ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
The wavy steel roof truss of the main building of the terminal is a long-span spatial structure. A rigid-flexible hybrid structure system, one-three-span continuous beam string, is adopted to support the lower concrete frame structure through Y-shaped bifurcated middle column and side inclined column. The upper chord of the beam string is a single box-shaped member at the top of the column, and is divided into two box-shaped members in the yoke. The height of the section decreases gradually from the maximum at the top of the column to the middle of the yoke. The lower chord of the beam string is connected with the upper chord by a single high strength steel tie rod and a cast steel anchor. The upper end of the inclined column on the side of the middle column and the elevated road is articulated to the lower flange of the beam string, and the lower end is rigidly connected to the top of the steel concrete cantilever column. The upper and lower ends of the oblique column on the other side are hinged. The Y-type middle column, side inclined column, transverse beam string and longitudinal continuous beam form a complete lateral resistance system of the roof truss. The main body of the roof truss of the main building of the terminal is 46 curved box girder roof trusses with variable cross-section. The cross-section of the basic box girder of the upper chord is 300 mm to 1622 mm, the height of the box girder is 768 mm to 2288 mm, and the welding box tube of the upper chord of the roof truss is 600 to 200 x 300.
The steel cable with the lower chord of p100~180 passes through the cast steel joints and forms a mixed structure with the belly cable and the upper chord box girder. The span of the three-legged continuous beams is 46.85 meters, 89 meters and 46.85 meters respectively. The length of the single roof truss is about 218 meters. The supporting structure is a single box steel column, single Y box steel column and double Y box steel column combination system. The upper end of the steel column is articulated joints. The overpin shaft is connected with the special-shaped steel castings at the lower end of the roof truss. The roof truss beam is connected by box girder, I-beam, bracing system, bracing and louver steel beam, forming a stable roof truss system. The total length of the roof truss of the terminal building is 415 meters, the total width is 218 meters, and the total weight of the steel structure is about 15,000 tons. Figure 2. Technical difficulties in engineering construction 2.1 Roof truss beams are composed of two-way curved box girders with variable cross-section. Complex shape and large cross-section variation are the characteristics of the roof truss beams. How to control the deformation in the process of assembling and welding is the guarantee. Dimensional accuracy is the key to the processing of roof truss beams. Roof truss beams are connected with steel columns through special-shaped cast steel joints. The installation dimensional accuracy of cast steel joints directly affects the installation accuracy of structures.
2.2 The particularity of Engineering structure, diversity and complexity of roof truss joints bring many difficulties to engineering inspection. A considerable number of acceptance projects do not have ready-made specifications and standards that can be directly quoted. Therefore, to formulate a steel tie rod system for the lower chord of the roof truss beam, which is a pass for the acceptance standard of the project and a quality certificate of the project, not only the architectural shape but also the functional use should be considered. This brings great difficulties to the determination and installation control of the scheme of the steel tie rod and the joint, and the space angle of the base plane and the axis of the cast steel joint. The external surface is a torsional surface, which puts forward a high requirement for the inspection and installation of steel castings. The delivery state of 2.5 chord beams in segments is in stable two-fulcrum state. It has its particularity. Corresponding technical measures must be taken. 3.Key manufacturing technology 3.1 Precision control technology for steel roof truss construction of main building 3.1 Roof truss beams from two-way bending to truncation. The surface box girder is composed of 500 *2200 maximum section and 300 *200 minimum section. The cross section varies greatly and the shape of the box girder is complex.
In view of its composition characteristics, we have carried out technological research from the aspects of assembly and welding, and formulated many corresponding measures to ensure the quality and accuracy requirements of the project.