused by nonuniform and asymmetrical loads. In this paper, a numerical study on the effect of normative loads on a thin triangular concrete shell with three supports is presented. Two actions were considered, wind and snow, which present high spatial variability in both intensity and direction, assuming the values established in Eurocode 1 for the worst possible location, in Portugal. Linear, nonlinear and stability analyses were performed using the ABAQUS software. Results suggest that the wind action, but especially the exceptional snow load in drifted arrangement, produce significant bending moments, leading to decompression, and eventually to the development of stresses above the tensile strength of current concrete classes. Therefore, the production of these shells by assembling prefabricated un‐reinforced modules, requires the use of ultrahigh‐performance fiber reinforced concrete, combined with prestressing. [ABSTRACT FROM AUTHOR]

This paper presents an arch structure called the circular box arch with sinusoidal corrugated webs (CBASCW). This study investigates the out-of-plane elastic buckling behavior and elastoplastic stability capacity of the arch through a combined approach of theoretical derivation and finite element simulation. The section stiffness of the arch, including flexural stiffness, shear stiffness, and torsional stiffness, is achieved through theoretical derivation. Additionally, the elastic buckling load in both pure compression and pure bending states is derived. A simplified model is also introduced, which can conveniently simulate the internal force and deformation of the arch. The elastoplastic instability mechanism and failure mode are studied under various loading conditions, including uniform radial load, end bending moment, vertical load uniformly distributed in full-span, and vertical load uniformly distributed in half-span. Furthermore, the stability curves of the arch under conditions of pure compression and pure bending are graphed by incorporating stability coefficient and regularized slenderness ratio. According to the simulation results obtained from the simplified model and the analysis of stability curves, a design formula for stability capacity is proposed. [ABSTRACT FROM AUTHOR]

AbstractA series of 3D finite element analyses were performed to examine the influence of loose sand layers on the monotonic lateral capacity of an extra-extra-large semirigid monopile in dense sand. The SANISAND-04 advanced constitutive model, which was meticulously calibrated, validated and verified using triaxial compression tests, centrifuge tests and a numerical study based on field tests, was adopted for this study. The impact of loose sand layers on monopile response is discussed in terms of its mode of deformation, critical lateral capacity, bending moment, shear force and soil resistance. Results show that the magnitude of the reduction in the monopile lateral capacity is dependent on the thickness and depth of the loose sand layer. Presence of loose sand at the tip of the monopile is also shown to have a significant effect on its lateral capacity. [ABSTRACT FROM AUTHOR]