Determination of the distance between pile when the foundation under a private house requires compliance with the methodology that takes into account many factors. They include parameters describing both the properties of the piles themselves and the specifics of the soil and weather conditions. But the main point is the overall load, which the structure has on the foundation.
There are methods of typical placement of piles, as well as the rules indicating the most loaded areas of the building. To determine the accurate placement of piles, it is necessary to calculate their number and following the prescriptions, arrange support in terms of foundation.
The specificity of the placement of piles depending on the type of foundation
To determine the exact distance between the screw piles during the construction of a frame or brusade house, some computations must be made. Usually this distance ranges in the range from 1 to 3 meters. During the construction of temporary or minor insignificant buildings, it is calculated on the eye, which is not allowed when designing permanent buildings.
When the exact distance between the pile is taken into account the length of the heads of the frame, because they should be resting in the heads of the screwdrive supports. This rule is valid for frame, and for brusal houses, but it does not matter if Scarlet is cast from concrete. In this case, the beams in it are simply not used.
When using plates as a material for the foundation, the interval between the screw pile is determined by the project documentation that takes into account their weight and structural features. In this case, the calculations are complicated, but the principles of placement of support beams remain the same – piles should be installed under the carrier walls, at the input portal, under columns and t. NS.
Pui accommodation options and their purpose
Proper placement of piles – the basis of the integrity and durability of the foundation and the whole structure. Under the arrangement of supports, according to the rendered load, it is possible to avoid critical zones, threatening piles and individual parts of the house. If the building has complicated contours, the placement of the support requires special attention.
For this purpose, several main techniques have been developed.
- Single placement. Piles are installed under the supports of frame structures, in the angular joints of the walls and under all carriage elements. At the same time, their interval can not be more than 3 meters.
- Ribbon accommodation. Piles are located under the bearing walls with the difference from the single type, that the range of their location decreases markedly and is often only half a meter. This technique is used if necessary to withstand a larger load (for example, a heavy 2 or 3-storey house).
- Beware accommodation. This type is necessary to maintain heavy single or group structures. There is no certain step for this type, since often piles are placed close to each other in chaotic order corresponding to the load. Their placement directly depends on the calculation of pressure zones. The only condition – the elements must be present around the perimeter and the area of the slab foundation for which they are supports.
- Complete placement or pile field. Supports are installed everywhere under the area of the slab foundation, step – approximately 1 meter. This technique is used for massive buildings or on soils with a weak bearing capacity.
During the construction of standard framework private houses that are not distinguished by a huge mass, it is almost always used by a single or ribbon placement of piles.
Features of calculation
When calculating the interval of piles, it is necessary to take into account certain significant criteria. This will not allow the elements too close, consuming the means in vain, and do not put them too far, exposing the foundation and the whole house hazard drawdown.
The calculations of professional builders take into account the following points:
- Mass building (frame, roof, finish and t. NS. );
- Mass of internal filling (equipment, furniture, things and tenants);
- Dynamic factors (wind load, snow weight on the roof in winter);
- carrying capacity of the soil;
- Technical parameters of screw piles;
- Reserve coefficient.
To determine the payload when calculating the interval of Piai, the corresponding SNiP is used. For example, for a single-storey residential building load installed at the level of 150 kg per 1 kV. M. Square. The indicators of the wind and snow load are reference and installed for each region depending on local weather specifics. The reserve coefficient on average is from 1.1 to 1.25.
Before planning the layout of the piles, it is necessary to calculate their number. It is determined on the basis of a total load on support. The total weight is divided into the carrying ability of one pile, as a result of which the exact amount of supports is found. Next occurs their placement with an equal interval around the perimeter of the structure and under the supporting structures.
The second option is the arrangement of piles, planned on the basis of the definition of the load on 1 mongor meter. To calculate it, it is necessary to divide the general load of the building to the total length of all bearing walls, and then divided into the carrying capacity of the selected type of piles. As a result, an indicator is obtained that determines the required amount of supports to maintain 1 meter Scarlet. After that, the required pile accommodation interval is defined, sufficient to maintain the foundation. This method is used for more massive buildings and is rarely used for low-rise frame houses.
To determine the exemplary bearing capacity of the piles of a particular type, you need to be viewed in the table with the corresponding indicators. More accurate information used in final computing is indicated by the manufacturer in the specification for a specific product. It should be borne in mind that the minimum distance on which piles for home and the terrace are screwed – 108 cm.
Rules for the location of screw piles under the foundation
To maintain the structure and ensure the uniform load, the supports should be located according to the established order in places with the highest load.
The following zones can be distinguished:
- in the corners of the combination of facade walls;
- At the intersection points of the bearing walls and interroom partitions;
- near the input opening;
- on the inner area with an interval of no more than 2 meters;
- under a furnace or fireplace (from 2 piles and more);
- Under the bearing wall, on which the additional design of the type of balcony or mezzanine is located, locally reinforcing the load on the wall.
After finding an accurate amount of piles, the stage of the schematic arrangement of supports in the foundation plan comes. At the same time, the above rules for their placement under the supporting elements and critical points of the structure should be taken into account. The residue should be uniformly located in the intervals between the key supports. So determines the step in the arrangement of screw piles.
Example of calculating the number of piles
Consider the features of the calculation on the example of a square shape with a perimeter of 8×8.
Other features of the structure include:
- frame type, roof from slate, porch;
- The size of the foundation – 8×8, the height of the structure is 3 meters;
- In the house 3 rooms formed by the intersection of a solid wall of 8 meters long and a partition 4 meters long;
- The frame is made of a bar of 150×150, Ruralsk – 200×200;
- Walls are covered with sandwich panels.
Calculation of wall area:
- external – 8 * 3 * 4 = 96 kV. m;
- internal – 8 * 3 + 4 * 3 = 36 kV. M.
Calculation of the mass of walls when using table values for mass 1 kV. M:
- external (carriers) – 50 * 96 = 4800 kg;
- partitions – 30 * 36 = 1080 kg;
- Total weight – 4800 + 1080 = 5880 kg.
Calculation of mass base and attic floors when using table values for weight of 1 kV. M:
- base – 8 * 8 * 150 = 9600 kg;
- attic – 8 * 8 * 100 = 6400 kg;
- Total weight – 9600 + 6400 = 16000 kg.
To determine the mass of additional load (internal household filling: finishing materials, things, equipment) uses table value 350kg / 1kV. M. When calculating the load for a two-storey building, the weight of additional load is multiplied by 2.
8 * 8 * 350 = 22400 kg.
Calculation of a general load on the foundation:
16000 + 22400 = 38400 kg.
Calculation of the amount of piles according to the formula K = P * K / S, where:
“P” is a total load;
“K” – the reliability coefficient (in the example – 1.4);
“S” – maximum load on 1 pile (this value is based on the specifics of pile, in the example it is a support with a diameter of 300 mm).
The soil resistance is determined by the specifics of the terrain on which the house is erected. In the example, this is a soil with an average density of 3 kg. / cubic. cm., Weak 2 meter freezing and deep groundwater.
38400 * 1.4/2600 = 20.6
Based on the calculation, we can conclude that in this case you need to use 21 pile.
The example shows the possible option of calculations. It does not take into account the specific specifics of a separate structure, which can affect the final amount of piles and their placement in terms of the foundation.
One of the main points – finishing materials and other filling of the house, which is approximately half of the load. Table value is repelled from the averaged weight of materials. If a massive trim is used, for example, granite or marble slabs, stone laying or brick and t. NS., The total load indicator can change significantly. In such circumstances, without accurately calculate the weight of all elements relating to additional load, can not do.
About pile foundations and recommended distance between pile, see this video.