Profiled pipe farms have become widespread in the household and industry. On the basis of such a framework, you can build any structure: from a house to the hangar, warehouse or even stadium. Types and sizes of such metal structures are very diverse: trusses can even serve as a framework for chimneys. The basis of any building will be drawings, therefore, special attention should be paid to the correctness of its composition.
Farms are a mandatory part of the canopy structure, garage or hangar
The list of types of farms from a profile pipe
Metal trusses from a profile pipe for a canopy construct from a profile, most often steel. The profile can have different cross-sectional shapes: rectangular, square and the most popular - rectangular.
Types of farms have divisions into two categories: farms, where all the elements are fastened together in one plane and the structure with a suspended structure (includes upper and lower belts).
Constructions are divided on the following grounds: required load on the profile, slope system, type of floor arrangement, flight length and degree of inclination. Depending on these factors, farms may be as follows:
1. Buildings with a slope, which is 22-30 degrees. Requirements for the sustainability of farms of this plan show, that their height should not exceed 1/5 from the entire length. Usually the calculation of the height is based on this principle, dividing the planned length of the hangar by 5. This bias is chosen then, when they want to achieve the relative lightness of the system.
If the length of the entire structure exceeds 14 meters, in this case, the braces should be placed in the direction from top to bottom. At the same time on the top tier place the panel length 150-250 div. In the end, the building with two belts, the number of panels will also be even.
The shape of the farms and their number depends on the type and size of the structure, as well as from the expected load on its roof
Wrinkle! If you plan to build a farm span more 20 meters, installation of rafter elements is necessary, which will be supported by additional columns.
Another commonly used variety of this species will be the so-called Polonso farms - triangular structures with a connection in the form of a puff. Polonso profile pipe truss is considered very light, as at its construction it is possible to avoid too long braces.
2. Farms with a nominal slope of the roof in the border 15-22 degrees. This option is considered for buildings, which will not end up having a span length longer 20 meters. Types of farms with such a slope have a height, component 1/7 of the total length. If you need to increase the height of the lower belt should be made of broken segments.
3. Designs with a minimum slope, not exceeding 15 degrees. With the planned coal of the farm to 15 degrees the best option would be trapezoidal structures. The calculation of the height is based on individual considerations, it all depends on the specific angle of the roof and the purpose of the hangar. The height can be within 1/7 to 1/12 length.
For trapezoidal trusses, the optimal length of the metal panels should be 1,5-2,5 m. If the drawing does not include a suspended ceiling, braces can be replaced by a triangular lattice.
If we are talking about the shape of the structure, trusses from a profile pipe happen the following type:
- one-slope;
- two-slope;
- direct;
- arched.
The latter variety - arch-type farms - are the most common. They are quite strong, they can be lined with polycarbonate sheets. The calculation of the arched canopy must be very accurate, so that the weight is distributed on the profile as evenly as possible. Arched trusses are also built from ordinary profile pipes, and of welded together.
The arched type of trusses allows to make a semicircular roof from polycarbonate
Calculation of a truss from a profile pipe steel
The mechanism of calculation and creation of the drawing of a truss from a profile pipe is carried out in some important stages:
- The initial stage is the calculation of the length of the hangar (garage, barn - room, the construction of which is planned). The height of a metalwork will depend on this indicator. In turn, the length of the structure directly depends on the angle of the roof.
- Then the contours of the profile belts are selected. The choice will be influenced by the type of hangar destination, the type of roof covering and the angle of its slope.
- Now, when all the dimensions of the metal structure are known, it is necessary to be defined with that, whether it will be possible to transport the farm to the facility, if construction is carried out on a construction site.
- It is necessary to provide for the presence of construction lifting of the roof, if the length of the hangar is in the range 12-36 m.
- Calculate the dimensions of the panels. The calculation is based on the load indicator, constantly or periodically affect the structure. If the farm is triangular in shape, the nominal angle of inclination will be 45 degrees.
- The distances between all nodes are determined, the drawing of a truss from a profile pipe on the basis of the carried-out measurements and calculations consists.
Wrinkle! For more accurate calculations of the construction of the arched hangar from the profile pipe, it is recommended to use a construction calculator. In general, conducting such calculations manually is now very rare, claim accuracy of calculations can be obtained, using special programs for architects and builders on the PC.
You can create farm drawings manually or with a computer program
Calculation of an arched truss from a profile pipe
Consider a specific example of calculation for an arched canopy. The parameters of the proposed structure will be as follows: farms are located with a step 1,05 m, loads will be concentrated on nodal areas. The height of the arch in our case should not exceed 3 meters. The recommended height of the farm will be 1,5 m - this parameter is considered more attractive from an aesthetic point of view, and for reasons of strength. A span is taken between the supports 6 m (L), lower level arrow - 1,3 m (f). The circle in the lower tier will have a radius 4,1 m (r). The angle between the radii will be ?=105.9776°.
The length of the profile from the lower belt is calculated by the formula:
mn = ?*Ra/180.
In her: mn - the value of the profile of the lower belt; R is the radius of the circle; A is the angle between the radii; ? - constant.
As a result:
mn = 3,14 X 4,1 X 106 / 180 = 7,58 (m).
The step between the nodes of the structure in the lower belt should be 55,1 cm, while the steps between the extreme sections are calculated individually. To simplify installation, the figure can be rounded to 55 cm, but do not increase the step.
The calculation of the canopy of small dimensions allows the number of spans in the area 8-16. For a minimum number of lengths of rods will be 95,1 cm at the step between the belts in the area 87-90 div. For the maximum number of flights, the step will be 40-45 div.
Requirements for the calculation of profile pipe for farm construction
When choosing profiled products, especially for large canopies, should be guided by data, provided by SNiP:
- 07-85 - data on the interaction of snow loads and weights of other structural parts of the structure;
- P-23-81 - algorithm for working with profiled steel products.
The wall canopy also carries a load, and its design must also be carried out taking into account the snow cover in winter
The data from the presented provisions will help to orientate faster in choosing the type of farm, roof angle and cross section, the size of a profile pipe for racks of a construction.
Importantly! The location of the region will also influence the choice, precipitation, falling out during the winter.
Consider the following example: it is planned to build a wall canopy with dimensions of 4.7x9 meters. Its leading edge rests on the rack, and the back is attached to the outside wall of the house. The building will be erected in the southern region, example, in the Krasnodar Territory. Information on snow load for each region can be found on the Internet, in our case it will be 84 kg / m2. The optimal angle of the roof for a canopy of this size will be everything 8 degrees.
One rack tall 2,2 meter weighs up to 150 kg, and its vertical load will approach 1,1 tons. Profile pipes round (oval) cross-sections for these purposes are not suitable, the minimum values for the profile square pipe - section 45 mm and wall thickness 4 mm, But if you upgrade the design a bit, entering into it two parallel belts with an oblique grid, for them you can take a profile with a cross section 25 mm and wall thickness 3 mm At the height of the truss of the profile pipe 40 cm for belts it is necessary to apply square professional pipes with indicators 35 mm and 4 mm respectively.
For simplicity of calculation of a truss from a profile pipe for a canopy it is possible to use the table of correspondence of section and thickness of walls with GOST 30245.
Table 1
| closed. about- fil straight- ug. cross section | closed. about- fil square. cross section | Indicators of wall thickness | |||||||||||||||||
| One | 1,5 | 1,8 | Two | 2,5 | Three | 3,5 | Four | Five | 5,5 | Seven | Eight | Nine | Ten | Twelve | 12,5 | Fourteen | Sixteen | ||
| — | Fifteen | + | |||||||||||||||||
| — | twenty | + | + | + | |||||||||||||||
| 40x20 | Twenty five Thirty | + | + | ||||||||||||||||
| 40x25 | — | + | + | + | |||||||||||||||
| 60x30 and 60x40 | Fourty Fifty | + | + | + | + | ||||||||||||||
| 80 X 40 | — | + | + | + | |||||||||||||||
| — | Sixty | + | + | + | + | + | + | + | |||||||||||
| — | Eighty | + | + | + | + | + | |||||||||||||
| 120x80 | Ninety | + | + | + | + | + | + | ||||||||||||
| 140х120 150х100 | A table One hundred twenty | + | + | + | + | + | + | + | + | ||||||||||
| 160х140 180х120 180х140 240х120 | One hundred forty Hundred and fifty One hundred and sixty One hundred and eighty | + | + | + | + | + | + | + | |||||||||||
| 150x130, 160x120, 180х100 | — | + | + | + | + | + | + | + | + | ||||||||||
| 240х150 250х140 | Two hundred Two hundred and twenty | + | + | + | + | + | + | ||||||||||||
| 300х100 | — | + | + | + | + | + | + | + | + | + | + | ||||||||
| 260х240 300х200 | Two hundred and fifty Three hundred | + | + | + | + | + | + | + | + | ||||||||||
That the design did not collapse under the influence of corrosion, for its basis it is necessary to choose pipes from alloy steel
Metal pipes for the construction of an arched canopy should be bought high quality, preferably of alloy steel. The alloy should contain a large amount of carbohydrates - this creates sufficient protection of the metal from the effects of natural factors and the environment..
Recommendation for the calculation of a metal truss from a profile pipe
There are some subtleties in farm design:
- To forcibly reduce the weight of the structure, it is possible to build a hangar with additional bars (in that case, there is a minimum slope of the roof);
- to lighten the roof with a medium slope, broken lower belts are used;
- the distance between individual farms does not exceed 175 div.
The following rules should be observed when manufacturing and welding metal trusses from profile pipe:
- The hangar elements are connected by tack and paired corners.
- Details of the lower belt are welded at equilateral angles.
- The truss frame in the upper belts is connected by I-beams. Their sides must be of different lengths, and the joint is made on the smaller side.
- For distribution of loadings channels of pair type and overhead plates are applied, welded together. This method of connection is used if necessary to increase the length of the canopy.
- The quality of each weld is strictly controlled during the works. At the end of the welding process, each seam should be cleaned.
- If necessary, you can paint the canopy with anti-corrosion paint. Alloy steels, do not require additional painting.
Profile pipe trusses are the optimal basis for domestic and commercial use. The calculation of the hangar is time consuming, it must be performed by a specialist, only in this case you can get a reliable scheme of future design.