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2026 Vol. 56, No. 6
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2026, 56(6): 1-8.
doi: 10.3724/j.gyjzG24101507
Abstract:
The airport terminal layout and stream design are complex and closely interconnected. The design of Fuzhou Changle Airport terminal starts from extreme site constraints and addresses spatial limitations through innovative approaches， including the integration of the international check-in area with the Ground Transportation Center （GTC）， the hotel-office building with the GTC， layout with passenger flow， multi-level transportation organization， and architectural styling. These design strategies have not only improved the efficiency of airside operations， passenger travel， passenger transfers， and airport staff， but also enhanced the airport's commercial value. Furthermore， they also preserve Fuzhou's unique traditional cultural context， forming a unique cultural and artistic value for the airport.
The airport terminal layout and stream design are complex and closely interconnected. The design of Fuzhou Changle Airport terminal starts from extreme site constraints and addresses spatial limitations through innovative approaches， including the integration of the international check-in area with the Ground Transportation Center （GTC）， the hotel-office building with the GTC， layout with passenger flow， multi-level transportation organization， and architectural styling. These design strategies have not only improved the efficiency of airside operations， passenger travel， passenger transfers， and airport staff， but also enhanced the airport's commercial value. Furthermore， they also preserve Fuzhou's unique traditional cultural context， forming a unique cultural and artistic value for the airport.
2026, 56(6): 9-16.
doi: 10.3724/j.gyjzG24101703
Abstract:
Taking the wooden frame of the Shang-Character Gate from an ancestral hall in Shexian County as a case study， this paper begins by categorizing its components and tracing their historical evolution. It then analyzes the characteristics of decorative components integrated with both structure and space from the perspectives of decoration-structure integration and decoration-space integration. Moreover， through mechanical analysis and eye-tracking experiments， this research adoptes a combined qualitative and quantitative approach to verify the regularity characteristics in the integration of structure， decoration， and space within the Shang-Character Gate style wooden frame across different component combinations. These findings demonstrate that the design and placement of the decorative components fully reflect both mechanical principles and aesthetic considerations. From a viewer's perspective， the spatial interest points in the perception of the wooden carvings show marked centripetal and hierarchical tendencies.
Taking the wooden frame of the Shang-Character Gate from an ancestral hall in Shexian County as a case study， this paper begins by categorizing its components and tracing their historical evolution. It then analyzes the characteristics of decorative components integrated with both structure and space from the perspectives of decoration-structure integration and decoration-space integration. Moreover， through mechanical analysis and eye-tracking experiments， this research adoptes a combined qualitative and quantitative approach to verify the regularity characteristics in the integration of structure， decoration， and space within the Shang-Character Gate style wooden frame across different component combinations. These findings demonstrate that the design and placement of the decorative components fully reflect both mechanical principles and aesthetic considerations. From a viewer's perspective， the spatial interest points in the perception of the wooden carvings show marked centripetal and hierarchical tendencies.
2026, 56(6): 17-24.
doi: 10.3724/j.gyjzG25070102
Abstract:
To address the challenges of fragmented urban fabric and lack of vitality faced by industrial megastructures in urban renewal， this study proposes the adaptive renewal concept of the “internalized neighborhood”. The research posits that the regeneration of such spaces should transcend singular modifications to the building structure itself. Instead， it should focus on systematically “internalizing” the spatial logic of an urban neighborhood—including its human-scale proportions， functional hybridity， public circulation networks， and permeable interfaces—into the building interior. This approach facilitates a fundamental transformation from an isolated megastructure into a vibrant urban node. The paper systematically constructs a four-dimensional spatial restructuring framework comprising “Scale Transformation， Functional Hybridity， Circulation Reorganization， and Interface Blurring”. Using the renovation of Building 8 at Shanghai Huayi Wanchuang Park as a case study， it elaborates on how specific design techniques—namely “disaggregation”， “multi-level circulation networks”， and a “three-dimensional park”—synergistically interact to convert an industrial plant into an “internalized neighborhood” characterized by diverse functions， rich circulation paths， and seamless integration between interior and exterior. The study demonstrates that this strategy effectively mends the urban fabric， enhances spatial quality and public value， offering a new theoretical perspective and practical pathway for the adaptive regeneration of industrial heritage.
To address the challenges of fragmented urban fabric and lack of vitality faced by industrial megastructures in urban renewal， this study proposes the adaptive renewal concept of the “internalized neighborhood”. The research posits that the regeneration of such spaces should transcend singular modifications to the building structure itself. Instead， it should focus on systematically “internalizing” the spatial logic of an urban neighborhood—including its human-scale proportions， functional hybridity， public circulation networks， and permeable interfaces—into the building interior. This approach facilitates a fundamental transformation from an isolated megastructure into a vibrant urban node. The paper systematically constructs a four-dimensional spatial restructuring framework comprising “Scale Transformation， Functional Hybridity， Circulation Reorganization， and Interface Blurring”. Using the renovation of Building 8 at Shanghai Huayi Wanchuang Park as a case study， it elaborates on how specific design techniques—namely “disaggregation”， “multi-level circulation networks”， and a “three-dimensional park”—synergistically interact to convert an industrial plant into an “internalized neighborhood” characterized by diverse functions， rich circulation paths， and seamless integration between interior and exterior. The study demonstrates that this strategy effectively mends the urban fabric， enhances spatial quality and public value， offering a new theoretical perspective and practical pathway for the adaptive regeneration of industrial heritage.
2026, 56(6): 25-34.
doi: 10.3724/j.gyjzG26012703
Abstract:
Online digital information is increasingly influencing individuals’ spatial cognitive processes and has become an important medium for perceiving urban images. This study took the historic district of Hohhot as the research object， aimed to simulate the influence of virtual space on cognitive behavioral choices by identifying elements of image perception and cognitive emotions， so as to effectively determine optimal experiential paths and modes within physical space. Based on online videos and textual information， public perceptions of physical space were extracted to identify spatial experience hotspots， analyze emotional tendencies and behavioral choice weights， and simulate perceptual paths of urban image elements under multiple weighting scenarios. The results indicate that features derived from online video and textual data effectively reveal the clustered distribution patterns of image perception spaces； the frequency of image-related mentions and emotional characteristics provide a basis for determining behavioral choice weights； and the simulated paths within historic urban areas exhibit behavioral characteristics of “main corridor movement-alley attraction-node stopping-plaza diffusion”. The analytical framework of “image hotspot extraction-emotional perception analysis-cognitive path simulation” provides a basis for delineating spatial renewal areas and optimizing experiential design.
Online digital information is increasingly influencing individuals’ spatial cognitive processes and has become an important medium for perceiving urban images. This study took the historic district of Hohhot as the research object， aimed to simulate the influence of virtual space on cognitive behavioral choices by identifying elements of image perception and cognitive emotions， so as to effectively determine optimal experiential paths and modes within physical space. Based on online videos and textual information， public perceptions of physical space were extracted to identify spatial experience hotspots， analyze emotional tendencies and behavioral choice weights， and simulate perceptual paths of urban image elements under multiple weighting scenarios. The results indicate that features derived from online video and textual data effectively reveal the clustered distribution patterns of image perception spaces； the frequency of image-related mentions and emotional characteristics provide a basis for determining behavioral choice weights； and the simulated paths within historic urban areas exhibit behavioral characteristics of “main corridor movement-alley attraction-node stopping-plaza diffusion”. The analytical framework of “image hotspot extraction-emotional perception analysis-cognitive path simulation” provides a basis for delineating spatial renewal areas and optimizing experiential design.
2026, 56(6): 35-45.
doi: 10.3724/j.gyjzG24022303
Abstract:
The controlled rocking steel frame with column-base uplift system not only improves the seismic performance of the structure but also increases the overturning moment generated by second-order effects， thereby increasing the risk of structural overturning and limiting the full utilization of its structural seismic performance. To address these limitations， this paper proposes a controlled rocking steel frame with column mid-height uplift system. This system features a liftable rocking form with relaxed constraints at the mid-height of the ground-floor columns， causing the upper and lower segments of the columns to bend in opposite curvatures. This creates a reverse bending point at the column's mid-height， reducing the rocking of the upper structure under seismic actions， consequently mitigating the risk of structural overturning. Utilizing the finite element software OpenSEES， a finite element model for controlled rocking steel frames with column mid-height uplift system was developed. Based on this model， time-history analyses under minor， moderate， major， and extreme seismic events were performed for four structural configurations： the steel frame structure， the braced-steel frame structure， the self-centering rocking frame with column-base uplift system， and the self-centering rocking frame with column mid-height uplift system. The seismic performance of these structures was compared and analyzed based on the maximum inter-story drift ratio， top-story displacement response， inter-story drift concentration factor， residual inter-story drift ratio， and the distribution of plastic hinges. The analysis results indicated that the rocking frame with column mid-height uplift system demonstrated superior control over the maximum inter-story drift ratio， top-story displacement， and residual inter-story drift ratio compared to the other structures. Additionally， it optimized the plastic hinge development pattern of the ssystem during earthquakes， providing a higher safety margin against strong seismic actions.
The controlled rocking steel frame with column-base uplift system not only improves the seismic performance of the structure but also increases the overturning moment generated by second-order effects， thereby increasing the risk of structural overturning and limiting the full utilization of its structural seismic performance. To address these limitations， this paper proposes a controlled rocking steel frame with column mid-height uplift system. This system features a liftable rocking form with relaxed constraints at the mid-height of the ground-floor columns， causing the upper and lower segments of the columns to bend in opposite curvatures. This creates a reverse bending point at the column's mid-height， reducing the rocking of the upper structure under seismic actions， consequently mitigating the risk of structural overturning. Utilizing the finite element software OpenSEES， a finite element model for controlled rocking steel frames with column mid-height uplift system was developed. Based on this model， time-history analyses under minor， moderate， major， and extreme seismic events were performed for four structural configurations： the steel frame structure， the braced-steel frame structure， the self-centering rocking frame with column-base uplift system， and the self-centering rocking frame with column mid-height uplift system. The seismic performance of these structures was compared and analyzed based on the maximum inter-story drift ratio， top-story displacement response， inter-story drift concentration factor， residual inter-story drift ratio， and the distribution of plastic hinges. The analysis results indicated that the rocking frame with column mid-height uplift system demonstrated superior control over the maximum inter-story drift ratio， top-story displacement， and residual inter-story drift ratio compared to the other structures. Additionally， it optimized the plastic hinge development pattern of the ssystem during earthquakes， providing a higher safety margin against strong seismic actions.
2026, 56(6): 46-52.
doi: 10.3724/j.gyjzG24051602
Abstract:
Λ-shaped folding plate grid structure is a type of folding plate structure， and its component element form is Λ-shaped. First， the classification of this kind of structure and the configuration of the Λ-shaped folding plate elements were introduced. Then， a static analysis of the folding plate grid structure with isosceles triangular Λ-elements was carried out， and formulas for the moment of inertia， the stresses in the upper and lower chords， and deflection were derived. Subsequently， a series of key problems related to the Λ-shaped folding plate grid structure were studied， including the flexural rigidity of the grid structure， the out-of-plane stability of its compression chords， the effects of uneven snow load distribution， and some strengthening measures necessary for cantilevered Λ-shaped folding plate grid structures. Finally， an economic analysis of Λ-shaped folding plate grid structures was conducted. Focusing on the steel consumption of the top and bottom chords， the relationship between steel consumption and the form of the Λ-shape element was established.
Λ-shaped folding plate grid structure is a type of folding plate structure， and its component element form is Λ-shaped. First， the classification of this kind of structure and the configuration of the Λ-shaped folding plate elements were introduced. Then， a static analysis of the folding plate grid structure with isosceles triangular Λ-elements was carried out， and formulas for the moment of inertia， the stresses in the upper and lower chords， and deflection were derived. Subsequently， a series of key problems related to the Λ-shaped folding plate grid structure were studied， including the flexural rigidity of the grid structure， the out-of-plane stability of its compression chords， the effects of uneven snow load distribution， and some strengthening measures necessary for cantilevered Λ-shaped folding plate grid structures. Finally， an economic analysis of Λ-shaped folding plate grid structures was conducted. Focusing on the steel consumption of the top and bottom chords， the relationship between steel consumption and the form of the Λ-shape element was established.
2026, 56(6): 53-62.
doi: 10.3724/j.gyjzG24052601
Abstract:
The double-square-steel tubular buckling-restrained brace is a novel type of buckling-restrained brace composed of welded energy dissipation plates，inner tubes， and outer tubes，which can effectively avoid weak damage at the ends of buckling-restrained braces. In order to explore the hysteretic behavior of buckling-restrained braces with stainless steel energy dissipation plates，the energy-dissipating behavior of the braces was studied through quasi-static loading tests and finite element analysis.The test results showed that this type of brace exhibited significant hysteretic behavior. Under axial loading，the brace mainly depended on the plates’ entering the plasticity stage to dissipate energy. During loading， the tubes remained elastic，but local buckling occurred on the surfaces of the outer tubes.Compared with braces of the same size made of carbon steel Q235B plates，this brace exhibited better strength. Four algorithms of different plate arrangements were designed in order to study the effect of plate arrangement on the hysteretic behavior of this type of brace using ABAQUS.The optimal plate arrangement was determined based on the study. A finite element parametric analysis was carried on the brace with the optimal plate arrangement，analyzing the effects of the middle and terminal widths of the dissipation section on the plates， as well as the plate thickness， on the hysteretic behavior of the brace.The FEM results showed that changing the middle width of the energy dissipation section on the plates had a greater effect on the strength， stiffness， and energy dissipation capacity of the braces， while changing the terminal width of the dissipation section and the plate thickness had a lesser effect on the braces.
The double-square-steel tubular buckling-restrained brace is a novel type of buckling-restrained brace composed of welded energy dissipation plates，inner tubes， and outer tubes，which can effectively avoid weak damage at the ends of buckling-restrained braces. In order to explore the hysteretic behavior of buckling-restrained braces with stainless steel energy dissipation plates，the energy-dissipating behavior of the braces was studied through quasi-static loading tests and finite element analysis.The test results showed that this type of brace exhibited significant hysteretic behavior. Under axial loading，the brace mainly depended on the plates’ entering the plasticity stage to dissipate energy. During loading， the tubes remained elastic，but local buckling occurred on the surfaces of the outer tubes.Compared with braces of the same size made of carbon steel Q235B plates，this brace exhibited better strength. Four algorithms of different plate arrangements were designed in order to study the effect of plate arrangement on the hysteretic behavior of this type of brace using ABAQUS.The optimal plate arrangement was determined based on the study. A finite element parametric analysis was carried on the brace with the optimal plate arrangement，analyzing the effects of the middle and terminal widths of the dissipation section on the plates， as well as the plate thickness， on the hysteretic behavior of the brace.The FEM results showed that changing the middle width of the energy dissipation section on the plates had a greater effect on the strength， stiffness， and energy dissipation capacity of the braces， while changing the terminal width of the dissipation section and the plate thickness had a lesser effect on the braces.
2026, 56(6): 63-70.
doi: 10.3724/j.gyjzG24091501
Abstract:
To investigate the classification of stainless steel H-sections under cyclic loading， this study established models for austenitic and duplex stainless steel beams and beam-columns using ABAQUS finite element software， which verified the reasonableness of the finite element models based on the test results. Subsequently， an extensive parametric analysis was carried out to evaluate the applicability of the European stainless steel design code EN 1993-1-4， the Standard for Design of Steel Structures （GB 50017-2017）， and the Technical Specification for Stainless Steel Structures （CECS 410∶2015） with regard to the limits for the classification of H-sections. The results indicated that the current code results are conservative because they do not consider the effects of interaction constraints between the flange and web or material strengthening under cyclic loading. Finally， a methodology for classification of stainless steel H-sections under cyclic loading was proposed.
To investigate the classification of stainless steel H-sections under cyclic loading， this study established models for austenitic and duplex stainless steel beams and beam-columns using ABAQUS finite element software， which verified the reasonableness of the finite element models based on the test results. Subsequently， an extensive parametric analysis was carried out to evaluate the applicability of the European stainless steel design code EN 1993-1-4， the Standard for Design of Steel Structures （GB 50017-2017）， and the Technical Specification for Stainless Steel Structures （CECS 410∶2015） with regard to the limits for the classification of H-sections. The results indicated that the current code results are conservative because they do not consider the effects of interaction constraints between the flange and web or material strengthening under cyclic loading. Finally， a methodology for classification of stainless steel H-sections under cyclic loading was proposed.
2026, 56(6): 71-81.
doi: 10.3724/j.gyjzG24101705
Abstract:
To solve the problem of weak restraint capacity around the cross-section of square concrete-filled steel tubular（CFST） columns， this paper proposes incorporating multi-spiral stirrups inside the steel tube and study the axial compressive performance of this type of square column. Based on the existing experimental research， this study conducted numerical simulation analysis using the finite element software ABAQUS and verified the validity of the established finite element model for square CFST columns confined with multi-spiral stirrups. Based on this method， the finite element model of square CFST columns confined with five-spiral stirrups was established to further study the effects of stirrup spacing， stirrup diameter， stirrup strength， steel tube thickness， concrete strength， and other factors on their axial compressive performance. The results showed that the built-in five-spiral stirrups compensated for the weak restraint capacity of the square steel tube on the concrete in the middle of the periphery of the cross-section， and improved the bearing capacity and ductility of the square CFST column； under the same stirrup ratio by volume， the bearing capacity and ductility coefficient of CFST square columns confined with five-spiral stirrups were significantly higher than those of square CFST columns confined with single-spiral stirrups. In addition， the paper discussed the restraining mechanism of square CFST columns confined with multi-spiral stirrups and adopted the principle of strength superposition to derive the calculation formula for the axial compressive bearing capacity of square CFST columns confined with multi （single）-spiral stirrups.
To solve the problem of weak restraint capacity around the cross-section of square concrete-filled steel tubular（CFST） columns， this paper proposes incorporating multi-spiral stirrups inside the steel tube and study the axial compressive performance of this type of square column. Based on the existing experimental research， this study conducted numerical simulation analysis using the finite element software ABAQUS and verified the validity of the established finite element model for square CFST columns confined with multi-spiral stirrups. Based on this method， the finite element model of square CFST columns confined with five-spiral stirrups was established to further study the effects of stirrup spacing， stirrup diameter， stirrup strength， steel tube thickness， concrete strength， and other factors on their axial compressive performance. The results showed that the built-in five-spiral stirrups compensated for the weak restraint capacity of the square steel tube on the concrete in the middle of the periphery of the cross-section， and improved the bearing capacity and ductility of the square CFST column； under the same stirrup ratio by volume， the bearing capacity and ductility coefficient of CFST square columns confined with five-spiral stirrups were significantly higher than those of square CFST columns confined with single-spiral stirrups. In addition， the paper discussed the restraining mechanism of square CFST columns confined with multi-spiral stirrups and adopted the principle of strength superposition to derive the calculation formula for the axial compressive bearing capacity of square CFST columns confined with multi （single）-spiral stirrups.
2026, 56(6): 82-89.
doi: 10.3724/j.gyjzG24090502
Abstract:
In order to study the crack resistance of lightweight ultra-high perfor mance concrete（UHPC） ribbed panels， four UHPC ribbed panel models were designed and subjected to loading tests. The crack development patterns and failure modes of the specimens were analyzed. On this basis， finite element software was used to simulate the tests， and the effects of reinforcement ratio， yield strength of longitudinal tensile reinforcement， rib dimensions， UHPC compressive strength， and UHPC tensile strength on the cracking moment were analyzed. Combined with existing specifications， a calculation method for the cracking moment of lightweight UHPC ribbed panels was derived. The results showed that the cracking load was significantly affected by the reinforcement ratio， rib height， rib width， and UHPC tensile strength. A mong these factors， increasing the rib height had the greatest effect on improving the cracking load， followed by the reinforcement ratio， whereas the UHPC compressive strength and the yield strength of the reinforcement had almost no effect on the crack resistance. Based on the plane section assumption， the cracking moment of the lightweight UHPC ribbed panels was determined. The calculated values agreed well with the experimental measurements and finite element simulations， demonstrating high reliability， which can provide a reference for design and engineering applications.
In order to study the crack resistance of lightweight ultra-high perfor mance concrete（UHPC） ribbed panels， four UHPC ribbed panel models were designed and subjected to loading tests. The crack development patterns and failure modes of the specimens were analyzed. On this basis， finite element software was used to simulate the tests， and the effects of reinforcement ratio， yield strength of longitudinal tensile reinforcement， rib dimensions， UHPC compressive strength， and UHPC tensile strength on the cracking moment were analyzed. Combined with existing specifications， a calculation method for the cracking moment of lightweight UHPC ribbed panels was derived. The results showed that the cracking load was significantly affected by the reinforcement ratio， rib height， rib width， and UHPC tensile strength. A mong these factors， increasing the rib height had the greatest effect on improving the cracking load， followed by the reinforcement ratio， whereas the UHPC compressive strength and the yield strength of the reinforcement had almost no effect on the crack resistance. Based on the plane section assumption， the cracking moment of the lightweight UHPC ribbed panels was determined. The calculated values agreed well with the experimental measurements and finite element simulations， demonstrating high reliability， which can provide a reference for design and engineering applications.
2026, 56(6): 90-96.
doi: 10.3724/j.gyjzG24041102
Abstract:
In order to obtain a more accurate calculation method for the bearing capacity of angle steel bolt connections， experimental research on the tensile bearing capacity of angle steel single row bolt connection nodes was carried out. Firstly， 150 sets of uniaxial angle steel tensile tests were conducted to study the failure mode and tensile bearing capacity of single row one， single row two， and single row three angle steel bolt connection components， with a focus on evaluating the influence of end distance and spacing on the tensile bearing performance of angle steel.The results indicate that the angle steel undergoes compressive damage to the hole wall and tearing damage to the net section， and the end distance and spacing are important influencing factors on the tensile bearing capacity of the angle steel.The experimental results were compared with the corresponding calculation results of various national standards， and it was found that the Chinese standards considered fewer factors and could not reflect the actual bearing capacity. The European standards considered a comprehensive range of influencing factors but underestimated the actual bolt bearing capacity， while the American standards exaggerated the internal bolt strength and overestimated the bearing capacity of bolt connections.Finally， by fitting the experimental data， an empirical formula for the tensile bearing capacity of bolted angle steel joints was obtained， which improved the calculation accuracy.
In order to obtain a more accurate calculation method for the bearing capacity of angle steel bolt connections， experimental research on the tensile bearing capacity of angle steel single row bolt connection nodes was carried out. Firstly， 150 sets of uniaxial angle steel tensile tests were conducted to study the failure mode and tensile bearing capacity of single row one， single row two， and single row three angle steel bolt connection components， with a focus on evaluating the influence of end distance and spacing on the tensile bearing performance of angle steel.The results indicate that the angle steel undergoes compressive damage to the hole wall and tearing damage to the net section， and the end distance and spacing are important influencing factors on the tensile bearing capacity of the angle steel.The experimental results were compared with the corresponding calculation results of various national standards， and it was found that the Chinese standards considered fewer factors and could not reflect the actual bearing capacity. The European standards considered a comprehensive range of influencing factors but underestimated the actual bolt bearing capacity， while the American standards exaggerated the internal bolt strength and overestimated the bearing capacity of bolt connections.Finally， by fitting the experimental data， an empirical formula for the tensile bearing capacity of bolted angle steel joints was obtained， which improved the calculation accuracy.
2026, 56(6): 97-106.
doi: 10.3724/j.gyjzG24102802
Abstract:
When a concentrically braced steel frame structure is subjected to seismic fortification-level or rare earthquake action， the central brace often loses its bearing capacity due to the buckling instability of diagonal brace members under compression. To prevent brace instability， an energy-dissipating brace composed of a rectangular steel tube and perforated web plates is proposed. This brace not only retains the advantages of the central brace， but also incorporates the benefits of metal dampers. Under fortification-level earthquakes， the metal dampers installed at both ends of the square steel tube of the brace yield first and dissipate seismic energy， thus ensuring that the square steel tube of the brace remains in an elastic state at all times. A quasi-static loading test was conducted on an energy-dissipating brace. The effects of different arrangements of perforated energy-dissipation plates on the brace’s hysteretic performance， bearing capacity， stiffness degradation， and energy dissipation capacity were studied. The experimental results indicated that the brace was mainly dissipated by the yielding of the inter-perforation plate components of the energy-dissipating plate. The hysteresis curve of the specimen was full， demonstrating good energy dissipation capacity. During the loading process， the force-transmitting square steel tube of the energy dissipation brace always maintained elastic， but the brace failed due to the failure of the perforated web plate. Before the specimen lost its load-bearing capacity， there was no sudden decrease in strength or stiffness， and the brace did not become unstable during the loading process. Under cycles of the same magnitude， the brace's strength did not degrade significantly.
When a concentrically braced steel frame structure is subjected to seismic fortification-level or rare earthquake action， the central brace often loses its bearing capacity due to the buckling instability of diagonal brace members under compression. To prevent brace instability， an energy-dissipating brace composed of a rectangular steel tube and perforated web plates is proposed. This brace not only retains the advantages of the central brace， but also incorporates the benefits of metal dampers. Under fortification-level earthquakes， the metal dampers installed at both ends of the square steel tube of the brace yield first and dissipate seismic energy， thus ensuring that the square steel tube of the brace remains in an elastic state at all times. A quasi-static loading test was conducted on an energy-dissipating brace. The effects of different arrangements of perforated energy-dissipation plates on the brace’s hysteretic performance， bearing capacity， stiffness degradation， and energy dissipation capacity were studied. The experimental results indicated that the brace was mainly dissipated by the yielding of the inter-perforation plate components of the energy-dissipating plate. The hysteresis curve of the specimen was full， demonstrating good energy dissipation capacity. During the loading process， the force-transmitting square steel tube of the energy dissipation brace always maintained elastic， but the brace failed due to the failure of the perforated web plate. Before the specimen lost its load-bearing capacity， there was no sudden decrease in strength or stiffness， and the brace did not become unstable during the loading process. Under cycles of the same magnitude， the brace's strength did not degrade significantly.
2026, 56(6): 107-118.
doi: 10.3724/j.gyjzG24112103
Abstract:
An innovative sectional control-type steel brace （SCTS） was developed to fully utilize the advantages of traditional steel braces， such as their high stiffness， while effectively enhancing deformation and hysteretic performance， and addressing the construction inconveniences associated with traditional buckling-restrained braces. A numerical model of the SCTS was established adopting ABAQUS finite element software， and its accuracy was verified through a quasi-static test. The hysteretic performance of the SCTS was investigated in detail and compared with that of a traditional steel brace. A parametric study was conducted to analyze the influence of initial imperfection， length of the energy dissipation section， cross-sectional dimensions of the energy dissipation section， and cross-sectional dimensions of the elastic section on the hysteretic performance of the SCTS. The results showed that the SCTS exhibited excellent deformation capacity and hysteretic performance. The performance of the SCTS was not sensitive to variations in initial imperfection. As the length of the energy dissipation section decreased， the bearing capacity， stiffness， and energy dissipation capacity increased. However， an excessively short energy dissipation section could lead to premature failure of the SCTS. Therefore， it is recommended that the ratio of the combined length of the two end energy dissipation sections to the total length should be between 0.3 and 0.4. The hysteretic performance of the SCTS was most affectd by the cross-sectional dimensions of the energy dissipation section. Increasing these dimensions significantly enhanced the bearing capacity， stiffness， and energy dissipation capacity. Conversely， an overly large cross-section for the elastic section could lead to premature failure or stiffness degradation. Thus， the recommended ratio of the cross-sectional area of the energy dissipation section to that of the elastic section should be between 0.3 and 0.4.
An innovative sectional control-type steel brace （SCTS） was developed to fully utilize the advantages of traditional steel braces， such as their high stiffness， while effectively enhancing deformation and hysteretic performance， and addressing the construction inconveniences associated with traditional buckling-restrained braces. A numerical model of the SCTS was established adopting ABAQUS finite element software， and its accuracy was verified through a quasi-static test. The hysteretic performance of the SCTS was investigated in detail and compared with that of a traditional steel brace. A parametric study was conducted to analyze the influence of initial imperfection， length of the energy dissipation section， cross-sectional dimensions of the energy dissipation section， and cross-sectional dimensions of the elastic section on the hysteretic performance of the SCTS. The results showed that the SCTS exhibited excellent deformation capacity and hysteretic performance. The performance of the SCTS was not sensitive to variations in initial imperfection. As the length of the energy dissipation section decreased， the bearing capacity， stiffness， and energy dissipation capacity increased. However， an excessively short energy dissipation section could lead to premature failure of the SCTS. Therefore， it is recommended that the ratio of the combined length of the two end energy dissipation sections to the total length should be between 0.3 and 0.4. The hysteretic performance of the SCTS was most affectd by the cross-sectional dimensions of the energy dissipation section. Increasing these dimensions significantly enhanced the bearing capacity， stiffness， and energy dissipation capacity. Conversely， an overly large cross-section for the elastic section could lead to premature failure or stiffness degradation. Thus， the recommended ratio of the cross-sectional area of the energy dissipation section to that of the elastic section should be between 0.3 and 0.4.
2026, 56(6): 119-132.
doi: 10.3724/j.gyjzG24120304
Abstract:
Displacement amplification mechanisms for existing displacement-dependent dampers are typically arranged between the inter-story spaces of steel frames， but the inter-story displacement of the structure is limited， and such dampers exhibit significant residual deformation after experiencing large displacements. To address these issues， a displacement amplification device was combined with a friction-based self-resetting damper to propose the external displacement amplification self-resetting energy dissipation system （EDAS）， which is connected to the frame in an inter-story， externally mounted configuration on the building facade. The basic structure and working principle of EDAS were first introduced， and the formula for calculating the displacement amplification coefficients of EDAS was derived. Finite element models of steel frames with EDAS installed and traditional steel frame substructures were subsequently developed to compare their hysteretic performance. Through parametric analysis of the finite element model of the EDAS-installed steel frame substructure， the accuracy of the proposed displacement amplification coefficient formula was validated. The results show that EDAS can effectively enhance the energy dissipation capacity of friction-based self-resetting dampers， giving EDAS both high energy dissipation and self-resetting capabilities. Installing EDAS significantly improves the energy dissipation and post-earthquake residual deformation control of steel frames. The parametric analysis results confirm the high accuracy of the proposed displacement amplification coefficient formula.
Displacement amplification mechanisms for existing displacement-dependent dampers are typically arranged between the inter-story spaces of steel frames， but the inter-story displacement of the structure is limited， and such dampers exhibit significant residual deformation after experiencing large displacements. To address these issues， a displacement amplification device was combined with a friction-based self-resetting damper to propose the external displacement amplification self-resetting energy dissipation system （EDAS）， which is connected to the frame in an inter-story， externally mounted configuration on the building facade. The basic structure and working principle of EDAS were first introduced， and the formula for calculating the displacement amplification coefficients of EDAS was derived. Finite element models of steel frames with EDAS installed and traditional steel frame substructures were subsequently developed to compare their hysteretic performance. Through parametric analysis of the finite element model of the EDAS-installed steel frame substructure， the accuracy of the proposed displacement amplification coefficient formula was validated. The results show that EDAS can effectively enhance the energy dissipation capacity of friction-based self-resetting dampers， giving EDAS both high energy dissipation and self-resetting capabilities. Installing EDAS significantly improves the energy dissipation and post-earthquake residual deformation control of steel frames. The parametric analysis results confirm the high accuracy of the proposed displacement amplification coefficient formula.
2026, 56(6): 133-141.
doi: 10.3724/j.gyjzG24102106
Abstract:
To investigate the wind-induced vibrations of high-rise buildings under bidirectional fluid-structure interaction （FSI）， a Computational Fluid Dynamics （CFD） numerical simulation was conducted on a high-rise building characterized by an aspect ratio （width-to-height） of 1∶10. A three-dimensional finite element model of the building was established for modal analysis. By fitting the modal coordinates， modal shape functions were obtained. Subsequently， these modal shape functions were incorporated into a User-Defined Function （UDF） that combines the fourth-order Runge-Kutta method with the mode superposition technique. This UDF was utilized to derive the time-history data of the crosswind vibration displacement at the top of the building. The computational results were then compared with those from wind tunnel experiments， which demonstrated the validity of the computational approach employed. On this basis， a comparative analysis was conducted to examine the flow field distribution surrounding the building， the crosswind displacement response at the top of the building， and the energy interaction between the building and the flow field under both bidirectional and unidirectional FSI conditions. The results indicate that when the bidirectional FSI effect is accounted for， the vortex shedding at the building rear intensifies， accompanied by an increase in vortex size. Under bidirectional FSI， the crosswind displacement at the top decreases by approximately 15% compared to the rigid model and aligns more closely with wind tunnel data. During vortex-induced resonance， a notable phase difference discrepancy arises between the crosswind vibration response and the lift coefficient time-histories for bidirectional versus unidirectional FSI. The underlying mechanisms of unidirectional and bidirectional FSI differ substantially. Unidirectional FSI results exhibit significantly stronger regularity than their bidirectional counterparts. Owing to the mutual structure-fluid interaction， bidirectional FSI outcomes display a higher degree of randomness.
To investigate the wind-induced vibrations of high-rise buildings under bidirectional fluid-structure interaction （FSI）， a Computational Fluid Dynamics （CFD） numerical simulation was conducted on a high-rise building characterized by an aspect ratio （width-to-height） of 1∶10. A three-dimensional finite element model of the building was established for modal analysis. By fitting the modal coordinates， modal shape functions were obtained. Subsequently， these modal shape functions were incorporated into a User-Defined Function （UDF） that combines the fourth-order Runge-Kutta method with the mode superposition technique. This UDF was utilized to derive the time-history data of the crosswind vibration displacement at the top of the building. The computational results were then compared with those from wind tunnel experiments， which demonstrated the validity of the computational approach employed. On this basis， a comparative analysis was conducted to examine the flow field distribution surrounding the building， the crosswind displacement response at the top of the building， and the energy interaction between the building and the flow field under both bidirectional and unidirectional FSI conditions. The results indicate that when the bidirectional FSI effect is accounted for， the vortex shedding at the building rear intensifies， accompanied by an increase in vortex size. Under bidirectional FSI， the crosswind displacement at the top decreases by approximately 15% compared to the rigid model and aligns more closely with wind tunnel data. During vortex-induced resonance， a notable phase difference discrepancy arises between the crosswind vibration response and the lift coefficient time-histories for bidirectional versus unidirectional FSI. The underlying mechanisms of unidirectional and bidirectional FSI differ substantially. Unidirectional FSI results exhibit significantly stronger regularity than their bidirectional counterparts. Owing to the mutual structure-fluid interaction， bidirectional FSI outcomes display a higher degree of randomness.
2026, 56(6): 142-151.
doi: 10.3724/j.gyjzG24041012
Abstract:
This study investigates fatigue crack propagation at critical locations of a crane truss under repeated loading. A solid element model of the truss was developed in ABAQUS， and multiple fatigue-critical locations were analyzed in conjunction with FRANC3D crack analysis software. Key parameters， including the geometric dimensions of crack defects， crack propagation area， model mesh size， and Paris' law coefficients， were determined. Fatigue crack propagation simulations and fatigue life predictions were conducted for four critical locations， with analysis of the factors leading to the final crack morphology. Parametric analysis was carried out to examine the influence of crack geometry， crack shape， and initial crack angle on fatigue life.The results showed that as the initial crack size increased， the fatigue life decreased. For thin plate components， the crack shapes were mainly semi-elliptical or long straight. The difference between the two types of crack shapes would not have a significant impact on fatigue life. When the crack angle θ was less than -20°， the fatigue life increased sharply with the increase of the crack angle.
This study investigates fatigue crack propagation at critical locations of a crane truss under repeated loading. A solid element model of the truss was developed in ABAQUS， and multiple fatigue-critical locations were analyzed in conjunction with FRANC3D crack analysis software. Key parameters， including the geometric dimensions of crack defects， crack propagation area， model mesh size， and Paris' law coefficients， were determined. Fatigue crack propagation simulations and fatigue life predictions were conducted for four critical locations， with analysis of the factors leading to the final crack morphology. Parametric analysis was carried out to examine the influence of crack geometry， crack shape， and initial crack angle on fatigue life.The results showed that as the initial crack size increased， the fatigue life decreased. For thin plate components， the crack shapes were mainly semi-elliptical or long straight. The difference between the two types of crack shapes would not have a significant impact on fatigue life. When the crack angle θ was less than -20°， the fatigue life increased sharply with the increase of the crack angle.
2026, 56(6): 152-161.
doi: 10.3724/j.gyjzG24120901
Abstract:
To address the fatigue cracking phenomenon in the connection weld between the upper flange and the web of steel crane beams， a statistical analysis was conducted on actual engineering cases involving such fatigue cracking. Taking a crane beam from a steel plant as the research subject， the rainflow counting method was used to measure the equivalent coefficient of underload effects， and the strain time history and statistical results of stress cycle counts are obtained. Based on finite element models under different eccentric loads， the stress distribution in the crane beam under fatigue loading with varying eccentricities was compared and analyzed. Additionally， the fatigue strength of the crane beam under different web thickness conditions was verified. The results indicate that eccentric loading adversely affects the fatigue performance of steel crane beam webs. Increasing web thickness significantly reduces the shear stress level in the web and enhances the overall fatigue strength of the beam. In future fatigue design of steel crane girders， eccentric loading should be taken into account， and it is recommended to moderately increase the web thickness.
To address the fatigue cracking phenomenon in the connection weld between the upper flange and the web of steel crane beams， a statistical analysis was conducted on actual engineering cases involving such fatigue cracking. Taking a crane beam from a steel plant as the research subject， the rainflow counting method was used to measure the equivalent coefficient of underload effects， and the strain time history and statistical results of stress cycle counts are obtained. Based on finite element models under different eccentric loads， the stress distribution in the crane beam under fatigue loading with varying eccentricities was compared and analyzed. Additionally， the fatigue strength of the crane beam under different web thickness conditions was verified. The results indicate that eccentric loading adversely affects the fatigue performance of steel crane beam webs. Increasing web thickness significantly reduces the shear stress level in the web and enhances the overall fatigue strength of the beam. In future fatigue design of steel crane girders， eccentric loading should be taken into account， and it is recommended to moderately increase the web thickness.
2026, 56(6): 162-169.
doi: 10.3724/j.gyjzG24102504
Abstract:
The under-construction medium-bearing space Y-shaped steel box-rib arch bridge is the first of its kind in China as a new type of shaped arch bridge. This paper takes the most important structural tower system in its cable lifting construction as the background， and increases the transverse width of the tower to 47.6 m by adjusting the setting of universal bars on the basis of the conventional tower to form an extra-wide tower， and uses the analytical method and finite element analysis method to establish the SAP 2000 numerical model to analyze the overall and internal components of the integrated system of cable and buckle tower for stiffness， strength and stability refinement to verify whether the extra-wide tower has good mechanical performance. The analytical formula for the force of the lifting cable on the tower is given， and the force of the lifting cable on the tower is calculated by this formula. Considering the wind cable as a spring unit capable of withstanding tension and compression， formulas are given for converting the spring stiffness and for calculating the strain value corresponding to the initial tension of the wind cable. Design recommendations are given for wind cables and tower rods settings： after setting a certain initial tension of wind cable， it can effectively reduce the non-linear effect of wind cable drape and increase its restraining effect on the tower， and can pre-deflect the tower by the initial tension of wind cable to achieve the purpose of making the maximum forward and backward displacement of the tower tend to be close. The universal rod webs have a small radius of inertia in the direction of the weak axis and a relatively large length and slenderness， so the stress increase after considering the stability is large and should be given attention when designing.
The under-construction medium-bearing space Y-shaped steel box-rib arch bridge is the first of its kind in China as a new type of shaped arch bridge. This paper takes the most important structural tower system in its cable lifting construction as the background， and increases the transverse width of the tower to 47.6 m by adjusting the setting of universal bars on the basis of the conventional tower to form an extra-wide tower， and uses the analytical method and finite element analysis method to establish the SAP 2000 numerical model to analyze the overall and internal components of the integrated system of cable and buckle tower for stiffness， strength and stability refinement to verify whether the extra-wide tower has good mechanical performance. The analytical formula for the force of the lifting cable on the tower is given， and the force of the lifting cable on the tower is calculated by this formula. Considering the wind cable as a spring unit capable of withstanding tension and compression， formulas are given for converting the spring stiffness and for calculating the strain value corresponding to the initial tension of the wind cable. Design recommendations are given for wind cables and tower rods settings： after setting a certain initial tension of wind cable， it can effectively reduce the non-linear effect of wind cable drape and increase its restraining effect on the tower， and can pre-deflect the tower by the initial tension of wind cable to achieve the purpose of making the maximum forward and backward displacement of the tower tend to be close. The universal rod webs have a small radius of inertia in the direction of the weak axis and a relatively large length and slenderness， so the stress increase after considering the stability is large and should be given attention when designing.
2026, 56(6): 170-177.
doi: 10.3724/j.gyjzG24080105
Abstract:
As a key component of load transfer in the joint components of the disc-buckled steel tube scaffold， the disc plays a decisive role in the overall stability. However， when multiple bending crossbars are connected simultaneously， stress concentration occurs in the disc， leading to a reduction in the joint stiffness value.To improve the stiffness value and flexural capacity of the disc， this paper explored material distribution in the disc that can maintain the stiffness value through topology optimization， followed by an optimized design of the disc. A trilinear model and a cubic B-spline mathematical fitting method were applied for numerical fitting， the feasibility of the optimization scheme was verified， and the bending moment values for the scaffold joints entering the elastic-plastic stage under different numbers of crossbar connections were proposed. The results showed that the moment of inertia of the contact section between the disc and the lock had a significant influence on the joint stiffness value. The optimized design of Disc 1 increased the stiffness value by 2%-3%， 19%-23%， and 13%-19% in the three stages of the trilinear model， respectively， and raised the bending moment value by 7.5%. The optimized design of Disc 2 increased the stiffness value by 4%-6%， 29%-37%， and 20%-26% in the three stages of the trilinear model， respectively， with a notable enhancement in the ultimate bearing capacity. As the number of crossbars increased， the bending moment at which the joints entered the elastic-plastic stage decreased. Specifically， the values were 0.6 kN·m， 0.5 kN·m， and 0.4 kN·m for the joints connected with one， two （right-angled）， and four crossbars， respectively. Therefore， it is recommended to avoid joints with multiple connected crossbars in scaffold construction.
As a key component of load transfer in the joint components of the disc-buckled steel tube scaffold， the disc plays a decisive role in the overall stability. However， when multiple bending crossbars are connected simultaneously， stress concentration occurs in the disc， leading to a reduction in the joint stiffness value.To improve the stiffness value and flexural capacity of the disc， this paper explored material distribution in the disc that can maintain the stiffness value through topology optimization， followed by an optimized design of the disc. A trilinear model and a cubic B-spline mathematical fitting method were applied for numerical fitting， the feasibility of the optimization scheme was verified， and the bending moment values for the scaffold joints entering the elastic-plastic stage under different numbers of crossbar connections were proposed. The results showed that the moment of inertia of the contact section between the disc and the lock had a significant influence on the joint stiffness value. The optimized design of Disc 1 increased the stiffness value by 2%-3%， 19%-23%， and 13%-19% in the three stages of the trilinear model， respectively， and raised the bending moment value by 7.5%. The optimized design of Disc 2 increased the stiffness value by 4%-6%， 29%-37%， and 20%-26% in the three stages of the trilinear model， respectively， with a notable enhancement in the ultimate bearing capacity. As the number of crossbars increased， the bending moment at which the joints entered the elastic-plastic stage decreased. Specifically， the values were 0.6 kN·m， 0.5 kN·m， and 0.4 kN·m for the joints connected with one， two （right-angled）， and four crossbars， respectively. Therefore， it is recommended to avoid joints with multiple connected crossbars in scaffold construction.
2026, 56(6): 178-186.
doi: 10.3724/j.gyjzG24071805
Abstract:
In recent years， prefabricated construction has demonstrated significant development potential. The grouted sleeve method， as the most commonly used technique for connecting prefabricated components， often encounters issues such as incomplete grout filling at joints， low grout strength， and the cutoff of embedded rebars， all of which compromise structural safety. To address these challenges， a novel connection method for prefabricated components was proposed， and its mechanical properties were validated through flexural and shear tests. The following conclusions were derived from this study： 1） In terms of flexural performance， the ultimate bending load of the sleeve-connected prefabricated beam was reduced by 8.8% compared to that of the monolithic beam， while the ultimate load of the sleeve-connected reinforced prefabricated beam was increased by 23%. Regarding shear performance， the sleeve-connected reinforced prefabricated beam exhibited the highest shear capacity， with differences among the three beams within 5%. 2） The strain values of longitudinal reinforcement at different positions along the beam showed minimal variation. These values exhibited a non-linear pattern at the initial load stage， transitioned to a linear relationship， and reverted to non-linear behavior with further load increase. 3） Under loading， the deflection of the sleeve-connected prefabricated beam increased the fastest， followed by the monolithic beam， while the sleeve-connected reinforced prefabricated beam showed the slowest increase. The analysis demonstrated that the reverse-rotation locking sleeve connection method meets all engineering requirements for both flexural and shear performance as a prefabricated beam joint solution. Furthermore， this method significantly simplifies construction， enhances operational efficiency， and holds substantial practical value.
In recent years， prefabricated construction has demonstrated significant development potential. The grouted sleeve method， as the most commonly used technique for connecting prefabricated components， often encounters issues such as incomplete grout filling at joints， low grout strength， and the cutoff of embedded rebars， all of which compromise structural safety. To address these challenges， a novel connection method for prefabricated components was proposed， and its mechanical properties were validated through flexural and shear tests. The following conclusions were derived from this study： 1） In terms of flexural performance， the ultimate bending load of the sleeve-connected prefabricated beam was reduced by 8.8% compared to that of the monolithic beam， while the ultimate load of the sleeve-connected reinforced prefabricated beam was increased by 23%. Regarding shear performance， the sleeve-connected reinforced prefabricated beam exhibited the highest shear capacity， with differences among the three beams within 5%. 2） The strain values of longitudinal reinforcement at different positions along the beam showed minimal variation. These values exhibited a non-linear pattern at the initial load stage， transitioned to a linear relationship， and reverted to non-linear behavior with further load increase. 3） Under loading， the deflection of the sleeve-connected prefabricated beam increased the fastest， followed by the monolithic beam， while the sleeve-connected reinforced prefabricated beam showed the slowest increase. The analysis demonstrated that the reverse-rotation locking sleeve connection method meets all engineering requirements for both flexural and shear performance as a prefabricated beam joint solution. Furthermore， this method significantly simplifies construction， enhances operational efficiency， and holds substantial practical value.
2026, 56(6): 187-194.
doi: 10.3724/j.gyjzG26011404
Abstract:
With the deepening application of Building Information Modeling （BIM） throughout the lifecycle of construction projects， achieving efficient and high-fidelity data exchange between BIM platforms and finite element analysis （FEA） software has become a critical step toward intelligent structural design. However， conventional data exchange methods often suffer from information loss and insufficient automation in the transfer of geometric data， material property mapping， inheritance of loading and boundary conditions， and representation of structural connectivity. To address these challenges， this study proposed and implemented a direct model conversion interface method based on the Revit API and ANSYS APDL （ANSYS Parametric Design Language） command scripts. The method employed C#-based secondary development of the Revit platform to accurately extract key information from structural components， including spatial geometry， material properties， load cases， and constraint conditions. These data were then transformed into executable APDL scripts for ANSYS， enabling full automation of the finite element modeling， solution process， and post-processing result extraction. This method was validated through a multi-stage construction simulation of a high-rise steel-concrete composite structure. The results demonstrate that the proposed interface effectively maintains information consistency between the BIM and FEA models， significantly improves modeling efficiency and analysis accuracy， and yields stress results in good agreement with those from MIDAS/Gen， with a maximum relative error within 10%.
With the deepening application of Building Information Modeling （BIM） throughout the lifecycle of construction projects， achieving efficient and high-fidelity data exchange between BIM platforms and finite element analysis （FEA） software has become a critical step toward intelligent structural design. However， conventional data exchange methods often suffer from information loss and insufficient automation in the transfer of geometric data， material property mapping， inheritance of loading and boundary conditions， and representation of structural connectivity. To address these challenges， this study proposed and implemented a direct model conversion interface method based on the Revit API and ANSYS APDL （ANSYS Parametric Design Language） command scripts. The method employed C#-based secondary development of the Revit platform to accurately extract key information from structural components， including spatial geometry， material properties， load cases， and constraint conditions. These data were then transformed into executable APDL scripts for ANSYS， enabling full automation of the finite element modeling， solution process， and post-processing result extraction. This method was validated through a multi-stage construction simulation of a high-rise steel-concrete composite structure. The results demonstrate that the proposed interface effectively maintains information consistency between the BIM and FEA models， significantly improves modeling efficiency and analysis accuracy， and yields stress results in good agreement with those from MIDAS/Gen， with a maximum relative error within 10%.
2026, 56(6): 195-203.
doi: 10.3724/j.gyjzG24102108
Abstract:
Combined with the characteristics of nuclear power tunnels， such as large burial depths and heavy loads， and the needs for assembly and modularization， the company has optimized a series of key technologies for the structural form of composite slab utility tunnels， component processing， and on-site assembly and construction in nuclear power engineering， thereby developing a new type of reinforced concrete composite slab utility tunnel for nuclear power projects. Regarding the key load-bearing members of the designed composite slab utility tunnel structural system， a full-scale test was first conducted on a single prefabricated slab specimen. The test investigated the crack initiation and propagation， deformation development， failure mode， and ultimate bearing capacity throughout the loading process. The test results demonstrated that the failure mode of the prefabricated slab was bending failure， and its ultimate bearing capacity and crack resistance fully satisfied the requirements of both the construction and use phases. Subsequently， an experimental study was conducted on four full-scale corbel specimens. The crack propagation process， failure mode， reinforcement stress， and ultimate bearing capacity of the corbel specimens were thoroughly investigated， with a focus on the influence and underlying mechanisms of different tensile reinforcement anchorage forms and horizontal stirrup arrangements on the cracking load， crack width， and ultimate load. The test results showed that， for the same anchorage length， bent anchorages exhibited superior performance compared to horizontal anchorages. The bent anchorage enhanced the cracking load and restrained crack propagation， while the arrangement of horizontal stirrups significantly improved the ultimate load.
Combined with the characteristics of nuclear power tunnels， such as large burial depths and heavy loads， and the needs for assembly and modularization， the company has optimized a series of key technologies for the structural form of composite slab utility tunnels， component processing， and on-site assembly and construction in nuclear power engineering， thereby developing a new type of reinforced concrete composite slab utility tunnel for nuclear power projects. Regarding the key load-bearing members of the designed composite slab utility tunnel structural system， a full-scale test was first conducted on a single prefabricated slab specimen. The test investigated the crack initiation and propagation， deformation development， failure mode， and ultimate bearing capacity throughout the loading process. The test results demonstrated that the failure mode of the prefabricated slab was bending failure， and its ultimate bearing capacity and crack resistance fully satisfied the requirements of both the construction and use phases. Subsequently， an experimental study was conducted on four full-scale corbel specimens. The crack propagation process， failure mode， reinforcement stress， and ultimate bearing capacity of the corbel specimens were thoroughly investigated， with a focus on the influence and underlying mechanisms of different tensile reinforcement anchorage forms and horizontal stirrup arrangements on the cracking load， crack width， and ultimate load. The test results showed that， for the same anchorage length， bent anchorages exhibited superior performance compared to horizontal anchorages. The bent anchorage enhanced the cracking load and restrained crack propagation， while the arrangement of horizontal stirrups significantly improved the ultimate load.
2026, 56(6): 204-210.
doi: 10.3724/j.gyjzG25011301
Abstract:
To address the challenge of quantitatively exerting bolt pre-tightening force in roadway support and to clarify the control effect on surrounding rock under different combinations of anchorage length and pre-tightening force， a self-retracting pre-tightening force quantitative exerting device was developed， and four field comparative tests of different bolt anchorage length and pre-tightening force combinations were designed and carried out. The results showed that the device exhibited a deviation of less than 4% between the design and actual pre-tightening force values in laboratory tests and less than 10% in field tests， demonstrating that it met all operational requirements. The bolt stress evolution exhibited three distinct stages： a rapid increase， a slow increase， and a stabilization stage， which was basically consistent with the deformation behavior of the surrounding rock. Furthermore， the measured average values of the anchorage agent installation fell below the design values. The loss rate of the anchorage length increased with a higher deformation rate of the surrounding rock. This loss essentially ceased as the deformation tended to stabilize. When the anchorage length remained constant， doubling the pre-tightening force resulted in a reductions in surrounding rock deformation of 40% and 35% in the respective tests， demonstrating a significant control effect. When a pre-tension force of 60 kN was applied and the anchorage length was reduced by 0.4 meters， the deviation in surrounding rock deformation maintained within 16%. This confirmed that increasing the pre-tension force significantly enhanced surrounding rock stability. The experimental results indicated that a moderate reduction in anchorage length， under specific conditions， did not significantly affect the support effect of the surrounding rock， which is consistent with existing research conclusions.
To address the challenge of quantitatively exerting bolt pre-tightening force in roadway support and to clarify the control effect on surrounding rock under different combinations of anchorage length and pre-tightening force， a self-retracting pre-tightening force quantitative exerting device was developed， and four field comparative tests of different bolt anchorage length and pre-tightening force combinations were designed and carried out. The results showed that the device exhibited a deviation of less than 4% between the design and actual pre-tightening force values in laboratory tests and less than 10% in field tests， demonstrating that it met all operational requirements. The bolt stress evolution exhibited three distinct stages： a rapid increase， a slow increase， and a stabilization stage， which was basically consistent with the deformation behavior of the surrounding rock. Furthermore， the measured average values of the anchorage agent installation fell below the design values. The loss rate of the anchorage length increased with a higher deformation rate of the surrounding rock. This loss essentially ceased as the deformation tended to stabilize. When the anchorage length remained constant， doubling the pre-tightening force resulted in a reductions in surrounding rock deformation of 40% and 35% in the respective tests， demonstrating a significant control effect. When a pre-tension force of 60 kN was applied and the anchorage length was reduced by 0.4 meters， the deviation in surrounding rock deformation maintained within 16%. This confirmed that increasing the pre-tension force significantly enhanced surrounding rock stability. The experimental results indicated that a moderate reduction in anchorage length， under specific conditions， did not significantly affect the support effect of the surrounding rock， which is consistent with existing research conclusions.
2026, 56(6): 211-216.
doi: 10.3724/j.gyjzG25012402
Abstract:
During deformation monitoring by a measuring robot， the measurement signal drifts due to meteorological factors， resulting in significant measurement errors. If raw data are directly exported as final monitoring results， this will lead to wide deformation fitting intervals and low monitoring accuracy. To address this issue， this paper proposes a method for deformation monitoring in complex tunnel construction environments using measuring robots. This method utilizes measuring robots to conduct high-precision measurements and effectively eliminates errors induced by meteorological factors through differential correction technology. The differentially corrected measurement values serve as the observation input for the Kalman filtering algorithm to dynamically estimate and predict the deformation states of the tunnel. Data containing tunnel deformation predictions are taken as feature vectors and combined with a Long Short-Term Memory （LSTM） network to calculate dynamic early warning risk values. The test results showed that the proposed method achieved a significantly narrower deformation fitting interval and more reliable monitoring accuracy.
During deformation monitoring by a measuring robot， the measurement signal drifts due to meteorological factors， resulting in significant measurement errors. If raw data are directly exported as final monitoring results， this will lead to wide deformation fitting intervals and low monitoring accuracy. To address this issue， this paper proposes a method for deformation monitoring in complex tunnel construction environments using measuring robots. This method utilizes measuring robots to conduct high-precision measurements and effectively eliminates errors induced by meteorological factors through differential correction technology. The differentially corrected measurement values serve as the observation input for the Kalman filtering algorithm to dynamically estimate and predict the deformation states of the tunnel. Data containing tunnel deformation predictions are taken as feature vectors and combined with a Long Short-Term Memory （LSTM） network to calculate dynamic early warning risk values. The test results showed that the proposed method achieved a significantly narrower deformation fitting interval and more reliable monitoring accuracy.
2026, 56(6): 217-228.
doi: 10.3724/j.gyjzG24112901
Abstract:
To investigate the uplift bearing performance of helical anchors in self-weight collapsible loess， in-situ experiments and CEL numerical simulations were conducted on helical anchors embedded in collapsible loess， based on an ultra-high voltage project. This study revealed the force-displacement relationship of helical anchors under uplift load in collapsible loess， clarified the stress and strain distribution patterns of the soil surrounding the helical plates， and elucidated how these patterns varied with the spacing between helical plates. Furthermore， the failure modes of helical anchors in collapsible loess were identified， and a bearing capacity calculation formula tailored to different displacement control conditions was established. The results indicated that when the limit state of helical anchors was governed by displacement， the contribution of soil internal friction angle to bearing capacity could be neglected. During uplift， the maximum strain initially occurred in the bottom helical plate， followed by the intermediate helical plate， and gradually extended upward to encompass the entire region. When the spacing between helical plates was 1D（D=anchor plate diameter）， the helical anchor experienced overall shear failure of the soil between plates. Conversely， at a spacing of 3D， independent failure of individual helical plates occurred. At a spacing of 2D， the failure mode of the helical anchor lay between these two extremes. The bearing capacity calculated using the overall shear method for soil between helical plates agreed well with the experimental bearing capacity determined by the 10%D method. Additionally， the minimum calculated bearing capacity， which incorporates both the overall shear failure of soil between helical plates and local failure of soil around helical plates， agreed well with the experimental bearing capacity determined by a 50 mm displacement criterion.
To investigate the uplift bearing performance of helical anchors in self-weight collapsible loess， in-situ experiments and CEL numerical simulations were conducted on helical anchors embedded in collapsible loess， based on an ultra-high voltage project. This study revealed the force-displacement relationship of helical anchors under uplift load in collapsible loess， clarified the stress and strain distribution patterns of the soil surrounding the helical plates， and elucidated how these patterns varied with the spacing between helical plates. Furthermore， the failure modes of helical anchors in collapsible loess were identified， and a bearing capacity calculation formula tailored to different displacement control conditions was established. The results indicated that when the limit state of helical anchors was governed by displacement， the contribution of soil internal friction angle to bearing capacity could be neglected. During uplift， the maximum strain initially occurred in the bottom helical plate， followed by the intermediate helical plate， and gradually extended upward to encompass the entire region. When the spacing between helical plates was 1D（D=anchor plate diameter）， the helical anchor experienced overall shear failure of the soil between plates. Conversely， at a spacing of 3D， independent failure of individual helical plates occurred. At a spacing of 2D， the failure mode of the helical anchor lay between these two extremes. The bearing capacity calculated using the overall shear method for soil between helical plates agreed well with the experimental bearing capacity determined by the 10%D method. Additionally， the minimum calculated bearing capacity， which incorporates both the overall shear failure of soil between helical plates and local failure of soil around helical plates， agreed well with the experimental bearing capacity determined by a 50 mm displacement criterion.
2026, 56(6): 229-236.
doi: 10.3724/j.gyjzG25110607
Abstract:
Onshore wind turbine foundations are currently constructed using cast-in-place methods， which involve prolonged construction periods， extensive on-site wet operations， and significant environmental pollution， thereby hindering the sustainable development of the wind power industry. In contrast， prefabricated raft foundations adopt a factory-precast and on-site rapid assembly method， which significantly shortens on-site construction time， simplifies construction processes， and reduces site pollution. This approach offers an efficient and eco-friendly solution for onshore wind turbine foundations. This study systematically conducted the structural configurations and research status of both partially prefabricated and fully prefabricated raft foundations. Their mechanical characteristics， including load-transfer mechanisms， connection behaviors， and failure modes， were analyzed. Furthermore， the influence of complex loading conditions， specific site properties， and structural detailing on the mechanical properties was investigated. Future research directions were proposed to advance the development of prefabricated raft foundations for wind turbine foundation engineering.
Onshore wind turbine foundations are currently constructed using cast-in-place methods， which involve prolonged construction periods， extensive on-site wet operations， and significant environmental pollution， thereby hindering the sustainable development of the wind power industry. In contrast， prefabricated raft foundations adopt a factory-precast and on-site rapid assembly method， which significantly shortens on-site construction time， simplifies construction processes， and reduces site pollution. This approach offers an efficient and eco-friendly solution for onshore wind turbine foundations. This study systematically conducted the structural configurations and research status of both partially prefabricated and fully prefabricated raft foundations. Their mechanical characteristics， including load-transfer mechanisms， connection behaviors， and failure modes， were analyzed. Furthermore， the influence of complex loading conditions， specific site properties， and structural detailing on the mechanical properties was investigated. Future research directions were proposed to advance the development of prefabricated raft foundations for wind turbine foundation engineering.
2026, 56(6): 237-246.
doi: 10.3724/j.gyjzG26010902
Abstract:
To investigate the bond behavior of reinforcing bars embedded in full lightweight shale ceramsite concrete， thirty beam specimens were tested to examine the effects of concrete strength， cover thickness， bar diameter， surface configuration， and anchorage length. The results indicate that specimens reinforced with plain bars mainly fail by synchronous pull-out， whereas those with low-strength concrete or thin cover tend to exhibit a mixed pull-out-splitting failure， while specimens made with medium- to high-strength concrete predominantly undergo brittle splitting characterized by load-slip curves with only an ascending branch. The ultimate bond strength of plain round steel bars is significantly lower than that of ribbed steel bars of the same diameter.For pull-out failure specimens， it decreases as the concrete cover thickness increases； for splitting failure specimens， it increases with the cover thickness， and decreases with an increase in bar diameter. Bond stress is non-uniformly distributed along the anchorage length， with greater cover thickness and higher concrete strength promoting more uniform stress transfer， while bar diameter and anchorage length significantly influence both the peak bond stress and its distribution pattern.
To investigate the bond behavior of reinforcing bars embedded in full lightweight shale ceramsite concrete， thirty beam specimens were tested to examine the effects of concrete strength， cover thickness， bar diameter， surface configuration， and anchorage length. The results indicate that specimens reinforced with plain bars mainly fail by synchronous pull-out， whereas those with low-strength concrete or thin cover tend to exhibit a mixed pull-out-splitting failure， while specimens made with medium- to high-strength concrete predominantly undergo brittle splitting characterized by load-slip curves with only an ascending branch. The ultimate bond strength of plain round steel bars is significantly lower than that of ribbed steel bars of the same diameter.For pull-out failure specimens， it decreases as the concrete cover thickness increases； for splitting failure specimens， it increases with the cover thickness， and decreases with an increase in bar diameter. Bond stress is non-uniformly distributed along the anchorage length， with greater cover thickness and higher concrete strength promoting more uniform stress transfer， while bar diameter and anchorage length significantly influence both the peak bond stress and its distribution pattern.
2026, 56(6): 247-255.
doi: 10.3724/j.gyjzG24111906
Abstract:
To address the issue of slow hydration and prolonged setting time in ultra-high performance concrete （UHPC），which often lead to extended construction schedules， increased curing costs， and insufficient early-age strength， this study investigated the effects of incorporating accelerators （AC）， binary blends with sulfoaluminate cement （SAC）， substituting sintered bauxite （CB） aggregates， and combinations of these three materials （external-binary， external-substitution， binary-substitution， and external-binary-substitution） on the flowability， setting time， and mechanical properties of UHPC. The results indicated that incorporating 5% SAC and substituting 400 kg/m³ CB aggregates achieved controlled setting time， good workability， and excellent mechanical properties in UHPC. The initial and final setting times decreased to 59 min and 80 min， respectively， the expansion degree decreased by 39.3%， and the compressive strength increased significantly at 1， 7， and 28 days， with a maximum growth rate of 20%. The flexural strength did not increase significantly. However， excessive SAC content （≥5%） significantly increased the risk of autogenous shrinkage and cracking in UHPC and decreased its 28-day impact resistance. This rapid-setting UHPC is suitable for construction scenarios with stringent requirements on setting time， such as rapid repair and reinforcement， enhanced production efficiency of prefabricated components， and emergency engineering repairs in disaster situations.
To address the issue of slow hydration and prolonged setting time in ultra-high performance concrete （UHPC），which often lead to extended construction schedules， increased curing costs， and insufficient early-age strength， this study investigated the effects of incorporating accelerators （AC）， binary blends with sulfoaluminate cement （SAC）， substituting sintered bauxite （CB） aggregates， and combinations of these three materials （external-binary， external-substitution， binary-substitution， and external-binary-substitution） on the flowability， setting time， and mechanical properties of UHPC. The results indicated that incorporating 5% SAC and substituting 400 kg/m³ CB aggregates achieved controlled setting time， good workability， and excellent mechanical properties in UHPC. The initial and final setting times decreased to 59 min and 80 min， respectively， the expansion degree decreased by 39.3%， and the compressive strength increased significantly at 1， 7， and 28 days， with a maximum growth rate of 20%. The flexural strength did not increase significantly. However， excessive SAC content （≥5%） significantly increased the risk of autogenous shrinkage and cracking in UHPC and decreased its 28-day impact resistance. This rapid-setting UHPC is suitable for construction scenarios with stringent requirements on setting time， such as rapid repair and reinforcement， enhanced production efficiency of prefabricated components， and emergency engineering repairs in disaster situations.
2026, 56(6): 256-264.
doi: 10.3724/j.gyjzG24082707
Abstract:
As a low-carbon and eco-friendly cementitious material， geopolymer exhibits excellent mechanical properties and is an ideal substitute for cement in high-strength concrete. However， elevated temperatures degrade the performance of concrete， compromising structural safety. This study investigated the mechanical properties of high-strength geopolymer concrete （HGPC） under uniaxial compression， considering temperature （20 ℃， 200 ℃， 400 ℃， and 600 ℃） and concrete strength grade （C70， C80） as variables. The results indicated that the failure mode of HGPC shifted from aggregate penetration to failure at the interfacial transition zone， accompanied by significant mass and strength loss. At 600 ℃， the mass loss rate reached 6.8%， whilef c u T / f c u 20 f c T / f c u T
As a low-carbon and eco-friendly cementitious material， geopolymer exhibits excellent mechanical properties and is an ideal substitute for cement in high-strength concrete. However， elevated temperatures degrade the performance of concrete， compromising structural safety. This study investigated the mechanical properties of high-strength geopolymer concrete （HGPC） under uniaxial compression， considering temperature （20 ℃， 200 ℃， 400 ℃， and 600 ℃） and concrete strength grade （C70， C80） as variables. The results indicated that the failure mode of HGPC shifted from aggregate penetration to failure at the interfacial transition zone， accompanied by significant mass and strength loss. At 600 ℃， the mass loss rate reached 6.8%， while
2026, 56(6): 265-272.
doi: 10.3724/j.gyjzG24070701
Abstract:
In order to describe the changes in water content during the hydration process of cement-based materials， a monitoring system for the dielectric constant of cement-based materials was established based on the theory of parallel plate capacitance. The relationship between the dielectric constant and water content was investigated， and the effects of water-cement ratios and mineral admixtures such as fly ash， silica fume， and slag on the hydration water consumption were analyzed. The results indicated that the dielectric constant-based method was reasonable and accurate for determining water content. During the hydration of cement-based materials， the water content decreased rapidly at first， and then the rate of decrease slowed down. A higher water-cement ratio accelerated the early hydration rate and prolonged the hydration duration， which was characterized by a higher rate of water consumption. The incorporation of fly ash into the cement system reduced the water consumption rate as its dosage increased， whereas silica fume exhibited the opposite effect. Although slag generally enhanced the hydration rate and increased water consumption， a higher dosage of slag ultimately led to a reduction in water consumption.
In order to describe the changes in water content during the hydration process of cement-based materials， a monitoring system for the dielectric constant of cement-based materials was established based on the theory of parallel plate capacitance. The relationship between the dielectric constant and water content was investigated， and the effects of water-cement ratios and mineral admixtures such as fly ash， silica fume， and slag on the hydration water consumption were analyzed. The results indicated that the dielectric constant-based method was reasonable and accurate for determining water content. During the hydration of cement-based materials， the water content decreased rapidly at first， and then the rate of decrease slowed down. A higher water-cement ratio accelerated the early hydration rate and prolonged the hydration duration， which was characterized by a higher rate of water consumption. The incorporation of fly ash into the cement system reduced the water consumption rate as its dosage increased， whereas silica fume exhibited the opposite effect. Although slag generally enhanced the hydration rate and increased water consumption， a higher dosage of slag ultimately led to a reduction in water consumption.
2026, 56(6): 273-281.
doi: 10.3724/j.gyjzG24071003
Abstract:
In this paper， the intelligent counting problem of special-shaped section construction materials was comparatively studied through two methods： establishing a dedicated model and conducting secondary development based on large models. First， a large number of images of angle steel and wheel locks were taken on-site and labeled， and a basic dataset was constructed combined with image enhancement. Furthermore， by introducing measures such as the SE attention mechanism， WIoU loss function， dynamic snake convolution， and lightweight network architecture improvement to the classic YOLOv8 framework， high-precision counting of densely arranged special-shaped section construction materials was achieved. The average detection accuracy of the model in this paper for angle steel and wheel locks in the field environment reached 91.8% and 99.4%， respectively， showing good practical application effects. Subsequently， the same dataset was used for the secondary development of the special-shaped section detection model on the large model platform EasyDL. The comparison results showed that currently， the detection accuracy， training efficiency， and clarity of display effect of the secondary development model based on the large model platform were lower than those of the dedicated model. However， due to its low development technical threshold， convenient modeling， and strong versatility， it remained a very promising approach for the development of future general counting tasks.
In this paper， the intelligent counting problem of special-shaped section construction materials was comparatively studied through two methods： establishing a dedicated model and conducting secondary development based on large models. First， a large number of images of angle steel and wheel locks were taken on-site and labeled， and a basic dataset was constructed combined with image enhancement. Furthermore， by introducing measures such as the SE attention mechanism， WIoU loss function， dynamic snake convolution， and lightweight network architecture improvement to the classic YOLOv8 framework， high-precision counting of densely arranged special-shaped section construction materials was achieved. The average detection accuracy of the model in this paper for angle steel and wheel locks in the field environment reached 91.8% and 99.4%， respectively， showing good practical application effects. Subsequently， the same dataset was used for the secondary development of the special-shaped section detection model on the large model platform EasyDL. The comparison results showed that currently， the detection accuracy， training efficiency， and clarity of display effect of the secondary development model based on the large model platform were lower than those of the dedicated model. However， due to its low development technical threshold， convenient modeling， and strong versatility， it remained a very promising approach for the development of future general counting tasks.
