ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
2. Engineering characteristics and difficulties 2,1. Precision control of steel pipe truss manufacturing The roof of this project is a pipe truss structure with super large cross-section size. The support is manufactured by factory loose truss parts. After pre-assembly and disintegration, it is transported to the site and assembled by the site. Therefore, how to ensure the manufacturing accuracy has become a major difficulty in this project. The upper steel structure of platform layer is very large. Its East-West length is 186 meters (only PX axis) and North-South width is 245 meters. The platform layer can not directly walk outside the silk hoist of the crane to cover such a large area, which brings great difficulties to installation. 2.3. The viaduct, sandwich and roof all have large span, so it is difficult to select the type of tyre frame and prepare the material. 2.4. The number and level of the brackets are large, and the installation of roof truss with difficult unloading process uses a large number of bracing brackets. How to unload and remove the bracing brackets and ensure the large structural deformation of the structure is another difficulty in the construction of this project. 2.5. Installation of track layer and steel-bonded truss is carried out step by step in the difficult site of assembly and component stacking. The site lacks site. The assembly of truss parts and truss yard national disaster 2.6, the construction of truss bridge and ramp is difficult because the crane can not be constructed on the ground floor and the crane is located in the direction of vertical track. Therefore, trestle and ramp need to be laid for the crane. The trestle is laid out for 2.7, and the crane is erected. The locomotive gets off because the ramp is laid and there is a space for getting on. There is no ramp position when getting off, so it is difficult to get off.
2.8. Installation organization is difficult because of the number of structural layers, cranes are not suitable to be deployed, civil engineering and other related operations intersect seriously, component is very difficult. 3. Installation scheme introduction and execution process. Because the production is made in Shanghai Processing Plant, the scheme mainly introduces the technology of site installation and construction. Station steel structure installation is divided into three horizontal layers: elevated layer, sandwich layer, roof, and steel column in each layer. In order to ensure installation, combined with the actual situation of the site, the following aspects are well prepared 3.1. According to the division of labor in the general contract, the working flow direction is formulated, and the construction plan and sequence are determined by itself with the P axis of the joint plan as the boundary (the P axis of the first edition of the national paper is the expansion joint, the second edition is the M axis), and the P~X axis as the east. According to the drawing, the central line of the 18-19 line is the symmetrical axis in the eastern district, and the center line of the 18-19 line is the symmetrical axis in the platform layer, the elevated layer, the commercial interlayer and the roof. The elevated layer and the commercial interlayer are the frame structure. There are not too many requirements for the lifting sequence. The winter direction can meet the lifting requirements, but the ground layer of the 18-19 line has the completed structural parts. This part can not bear the load, especially the load of silk machine.
Secondly, the roof is an integral truss. All the longitudinal and transverse trusses except the supporting poles are welded through the central line of the 18-19 lines. Therefore, our company decided to take the vertical direction of the symmetrical axis as the main truss, and the truss parallel to the symmetrical axis as the secondary truss, which is conducive to the installation of the roof truss, as shown in Figure 4.