High-altitude bulk installation method and integral hoisting method for grid frame
# Grid Frame Installation 1. According to the actual site conditions and construction schedule requirements, the grid frame shall be installed by means of **integral hoisting of single segments**, **high‑altitude bulk installation**, and **strip‑by‑strip or block‑by‑block installation**. 2. **Integral Hoisting Method** The integral hoisting method is to assemble the grid frame structure into an integral unit on the ground in a staggered layout, as required by the hoisting technology. The grid frame is then integrally lifted to the design elevation by hoisting equipment, shifted in the air, locked at the edges, and finally positioned and fixed. **Process Flow:** Technical preparation before installation → Ground assembly and inspection of the grid frame → Hoisting preparation → Test hoisting and formal hoisting → Positioning in the air → Support fixing **Notes on ground assembly:** During assembly, supports shall be set under the bolted balls according to their internal forces to prevent deformation of the grid frame members. After assembly, inspect each member for deformation and check whether the bolts at the bolted ball joints are fully tightened one by one. **Selection of hoisting scheme** Four cranes shall be used for synchronous hoisting. When arranging the cranes for four‑crane lifting, the working performance of each crane and the requirements for air shifting of the grid frame shall be taken into account. The hoisting speed of each crane shall be measured before lifting for coordinated control. When the lifting capacity of all four cranes meets the requirements, the cranes are preferably arranged on both sides of the grid frame. After the grid frame is vertically lifted above the column tops, it can be shifted in the air by rotating a certain angle. **Selection of hoisting points** The layout of hoisting points shall ensure that the internal forces of the grid frame during hoisting are basically consistent with those in its service state. The weight, area and position of hoisting points shall be carefully calculated based on actual site conditions to ensure the safety of hoisting. Fasten the hoisting slings, complete all inspections, and then start hoisting. **Test hoisting and formal hoisting of the grid frame** - **Test hoisting**: Lift the grid frame 50 cm off the ground, inspect the slings at hoisting points and the profile of the grid frame. Confirm everything is normal before formal lifting. - **Formal hoisting**: Lift the grid frame to the target position in one lift and place it on the ball supports at the column tops. When the grid frame is lifted 300 mm above the column tops, perform air shifting. Once the center of the grid frame is aligned with the center of the grid frame supports, lower the hooks of the four cranes simultaneously to set the grid frame in place on the column tops.