How to calculate farm

How to calculate farm

The building sector is constantly improved. And if earlier for construction of buildings the stone was used, then now the special popularity was gained by pre-fabricated constructions at which construction light strong and dense material, for example, steel is used. And the most widespread elements of building construction are metal farms.

It is required to you

  • - calculator;
  • - building regulations of P-23-81 "Steel structures";
  • - building regulations 2.01.07-85 "Loadings and influences";
  • - production requirements.


1. Choose the static scheme of farms and decide on outline of belts of this design. The choice of that or other outline of farms is caused by assignment of construction, roof type and also corner of its bias and other factors. As a rule, for buildings of civil and industrial purpose cutting farms of trapezoid outline and with parallel belts are used.

2. Determine the general sizes of farms. Provided that production requirements do not provide something other, length of farms is appointed so that the total cost of farms and support was minimum. In other words, at assignment of the general sizes lean on economic reasons. When determining height of farms consider the following indicators: the material used for roof covering, possibility of transportation of design, the requirement of the minimum weight and also opportunity to provide the set corner of bias of belts.

3. Calculate construction rise, that is the return curve which under the influence of strong loading is repaid - farms adopt the design provision. Construction rise pays off in metal farms with flight more than 36 meters and farms from high-yield-point steel and aluminum alloys.

4. Determine the panel sizes: they have to correspond to distance between elements which transfer load of metal design. You remember: the sizes of the panel have to answer drag strut tilt angle. For different designs of farms the corner of drag strut can differ. For example, if grid triangular, the tilt angle of drag strut is equal 45 °, and at the truss - 35 °.

5. When calculating farms specify distance between their knots (provided that the covering will be executed from metal panels or huge reinforced concrete slabs) equal to width of the panel or (in coverings on run) to run step.

Author: «MirrorInfo» Dream Team