Roof Space Frame Reinforcement Technology In Hall Reconstruction Project

The variety show steel hall was originally an open-type single-layer steel bent-frame factory structure, and the roof is a single-layer space frame structure. In the renovation process, in order to meet the audio-visual visual effects of the main stage, the original plant structure needs to be joisted and pulled out, and the roof frame structure also needs to be reinforced according to the force. The frame is a conical flat single-layer frame, the fulcrum distance is 6m, the span is 33ffl, the height is 2.5m, and the length of the upper and lower chords of the frame is 3m each. According to the overall analysis and calculation results, the bearing capacity of part of the tension rod, compression rod, and part of the web rod of the frame is insufficient. Among them, the tension rod is mainly controlled by the tensile yield load, and the compression rod stability mainly controls the compression rod and the web rod. Therefore, reinforcement needs to improve its tensile and compressive bearing capacity for different types of components.

According to previous engineering practice, there are few precedents for reinforcement engineering of the space frame structure, and there is no similar engineering practice experience for reference. At the same time, because the frame is mostly light pipe fittings, there are many taboos in reinforcement construction, especially welding construction in reinforcement construction is avoided. Therefore, in the selection of the reinforcement scheme, we synthesized the results of theoretical and experimental analysis and adopted the reinforcement form of outsourcing steel pipe. The joint force of the cross-section of the reinforcement method is used to improve its tensile bearing capacity. At the end ball nodes, welded stiffening plates are used to smoothly transfer the rod tension from the outer rod to the ball nodes.

The non-bonded restraint sleeve is mainly used to reinforce the buckling of the compression rod. Its mechanism of action is that when the inner rod is buckling and unstable under compression, the outer casing provides additional constraints to prevent further buckling and deformation, thereby increasing its compressive bearing capacity. Since the outer sleeve does not directly participate in the compression of the rod, the inner and outer rods do not need to be bonded to work together.

The reinforcement of the frame members is rarely encountered in the project, and there is not much actual construction experience. Based on the Shanghai World Expo venue project, in view of the different stress characteristics of the tension and compression members, this paper proposes two different reinforcement schemes: “bonded casing” and “non-bonded restraint casing”, which can effectively improve The tensile and compressive buckling capacities of the rods are measured.