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Steel Construction Published the List of Highly Influential Articles of 2020
Current Issue
2026 Vol. 41, No. 7
Display Method:
2026, 41(7): 1-7.
doi: 10.13206/j.gjgS25060301
Abstract
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Abstract:
In order to reduce the slip of the bonding medium of the bonded inner conical anchorage when the CFRP bar is stressed，a novel bonded anchorage is proposed，which increases the contact area and friction between the bonding medium and the steel anchor cylinder through the setting of an inner step，and then reduces the slip of the bonding medium. In order to verify the effectiveness of the novel bonded inner stepped anchorage，the finite element models of single-bar inner conical anchorage and inner stepped anchorage were established using finite element software ABAQUS，and a comparative study on axial tensile performance was carried out. The analysis results showed that compared with the inner conical anchorage，the ultimate load of the inner stepped anchorage had increased by 10. 5%，and the bond medium slippage at the loading end had decreased by 16. 4%，indicating that the proposed novel CFRP ribbed bonding anchorage had better mechanical properties. On the basis of this analysis of anchorage parameters，the results showed that the length of the straight section of the anchorage had the greatest influence on the anchorage performance，followed by the anchorage length；the step height and the inclination angle of the anchor cup had a smaller influence on the anchorage performance of the inner stepped anchorage. Finally，the suggested ranges of the influence parameters for single-bar stepped anchorage with a CFRP bar diameter of 5 mm are given as follows：the anchoring length is 180 to 220 mm，the straight section length is 20 to 40 mm，the step height is 4 to 6 mm，and the anchor cup inclination angle is 2° to 3°.
In order to reduce the slip of the bonding medium of the bonded inner conical anchorage when the CFRP bar is stressed，a novel bonded anchorage is proposed，which increases the contact area and friction between the bonding medium and the steel anchor cylinder through the setting of an inner step，and then reduces the slip of the bonding medium. In order to verify the effectiveness of the novel bonded inner stepped anchorage，the finite element models of single-bar inner conical anchorage and inner stepped anchorage were established using finite element software ABAQUS，and a comparative study on axial tensile performance was carried out. The analysis results showed that compared with the inner conical anchorage，the ultimate load of the inner stepped anchorage had increased by 10. 5%，and the bond medium slippage at the loading end had decreased by 16. 4%，indicating that the proposed novel CFRP ribbed bonding anchorage had better mechanical properties. On the basis of this analysis of anchorage parameters，the results showed that the length of the straight section of the anchorage had the greatest influence on the anchorage performance，followed by the anchorage length；the step height and the inclination angle of the anchor cup had a smaller influence on the anchorage performance of the inner stepped anchorage. Finally，the suggested ranges of the influence parameters for single-bar stepped anchorage with a CFRP bar diameter of 5 mm are given as follows：the anchoring length is 180 to 220 mm，the straight section length is 20 to 40 mm，the step height is 4 to 6 mm，and the anchor cup inclination angle is 2° to 3°.
2026, 41(7): 8-18.
doi: 10.13206/j.gjgS26011301
Abstract:
In practical engineering， steel columns are often subjected to different vertical axial compression ratios. To study the mechanical properties of the octagonal core tube full-bolted connection joints of square steel tube columns under different axial compression ratios， eight sets of finite element joint models were established， with axial compression ratios of vertical -0.2， -0.1， 0， 0.1， 0.2， 0.3， 0.4， and 0.5. The influence of different axial compression ratios on the seismic performance of the joints under bidirectional horizontal loading was analyzed. The results showed that when subjected to tension-bending and pure bending， the joints ultimately exhibited tensile failure of the flange high-strength bolts； when subjected to compression-bending with an the axial compression ratio of 0.1， the joints ultimately still failed due to tensile failure of the flange high-strength bolts， whereas when the axial compression ratio ranged from 0.2 to 0.5， the failure occurred at the connection between the lower column and the column base stiffener. Under tension-bending condition， the flange plates， flange high-strength bolts， and the lower section of the core tube bore substantial loads， while the load-transfer capacity of the joints was relatively weak， resulting in less load being transferred to the lower column. During severe earthquakes， when the structural elastic-plastic inter-story drift angle reached the limit value of 0.02 rad， excessive tensile deformation of the flange high-strength bolts led to joint failure. In practical engineering， special attention should be paid to the design of flanges and high-strength bolts for scenarios where tension or excessive seismic intensity may occur. Under pure bending and compression-bending loading， as the axial compression ratio increased， the bearing capacities of the flange plates， flange high-strength bolts， and the lower section of the core tube decreased， while the bearing capacity of the lower column increased. Concurrently， the joints' load-transfer capacity， energy dissipation capacity， and ductility were enhanced， but the overall bearing capacity decreased and stiffness degradation accelerated. When the axial compression ratio was 0， the joints had the highest bearing capacity， but relatively weak energy dissipation capacity， and ultimately underwent joint failure. Therefore， it is recommended to control the axial compression ratio at 0.2 in joint design， to ensure the joint possesses both high bearing capacity and favorable ductility and energy dissipation capacity.
In practical engineering， steel columns are often subjected to different vertical axial compression ratios. To study the mechanical properties of the octagonal core tube full-bolted connection joints of square steel tube columns under different axial compression ratios， eight sets of finite element joint models were established， with axial compression ratios of vertical -0.2， -0.1， 0， 0.1， 0.2， 0.3， 0.4， and 0.5. The influence of different axial compression ratios on the seismic performance of the joints under bidirectional horizontal loading was analyzed. The results showed that when subjected to tension-bending and pure bending， the joints ultimately exhibited tensile failure of the flange high-strength bolts； when subjected to compression-bending with an the axial compression ratio of 0.1， the joints ultimately still failed due to tensile failure of the flange high-strength bolts， whereas when the axial compression ratio ranged from 0.2 to 0.5， the failure occurred at the connection between the lower column and the column base stiffener. Under tension-bending condition， the flange plates， flange high-strength bolts， and the lower section of the core tube bore substantial loads， while the load-transfer capacity of the joints was relatively weak， resulting in less load being transferred to the lower column. During severe earthquakes， when the structural elastic-plastic inter-story drift angle reached the limit value of 0.02 rad， excessive tensile deformation of the flange high-strength bolts led to joint failure. In practical engineering， special attention should be paid to the design of flanges and high-strength bolts for scenarios where tension or excessive seismic intensity may occur. Under pure bending and compression-bending loading， as the axial compression ratio increased， the bearing capacities of the flange plates， flange high-strength bolts， and the lower section of the core tube decreased， while the bearing capacity of the lower column increased. Concurrently， the joints' load-transfer capacity， energy dissipation capacity， and ductility were enhanced， but the overall bearing capacity decreased and stiffness degradation accelerated. When the axial compression ratio was 0， the joints had the highest bearing capacity， but relatively weak energy dissipation capacity， and ultimately underwent joint failure. Therefore， it is recommended to control the axial compression ratio at 0.2 in joint design， to ensure the joint possesses both high bearing capacity and favorable ductility and energy dissipation capacity.
2026, 41(7): 19-25.
doi: 10.13206/j.gjgS25091602
Abstract:
To address the vulnerability of traditional standing-seam metal roofing systems to wind-induced uplift failure under strong winds， this paper proposes a novel high-rib welded stainless steel roofing system. Full-scale 1∶1 model tests were carried out on two material configurations： Model 1， fabricated from 0.6 mm thick 445J2 ferritic stainless steel， and Model 2， fabricated from 0.7 mm thick 316L austenitic stainless steel. The test results demonstrated that Models 1 and 2 successfully withstood 5000 cycles of dynamic fluctuating pressure at 5.39 kPa and 8.0 kPa， respectively， with static ultimate bearing capacities reaching 11.2 kPa and 9.8 kPa， respectively. In addition， a finite element numerical model was established to analyze the influence of stiffening rib height on system performance. The computational results indicated that increasing the rib height significantly reduced panel deformation and the stress in the plate rib beneath the weld. When the rib height was increased from 1.5 mm to 5.0 mm， both deformation and stress decreased markedly； however， the difference between 3.0 mm and 5.0 mm tended to plateau. This study proves that the proposed roofing system exhibits excellent wind uplift resistance and holds significant potential for engineering applications.
To address the vulnerability of traditional standing-seam metal roofing systems to wind-induced uplift failure under strong winds， this paper proposes a novel high-rib welded stainless steel roofing system. Full-scale 1∶1 model tests were carried out on two material configurations： Model 1， fabricated from 0.6 mm thick 445J2 ferritic stainless steel， and Model 2， fabricated from 0.7 mm thick 316L austenitic stainless steel. The test results demonstrated that Models 1 and 2 successfully withstood 5000 cycles of dynamic fluctuating pressure at 5.39 kPa and 8.0 kPa， respectively， with static ultimate bearing capacities reaching 11.2 kPa and 9.8 kPa， respectively. In addition， a finite element numerical model was established to analyze the influence of stiffening rib height on system performance. The computational results indicated that increasing the rib height significantly reduced panel deformation and the stress in the plate rib beneath the weld. When the rib height was increased from 1.5 mm to 5.0 mm， both deformation and stress decreased markedly； however， the difference between 3.0 mm and 5.0 mm tended to plateau. This study proves that the proposed roofing system exhibits excellent wind uplift resistance and holds significant potential for engineering applications.
2026, 41(7): 26-35.
doi: 10.13206/j.gjgS25121901
Abstract:
Currently， Chinese transmission line design specifications provide clear guidelines for the bearing capacity calculation of bolted connections， but the relevant formulas do not account for the influence of bolt preload. Meanwhile， construction acceptance standards indirectly specify the preload magnitude by defining tightening torque values. Although both academia and the engineering community widely recognize the contribution of preload to joint performance， debate persists over the recommended preload values in the specifications， primarily due to the lack of systematic research on the frictional behavior at rough contact interfaces in bolted joints. This paper focuses on a typical angle steel joint as the research object， analyzing the influence of interface friction on its load-bearing performance. Through a well-designed research program and finite element simulations， the dynamic evolution of the load-transfer mechanism in the joint is revealed： initially， the load is primarily supported by interface friction； as bolt slippage occurs， the load-transfer mechanism gradually shifts to being dominated by the bearing action between the bolt shank and the hole wall. The results demonstrate that the ultimate bearing capacity of the joint is provided jointly by the bearing capacity of the bolt hole wall and the friction at the contact surface， with friction accounting for approximately 20% of the total bearing capacity. This study systematically elucidates the complementary relationship between the friction and the hole-wall bearing force， providing an important theoretical foundation for improving the design theory and performance evaluation of bolted connections.
Currently， Chinese transmission line design specifications provide clear guidelines for the bearing capacity calculation of bolted connections， but the relevant formulas do not account for the influence of bolt preload. Meanwhile， construction acceptance standards indirectly specify the preload magnitude by defining tightening torque values. Although both academia and the engineering community widely recognize the contribution of preload to joint performance， debate persists over the recommended preload values in the specifications， primarily due to the lack of systematic research on the frictional behavior at rough contact interfaces in bolted joints. This paper focuses on a typical angle steel joint as the research object， analyzing the influence of interface friction on its load-bearing performance. Through a well-designed research program and finite element simulations， the dynamic evolution of the load-transfer mechanism in the joint is revealed： initially， the load is primarily supported by interface friction； as bolt slippage occurs， the load-transfer mechanism gradually shifts to being dominated by the bearing action between the bolt shank and the hole wall. The results demonstrate that the ultimate bearing capacity of the joint is provided jointly by the bearing capacity of the bolt hole wall and the friction at the contact surface， with friction accounting for approximately 20% of the total bearing capacity. This study systematically elucidates the complementary relationship between the friction and the hole-wall bearing force， providing an important theoretical foundation for improving the design theory and performance evaluation of bolted connections.
2026, 41(7): 36-46.
doi: 10.13206/j.gjgS25101301
Abstract:
In order to obtain fatigue damage characteristics as early as possible and to quickly evaluate the fatigue state of in-service bridge steel structures， it is necessary to explore new methods for identifying fatigue damage characteristics. Magnetic memory signals were measured on real-time fatigue samples of steel plates used in steel bridges， and the evolution of the signals during the fatigue process was obtained. The results showed that， under constant ambient conditions， the distribution of the signal curves exhibited similarity and successive evolution during the fatigue process. The identification range of a single probe in the magnetic memory signal measurement reached 40 mm. Additionally， the magnetic memory signal strength and its slope provided strong identification capability when the measurement direction was perpendicular to the crack orientation. When fatigue cracks developed in the steel plate， the magnetic memory strength signals and their slope signals showed distinct curve characteristics. Specifically， the strength signals showed extreme values and a zero-crossing point， while the slope signals presented M-shaped and ∧-shaped patterns. Due to the limited number of specimens in this experimental study， the trend of magnetic memory signals with the increase of fatigue cycles was not yet obvious. Future work should focus on accumulating a larger dataset， expanding to a sufficient number of samples， and exploring more effective methods to obtain the evolving trends.
In order to obtain fatigue damage characteristics as early as possible and to quickly evaluate the fatigue state of in-service bridge steel structures， it is necessary to explore new methods for identifying fatigue damage characteristics. Magnetic memory signals were measured on real-time fatigue samples of steel plates used in steel bridges， and the evolution of the signals during the fatigue process was obtained. The results showed that， under constant ambient conditions， the distribution of the signal curves exhibited similarity and successive evolution during the fatigue process. The identification range of a single probe in the magnetic memory signal measurement reached 40 mm. Additionally， the magnetic memory signal strength and its slope provided strong identification capability when the measurement direction was perpendicular to the crack orientation. When fatigue cracks developed in the steel plate， the magnetic memory strength signals and their slope signals showed distinct curve characteristics. Specifically， the strength signals showed extreme values and a zero-crossing point， while the slope signals presented M-shaped and ∧-shaped patterns. Due to the limited number of specimens in this experimental study， the trend of magnetic memory signals with the increase of fatigue cycles was not yet obvious. Future work should focus on accumulating a larger dataset， expanding to a sufficient number of samples， and exploring more effective methods to obtain the evolving trends.
2026, 41(7): 47-53.
doi: 10.13206/j.gjgS25112101
Abstract:
The roof structure of the China-Korea City Pavilion features a bidirectional free-form surface design. The building’s facade primarily consists of glass and aluminum panel curtain walls. The roof envelope applies an aluminum-magnesium-manganese panel standing seam roofing system. The roof of each exhibition hall is equipped with glass skylights for natural lighting. Taking this project as an example，this paper discusses the key technical points of structural design in metal roof systems，including drainage design， purlin design，deformation release，and wind uplift resistance testing.
The roof structure of the China-Korea City Pavilion features a bidirectional free-form surface design. The building’s facade primarily consists of glass and aluminum panel curtain walls. The roof envelope applies an aluminum-magnesium-manganese panel standing seam roofing system. The roof of each exhibition hall is equipped with glass skylights for natural lighting. Taking this project as an example，this paper discusses the key technical points of structural design in metal roof systems，including drainage design， purlin design，deformation release，and wind uplift resistance testing.
2026, 41(7): 54-61.
doi: 10.13206/j.gjgS25072101
Abstract:
Addressing the challenges of height constraints， tight construction schedules， and significant traffic disruption encountered during the reconstruction of widely used small-to-medium span hollow slab bridges， this study proposes a rapid replacement technology for fully prefabricated steel-concrete composite girders based on epoxy mortar connections. In a 13 m span slab replacement project， the structural system adopted an “I-shaped steel girder + epoxy mortar bedding + prefabricated concrete deck panel” configuration. By replacing traditional cast-in-place concrete joints with epoxy mortar wet joints， an equal-height replacement of the original hollow slabs was achieved. The mechanical properties and construction processes of this bridge type were systematically investigated through refined finite element analysis， laboratory tests， and on-site engineering verification. The results indicated that the ultimate bearing capacity of the composite girder reached 4.8 times the service load， exhibiting a distinct ductile failure characteristic where the “steel girder yields before concrete crushing occurs”. Implementation of this technology allowed rapid installation of the superstructure within 24 hours. Although the direct material cost was approximately 20% higher than that of hollow slabs， the technology presented a significant advantage in total integrated cost due to reduced social costs from shortened construction periods and the full utilization of existing substructures. This study provides a feasible solution for the rapid renovation of small-to-medium span （10~16 m） hollow slab bridges.
Addressing the challenges of height constraints， tight construction schedules， and significant traffic disruption encountered during the reconstruction of widely used small-to-medium span hollow slab bridges， this study proposes a rapid replacement technology for fully prefabricated steel-concrete composite girders based on epoxy mortar connections. In a 13 m span slab replacement project， the structural system adopted an “I-shaped steel girder + epoxy mortar bedding + prefabricated concrete deck panel” configuration. By replacing traditional cast-in-place concrete joints with epoxy mortar wet joints， an equal-height replacement of the original hollow slabs was achieved. The mechanical properties and construction processes of this bridge type were systematically investigated through refined finite element analysis， laboratory tests， and on-site engineering verification. The results indicated that the ultimate bearing capacity of the composite girder reached 4.8 times the service load， exhibiting a distinct ductile failure characteristic where the “steel girder yields before concrete crushing occurs”. Implementation of this technology allowed rapid installation of the superstructure within 24 hours. Although the direct material cost was approximately 20% higher than that of hollow slabs， the technology presented a significant advantage in total integrated cost due to reduced social costs from shortened construction periods and the full utilization of existing substructures. This study provides a feasible solution for the rapid renovation of small-to-medium span （10~16 m） hollow slab bridges.
2026, 41(7): 62-69.
doi: 10.13206/j.gjgS25051202
Abstract:
To address the challenges of installing stiffening girders for long-span suspension bridges in mountainous deep canyons with complex terrain， this study conducted innovative research on construction techniques based on the Jixin Yellow River Three Gorges Bridge project. Confronting special conditions including restricted road transportation in U-shaped valleys， 30-meter annual water level variations of the Yellow River， and non-navigable waterways， this paper proposed an integrated construction scheme of "modular decomposition + on-site assembly， component transportation + intelligent cable lifting". Key technical solutions include： 1） factory prefabrication of each steel truss segment into 58 components （upper/lower chords， webs， deck panels， upper/lower crossbeams）， followed by road transportation to on-site assembly yards for "3+1" preassembly into standard lifting units； 2） the development and deployment of specialized multi-axle modular transporters for segment transportation within the canyon significantly improved transport efficiency； 3） an intelligent cable lifting system was implemented， achieving millimeter-level positioning accuracy at a rate of 2 segments per day； 4） an innovative "scaffolding + swing method" combination for cable lifting blind zones， enabling precise placement through hydraulic synchronization control for a maximum inclination of 63° and horizontal displacement of 15 m. Practical results demonstrated that the vertical installation accuracy was within ±2 mm for all 34 segments， the construction period was reduced by 20%， and the structure achieved a 100% acceptance rate in the initial inspection. The research validated the applicability of modular transportation and intelligent lifting techniques in deep-canyon suspension bridges， while the swing method effectively extended cable lifting coverage. The developed integrated technical system provides a valuable reference for similar canyon bridge projects， demonstrating significant economic benefits and promotion potential.
To address the challenges of installing stiffening girders for long-span suspension bridges in mountainous deep canyons with complex terrain， this study conducted innovative research on construction techniques based on the Jixin Yellow River Three Gorges Bridge project. Confronting special conditions including restricted road transportation in U-shaped valleys， 30-meter annual water level variations of the Yellow River， and non-navigable waterways， this paper proposed an integrated construction scheme of "modular decomposition + on-site assembly， component transportation + intelligent cable lifting". Key technical solutions include： 1） factory prefabrication of each steel truss segment into 58 components （upper/lower chords， webs， deck panels， upper/lower crossbeams）， followed by road transportation to on-site assembly yards for "3+1" preassembly into standard lifting units； 2） the development and deployment of specialized multi-axle modular transporters for segment transportation within the canyon significantly improved transport efficiency； 3） an intelligent cable lifting system was implemented， achieving millimeter-level positioning accuracy at a rate of 2 segments per day； 4） an innovative "scaffolding + swing method" combination for cable lifting blind zones， enabling precise placement through hydraulic synchronization control for a maximum inclination of 63° and horizontal displacement of 15 m. Practical results demonstrated that the vertical installation accuracy was within ±2 mm for all 34 segments， the construction period was reduced by 20%， and the structure achieved a 100% acceptance rate in the initial inspection. The research validated the applicability of modular transportation and intelligent lifting techniques in deep-canyon suspension bridges， while the swing method effectively extended cable lifting coverage. The developed integrated technical system provides a valuable reference for similar canyon bridge projects， demonstrating significant economic benefits and promotion potential.
2026, 41(7): 70-74.
doi: 10.13206/j.gjgS25021335
Abstract:
This study investigated the buckling behavior of I-section beams with a floor slab or profiled steel sheeting attached to the top flange. The upper and lower flanges were modeled as individual thin-walled members， and the web as a plate subjected to axial forces and bending moment. A total potential energy expression was established accordingly. Displacement functions were formulated on the premise that the web remains perpendicular to the flanges， and these functions were substituted into the total potential energy expression to obtain the critical load. The torsional buckling of the section around the upper flange was analyzed based on thin-walled member theory. Considering the torsional restraint on the upper flange， the formula for critical stress was derived. When the floor slab was sufficiently thick， the section exhibited distortional buckling， and the corresponding critical distortional buckling stress formula was proposed. By comparing the above three groups of solutions， a simple formula with satisfactory accuracy and a reasonable safety margin was developed by modifying the thin-walled member theory formula for fixed-axis torsional buckling， which is applicable to the calculation of distortional buckling stress when the upper flange is permitted to rotate.
This study investigated the buckling behavior of I-section beams with a floor slab or profiled steel sheeting attached to the top flange. The upper and lower flanges were modeled as individual thin-walled members， and the web as a plate subjected to axial forces and bending moment. A total potential energy expression was established accordingly. Displacement functions were formulated on the premise that the web remains perpendicular to the flanges， and these functions were substituted into the total potential energy expression to obtain the critical load. The torsional buckling of the section around the upper flange was analyzed based on thin-walled member theory. Considering the torsional restraint on the upper flange， the formula for critical stress was derived. When the floor slab was sufficiently thick， the section exhibited distortional buckling， and the corresponding critical distortional buckling stress formula was proposed. By comparing the above three groups of solutions， a simple formula with satisfactory accuracy and a reasonable safety margin was developed by modifying the thin-walled member theory formula for fixed-axis torsional buckling， which is applicable to the calculation of distortional buckling stress when the upper flange is permitted to rotate.
2026, 41(7): 75-79.
doi: 10.13206/j.gjgS26060840
Abstract:
The 17 Steel Code comprehensively accounts for initial defects through equivalent initial deflection，references experimental data， employs computational fitting，and determines the column curve by calculating the buckling behavior of axially compressed members under compression-bending. The column curve specified in the American Steel Code consists of two distinct phases：during the elastic stage，it uses the Euler critical force as a reference with a reduction factor of 0. 877 to account for geometric defects；in the inelastic stage，it incorporates the nonlinear characteristics of the generalized Euler's formula when materials approach their proportional limit.
The 17 Steel Code comprehensively accounts for initial defects through equivalent initial deflection，references experimental data， employs computational fitting，and determines the column curve by calculating the buckling behavior of axially compressed members under compression-bending. The column curve specified in the American Steel Code consists of two distinct phases：during the elastic stage，it uses the Euler critical force as a reference with a reduction factor of 0. 877 to account for geometric defects；in the inelastic stage，it incorporates the nonlinear characteristics of the generalized Euler's formula when materials approach their proportional limit.
