The installation of the steel structure of the LED display screen is a relatively complex and comprehensive technology with more content and a wider range. The following is a small series combining some steel structure projects, expounding the basic principles and applicable conditions of steel structure hoisting scheme design, summarizing the feasibility of conventional installation methods and corresponding technical measures.

With the continuous development of science and technology, the shape and structure of steel structures are becoming more and more complex, which brings new challenges to the design and construction of steel structures. For example, Olympic venues represented by "Bird's Nest" and "Water Cube", as well as influential steel structure projects such as the National Centre for the Performing Arts, the new CCTV site, Guangzhou TV Tower, and Famen Temple stupa, not only have innovations and developments in design At the same time, new achievements have been made in steel structure installation technology. Many mature and advanced process methods have successively become construction methods, which have played a role in promoting the development of the steel structure industry.

Due to market reasons, steel structure installation accidents and violations have occurred from time to time, causing unnecessary economic losses and social impacts. In order to further improve the overall level of steel structure construction and promote the development of the industry, in addition to strengthening construction site management, steel structure construction should also conduct research and summary in construction organization design, schemes, technical measures, etc.; vigorously promote new technologies and processes; target engineering Features, choose an advanced, reliable and economical construction plan.

1. The basic principles of the LED display steel structure hoisting plan

1.1. Policy: Based on drawings and norms, strictly implement the relevant national safety production regulations.

1.2. Reliability: Adhere to safety first, ensure the feasibility of the implementation of the plan, and increase its reliability. No matter which method is adopted, we must first consider whether the program has a successful precedent and supporting equipment, otherwise the program must be demonstrated. According to the characteristics of the structure, the construction check is carried out to prove whether the stability of the structure and the stress and deformation of the rods meet the requirements during the construction phase of the method. Whether the mechanical equipment used can meet the installation requirements. Whether the construction site conditions are met, such as whether the civil construction environment and surrounding structures restrict the implementation of the plan, etc.

1.3. Advancement: With the development of science and technology, new processes, new technologies and new equipment in the field of structural installation are emerging in endlessly. For example, the advent of large-tonnage cranes, and computer-synchronized control of overall lifting and sliding technology have added a new chapter to structural installation. Especially for large-scale steel structure projects, when the site conditions and structural forms permit, new technologies and new processes should be vigorously promoted; the amount of high-altitude work should be reduced as much as possible, and the installation efficiency of steel structures should be continuously improved.

1.4. Economical: A good installation plan should have simple methods, appropriate measures, high efficiency, low construction cost, wide range of applications, and stand the review and test. Therefore, we must adhere to the principle of program comparison, conduct technical and economic analysis, and choose a program with a short construction period and low cost.

2. The applicable conditions of the LED display steel structure hoisting plan

Due to the inconsistency of architectural modeling and structural form, the construction site conditions are very different. It can be said that no construction method or scheme is suitable for the installation of any steel structure project, so each installation method has its own supporting conditions.

Commonly used installation methods for grid structure are: high-altitude bulk method, strip and block installation method, structure slip method, support frame slip method, integral hoisting method, integral lifting method, etc.

2.1. Consider the process method: understand the characteristics of structure form, structure weight, installation height, span, etc., and choose mature and advanced installation technology as far as possible in combination with the actual situation of the site.

2.2. Consider according to lifting equipment: firstly select own equipment, make full use of on-site lifting equipment, and secondly rent it nearby. General situation: when the number of components is small, truck cranes are often used; gantry frame hoisting is mostly small and medium-sized truck cranes; when the installation period is longer, the installation height and the turning radius are large, crawler cranes are more economical than truck cranes; overall Hoisting and sliding mostly use hydraulic synchronous lifting (incrementing) devices; middle and high-rise steel structure installations generally use tower cranes; ordinary bridge installations mostly use gantry cranes and bridge erecting machines.

2.3. Inverted installation method: Inverted installation method is a special installation process of up and down. It is suitable for structures with large height-to-width ratios, such as steel towers, masts and other structures. When it is difficult for conventional cranes to approach the hoisting, the upside-down method is generally used. When adopting this method, it is necessary to focus on the overall stability of the structure during the installation process and the stability of the equipment itself, and reliable support and stability measures must be taken. Structure slip method-The structure slip method has been developed to adopt hydraulic pusher and computer synchronous control technology, which is a step more advanced than the past grid slip method.

Its applicable conditions are: first, due to site conditions, no crane and support frame can be installed in the span; second, the structural support conditions are conducive to laying slip tracks; third, the strength and strength of the slip unit structure determined by calculation The rigidity meets the requirements; fourth, understand the form of structural support and fixing methods; fifth, the longer the longitudinal slip path, the higher the efficiency. Support frame sliding method-its applicable conditions are the occupation of the inner space, the lower installation height, the larger structural area or the longer longitudinal length. First, when the installation height is less than 15 meters, you can choose ordinary fastener-type steel tube scaffolding or bowl-type scaffolding as the support frame; second, when the frame is higher and the load-bearing capacity is large, the steel support frame should be used. No matter which scheme is adopted, in addition to the requirements of the code, the horizontal dynamic load must be considered in the design calculation, and large diagonal braces should be added when necessary to improve its overall stability.

2.4. Overall lifting method: The overall lifting method currently mostly uses the computer synchronization control and hydraulic lifting equipment developed by Tongji University. This process has gradually replaced the through-core motorized lifting and jack lifting schemes. The equipment is light and the technology is advanced.

Its applicable conditions are: first, it occupies the space within the span; second, the installation height is higher; third, the components are heavier; fourth, it is limited to vertical lifting and cannot be displaced horizontally. That is, the higher the installation height, the heavier the lifting weight and the better the effect.

2.5. Indigenous hoisting: Indigenous hoisting is to use single-angle bar, herringbone, rolling machine, pulley block, etc. as lifting equipment for structural hoisting. It is suitable for projects with heavy components, small quantity and high installation height. As there are more and more large-tonnage lifting equipment and advanced installation technology, so the local method of hoisting is also less and less.

2.6. Rotation method construction: This method is mainly used for bridge installation. Due to the influence of railway and highway traffic, and under special circumstances such as mountains, rivers and ditches, when other bridge erection methods are restricted, the rotation method is often used.

2.7. Overall hoisting method: It is basically similar to the overall hoisting method, except that the lifting equipment is different, and it is suitable for small and medium-sized structure installation. In the early days, several single-leg poles or herringbone frames, hoists, pulley blocks and cable wind systems were used for large-tonnage hoisting. Now, due to the large number of large-tonnage cranes, multiple cranes are selected for centralized lifting and installation for small and medium-sized projects according to the needs.