Dapeng Town Industrial Park, Tongshan District, Xuzhou City, Jiangsu Province, China
A surface is a three-dimensional shape produced by rotation around the axis of symmetry and has the characteristics of smoothness and symmetry. The curved large-span steel component distribution space frame in the construction project is to make full use of its three-dimensional characteristics, so that the original steel structure system of the building is transformed into a certain bending steel structure form, which has played an important supporting function of expanding the bearing surface of the steel structure and expanding the mechanical strength of the building. The wide use of curved large-span steel distribution space frames in buildings has the advantages of rapidly disperses the overall load bearing of buildings and enhances the construction safety of structures for the main bearing components of buildings.
According to the practical application of curved long-span structure space frame in modern architecture, this paper includes two parts of curved long-span steel space frame structure: internal space frame structure and external truss beam structure. The internal space frame structure is generally used as an assembly part of the main body of the construction structure, and has the function of setting off the internal system of the steel structure and connecting with other components of the building. The double-mesh large-span structure is the support of the distribution network, which is generally connected with the outer pyramidal structure level of the engineering building, and is the most important structural part of the steel structure building. The external truss column structure is connected with the internal space frame structure as a whole, and the method of aerial scattered assembly is generally used to connect with the curved ball support rod in the building, so as to realize the dual combination of the joint position of the welded structure in the engineering building and the external assembly work of the building.
The wide application of curved large span steel members in modern construction engineering system is a direct expression of the overall improvement of construction technology level in infrastructure engineering. According to the technical research results of the steel members with large span curved surface, its characteristics are summarized as follows: 1, single block combination. In actual use, the distribution space frame of curved large-span steel members is not limited by the internal structure of the external steel structure, and can be dismantled and installed, only to ensure that the internal space frame structure and the external longitudinal structure are reasonably connected, and the flexibility in actual use is also very good. Second, because the size of the curved large-span steel distribution space frame can be changed according to the construction requirements, the external compatibility of the curved large-span steel distribution space frame is also very good.
The application of distribution network support in construction of curved long-span steel structure can maximize the reliability of construction system. Compared with the conventional steel frame, the surface tilt of the curved large-span steel frame distribution network frame is large, and the internal triangular conical stability system is strong. Combined with the design of steel members, the design goal of the random adjustment of the tilt of steel members can be achieved. According to the comparison data with the design of steel components, it can be concluded that the total construction bearing capacity of curved steel frames is larger, and the bearing capacity is 150-200Pa higher than that of conventional steel frames of the same proportion.
Establishment of internal space frame structure. The internal space frame structure system is closely related to each component of the building and is the main aspect to ensure the safety of curved span structure. In general, the method of connecting joints and connecting pins is used to locate the space frame according to the curved steel structure design drawing. At the same time, the connection node is the basis of the initial division of the surface model, so the key to accurately judge the connection node through data simulation after the connection calculation of the connection node. Similarly, the upper end of the curved steel structure and the bottom of the steel pipe are horizontal, and welded with the place connecting the nail bolt, so that the span of the curved steel structure is partially connected into a large-span body of the steel structure. In addition, according to the basic design of the curved large-span steel structure, a mounting rod is arranged at the upper end and a lower chord ball is arranged at the bottom. In the process of implementing the basic connection and construction design of the curved steel member, the cell shape is kept in the up and down position, once the various components of the curved large-span steel member are placed and stabilized, the cell shape on the curved steel structure design will remain at the top of the installation rod, that is, at the highest point of the curved surface. At this time, because the force on both sides of the ball is uniform, its position is relatively stable; On the contrary, if the overall assembly structure of the curved large-span form of the building is not sound, the uniformity of the various groups inside the assembly rod will be low, if the lower string ball is affected by the weight imbalance on the upper part of the curved surface, then the lower ball will shake back and forth inside the assembly rod, at this time, it must be required to complete the curved steel structure assembly adjustment again to ensure that the lower part of the curved steel member is placed evenly.
Trigonal cone positioning. Since there are four elevation adjustments in the basic design of the curved steel structure, the internal structure of each curved steel structure changes, that is, the surface elevation changes on the previous elevation, and finally the final goal of the curved steel structure adjustment is reached. And because the basic structure of the curved steel structure distribution network frame is supported by a triangular cone, if we change the elevation of any curved steel structure, it can be considered as a change in the positioning of the large length triangular cone of the curved steel structure. First, when the triangular cone of the curved steel structure maintains a horizontal position with the earth, the merger of the triangular cone in the network structure, that is, the bottom positioning of the triangular cone is realized through the network frame. In the process of engineering construction, the stability of the steel frame plane can be checked by using the upper and lower string balls, and the method of fixing the nail-like bolt is used to stabilize the triangular cone. Second, according to the different local connections considered by the large-span model, gradually change the foundation elevation of the triangular cone of the internal space frame frame, at this time, the triangular cone elevation should exceed the curved steel structure of the foundation elevation of 10.5, the construction personnel to determine the height, re-carry out the triangular cone stability test. Thirdly, according to China’s first horizontal central three-cone span connection method, on the foundation stone of horizontal central three-cone measurement, it is connected with other remaining span curved steel structures one by one, and finally realizes the internal space frame structure; Fourth, by pulling the traction rope connected with the upper chord column, the curved steel mesh frame in the most central part of the construction component is raised to the highest part of the component. After the top position of the curved steel structure is relatively stable, the construction personnel use auxiliary devices such as jacks and electric hoists at the bottom to monitor the spatial position and level status of the curved steel structure, and implement year-on-year monitoring to complete the construction of the internal space frame structure.
Truss foundation frame construction. The basic structure construction of truss and beam combination is an external auxiliary component of modern curved steel structure long span system. According to the modern curved steel structure long span construction principle, the basic frame construction methods include: First, according to the modern curved steel structure model node, set up a stable platform of truss and beam combination. Generally, the section steel with a diameter of about 15-20mm is used as the bottom, and the triangle cone is built around the internal network, and the ring structure is established in the periphery, and the concrete is used to seal and strengthen the ring body. Second, around the center line of the surface of the truss beam structure, the height of the two-end section steel of the truss beam structure is adjusted according to the curvature of the surface. After the section steel is stabilized after adjusting its position, the section steel across all parts of the structure is fastened together by a small ball and two supporting rods. It is worth noting that in the construction of the basic truss of curved steel structure, it is necessary to ensure the position change space of the curved steel distribution basic space frame pyramid in the later period, and also to play the function of stability with the outer truss. Therefore, it is particularly important to control the gap distance and accuracy when the steel truss is integrated with the basic member steel plate structure.
