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The Top 20 Most-Cited Papers from 2022 to 2023
2024 Vol. 39, No. 3
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2024, 39(3): 1-6.
doi: 10.13206/j.gjgS22102202
Abstract
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Abstract:
Aluminum alloy has many advantages such as low density, good corrosion resistance, easy processing, high specific strength, and convenient forming. The density of aluminum alloy is about one-third of that of ordinary steel, and its strength is equivalent to the stiffness of conventional steel. Therefore, aluminum alloy structures can obtain larger spans, which is attracting more and more attention and favor from architects and structural engineers. In order to give full play to the advantages of lightweight and high strength of aluminum alloy honeycomb plates and overcome the shortcomings of low elastic modulus of aluminum alloy reticulated shells, this paper proposed a new type of aluminum alloy honeycomb plate cylindrical composite reticulated shell structure. The composite reticulated shell structure is composed of aluminum alloy honeycomb plate and aluminum alloy reticulated shell connected by locking riveting, in order to achieve the purpose that aluminum alloy honeycomb plate and aluminum alloy reticulated shell work together. In this paper, a cylindrical reticulated shell structure with a size of 4 400 mm×1 530 mm×1 100 mm was designed and prepared, and the bearing capacity test was carried out to study the stress characteristics and failure mechanism of the cylindrical composite reticulated shell. On the basis of considering the influence of double nonlinearity and instability, the nonlinear finite element analysis of cylindrical composite reticulated shell was carried out. The reliability of the finite element analysis method was verified by comparing the results of finite element analysis with the bearing capacity test. The results show that the main failure modes of the connector are that the corepulling rivet at the short span was cut off when the composite reticulated shell plate-bar was destroyed; the side span was pulled off by the core pulling rivet due to aluminum alloy warping; there is a trend of plate dislocation around the locking rivet connector, but it is not damaged. The failure modes of the aluminum alloy member include the fracture of the aluminum alloy member along the weak part of the opening at the maximum stress in the span and side span compression buckling. Aluminum alloy honeycomb plate also occurred degumming phenomenon in the larger bar deformation. Before the displacement of the loading point is 30 mm, the specimen is in the elastic stage and then enters the elastic-plastic stage. The nonlinear behavior of the cylindrical reticulated shell is mainly determined by the locking riveting performance between the aluminum alloy rod and the honeycomb panel. The bearing capacity of the cylindrical composite reticulated shell specimen is 6 951 N, and the load continues to decrease with the increase of displacement. The finite element analysis model considering double nonlinearity can effectively simulate the mechanical performance of the composite reticulated shell in the elastoplastic stage, and the deformation and mechanical performance of the composite cylindrical reticulated shell after instability can be well simulated after considering instability. The finite element simulation method proposed in this paper can accurately simulate the load-displacement curve of cylindrical reticulated shells. The calculation efficiency is high, the convergence is good, and the error of ultimate bearing capacity is about 2% . The locking riveting connection integrates opening and forming. Only positioning can use the locking riveting connection tool to form the locking riveting. The processing efficiency is the highest, the forming quality is guaranteed, and the stability is better than the traditional mechanical connections. In the future, " assembly line " production can be formed to improve the degree of building industrialization.
Aluminum alloy has many advantages such as low density, good corrosion resistance, easy processing, high specific strength, and convenient forming. The density of aluminum alloy is about one-third of that of ordinary steel, and its strength is equivalent to the stiffness of conventional steel. Therefore, aluminum alloy structures can obtain larger spans, which is attracting more and more attention and favor from architects and structural engineers. In order to give full play to the advantages of lightweight and high strength of aluminum alloy honeycomb plates and overcome the shortcomings of low elastic modulus of aluminum alloy reticulated shells, this paper proposed a new type of aluminum alloy honeycomb plate cylindrical composite reticulated shell structure. The composite reticulated shell structure is composed of aluminum alloy honeycomb plate and aluminum alloy reticulated shell connected by locking riveting, in order to achieve the purpose that aluminum alloy honeycomb plate and aluminum alloy reticulated shell work together. In this paper, a cylindrical reticulated shell structure with a size of 4 400 mm×1 530 mm×1 100 mm was designed and prepared, and the bearing capacity test was carried out to study the stress characteristics and failure mechanism of the cylindrical composite reticulated shell. On the basis of considering the influence of double nonlinearity and instability, the nonlinear finite element analysis of cylindrical composite reticulated shell was carried out. The reliability of the finite element analysis method was verified by comparing the results of finite element analysis with the bearing capacity test. The results show that the main failure modes of the connector are that the corepulling rivet at the short span was cut off when the composite reticulated shell plate-bar was destroyed; the side span was pulled off by the core pulling rivet due to aluminum alloy warping; there is a trend of plate dislocation around the locking rivet connector, but it is not damaged. The failure modes of the aluminum alloy member include the fracture of the aluminum alloy member along the weak part of the opening at the maximum stress in the span and side span compression buckling. Aluminum alloy honeycomb plate also occurred degumming phenomenon in the larger bar deformation. Before the displacement of the loading point is 30 mm, the specimen is in the elastic stage and then enters the elastic-plastic stage. The nonlinear behavior of the cylindrical reticulated shell is mainly determined by the locking riveting performance between the aluminum alloy rod and the honeycomb panel. The bearing capacity of the cylindrical composite reticulated shell specimen is 6 951 N, and the load continues to decrease with the increase of displacement. The finite element analysis model considering double nonlinearity can effectively simulate the mechanical performance of the composite reticulated shell in the elastoplastic stage, and the deformation and mechanical performance of the composite cylindrical reticulated shell after instability can be well simulated after considering instability. The finite element simulation method proposed in this paper can accurately simulate the load-displacement curve of cylindrical reticulated shells. The calculation efficiency is high, the convergence is good, and the error of ultimate bearing capacity is about 2% . The locking riveting connection integrates opening and forming. Only positioning can use the locking riveting connection tool to form the locking riveting. The processing efficiency is the highest, the forming quality is guaranteed, and the stability is better than the traditional mechanical connections. In the future, " assembly line " production can be formed to improve the degree of building industrialization.
2024, 39(3): 7-14.
doi: 10.13206/j.gjgS22101702
Abstract:
Welding is one of the most widely used techniques for connections in steel constructions. Materials in the heat affected zone ( HAZ) may be hardened due to phase transformation during the welding. Welding defects, such as cracks, may also exist in the HAZ. Therefore, the HAZ is often the most vulnerable link of welding connections. To investigate the ductile fracture at the HAZ of welding connections in beam-to-column joints and beam split joints, two specimens were made of Q355D steels, one for cross welding connections and the other for butt welding connections. The specimens were tested under monotonic tension. Perfect finite element ( FE) models and imperfect ones with a blunt notch at the stress concentration location were setup for the test specimens. Ductile fracture of the test specimens was predicted by the void growth model ( VGM) based on nonlinear FE analysis. A VUMAT subroutine was programmed for the simulation of ductile fracture propagation of the specimens by deleting fractured elements based on fracture criteria of the VGM during the FE analysis. FE models with different mesh sizes were established and mesh sensitivity analysis was conducted for ductile fracture simulation by the VGM. The tests showed that both specimens fractured at the HAZ with obvious plastic deformation after the peak load. The fracture displacements of the cross welding and the butt welding test specimens obtained by the tests are 15. 9 and 18. 3 mm respectively, indicating that both the welding connections have superior plasticity. The fracture locations predicted by the VGM based on the perfect FE models agree very well with the test observation of both specimens. However, the predicted fracture displacements of the two specimens are 30. 5 and 29. 1 mm respectively, which are much larger than the test results, indicating that welding defects have considerable adverse effect on ductile fracture of the welding connections. Based on the imperfect FE models with consideration of the defects, the fracture displacements of the two specimens predicted by the VGM are 14. 9 and 17. 2 mm, which agree well with the test results. The agreement indicates that introduction of blunt notches is a feasible approach of considering welding defects in ductile fracture analysis. The fracture paths obtained with the VUMAT subroutine are consistent with the test results, which verified the applicability of the VGM for the simulation of ductile fracture propagation of welding connections. Mesh sensitivity analysis showed that, because both specimens have low stress and strain gradient at the fracture location, ductile fracture simulation based on FE model with relatively coarse meshes can give accurate results at much lower computational cost.
Welding is one of the most widely used techniques for connections in steel constructions. Materials in the heat affected zone ( HAZ) may be hardened due to phase transformation during the welding. Welding defects, such as cracks, may also exist in the HAZ. Therefore, the HAZ is often the most vulnerable link of welding connections. To investigate the ductile fracture at the HAZ of welding connections in beam-to-column joints and beam split joints, two specimens were made of Q355D steels, one for cross welding connections and the other for butt welding connections. The specimens were tested under monotonic tension. Perfect finite element ( FE) models and imperfect ones with a blunt notch at the stress concentration location were setup for the test specimens. Ductile fracture of the test specimens was predicted by the void growth model ( VGM) based on nonlinear FE analysis. A VUMAT subroutine was programmed for the simulation of ductile fracture propagation of the specimens by deleting fractured elements based on fracture criteria of the VGM during the FE analysis. FE models with different mesh sizes were established and mesh sensitivity analysis was conducted for ductile fracture simulation by the VGM. The tests showed that both specimens fractured at the HAZ with obvious plastic deformation after the peak load. The fracture displacements of the cross welding and the butt welding test specimens obtained by the tests are 15. 9 and 18. 3 mm respectively, indicating that both the welding connections have superior plasticity. The fracture locations predicted by the VGM based on the perfect FE models agree very well with the test observation of both specimens. However, the predicted fracture displacements of the two specimens are 30. 5 and 29. 1 mm respectively, which are much larger than the test results, indicating that welding defects have considerable adverse effect on ductile fracture of the welding connections. Based on the imperfect FE models with consideration of the defects, the fracture displacements of the two specimens predicted by the VGM are 14. 9 and 17. 2 mm, which agree well with the test results. The agreement indicates that introduction of blunt notches is a feasible approach of considering welding defects in ductile fracture analysis. The fracture paths obtained with the VUMAT subroutine are consistent with the test results, which verified the applicability of the VGM for the simulation of ductile fracture propagation of welding connections. Mesh sensitivity analysis showed that, because both specimens have low stress and strain gradient at the fracture location, ductile fracture simulation based on FE model with relatively coarse meshes can give accurate results at much lower computational cost.
2024, 39(3): 15-27.
doi: 10.13206/j.gjgS23090103
Abstract:
The four floors above ground of the new Nanjing Art Museum are a composite tube inclined column steel truss hybrid structure system, with a total steel structure of approximately 15 000 tons. The upper structure is a complex multi-layer irregular circular steel truss structure, consisting of a large-span truss, a cantilever truss, and two circular trusses inside and outside the perimeter. It is divided into two levels: upper and lower, and locally three levels. The truss height is 14. 2 m, and the top elevation is 33. 7 m; the overall size of the outer wheel is 147. 5 m× 103. 3 m, and inner opening size is 102. 8 m × 38. 0 m. The steel truss is supported by 4 cylinders and 10 circular steel tube concrete inclined columns. The construction concept of " in-situ assembly on the ground and overall lifting" is adopted, and the core cylinder and temporary support tower are used as lifting supports to lift the steel truss. In response to the difficult problem of selecting lifting points, the principles of arranging lifting points that are as close as possible to the design state, short force transmission path, uniform structural stress, and small deformation have been determined. Through dynamic simulation analysis of the entire construction process, 29 mixed lifting points have been selected and determined; in response to the difficulty in setting up the lifting support system, a multi-point hybrid support system for the lifting of large and complex irregular trusses has been developed, including lifting reaction frames on the top of the core cylinder column and pre installed trusses, tower supports arranged at the support positions of eight diagonal columns in the south and north zones, and lifting bracket reinforcement and lifting tower reinforcement support systems, meeting the requirements of safety and installation accuracy; in response to the difficulty of hydraulic lifting synchronization for large and complex spatial structures with uneven stiffness, three methods for improving synchronization control were proposed: the minimum sum of squares of displacement deviation at all lifting points, the minimum difference between the minimum and maximum coordinates of lifting points, and the minimum absolute value of maximum deviation. Detailed calculation formulas were derived and successfully applied in the new museum project of Nanjing Art Museum, which achieves precise synchronization improvement under complex conditions; in terms of synchronous control, an automatic measurement system is adopted to enhance synchronous control data. By collecting data through an intelligent measurement robot, the asynchronous situation between each lifting point can be intuitively reflected. At the same time, static level measurement and manual measurement are also used for mutual verification. In response to the challenges of irregular structural plane and elevation, large number of matching points, irregular distribution of point positions, and different spatial angle positioning of matching points, the Bursa model was used to study the general rotation translation matching model with 3 coordinate system rotation parameters and 3 translation parameters as independent parameters. The solution method and analytical solution of the conventional 3D rotation translation matching model were provided. By combining the above methods and corresponding installation control measures, the adjusted alignment points have significantly improved in terms of mean, mean square deviation, and probability distribution, achieving precise alignment.
The four floors above ground of the new Nanjing Art Museum are a composite tube inclined column steel truss hybrid structure system, with a total steel structure of approximately 15 000 tons. The upper structure is a complex multi-layer irregular circular steel truss structure, consisting of a large-span truss, a cantilever truss, and two circular trusses inside and outside the perimeter. It is divided into two levels: upper and lower, and locally three levels. The truss height is 14. 2 m, and the top elevation is 33. 7 m; the overall size of the outer wheel is 147. 5 m× 103. 3 m, and inner opening size is 102. 8 m × 38. 0 m. The steel truss is supported by 4 cylinders and 10 circular steel tube concrete inclined columns. The construction concept of " in-situ assembly on the ground and overall lifting" is adopted, and the core cylinder and temporary support tower are used as lifting supports to lift the steel truss. In response to the difficult problem of selecting lifting points, the principles of arranging lifting points that are as close as possible to the design state, short force transmission path, uniform structural stress, and small deformation have been determined. Through dynamic simulation analysis of the entire construction process, 29 mixed lifting points have been selected and determined; in response to the difficulty in setting up the lifting support system, a multi-point hybrid support system for the lifting of large and complex irregular trusses has been developed, including lifting reaction frames on the top of the core cylinder column and pre installed trusses, tower supports arranged at the support positions of eight diagonal columns in the south and north zones, and lifting bracket reinforcement and lifting tower reinforcement support systems, meeting the requirements of safety and installation accuracy; in response to the difficulty of hydraulic lifting synchronization for large and complex spatial structures with uneven stiffness, three methods for improving synchronization control were proposed: the minimum sum of squares of displacement deviation at all lifting points, the minimum difference between the minimum and maximum coordinates of lifting points, and the minimum absolute value of maximum deviation. Detailed calculation formulas were derived and successfully applied in the new museum project of Nanjing Art Museum, which achieves precise synchronization improvement under complex conditions; in terms of synchronous control, an automatic measurement system is adopted to enhance synchronous control data. By collecting data through an intelligent measurement robot, the asynchronous situation between each lifting point can be intuitively reflected. At the same time, static level measurement and manual measurement are also used for mutual verification. In response to the challenges of irregular structural plane and elevation, large number of matching points, irregular distribution of point positions, and different spatial angle positioning of matching points, the Bursa model was used to study the general rotation translation matching model with 3 coordinate system rotation parameters and 3 translation parameters as independent parameters. The solution method and analytical solution of the conventional 3D rotation translation matching model were provided. By combining the above methods and corresponding installation control measures, the adjusted alignment points have significantly improved in terms of mean, mean square deviation, and probability distribution, achieving precise alignment.
2024, 39(3): 28-37.
doi: 10.13206/j.gjgS23050801
Abstract:
The new Shenzhen Cultural Center has complex architectural shape and many internal space changes, with a large cantilevered space of more than 21 meters. In order to ensure reasonable lateral and torsional stiffness of the whole structure, 8 reinforced concrete tubes are set up in staircase and elevator of the building, which form the frame shear wall structure with the surrounding frame columns. However, due to the changes in the inner and outer space of the building and the special requirements in the function, the structure has many irregular items and complex substructures. For example, the opening rate of the typical floor of the cultural museum is more than 32% , due to the large functional difference between the various areas in the museum and the connection between the areas only through the indoor corridor, the actual situation of the floor is not consistent with the rigid floor assumption. At this time, how to evaluate the deformation index of the structure and the ability of the floor to coordinate the deformation becomes a major difficulty in the design. The cultural center is divided into three areas, namely, the core tube group area on the left side, the core tube group area on the right side and the large-span steel structure area on the east side. The typical observation points in the three areas are selected to investigate the deformation of the observation points under earthquake action, and further judge whether the floor has the ability to coordinate the deformation differences among the three areas. The scheme of the large cantilevered area is compared, and the stress analysis of the floor members connected to the upper chord of the overhang truss is carried out. The force transfer between the truss and the core tube can be ensured when the structure is subjected to rare earthquake and the floor in the weak connection position is damaged and the floor stiffness is degraded or even completely withdrawn from work. The function of the building on the east side requires large column span and floor height. Typical column distance is 8. 4 m×16. 8 m, and steel columns can only be arranged in L4-L8 floors, and Y-shaped slanted columns can be set between B1-L4 floors to support the upper steel columns. The ability of Y-shaped slanted column to independently bear overturning load is analyzed when gravity is transferred. At the same time, Y-shaped slanted column is 3-4 stories cross-layer column. Whether it can meet the requirements of stable bearing capacity and resistance to continuous collapse is a key and difficult point to discuss. When the structural stiffness index ( such as the inter-story displacement angle) is investigated, the deformation value of key measuring points can be captured by sectional statistics according to the structural stress situation, and the ability of the floor to coordinate deformation can be comprehensively evaluated. For the indoor bridge and the weak connection position of the floor, the envelope design is carried out by establishing the separating model, and the floor reinforcement is strengthened. By setting steel beams, columns and inclined rods in the shear wall supporting the large cantilevered truss, the three-dimensional tube structure is formed, and the influence of floor stiffness degradation on the force and deformation of the components between the large cantilevered truss and the tube structure is fully considered. The analysis results show that the large cantilevered truss and the tube structure can meet the checking calculation. The ability of Y-shaped slanted column to independently bear overturning load is weak. In design, the floor connection between slanted column and core tube group is strengthened, and the stress ratio of pull beam between slanted column and core tube is strictly controlled. When designing the Y-shaped slanted column, the nonlinear stability bearing capacity analysis should be carried out considering the initial defects of the component, and the stable bearing capacity reserve of the slanted column should be defined. By using linear static alternate path method, the slanted column structure can be judged to meet the requirements of continuous collapse resistance. The typical joint of the large cantilevered truss and shear wall and the transfer joint of steel reinforced concrete truss are selected as the research object, and the corresponding joint strengthening structure is proposed.
The new Shenzhen Cultural Center has complex architectural shape and many internal space changes, with a large cantilevered space of more than 21 meters. In order to ensure reasonable lateral and torsional stiffness of the whole structure, 8 reinforced concrete tubes are set up in staircase and elevator of the building, which form the frame shear wall structure with the surrounding frame columns. However, due to the changes in the inner and outer space of the building and the special requirements in the function, the structure has many irregular items and complex substructures. For example, the opening rate of the typical floor of the cultural museum is more than 32% , due to the large functional difference between the various areas in the museum and the connection between the areas only through the indoor corridor, the actual situation of the floor is not consistent with the rigid floor assumption. At this time, how to evaluate the deformation index of the structure and the ability of the floor to coordinate the deformation becomes a major difficulty in the design. The cultural center is divided into three areas, namely, the core tube group area on the left side, the core tube group area on the right side and the large-span steel structure area on the east side. The typical observation points in the three areas are selected to investigate the deformation of the observation points under earthquake action, and further judge whether the floor has the ability to coordinate the deformation differences among the three areas. The scheme of the large cantilevered area is compared, and the stress analysis of the floor members connected to the upper chord of the overhang truss is carried out. The force transfer between the truss and the core tube can be ensured when the structure is subjected to rare earthquake and the floor in the weak connection position is damaged and the floor stiffness is degraded or even completely withdrawn from work. The function of the building on the east side requires large column span and floor height. Typical column distance is 8. 4 m×16. 8 m, and steel columns can only be arranged in L4-L8 floors, and Y-shaped slanted columns can be set between B1-L4 floors to support the upper steel columns. The ability of Y-shaped slanted column to independently bear overturning load is analyzed when gravity is transferred. At the same time, Y-shaped slanted column is 3-4 stories cross-layer column. Whether it can meet the requirements of stable bearing capacity and resistance to continuous collapse is a key and difficult point to discuss. When the structural stiffness index ( such as the inter-story displacement angle) is investigated, the deformation value of key measuring points can be captured by sectional statistics according to the structural stress situation, and the ability of the floor to coordinate deformation can be comprehensively evaluated. For the indoor bridge and the weak connection position of the floor, the envelope design is carried out by establishing the separating model, and the floor reinforcement is strengthened. By setting steel beams, columns and inclined rods in the shear wall supporting the large cantilevered truss, the three-dimensional tube structure is formed, and the influence of floor stiffness degradation on the force and deformation of the components between the large cantilevered truss and the tube structure is fully considered. The analysis results show that the large cantilevered truss and the tube structure can meet the checking calculation. The ability of Y-shaped slanted column to independently bear overturning load is weak. In design, the floor connection between slanted column and core tube group is strengthened, and the stress ratio of pull beam between slanted column and core tube is strictly controlled. When designing the Y-shaped slanted column, the nonlinear stability bearing capacity analysis should be carried out considering the initial defects of the component, and the stable bearing capacity reserve of the slanted column should be defined. By using linear static alternate path method, the slanted column structure can be judged to meet the requirements of continuous collapse resistance. The typical joint of the large cantilevered truss and shear wall and the transfer joint of steel reinforced concrete truss are selected as the research object, and the corresponding joint strengthening structure is proposed.
2024, 39(3): 38-46.
doi: 10.3724/j.gjgS22112501
Abstract:
The grid structure is a spatial grid structure with various forms. Because of its advantages of good force performance, light weight, large rigidity, good seismic performance, low cost and easy forming, it is widely used in the roof of terminals, hangars, gymnasiums, theaters, exhibition halls, stations and other buildings. The roof of the main building of Terminal 2 of Zhuhai Airport adopts a largespan continuous ultra-long variable curvature hyperboloid local evacuation steel grid structure system. The modeling characteristics and structural system composition of the roof are introduced, and the construction process is carried out by partition and blocking cumulative lifting process according to its complexity, and the construction sequence is proposed and the lifting scheme is given. The construction steps of the steel structure of the main building roof are expounded, the construction steps of each step are simulated and analyzed, and the design load is applied to the grid structure after the unloading of the supporting frame, and the displacement and stress indicators of the whole process of the steel structure roof construction of the main building are obtained, and the performance of the steel structure of the main building based on construction simulation under the design and use load is evaluated. The construction technology that combines the whole process monitoring of the grid frame with the construction simulation is adopted, and the lifting status and block size of the grid are adjusted in real time through the comparison and analysis of the stress and strain values in the actual monitoring data and the simulation, so as to realize the accurate control of the force state of the grid lifting process. The results show that the construction scheme of the steel structure roof of the main building is feasible, and the structural deformation and internal force meet the requirements during the lifting process. After considering the influence of the construction process, the vertical deflection of mid span of the steel grid increases, and reliable measures should be taken to reduce the adverse effects caused by the increase of deflection; in the process from the beginning of construction to the final forming of the steel grid frame, the force mode of the local member changes from length to slenderness ratio control to force control, and the cross-section needs to be enlarged; it is necessary for the large-span grid frame to be reviewed by using the load input construction simulation analysis model according to the design after the construction simulation unloads the tire frame. The monitoring results show that the measured stress displacement of the grid frame is basically consistent with the construction simulation, which indicates the accuracy of the construction simulation analysis.
The grid structure is a spatial grid structure with various forms. Because of its advantages of good force performance, light weight, large rigidity, good seismic performance, low cost and easy forming, it is widely used in the roof of terminals, hangars, gymnasiums, theaters, exhibition halls, stations and other buildings. The roof of the main building of Terminal 2 of Zhuhai Airport adopts a largespan continuous ultra-long variable curvature hyperboloid local evacuation steel grid structure system. The modeling characteristics and structural system composition of the roof are introduced, and the construction process is carried out by partition and blocking cumulative lifting process according to its complexity, and the construction sequence is proposed and the lifting scheme is given. The construction steps of the steel structure of the main building roof are expounded, the construction steps of each step are simulated and analyzed, and the design load is applied to the grid structure after the unloading of the supporting frame, and the displacement and stress indicators of the whole process of the steel structure roof construction of the main building are obtained, and the performance of the steel structure of the main building based on construction simulation under the design and use load is evaluated. The construction technology that combines the whole process monitoring of the grid frame with the construction simulation is adopted, and the lifting status and block size of the grid are adjusted in real time through the comparison and analysis of the stress and strain values in the actual monitoring data and the simulation, so as to realize the accurate control of the force state of the grid lifting process. The results show that the construction scheme of the steel structure roof of the main building is feasible, and the structural deformation and internal force meet the requirements during the lifting process. After considering the influence of the construction process, the vertical deflection of mid span of the steel grid increases, and reliable measures should be taken to reduce the adverse effects caused by the increase of deflection; in the process from the beginning of construction to the final forming of the steel grid frame, the force mode of the local member changes from length to slenderness ratio control to force control, and the cross-section needs to be enlarged; it is necessary for the large-span grid frame to be reviewed by using the load input construction simulation analysis model according to the design after the construction simulation unloads the tire frame. The monitoring results show that the measured stress displacement of the grid frame is basically consistent with the construction simulation, which indicates the accuracy of the construction simulation analysis.
2024, 39(3): 47-50.
doi: 10.13206/j.gjgS24032020
Abstract:
To prohibit severe consequence of the building from an unspecified cause, some building codes included some minimum requirements. Eurocode 1991-1-7 is first introduced briefly. Classification of buildings based on failure consequences is presented and required design strategies for each class of buildings and minimum tying capacity are given. Based on this Euronorm and domestic CECS standard, proposals are presented for the supports of steel roofs for the robustness of roofs in small and medium span steel structure, requirements of bearing capacity and construction are also presented for the steel roof themselves.
To prohibit severe consequence of the building from an unspecified cause, some building codes included some minimum requirements. Eurocode 1991-1-7 is first introduced briefly. Classification of buildings based on failure consequences is presented and required design strategies for each class of buildings and minimum tying capacity are given. Based on this Euronorm and domestic CECS standard, proposals are presented for the supports of steel roofs for the robustness of roofs in small and medium span steel structure, requirements of bearing capacity and construction are also presented for the steel roof themselves.
