1.High attitude assembly
The steel space frame structure is installed by means of the high-altitude assembly method, which firstly sets up the assembly bracket at the design position, and then uses the crane to lift the components (or blocks) of the space structure to the design position in the air, while the assembly is carried out on the bracket. This method sometimes does not require large lifting equipment, but the mounting bracket dosage is large, and mostly involve high attitude work. Therefore, it is suitable for the steel space frame made of shape steel or bolt ball joint with high strength bolt connection. At present, there are still some steel space frame constructed by this method.
The integral installation method is to assemble the space frame into a whole on the ground first, and then use the lifting equipment to lift it to the design position to be fixed. This kind of construction method does not need high height assembling bracket, the overhead work is less, easy to guarantee the welding quality, but needs the lifting equipment with large lifting weight, and involve a more complex technology . Thereby, making this method more suitable for the steel space frame of ball joint (especially the space frame with more bars such as three-way space frame). According to the different equipment used, the whole installation method can be divided into multiple lifting, bar lifting, and jack lifting.
3.High attitude sliding method
In recent years, the application of high altitude parallel sliding method to the roof construction has been increasing; It is especially suitable for theater, auditorium etc. projects. In this construction method, the space frame is usually set up on the roof of the front hall of the building for assembly (it can also be set up on the stand of the audience hall for assembly). When the first assembly unit (or the first section) is finished, it will fall to the sliding track and slide forward for a certain distance with the traction equipment. Next, assemble the second unit (or the second segment) on the assembly platform, and slide forward together with the first assembly unit (or the first segment), so that the segment assembly is constantly sliding forward until the whole space frame is assembled and slid to the position.
When the space frame is well assembled, the roller can be set under the support of the space frame, to allow the roller slide on the clear track. The support base plate can also be set under the grid support, so that the support base can be dragged along the embedded steel plate, embedded in the reinforced concrete frame beam.
Space frame slip can be drawn by winch or handle gourd. According to the size of traction force and the bearing capacity of the bar between the frame support, one or more traction can be adopted. The asynchronous value of both ends should not be greater than 50mm when the space frame slips.
In the process of sliding and assembly, the following calculations shall be performed for the space frame construction:
When there is no support in the middle of span, the internal force and mid-span deflection value should be calculated.
When there are supports in the middle of the span, the internal force of the bar, the reaction force of the fulcrum and deflection value should be calculated.
The temporary reinforcement measures should be taken to prevent the instability when the internal force of the bars changes, due to the addition of intermediate sliding rail.
The overhead sliding method is used to construct the space frame structure, since the space frame assembly is carried out on the top level of the front hall, which reduces the danger of overhead working. In comparison with the high-altitude assembly method, the assembly platform is small, which can save materials and ensure the assembly quality of the space structure. Because of the sliding construction of the space frame assembly, it can be proceeded together with the civil construction, so as to shorten the construction period of the whole project. The overhead slip method construction equipment is simple, and generally does not need the large lifting installation equipment.As a result, the construction cost can also be reduced.