Applicable conditions of LED display steel structure lifting program
Due to the non-uniformity of building shapes and structural forms, the construction site conditions are so different that it can be said that there is no one work method or program applicable to the installation of any steel structure project, so each installation method has its own supporting conditions.
Net frame structure
Commonly used installation methods include: overhead bulk installation method, strip and block installation method, structure sliding method, support frame sliding method, overall lifting method, overall lifting method and so on.
Consideration by process: understand the structure form, structure weight, installation height, span and other characteristics, combined with the actual situation of the site as far as possible to choose a mature, advanced installation process.
Consideration of lifting equipment: firstly, choose own equipment, make full use of lifting equipment on site, and secondly, rent nearby. General situation: when the number of components is small, more use of truck-type cranes; gantry rigging more use of small and medium-sized truck-type cranes; installation period is longer, the installation height and radius of gyration is larger, crawler cranes than truck-type cranes economic; the overall lifting and skidding more use of hydraulic synchronous lifting (push) device; medium and high-rise steel structure installation is generally used in the tower crane; ordinary bridge installation more use of gantry cranes and bridge cranes. Cranes and bridge cranes.
Inverted method construction
Inverted loading method is a special installation process which is applicable to structures with large height to width ratio, such as steel towers, masts and other structures. Conventional cranes are difficult to lift close to the case, generally more inverted loading method. The use of this method should focus on considering the overall stability of the structure during the installation process and the stability of the equipment itself, there should be reliable support and stabilization measures.
Structure sliding method
The structure slip method has been developed to use hydraulic jacking pusher and computer synchronization control technology, which is one step more advanced than the past net frame slip method. It is applicable to the following conditions: first, due to site conditions, the span can not be set up cranes and support frames; second, the structural support conditions are conducive to the laying of skidding track; third, the calculation of the strength and stiffness of the structure of the skidding unit are determined to meet the requirements; fourth, to understand the form of structural support and fixing methods; fifth, the longer the longitudinal skidding route, the higher the efficiency.
Support frame slip method
Its applicable conditions are occupying the site within the span, lower installation height, larger structural area or longer longitudinal length. Firstly, when the installation height is below 15 meters, ordinary fastener type steel pipe scaffolding or bowl-mouth type scaffolding can be used as the supporting frame; secondly, for the frame is higher and the load bearing capacity is larger, it is appropriate to use section steel supporting frame. Regardless of which program, in the design calculation in addition to the specification requirements, but also consider the horizontal dynamic load, if necessary, additional large diagonal braces to improve its overall stability.
Overall lifting method
Overall lifting method is currently used in Tongji University developed computer synchronous control, hydraulic lifting equipment, the process gradually replace the penetration of motorized lifting and jacking jacking program, its equipment is lightweight, advanced technology. It is applicable to the following conditions: firstly, occupying the site within the span; secondly, the installation height is higher; thirdly, the components are heavier; fourthly, it is limited to vertical lifting and cannot be displaced horizontally. That is, the higher the installation height, the heavier the lifting weight, the better the effect.
Soil method lifting
Soil method of lifting is the use of unicorn bar, herringbone frame, roll field machine, pulley block, etc. as lifting equipment for structural lifting, which is suitable for the project of heavy components, small quantity and high installation height. Since there are more and more large-tonnage lifting equipments and advanced installation techniques, so the earth method lifting is less and less.
Rotary method construction
This method is mainly used for bridge installation, due to the influence of railroad and highway traffic, as well as mountains, rivers and gorges and other special environments, other methods of bridge erection are restricted, the rotary method of construction is mostly used.
Integral lifting method
It is basically similar to the overall lifting method, only different lifting equipment, suitable for small and medium-sized structure installation. In the early days, multiple single foot bar or herringbone, winches, pulley blocks and cable wind system were used for large tonnage lifting. Now, due to the large tonnage crane more, for small and medium-sized projects according to the need to choose more than one crane centralized lifting for installation.
Net frame structure
Commonly used installation methods include: overhead bulk installation method, strip and block installation method, structure sliding method, support frame sliding method, overall lifting method, overall lifting method and so on.
Consideration by process: understand the structure form, structure weight, installation height, span and other characteristics, combined with the actual situation of the site as far as possible to choose a mature, advanced installation process.
Consideration of lifting equipment: firstly, choose own equipment, make full use of lifting equipment on site, and secondly, rent nearby. General situation: when the number of components is small, more use of truck-type cranes; gantry rigging more use of small and medium-sized truck-type cranes; installation period is longer, the installation height and radius of gyration is larger, crawler cranes than truck-type cranes economic; the overall lifting and skidding more use of hydraulic synchronous lifting (push) device; medium and high-rise steel structure installation is generally used in the tower crane; ordinary bridge installation more use of gantry cranes and bridge cranes. Cranes and bridge cranes.
Inverted method construction
Inverted loading method is a special installation process which is applicable to structures with large height to width ratio, such as steel towers, masts and other structures. Conventional cranes are difficult to lift close to the case, generally more inverted loading method. The use of this method should focus on considering the overall stability of the structure during the installation process and the stability of the equipment itself, there should be reliable support and stabilization measures.
Structure sliding method
The structure slip method has been developed to use hydraulic jacking pusher and computer synchronization control technology, which is one step more advanced than the past net frame slip method. It is applicable to the following conditions: first, due to site conditions, the span can not be set up cranes and support frames; second, the structural support conditions are conducive to the laying of skidding track; third, the calculation of the strength and stiffness of the structure of the skidding unit are determined to meet the requirements; fourth, to understand the form of structural support and fixing methods; fifth, the longer the longitudinal skidding route, the higher the efficiency.
Support frame slip method
Its applicable conditions are occupying the site within the span, lower installation height, larger structural area or longer longitudinal length. Firstly, when the installation height is below 15 meters, ordinary fastener type steel pipe scaffolding or bowl-mouth type scaffolding can be used as the supporting frame; secondly, for the frame is higher and the load bearing capacity is larger, it is appropriate to use section steel supporting frame. Regardless of which program, in the design calculation in addition to the specification requirements, but also consider the horizontal dynamic load, if necessary, additional large diagonal braces to improve its overall stability.
Overall lifting method
Overall lifting method is currently used in Tongji University developed computer synchronous control, hydraulic lifting equipment, the process gradually replace the penetration of motorized lifting and jacking jacking program, its equipment is lightweight, advanced technology. It is applicable to the following conditions: firstly, occupying the site within the span; secondly, the installation height is higher; thirdly, the components are heavier; fourthly, it is limited to vertical lifting and cannot be displaced horizontally. That is, the higher the installation height, the heavier the lifting weight, the better the effect.
Soil method lifting
Soil method of lifting is the use of unicorn bar, herringbone frame, roll field machine, pulley block, etc. as lifting equipment for structural lifting, which is suitable for the project of heavy components, small quantity and high installation height. Since there are more and more large-tonnage lifting equipments and advanced installation techniques, so the earth method lifting is less and less.
Rotary method construction
This method is mainly used for bridge installation, due to the influence of railroad and highway traffic, as well as mountains, rivers and gorges and other special environments, other methods of bridge erection are restricted, the rotary method of construction is mostly used.
Integral lifting method
It is basically similar to the overall lifting method, only different lifting equipment, suitable for small and medium-sized structure installation. In the early days, multiple single foot bar or herringbone, winches, pulley blocks and cable wind system were used for large tonnage lifting. Now, due to the large tonnage crane more, for small and medium-sized projects according to the need to choose more than one crane centralized lifting for installation.