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Steel Construction Published the List of Highly Influential Articles of 2020
Current Issue
2025 Vol. 40, No. 12
Display Method:
2025, 40(12): 1-7.
doi: 10.13206/j.gjgS24030802
Abstract
PDF (1958KB)
Abstract:
Shape memory alloy （SMA） possesses the characteristics of shape memory effect and superelasticity. Applying SMA materials to steel structure joints can impart self-centering and energy dissipation capabilities to the structures. Most existing studies focus on the performance of SMA-based beam-column joints， with limited research on the seismic performance of steel frames incorporating these self-centering joints. To investigate the behavior of steel frames with self-centering SMA joints under seismic action， a numerical model was developed using the finite element software OpenSEES. The accuracy of the simplified model was validated against experimental data. Using initial lateral stiffness， bearing capacity， maximum inter-story drift ratio， and residual inter-story drift ratio as analysis indexes， both nonlinear static analysis and dynamic analysis were carried out. The results showed that， compared to the traditional steel frame， the steel frame equipped with self-centering SMA joints exhibited lower initial lateral stiffness and bearing capacity. Under different lateral loading patterns， the maximum inter-story drift ratio in both frame types occurred in the lower stories； however， the frame with SMA joints demonstrated a smaller relative inter-story drift ratio. Due to the incorporation of self-centering SMA joints， this frame experienced larger inter-story deformation. Nevertheless， it essentially returned to its initial state post-earthquake， with a significantly reduced residual inter-story drift ratio compared to the traditional frame. The application of these SMA joints mitigated the considerable dispersion of inter-story displacements， leading to a more uniform distribution of forces. Consequently， the frame with SMA joints displayed superior seismic performance and stronger post-earthquake recoverability compared to the traditional steel frame， thereby enhancing the structural reparability.
Shape memory alloy （SMA） possesses the characteristics of shape memory effect and superelasticity. Applying SMA materials to steel structure joints can impart self-centering and energy dissipation capabilities to the structures. Most existing studies focus on the performance of SMA-based beam-column joints， with limited research on the seismic performance of steel frames incorporating these self-centering joints. To investigate the behavior of steel frames with self-centering SMA joints under seismic action， a numerical model was developed using the finite element software OpenSEES. The accuracy of the simplified model was validated against experimental data. Using initial lateral stiffness， bearing capacity， maximum inter-story drift ratio， and residual inter-story drift ratio as analysis indexes， both nonlinear static analysis and dynamic analysis were carried out. The results showed that， compared to the traditional steel frame， the steel frame equipped with self-centering SMA joints exhibited lower initial lateral stiffness and bearing capacity. Under different lateral loading patterns， the maximum inter-story drift ratio in both frame types occurred in the lower stories； however， the frame with SMA joints demonstrated a smaller relative inter-story drift ratio. Due to the incorporation of self-centering SMA joints， this frame experienced larger inter-story deformation. Nevertheless， it essentially returned to its initial state post-earthquake， with a significantly reduced residual inter-story drift ratio compared to the traditional frame. The application of these SMA joints mitigated the considerable dispersion of inter-story displacements， leading to a more uniform distribution of forces. Consequently， the frame with SMA joints displayed superior seismic performance and stronger post-earthquake recoverability compared to the traditional steel frame， thereby enhancing the structural reparability.
2025, 40(12): 8-15.
doi: 10.13206/j.gjgS23122102
Abstract:
The cable-supported photovoltaic （PV） power station structure uses suspension cables instead of traditional steel beams to support PV modules， representing a novel application of cable structures. Temperature effects are also a critical load for cable structures： under high temperatures， thermal expansion of the cables causes a reduction in cable force， which affects the overall structural geometry and stiffness； under low temperatures， thermal contraction increases cable force， impacting the structure’s bearing capacity. However， to date， scientists and engineers have conducted limited research on the temperature effects of cable-supported PV power stations. This paper systematically analyzed and studied the cable force and temperature effects on module frames in cable-supported PV power stations. It proposed empirical formulas to analyze the temperature effects on cable force and to determine the cable force without temperature effects， for two types of cable-supported PV power stations under various conditions. The accuracy of these empirical formulas was validated by comparing them with finite element analysis （FEA） results. The use of these formulas to calculate cable force reduced the need for finite element computation， improving the design efficiency of cable-supported PV power station structures. Furthermore， this study revealed the stress distribution patterns of PV module frames under temperature effects. Without cable structures， the most critical stress location on the PV module frame was at the junction of the long and short edges， showing a “concave” stress distribution. With cable structures， under cooling conditions， the critical stress location was at the connection between the frame and the prestressed steel strand， exhibiting an “M”-shaped stress distribution. Under heating conditions， the critical stress location shifted to the junction of the long and short edges， with a “W”-shaped stress distribution.
The cable-supported photovoltaic （PV） power station structure uses suspension cables instead of traditional steel beams to support PV modules， representing a novel application of cable structures. Temperature effects are also a critical load for cable structures： under high temperatures， thermal expansion of the cables causes a reduction in cable force， which affects the overall structural geometry and stiffness； under low temperatures， thermal contraction increases cable force， impacting the structure’s bearing capacity. However， to date， scientists and engineers have conducted limited research on the temperature effects of cable-supported PV power stations. This paper systematically analyzed and studied the cable force and temperature effects on module frames in cable-supported PV power stations. It proposed empirical formulas to analyze the temperature effects on cable force and to determine the cable force without temperature effects， for two types of cable-supported PV power stations under various conditions. The accuracy of these empirical formulas was validated by comparing them with finite element analysis （FEA） results. The use of these formulas to calculate cable force reduced the need for finite element computation， improving the design efficiency of cable-supported PV power station structures. Furthermore， this study revealed the stress distribution patterns of PV module frames under temperature effects. Without cable structures， the most critical stress location on the PV module frame was at the junction of the long and short edges， showing a “concave” stress distribution. With cable structures， under cooling conditions， the critical stress location was at the connection between the frame and the prestressed steel strand， exhibiting an “M”-shaped stress distribution. Under heating conditions， the critical stress location shifted to the junction of the long and short edges， with a “W”-shaped stress distribution.
2025, 40(12): 16-23.
doi: 10.13206/j.gjgS25032501
Abstract:
In order to study the change law of mechanical properties of Q420C steel after fire and high temperature， and to investigate the influence of high temperature and cooling on the impact toughness of steel， the test covers the temperature gradient of 200，400，600，800 ℃， natural cooling and immersion cooling. The impact test was carried out under five low temperature environments of 20，0，-20， -40 and-60 ℃， and the impact energy value of steel after high temperature cooling was measured. Combined with the test results of Q420C steel under normal temperature conditions， the Boltzmann function was used for regression analysis， and the change law of toughness of steel after treatment was systematically summarized. At the same time， the fracture modes of the specimens were observed by macroscopic observation and scanning electron microscopy. The results show that the steel exhibits different apparent characteristics， impact toughness and fracture modes under different test conditions. 1） In the high temperature environment of 400 ℃ and 600 ℃， the surface of the steel will form a blue oxide film and carbides， which are easy to fall off during the immersion cooling process； with the increase of temperature， the carbonization phenomenon becomes more and more obvious， and the carbides are more likely to peel off. The immersion cooling method can effectively reduce this phenomenon and make the steel surface more flat. 2） The impact energy value of steel treated by natural cooling increases with the increase of treatment temperature， but the critical temperature point of 600 ℃ for this trend， although the toughness decreases with the increase of temperature （800 ℃）， it is still greater than that of T = 400 ℃. Immersion cooling has a great influence on the toughness of the material. The impact energy value increases slightly at 400 ℃， which is slightly higher than that without high temperature treatment， and then continues to decrease significantly， with a minimum of 29 J. Compared with the impact test results of Q420C steel under normal temperature conditions， it is found that the change of impact energy value is in a multiple relationship. The reduction coefficient of impact energy value of the material after different treatments is calculated. The cooling method and the high temperature have a significant effect on the toughness of the steel. The effect of natural cooling is obviously better than that of immersion cooling. 3） The fracture surface of most specimens retains the fiber area and shear lip， indicating that the material exhibits good toughness.
In order to study the change law of mechanical properties of Q420C steel after fire and high temperature， and to investigate the influence of high temperature and cooling on the impact toughness of steel， the test covers the temperature gradient of 200，400，600，800 ℃， natural cooling and immersion cooling. The impact test was carried out under five low temperature environments of 20，0，-20， -40 and-60 ℃， and the impact energy value of steel after high temperature cooling was measured. Combined with the test results of Q420C steel under normal temperature conditions， the Boltzmann function was used for regression analysis， and the change law of toughness of steel after treatment was systematically summarized. At the same time， the fracture modes of the specimens were observed by macroscopic observation and scanning electron microscopy. The results show that the steel exhibits different apparent characteristics， impact toughness and fracture modes under different test conditions. 1） In the high temperature environment of 400 ℃ and 600 ℃， the surface of the steel will form a blue oxide film and carbides， which are easy to fall off during the immersion cooling process； with the increase of temperature， the carbonization phenomenon becomes more and more obvious， and the carbides are more likely to peel off. The immersion cooling method can effectively reduce this phenomenon and make the steel surface more flat. 2） The impact energy value of steel treated by natural cooling increases with the increase of treatment temperature， but the critical temperature point of 600 ℃ for this trend， although the toughness decreases with the increase of temperature （800 ℃）， it is still greater than that of T = 400 ℃. Immersion cooling has a great influence on the toughness of the material. The impact energy value increases slightly at 400 ℃， which is slightly higher than that without high temperature treatment， and then continues to decrease significantly， with a minimum of 29 J. Compared with the impact test results of Q420C steel under normal temperature conditions， it is found that the change of impact energy value is in a multiple relationship. The reduction coefficient of impact energy value of the material after different treatments is calculated. The cooling method and the high temperature have a significant effect on the toughness of the steel. The effect of natural cooling is obviously better than that of immersion cooling. 3） The fracture surface of most specimens retains the fiber area and shear lip， indicating that the material exhibits good toughness.
2025, 40(12): 24-30.
doi: 10.13206/j.gjgS24101802
Abstract:
Sliding scaffolding has been widely used in grid shell structures with long spans and long lengths， such as airport piers， train stations， and exhibition centers， due to its advantages of convenient operation and good comprehensive economy. To address the defects and dificiencies of conventional sliding scaffolding， the following key construction technologies have been developed and summarized through targeted research and upgrades： 1） The construction technology of sliding scaffolding with supports has been introduced. By adopting methods such as alternating block sliding with internal circular tube supports or parallel sliding with external circular tube supports， the upper assembled grid shell structure is maintained in a multi-point supported state throughout the process. This method reduces vertical deformation and cumulative assembly errors of the grid shell structure during construction， thereby mitigating adverse effects on the structural performance. 2） A construction method for arc-shaped sliding of scaffolding has been proposed， enabling the application of sliding scaffolding in the installation of grid shell structures arranged in an arc shape and expanding the scope of sliding scaffolding in grid shell structure installation. 3） A temporary reinforcement method for circular tubes has been introduced. It enhances the bearing capacity of the rod by using steel profiles to install an outer sleeve， which increases the rod's turning radius， reduces its slenderness ratio， and thus improves its stability coefficient. These reinforcement methods offer the advantages of a simple process， convenient material selection， ease of implementation， and reusability.
Sliding scaffolding has been widely used in grid shell structures with long spans and long lengths， such as airport piers， train stations， and exhibition centers， due to its advantages of convenient operation and good comprehensive economy. To address the defects and dificiencies of conventional sliding scaffolding， the following key construction technologies have been developed and summarized through targeted research and upgrades： 1） The construction technology of sliding scaffolding with supports has been introduced. By adopting methods such as alternating block sliding with internal circular tube supports or parallel sliding with external circular tube supports， the upper assembled grid shell structure is maintained in a multi-point supported state throughout the process. This method reduces vertical deformation and cumulative assembly errors of the grid shell structure during construction， thereby mitigating adverse effects on the structural performance. 2） A construction method for arc-shaped sliding of scaffolding has been proposed， enabling the application of sliding scaffolding in the installation of grid shell structures arranged in an arc shape and expanding the scope of sliding scaffolding in grid shell structure installation. 3） A temporary reinforcement method for circular tubes has been introduced. It enhances the bearing capacity of the rod by using steel profiles to install an outer sleeve， which increases the rod's turning radius， reduces its slenderness ratio， and thus improves its stability coefficient. These reinforcement methods offer the advantages of a simple process， convenient material selection， ease of implementation， and reusability.
2025, 40(12): 31-37.
doi: 10.13206/j.gjgS24122301
Abstract:
Taking the upper chord of the Huangshali steel truss bridge as an example， a systematic analysis was conducted on the characteristics and difficulties in the processing and manufacturing of integral double-jointed members with an anchor box structure. Starting from part production， a detailed analysis and control of the impact of cutting， welding， assembly， and other processes on the accuracy of large-sized vertical plate units were carried out. Subsequently， precision control in the manufacturing process of partition units that affect assembly accuracy was elaborated. Measures and methods for controlling precision during part manufacturing were provided， ensuring strict control over manufacturing accuracy from the source. In terms of member assembly， precision control points for each stage were explained one by one， from the selection of the initial assembly method to the subsequent assembly of welding plate units， welding groove types， welding box sections， welding anchor boxes， crossbeam joint plates， stiffening plates， and other components. The proposed measures include strict control over the shape and dimensions of the gusset plates， maintaining perpendicularity between the straight sections of the vertical plates and the gusset plates during material connection， controlling the spacing between the two joints， reasonably reserving welding shrinkage and secondary cutting allowances， improving the accuracy of partition plate manufacturing methods， rationally selecting assembly methods， and implementing precision control measures throughout the assembly process. As a result， the manufacturing accuracy of the members of the Huangshali steel truss bridge was effectively controlled， ensuring the overall quality of the members and fully meeting the precision requirements of the bridge manufacturing specifications. Furthermore， the proposed measures can accumulate valuable experience and provide a reference for the precision control in the manufacturing of integral double-jointed members for steel truss bridges in the future.
Taking the upper chord of the Huangshali steel truss bridge as an example， a systematic analysis was conducted on the characteristics and difficulties in the processing and manufacturing of integral double-jointed members with an anchor box structure. Starting from part production， a detailed analysis and control of the impact of cutting， welding， assembly， and other processes on the accuracy of large-sized vertical plate units were carried out. Subsequently， precision control in the manufacturing process of partition units that affect assembly accuracy was elaborated. Measures and methods for controlling precision during part manufacturing were provided， ensuring strict control over manufacturing accuracy from the source. In terms of member assembly， precision control points for each stage were explained one by one， from the selection of the initial assembly method to the subsequent assembly of welding plate units， welding groove types， welding box sections， welding anchor boxes， crossbeam joint plates， stiffening plates， and other components. The proposed measures include strict control over the shape and dimensions of the gusset plates， maintaining perpendicularity between the straight sections of the vertical plates and the gusset plates during material connection， controlling the spacing between the two joints， reasonably reserving welding shrinkage and secondary cutting allowances， improving the accuracy of partition plate manufacturing methods， rationally selecting assembly methods， and implementing precision control measures throughout the assembly process. As a result， the manufacturing accuracy of the members of the Huangshali steel truss bridge was effectively controlled， ensuring the overall quality of the members and fully meeting the precision requirements of the bridge manufacturing specifications. Furthermore， the proposed measures can accumulate valuable experience and provide a reference for the precision control in the manufacturing of integral double-jointed members for steel truss bridges in the future.
2025, 40(12): 38-44.
doi: 10.13206/j.gjgS25042801
Abstract:
Incremental launching construction is currently one of the most commonly used methods for the construction and erection of steel box girders. With the rapid development of bridge construction engineering technology in China， the incremental launching construction technology without a launching nose has begun to be applied. Compared with the traditional incremental launching method with a launching nose， the front end of the nose-less method is directly the steel girder itself， and the advantages of utilizing a lightweight launching nose and an internal nose beam structure are forfeited. This causes the steel girder to transition earlier from a cantilever state to a simply-supported or continuous state during the construction process， increasing the risk of permanent deformation and overturning of the steel girder. To gain a more comprehensive understanding of the nose-less incremental launching construction technology for steel box girders， a systematic analysis and research on this technology and its quality control methods were conducted in the steel box girder installation project of the Anhai Bay Extra-large Bridge on the Fuzhou-Xiamen Railway. First， an analysis was conducted on the characteristics and challenges of the nose-less incremental launching construction technology for steel box girders. Subsequently， the stress conditions during the nose-less incremental launching process were examined. Calculations were performed to determine the anti-overturning coefficient， stress distribution， and deflection magnitude of the steel girder under various construction conditions. Based on these analyses， key technical points and quality control measures for nose-less incremental launching were proposed. Finally， by analyzing monitoring data from the incremental launching process， it was verified that implementing the following measures ensured construction safety and achieved compliance with the required finished bridge alignment： controlling incremental launching steps， monitoring girder deformation and stress， and adding counterweight balancing. The nose-less incremental launching technology and quality control methodology presented in this study can reduce frequency of structural system transitions in the steel girder， elimination of fabrication， installation， and dismantling procedures for launching noses or auxiliary facilities， and enhance safety reliability and cost-effectiveness.
Incremental launching construction is currently one of the most commonly used methods for the construction and erection of steel box girders. With the rapid development of bridge construction engineering technology in China， the incremental launching construction technology without a launching nose has begun to be applied. Compared with the traditional incremental launching method with a launching nose， the front end of the nose-less method is directly the steel girder itself， and the advantages of utilizing a lightweight launching nose and an internal nose beam structure are forfeited. This causes the steel girder to transition earlier from a cantilever state to a simply-supported or continuous state during the construction process， increasing the risk of permanent deformation and overturning of the steel girder. To gain a more comprehensive understanding of the nose-less incremental launching construction technology for steel box girders， a systematic analysis and research on this technology and its quality control methods were conducted in the steel box girder installation project of the Anhai Bay Extra-large Bridge on the Fuzhou-Xiamen Railway. First， an analysis was conducted on the characteristics and challenges of the nose-less incremental launching construction technology for steel box girders. Subsequently， the stress conditions during the nose-less incremental launching process were examined. Calculations were performed to determine the anti-overturning coefficient， stress distribution， and deflection magnitude of the steel girder under various construction conditions. Based on these analyses， key technical points and quality control measures for nose-less incremental launching were proposed. Finally， by analyzing monitoring data from the incremental launching process， it was verified that implementing the following measures ensured construction safety and achieved compliance with the required finished bridge alignment： controlling incremental launching steps， monitoring girder deformation and stress， and adding counterweight balancing. The nose-less incremental launching technology and quality control methodology presented in this study can reduce frequency of structural system transitions in the steel girder， elimination of fabrication， installation， and dismantling procedures for launching noses or auxiliary facilities， and enhance safety reliability and cost-effectiveness.
2025, 40(12): 45-53.
doi: 10.13206/j.gjgS24110801
Abstract:
This study takes the first dual-purpose steel truss bridge in northwest China as the research background. Using ANSYS finite element software， a finite element model for incremental launching construction was established to analyze and compare the effects of two different arch construction sequences on the mechanical properties of the structure. The results showed that the construction sequence of erecting the girder prior to the arch resulted in lower structural stress， which proved more conducive to structural stability. In contrast， the “girder-and-arch simultaneous construction” sequence resulted in relatively smaller structural displacement. This was because the presence of the arch not only provided substantial vertical stiffness to the main girder but also effectively helped distribute the bridge’s self-weight.
This study takes the first dual-purpose steel truss bridge in northwest China as the research background. Using ANSYS finite element software， a finite element model for incremental launching construction was established to analyze and compare the effects of two different arch construction sequences on the mechanical properties of the structure. The results showed that the construction sequence of erecting the girder prior to the arch resulted in lower structural stress， which proved more conducive to structural stability. In contrast， the “girder-and-arch simultaneous construction” sequence resulted in relatively smaller structural displacement. This was because the presence of the arch not only provided substantial vertical stiffness to the main girder but also effectively helped distribute the bridge’s self-weight.
2025, 40(12): 54-57.
doi: 10.13206/j.gjgS24080825
Abstract:
Rectangular hollow tubes can be inserted horizontally into unstiffened steel plate shear walls. This arrangement reduces the wall’s vertical stiffness， thereby mitigating vertical stress and enabling the wall to primarily resist shear stress. This paper introduces vertical stiffness reduction factors for such walls. A numerical example shows that using two tubes per story with a flange width-to-thickness ratio of approximately 14 can reduce the vertical stiffness to about 0.3 times the original. The steel plate shear wall ultimately develops a diagonal tension field. The flexural stiffness and strength of the hollow steel tube walls provide anchorage for this tension field. Formulas for determining the required tube thickness in relation to the strength of the tension field are derived. Furthermore， 26 numerical examples are presented， calculating the tension field development factor and the vertical stiffness reduction factor. The range of parameters and results from these examples validates the feasibility of this approach.
Rectangular hollow tubes can be inserted horizontally into unstiffened steel plate shear walls. This arrangement reduces the wall’s vertical stiffness， thereby mitigating vertical stress and enabling the wall to primarily resist shear stress. This paper introduces vertical stiffness reduction factors for such walls. A numerical example shows that using two tubes per story with a flange width-to-thickness ratio of approximately 14 can reduce the vertical stiffness to about 0.3 times the original. The steel plate shear wall ultimately develops a diagonal tension field. The flexural stiffness and strength of the hollow steel tube walls provide anchorage for this tension field. Formulas for determining the required tube thickness in relation to the strength of the tension field are derived. Furthermore， 26 numerical examples are presented， calculating the tension field development factor and the vertical stiffness reduction factor. The range of parameters and results from these examples validates the feasibility of this approach.
