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Steel Construction Published the List of Highly Influential Articles of 2020
2023 Vol. 38, No. 5
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2023, 38(5): 1-21.
doi: 10.13206/j.gjgS22100103
Abstract
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Abstract:
In recent years, with the continuous emergence of a variety of new long-span spatial structure forms and their wide application in large public buildings, on-site prestressed construction is facing considerable challenges. Through a simple combing of the current prestressed tensioning construction process simulation methods, combined with specific engineering examples, the whole process of prestressed construction of the spoke-type cable-truss structure of Xiamen New Stadium was analyzed. Xiamen New Sports Center Stadium, also known as Bailu Stadium, has a construction area of 180 600 square meters. It is expected to be used as a football stadium for the 2023 Asian Cup. It is composed of north-south giant arches, inner ring trusses, peripheral trusses, orthogonal positive connection grids and a saddle-shaped spoke-type cable truss structure in the center of the shed. The spoke-type cable truss structure is composed of 40 groups of cable trusses and ring cables. The length of the steel roof is 326 m from east to west, and 350 m from north to south. The plane projection is an ellipse of 143 m×95 m, and the space is saddle-shaped. The maximum elevations on the east and west sides of the canopy are 77 m and 85 m respectively, and the maximum elevations on the north and south sides are 24 m and 32. 5 m respectively. It is the stadium structure with the largest height difference in China. The radial cables of the cable truss structure are anchored on the connection grids between the giant arch structure and the giant arch. In view of the complex structure, the enormous volume of the cable system, the large height difference of the saddle surface, and high synergy of the overall lifting and synchronous tensioning of the novel structural system, a five-stage lifting scheme of the spoke-type cable-truss structure was innovatively proposed, whose core steps were as follows:low-altitude assembling-traction lifting-batch anchoring-steel brace hoisting-high-altitude tensioning. Then, the LS-DYNA dynamic analysis software was used to carry out numerical simulation of the whole process of prestressed cable construction. Through the division of working conditions, the construction simulation check calculation was carried out for the lifting stage, the steel diagonal brace installation stage, the upper radial cable anchoring stage and the tensioning stage, and compared with the results of the design stage to verify the operability of the five-stage lifting scheme. The construction forming scheme of the saddle-shaped spoke-type cable structure of Xiamen New Sports Center Stadium with large height difference showed that:the simulated value of the displacement deformation and the cable force cloud image basically coincided with design values; Compared with the traditional lifting scheme, the five-stage lifting scheme had certain advantages in terms of safety, quality, temporary design and schedule control; the simplicity and convenience of form-finding analysis, force-finding analysis, and load analysis through finite element software still had room to be greatly improved; the development of integrated interactive analysis software for dynamic simulation of the construction process could provide stable technical support and broad application prospects for the whole process of prestressed cable structure construction.
In recent years, with the continuous emergence of a variety of new long-span spatial structure forms and their wide application in large public buildings, on-site prestressed construction is facing considerable challenges. Through a simple combing of the current prestressed tensioning construction process simulation methods, combined with specific engineering examples, the whole process of prestressed construction of the spoke-type cable-truss structure of Xiamen New Stadium was analyzed. Xiamen New Sports Center Stadium, also known as Bailu Stadium, has a construction area of 180 600 square meters. It is expected to be used as a football stadium for the 2023 Asian Cup. It is composed of north-south giant arches, inner ring trusses, peripheral trusses, orthogonal positive connection grids and a saddle-shaped spoke-type cable truss structure in the center of the shed. The spoke-type cable truss structure is composed of 40 groups of cable trusses and ring cables. The length of the steel roof is 326 m from east to west, and 350 m from north to south. The plane projection is an ellipse of 143 m×95 m, and the space is saddle-shaped. The maximum elevations on the east and west sides of the canopy are 77 m and 85 m respectively, and the maximum elevations on the north and south sides are 24 m and 32. 5 m respectively. It is the stadium structure with the largest height difference in China. The radial cables of the cable truss structure are anchored on the connection grids between the giant arch structure and the giant arch. In view of the complex structure, the enormous volume of the cable system, the large height difference of the saddle surface, and high synergy of the overall lifting and synchronous tensioning of the novel structural system, a five-stage lifting scheme of the spoke-type cable-truss structure was innovatively proposed, whose core steps were as follows:low-altitude assembling-traction lifting-batch anchoring-steel brace hoisting-high-altitude tensioning. Then, the LS-DYNA dynamic analysis software was used to carry out numerical simulation of the whole process of prestressed cable construction. Through the division of working conditions, the construction simulation check calculation was carried out for the lifting stage, the steel diagonal brace installation stage, the upper radial cable anchoring stage and the tensioning stage, and compared with the results of the design stage to verify the operability of the five-stage lifting scheme. The construction forming scheme of the saddle-shaped spoke-type cable structure of Xiamen New Sports Center Stadium with large height difference showed that:the simulated value of the displacement deformation and the cable force cloud image basically coincided with design values; Compared with the traditional lifting scheme, the five-stage lifting scheme had certain advantages in terms of safety, quality, temporary design and schedule control; the simplicity and convenience of form-finding analysis, force-finding analysis, and load analysis through finite element software still had room to be greatly improved; the development of integrated interactive analysis software for dynamic simulation of the construction process could provide stable technical support and broad application prospects for the whole process of prestressed cable structure construction.
2023, 38(5): 22-27.
doi: 10.13206/j.gjgS22092203
Abstract:
The traditional strengthening technology of building connecting corridor is easy to be affected by the tensile control force of concrete, resulting in the phenomenon that the stress and displacement of steel pipe are quite different from the actual data, which leads to the unsatisfactory reinforcement effect and seriously affects the construction quality and construction safety. In view of this, a new construction analysis and research of external prestressed reinforcement engineering of building connecting corridor was proposed. Taking the steel structure project of Sichuan Guantang Architectural Engineering Design Co., Ltd. as the research object, the reinforcement construction scheme of GL6, GL3 and GL4a in connecting corridor (一) and connecting corridor (二) was designed according to the structural reinforcement design drawings. After the completion of lifting and unloading, the external prestressed tension construction of the secondary beam of the corresponding team was carried out. The tensile length value, section area, bending radius and relative upward displacement value of the prestressed tendons were calculated by local cutting, so as to determine the reasonable tensile tension and prestress. The contact analysis of the steering block with external prestress was carried out by finite element ANSYS, and the finite element combination model of the steering gear was constructed. The vertical and transverse components of the external prestress bundle were applied. The external prestressed reinforcement engineering of the building corridor was divided into three construction parts:steel structure reinforcement, steel beam cutting reinforcement and bull leg reinforcement. Firstly, the pressure sensor was added to the unloading support point of the corridor, and synchronous grading counterjacking was used to support the steel plate, and the internal force generated by the prestress was used to offset the local force. The counterjacking force was controlled according to the synchronous value of the pressure sensor, to strengthen the steel structure. Plasma cutting machine was used to cut the steel beam and Q345B steel plate was used as the new flange. The new flange and the original structure need to be fully welded to ensure the construction quality of welding. The remaining section of the steel beam after cutting was reinforced by spot welding with the discontinuous weld of 20-30 mm, so as to complete the cutting and strengthening of the steel beam. According to the steps of material approach acceptance- processing of steel plate material number-drilling and anchoring of steel bars-gouging of the surface of the original reinforced beam-cleaning of the surface of the beam-installation of the processed steel leg-gluing of steel plate and the original leg-maintenance-acceptance, the reinforcement construction of the leg part was completed with planting reinforcement materials. In order to verify the reliability setting experiment studied in this paper, two working conditions, normal loading and ultimate loading, were designed, and the deformation state of the corridor was monitored during the reinforcement process. It can be seen from the experimental results that, using the external prestressed reinforcement engineering scheme of the building connecting corridor proposed in this paper, there was a maximum error of 0. 5 MPa between the stress analysis results and the actual stress analysis results in the X direction, and a maximum error of 2. 0 mm between the displacement analysis results and the actual displacement analysis results. The experimental results showed that there was a small difference between the studied method and the actual data. It could design effective reinforcement construction scheme on the basis of analyzing external prestress and tension, and provide technical support for stable construction of building corridor.
The traditional strengthening technology of building connecting corridor is easy to be affected by the tensile control force of concrete, resulting in the phenomenon that the stress and displacement of steel pipe are quite different from the actual data, which leads to the unsatisfactory reinforcement effect and seriously affects the construction quality and construction safety. In view of this, a new construction analysis and research of external prestressed reinforcement engineering of building connecting corridor was proposed. Taking the steel structure project of Sichuan Guantang Architectural Engineering Design Co., Ltd. as the research object, the reinforcement construction scheme of GL6, GL3 and GL4a in connecting corridor (一) and connecting corridor (二) was designed according to the structural reinforcement design drawings. After the completion of lifting and unloading, the external prestressed tension construction of the secondary beam of the corresponding team was carried out. The tensile length value, section area, bending radius and relative upward displacement value of the prestressed tendons were calculated by local cutting, so as to determine the reasonable tensile tension and prestress. The contact analysis of the steering block with external prestress was carried out by finite element ANSYS, and the finite element combination model of the steering gear was constructed. The vertical and transverse components of the external prestress bundle were applied. The external prestressed reinforcement engineering of the building corridor was divided into three construction parts:steel structure reinforcement, steel beam cutting reinforcement and bull leg reinforcement. Firstly, the pressure sensor was added to the unloading support point of the corridor, and synchronous grading counterjacking was used to support the steel plate, and the internal force generated by the prestress was used to offset the local force. The counterjacking force was controlled according to the synchronous value of the pressure sensor, to strengthen the steel structure. Plasma cutting machine was used to cut the steel beam and Q345B steel plate was used as the new flange. The new flange and the original structure need to be fully welded to ensure the construction quality of welding. The remaining section of the steel beam after cutting was reinforced by spot welding with the discontinuous weld of 20-30 mm, so as to complete the cutting and strengthening of the steel beam. According to the steps of material approach acceptance- processing of steel plate material number-drilling and anchoring of steel bars-gouging of the surface of the original reinforced beam-cleaning of the surface of the beam-installation of the processed steel leg-gluing of steel plate and the original leg-maintenance-acceptance, the reinforcement construction of the leg part was completed with planting reinforcement materials. In order to verify the reliability setting experiment studied in this paper, two working conditions, normal loading and ultimate loading, were designed, and the deformation state of the corridor was monitored during the reinforcement process. It can be seen from the experimental results that, using the external prestressed reinforcement engineering scheme of the building connecting corridor proposed in this paper, there was a maximum error of 0. 5 MPa between the stress analysis results and the actual stress analysis results in the X direction, and a maximum error of 2. 0 mm between the displacement analysis results and the actual displacement analysis results. The experimental results showed that there was a small difference between the studied method and the actual data. It could design effective reinforcement construction scheme on the basis of analyzing external prestress and tension, and provide technical support for stable construction of building corridor.
2023, 38(5): 28-32.
doi: 10.13206/j.gjgS22121902
Abstract:
The existing steel beam described in this paper has a span of 30 m. Due to the industrial adjustment, the external load of the new curtain wall is increased, and the deflection of the steel beam is too large to meet the actual use requirements. There are two traditional reinforcement methods:one is to add steel columns under the steel beams to reduce the span of the existing steel beams, thereby reducing the deflection, but the support points under the new steel columns expand the scope of the original building reinforcement; Another is to add section steel under the existing steel beam, so as to increase the rigidity of the steel beam, but with the increase of section steel, the dead weight of the whole steel beam also increases, which is obviously not economical. At the same time, due to the tight construction period and limited construction conditions of this project, in order to solve the deflection problem of steel beams more effectively under the existing conditions, in view of the particularity of this project, it was proposed to adopt the external prestressing method to strengthen the existing steel beams. Based on the span of the steel beam and the support at both ends, the double folded line type of the prestressed steel strand was adopted. By analyzing the prestress loss of external prestressed steel strand in the process of tension, the effective tensioning prestress was obtained. Then the effective area of prestressed steel strand was obtained. By applying tension at both ends of the original steel beam and setting a steering block in the middle, the two ends of the steel beam were tensioned in batches during the installation of the curtain wall. Thus, the deflection increased by the external load was controlled by the tensioning of the prestressed steel strand. Under the combined working condition of external load and prestress, the deflection deformation was zero, which avoided the increase of deflection of existing steel beams due to the increase of new loads. The two ends of the existing steel beam were tensioned by external prestress, and the reinforcement task of the steel beam was completed in a short time. The problem of excessive deflection of the existing steel beam was solved in the limited time and on the construction operation surface, and the application requirements of the project were met. Thus, it had obtained greater economic value in a relatively short period of time. It is hoped that this paper could provide reference for peers with similar reinforcement conditions and methods, so as to achieve low-carbon, environmental protection, sustainable development of the reinforcement model.
The existing steel beam described in this paper has a span of 30 m. Due to the industrial adjustment, the external load of the new curtain wall is increased, and the deflection of the steel beam is too large to meet the actual use requirements. There are two traditional reinforcement methods:one is to add steel columns under the steel beams to reduce the span of the existing steel beams, thereby reducing the deflection, but the support points under the new steel columns expand the scope of the original building reinforcement; Another is to add section steel under the existing steel beam, so as to increase the rigidity of the steel beam, but with the increase of section steel, the dead weight of the whole steel beam also increases, which is obviously not economical. At the same time, due to the tight construction period and limited construction conditions of this project, in order to solve the deflection problem of steel beams more effectively under the existing conditions, in view of the particularity of this project, it was proposed to adopt the external prestressing method to strengthen the existing steel beams. Based on the span of the steel beam and the support at both ends, the double folded line type of the prestressed steel strand was adopted. By analyzing the prestress loss of external prestressed steel strand in the process of tension, the effective tensioning prestress was obtained. Then the effective area of prestressed steel strand was obtained. By applying tension at both ends of the original steel beam and setting a steering block in the middle, the two ends of the steel beam were tensioned in batches during the installation of the curtain wall. Thus, the deflection increased by the external load was controlled by the tensioning of the prestressed steel strand. Under the combined working condition of external load and prestress, the deflection deformation was zero, which avoided the increase of deflection of existing steel beams due to the increase of new loads. The two ends of the existing steel beam were tensioned by external prestress, and the reinforcement task of the steel beam was completed in a short time. The problem of excessive deflection of the existing steel beam was solved in the limited time and on the construction operation surface, and the application requirements of the project were met. Thus, it had obtained greater economic value in a relatively short period of time. It is hoped that this paper could provide reference for peers with similar reinforcement conditions and methods, so as to achieve low-carbon, environmental protection, sustainable development of the reinforcement model.
2023, 38(5): 33-42.
doi: 10.13206/j.gjgS22102401
Abstract:
Considering the improvement of anti-explosion performance of existing facilities such as dangerous chemicals warehouse and ammunition depot, a explosion-proof wall structure was established. Using the numerical simulation method, taking the unreinforced masonry infilled wall and the composite masonry blast wall based on steel plate concrete as the research objects, the dynamic response test of the masonry wall under explosive load was carried out using the dynamic nonlinear finite element analysis software ABAQUS/Explicit. In the model, masonry wall, cast-in-place concrete, TNT and sandwich steel plate were solid unit type, and the reinforcement mesh was beam unit type; The reinforcement mesh was embedded in the cast-in-place concrete, and the brickwork wall, cast-in-place concrete and sandwich steel plate were in surface-to-surface contact contact; In the contact properties, the penalty function was used, the friction coefficient is 0. 75, and the bond slip between blocks adopted exponential damage evolution constitutive law; The structural model used the full constraint type to constrain the bottom and top of the wall, and used the fine finite element to divide the grid, with the size of 0. 01 m. The dynamic response and protective performance of the two kinds of walls under the impact of explosion were analyzed and compared by numerical simulation. The results showed that under the same level of explosion load, with the increase of the thickness of the steel plate, the rigidity of the explosion-proof wall would also increase, and the peak acceleration would continue to advance; The maximum instantaneous velocity of the wall appeared around 0. 1 ms. When the thickness of the steel plate was less than 10 mm, the center velocity of the explosion point was greater than 58 m/s; When the thickness of the steel plate was greater than 30 mm, the central velocity of the explosion point was less than 30 m/s. With the increase of explosion load, the maximum deformation displacement and stable deformation displacement of the center point of the blast wall would increase. The instantaneous displacement of the reinforced steel sandwich blast wall would decrease with the increase of the thickness of the steel plate. When the steel plate thickness of the steel plate sandwich explosion-proof wall was less than 20 mm, the maximum plastic displacement of the wall was greater than 0. 015 m; when the thickness of the steel plate was greater than 30 mm, the maximum plastic displacement of the wall was less than 0. 008 m. Due to the improvement of wall ductility by sandwich steel plate, the damage of steel plate sandwich masonry wall was obviously better than that of reinforced concrete masonry wall. The steel bar strain of the blast wall appeared alternately under the instantaneous tension and compression deformation under the action of the blast wave, and the center line showed an upward trend with the increase of the blast load and the passage of time. The tensile and compression strain of the steel bar at the center of the blast wall was the largest, and the increase of the steel plate thickness had little effect on the tensile and compression strain of the steel bar at the wall edge. The anti-explosion performance of the reinforced steel sandwich explosion-proof masonry wall was affected by the thickness of the steel plate. With the increase of the thickness of the steel plate, the anti-explosion performance of the original masonry wall and the concrete reinforced masonry wall could be significantly improved.
Considering the improvement of anti-explosion performance of existing facilities such as dangerous chemicals warehouse and ammunition depot, a explosion-proof wall structure was established. Using the numerical simulation method, taking the unreinforced masonry infilled wall and the composite masonry blast wall based on steel plate concrete as the research objects, the dynamic response test of the masonry wall under explosive load was carried out using the dynamic nonlinear finite element analysis software ABAQUS/Explicit. In the model, masonry wall, cast-in-place concrete, TNT and sandwich steel plate were solid unit type, and the reinforcement mesh was beam unit type; The reinforcement mesh was embedded in the cast-in-place concrete, and the brickwork wall, cast-in-place concrete and sandwich steel plate were in surface-to-surface contact contact; In the contact properties, the penalty function was used, the friction coefficient is 0. 75, and the bond slip between blocks adopted exponential damage evolution constitutive law; The structural model used the full constraint type to constrain the bottom and top of the wall, and used the fine finite element to divide the grid, with the size of 0. 01 m. The dynamic response and protective performance of the two kinds of walls under the impact of explosion were analyzed and compared by numerical simulation. The results showed that under the same level of explosion load, with the increase of the thickness of the steel plate, the rigidity of the explosion-proof wall would also increase, and the peak acceleration would continue to advance; The maximum instantaneous velocity of the wall appeared around 0. 1 ms. When the thickness of the steel plate was less than 10 mm, the center velocity of the explosion point was greater than 58 m/s; When the thickness of the steel plate was greater than 30 mm, the central velocity of the explosion point was less than 30 m/s. With the increase of explosion load, the maximum deformation displacement and stable deformation displacement of the center point of the blast wall would increase. The instantaneous displacement of the reinforced steel sandwich blast wall would decrease with the increase of the thickness of the steel plate. When the steel plate thickness of the steel plate sandwich explosion-proof wall was less than 20 mm, the maximum plastic displacement of the wall was greater than 0. 015 m; when the thickness of the steel plate was greater than 30 mm, the maximum plastic displacement of the wall was less than 0. 008 m. Due to the improvement of wall ductility by sandwich steel plate, the damage of steel plate sandwich masonry wall was obviously better than that of reinforced concrete masonry wall. The steel bar strain of the blast wall appeared alternately under the instantaneous tension and compression deformation under the action of the blast wave, and the center line showed an upward trend with the increase of the blast load and the passage of time. The tensile and compression strain of the steel bar at the center of the blast wall was the largest, and the increase of the steel plate thickness had little effect on the tensile and compression strain of the steel bar at the wall edge. The anti-explosion performance of the reinforced steel sandwich explosion-proof masonry wall was affected by the thickness of the steel plate. With the increase of the thickness of the steel plate, the anti-explosion performance of the original masonry wall and the concrete reinforced masonry wall could be significantly improved.
2023, 38(5): 43-45.
doi: 10.13206/j.gjgS22122820
Abstract:
Simple stiffening of web opening in Europe was introduced. Strength check required after web opening was pointed out, the anchorage length of horizontal stiffeners was recommended, the width-to-thickness limit was proposed when the opening was un-stiffended, and equation for incremental deflection due to web opening was put forward.
Simple stiffening of web opening in Europe was introduced. Strength check required after web opening was pointed out, the anchorage length of horizontal stiffeners was recommended, the width-to-thickness limit was proposed when the opening was un-stiffended, and equation for incremental deflection due to web opening was put forward.
