In the field of modern architecture, grid steel structures are widely used in large sports venues, exhibition halls, industrial plants, and other buildings due to their advantages of lightweight, high strength, and good spatial performance. The overall hoisting of the grid steel structure is a key construction process, and its construction quality and safety directly determine the success or failure of the entire project. The overall requirements will be introduced from the aspects of preparation before lifting, control during lifting process, and precautions.

Preparation before lifting

Structural verification

Before hoisting, a comprehensive structural verification must be carried out on the grid steel structure. Consider various load effects during the lifting process, such as self weight, wind load, dynamic load, etc., to ensure that the grid structure has sufficient strength, stiffness, and stability during the lifting stage. Using professional structural analysis software to simulate the stress situation of structures under different working conditions, providing a basis for setting lifting points and selecting lifting equipment.

Site and equipment preparation

The construction site should be flat and solid, meeting the requirements for the walking and standing of lifting equipment. If the site is narrow or the terrain is complex, it is necessary to carry out site treatment or develop special construction plans in advance. Reasonably select lifting equipment based on the weight, size, installation height, and construction site conditions of the grid structure, such as large crawler cranes, tower cranes, etc. Conduct a comprehensive inspection and debugging of the selected lifting equipment to ensure its good performance and complete and effective safety protection devices. At the same time, prepare auxiliary equipment such as slings, lifting devices, and ground anchors, and conduct strict inspections and tests.

Grid assembly

Build a flat and solid assembly platform on the ground, and accurately assemble the members and nodes according to the design drawings. During the assembly process, the assembly accuracy is strictly controlled to ensure the accurate position and firm connection of each member and node. Perform dimensional review and quality inspection on the assembled grid structure to ensure compliance with design requirements and relevant standards.

Hanging point setting

The reasonable setting of lifting points is the key to the overall lifting of grid steel structures. The number, location, and layout of lifting points need to be determined based on the shape of the grid, the distribution of the center of gravity, and the performance of the lifting equipment. The general principle is to arrange the lifting points evenly and avoid local stress concentration. At the same time, the connection method between the lifting point and the grid structure should be considered to ensure that the connection is firm and reliable, and can withstand various forces during the lifting process.

Lifting process control

Synchronous control

When multiple cranes are used for collaborative operation, synchronous control is crucial. The lifting speed and height of each crane must be consistent, otherwise it may cause uneven stress on the grid structure, leading to deformation or even damage. Adopting advanced synchronous control system, real-time monitoring of the operating status of each crane through sensors, once deviations are detected, they can be quickly adjusted to ensure a smooth and orderly lifting process.

process monitoring

During the lifting process, real-time monitoring is conducted on the deformation, stress, and operational status of the truss structure and lifting equipment. Use monitoring equipment such as total stations and stress-strain gauges to timely grasp the actual situation of the structure. If any abnormalities are found, immediately stop lifting, analyze the cause, and take corresponding measures for handling.

Positioning and fixation

After the grid is lifted to the design position, it is precisely positioned and fixed. By adjusting the position and angle of the lifting equipment, the grid can be accurately placed on the support. Then, according to the design requirements, connect and fix the grid and support to ensure a firm and reliable connection.

matters needing attention

The weather conditions at the construction site have a significant impact on lifting safety and accuracy. Severe weather conditions such as wind, rain, and heavy fog can reduce the performance of lifting equipment, affect the visibility of operators, and increase lifting risks. Therefore, it is necessary to strictly follow relevant standards and stop lifting operations under adverse weather conditions. Although sufficient preparation and careful planning are carried out before construction, unexpected situations such as equipment failure and sudden weather changes may still occur during the lifting process. Therefore, it is essential to develop a comprehensive emergency plan.

 
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