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Installation of a large-span farm is necessary in case of application in construction, to create projects of large-span structures.
The use of large-span farms allows to overcome the main disadvantages of monolithic construction: a high level of cost, material intensity, labor intensity and duration of work, the use of unreasonable structural and space-planning systems for the construction of buildings.
One of the varieties of long-span coatings are combined long-span farms, i.e. in one coating, a large-span metal structural structure of a system of two or more independent bearing structures can be combined, working together as a whole and in the case of local damage, capable of redistributing forces.
Since the geometric dimensions of the designed flat farms, more transport dimensions, the assembly of farms must be carried out on the construction site.
Raising and installing a large-span farm
For lifting large-span farms, wall panels and coatings, a lattice traverse design has been developed. The top of the corner of the traverse farm can be directed up or down. In the latter case, the loss of the lift height of the crane hook is reduced, but the design requires great manufacturing accuracy. Poor manufacturing can lead to the twisting of the farm.
When developing schemes for slinging goods, the following rules must be observed:
- Hooks of slings shall be free to enter the yawns of loops, grooves, dice or other load-grabbing device on the load;
- Hooks should be started from the inside of the products towards their center of gravity;
- Products should be attached to all hinges (tapfs, rims);
- Branches of slings during lifting should have the same tension;
- The angle between the branches of the slings should not exceed 90 °;
- Unused ends of the sling should be strengthened so that they do not touch objects encountered on the way when moving the cargo;
- The hook of the sling set in the mounting loop (trap, rum) should not come into contact with the surface of the slinging cargo.
Farms sling either directly behind the upper nodes or, if there are sling holes, with the help of fingers inserted into these holes.
The rigging of a large-span farm
Farms up to 18 m usually sling for two points, with a length of more than 18 m – for four points or use traverses of the lattice type of various structures, equipped with balancing blocks that provide the same tension of the ropes of the slings during lifting.
The branches of the sling should not deviate much from the vertical so as not to create excessive compression in the upper belt of the farm.
The company “Sintez TMK” will produce professional rigging of large-span farms.
Technological maps for installation
General instructions for work
Contractors before the start of work on the installation of the frame must:
– carry out delivery of metal structures from the manufacturer’s plant to the construction site,
– carry out layout (stacking) of metal frame elements directly in the places of their installation.
Unloading of farms at the facility, layout and installation of elements is usually done by a car crane in the range of the mounting crane. Installation of these structures can be performed with a preliminary layout of the elements (or directly from vehicles).The layout of the farms and beams is made in such a way that the crane from the mounting parking can install them in the design position without changing the arrow’s departure. To ensure the stability of mounted elements on the ground, they are stored in special cassettes. When supplying structures to the object in significant quantities, temporary storage in group cassettes without layout in the installation area is allowed.
If it is supposed to mount crane beams in an independent stream, then it is preferable to mount sub-stop farms with them in the same stream.
Technological map for the installation of the frame