Common Installation Methods and New Ideas of Long-Span Spatial Grid Structures

Spatial grid structure is widely used in large-scale public construction projects in recent years, such as terminal buildings, convention and exhibition centers and gymnasiums, etc. With the growing emergence of new structural form, on-site installation is also facing great challenges. Through combing the typical cases of spatial grid structure in recent years and analyzing the advantages and disadvantages of several common installation methods, it is found that the existing installation methods have certain limitations in practical application. So it is urgent to carry out in-depth research on the new installation technology. Guangzhou football field is built in accordance with international FIFA standards with 100 000 seats. It is a rare sports and cultural complex project in China that combines stadium and business and has a basement under the center of the field. The project design inspiration comes from “twin lotus flowers on one stalk”, take its “bud and tightly embrace” beautiful form, unique shape. The highest point elevation of the steel canopy structure is 88.6 m, and the maximum cantilever length is about 91 m. Three layers of diamond petal shaped blocks are arranged from top to bottom and the petal shape of each layer is composed of 12 units. The length of a single member is 40~64 m, forming a giant ribbed space folded plate grid structure. After the preliminary analysis of the existing methods of high-altitude in-situ installation and cumulative sliding installation, it was found that there were many problems, such as large amount of measures, many cross operations and difficult quality control. Referring to the idea of bridge vertical rotation installation, a negative angle vertical installation method of spatial grid structure was proposed. The core steps were as follows: low position assembly-vertical turning in place-nesting and closing-synchronous and graded unloading. Then the key points such as vertical rotation interface and unit division, vertical rotation system design and hinge structure were analyzed. From this, MIDAS/Gen software was used to carry out construction simulation calculation of deformation and force in key working conditions of vertical rotation process, and compared with the results of design conditions, so as to verify the operability of vertical rotation installation method. The results showed that the simulated deformation values of steel canopy after unloading were basically consistent with the design values. Compared with conventional installation methods, vertical rotating installation technology had certain advantages in safety, quality, quaitity of temporary measures and schedule control, and had a wide application prospect and practical value in the installation of large-span spatial grid structures.