After the calculation and assembly are completed, the mutual positioning between the ball and the rod is used to gradually expand the assembly outwards. The component placement sequence and method are used to expand and assemble the peripheral components in a similar way. The accuracy of the external expansion assembly ensures that the grid structure of the small assembly unit adopts the near-ground assembly method. After the assembly of the small assembly unit is completed and the installation accuracy is checked, it can be completely separated from the fulcrum of the brick pier and connected to the same bolt ball. The lengths of the three rods above are used as control indicators to perform spatial positioning of the next bolt ball. Since the area of ??the assembled units continues to change during the expansion process, the assembled structure will undergo a certain overall elastic deformation because the position of the hanging point remains unchanged. Since the relative stiffness of each small assembly unit is relatively large, the grid frame There will be no local deformation, so when expanding, use the other three installed bolt balls corresponding to one bolt ball as the reference for positioning and positioning using the length of the rod, which will not cause cumulative errors to the overall grid. After a part of the small units are assembled by external expansion, the three-dimensional model of the grid should be used to convert the coordinates of the corresponding positions in the Autocad software in a timely manner, and the installation accuracy of the assembled small units should be reviewed based on the converted relative coordinate positions. If there is a deviation, the installation accuracy of the assembled small units should be reviewed. Make adjustments in the next small unit. Overview of the hoisting of the grid. The grid size and height of the grid for this project are relatively large. Based on the characteristics of the project and the accumulated experience in the overall hoisting of similar projects, it was decided to use the overall hoisting method on the ground for this project. Hoisting construction method. The details are as follows: The top elevation of the grid column is meters, so the height of the central pull-out pole is meters, and each block is equipped with a set of poles.