Calculation and collection of loads to the foundation - a guarantee of long life

By Admin | Garden And Buildings / Banya
02 May 2016

question of foundations is extremely important, because it is the basis of longevity and reliability of the entire structure of a house.Directly before laying base needed to carry out a series of calculations, particularly the calculation load, which is the foundation of testing.Note, however, that the type of foundation and some of its features are largely dependent on the properties of the underlying rocks, so the load on the ground are also calculated and accounted for.

Content

Thus, answering the questionhow to calculate the load on the foundation, it is necessary to define the basic concepts that characterize the soil and foundation.These often include:

  • depth of the foundation, which is understood as the distance between the base of the foundation and the ground.
  • Underlying soil layer, which is a support for the foot of the basement.
  • depth of soil freezing.It represents the boundary of soil freezing on the level specified in the regulations (rules SNIP).
  • compresses the soil column, representing a deformable portion that receives the maximum load on the foundation.
  • level of groundwater.This position of the mirror relative to the ground level in conventionally defined open pits.
Laying the foundation depends on the level of soil freezing
Laying the foundation depends on the level of soil freezing

Calculation of bearing capacity of soil ↑

Depth of laying the foundation into the soil determines the value of these construction works: the greater the depth, the more costly will be the process of laying the foundation.Obviously, this is the reason that the majority tends to lift the sole owners of the foundation as close to the ground surface.However, this desire to save will have to collect and analyze information on the bearing capacity of the soil.

Thus, the resistance of the soil and the degree of its humidity depends on characteristics such as porosity.It is the ratio of pore volume to solids volume available and is inversely proportional to the density parameters.

Do not forget about the seismicity.The fact that the simultaneous effects of vibrations and a static load on the ground can lead to a reduction in strength of the soil.His status, experts are often called fluidized.When laying the foundation necessary to take into account the reduction in the carrying capacity of a particular type of soil under seismic vibrations occur.Typically, in such cases, the estimated resistance of the soil is increased 1.5 times, resulting in a corresponding increase in the area of ​​the foundation of the house.

Permissible deformation structures ↑

Currently, calculation of the load on the foundation is not possible without taking into account the permissible deformation of a house.Obviously, even laid on all the standards and regulations of the foundation involves a degree of precipitation of a residential house and its deformation.However, even in this case, they should not exceed the targets set by building codes.Exceeding these indicators and differential settlement house leads to deformation of the structure or noticeable change in its position.

Types deformations home:

  • arching and bending.Most often they arise in the case of uneven rainfall home.Danger zone at trough is considered the foundation, while arching - the roof structure.
  • shift.Occurs when a significant loss of the foundation on one side.Hazards are a wall in the middle zone.
  • bank.It is formed when a large enough height of the building, characterized by a high degree of flexural rigidity.Growth roll can lead to the destruction of the building.
  • skewed.The reason for this type of deformation is the differential settlement houses, which account for only a small part of the long side of the building.
  • horizontal displacement.The appearance is typical in the walls of the basement or foundation under excessive load horizontal forces.
Deformation of the structure changes
Possible deformation apartment house

The maximum amount of rainfall depends on several factors: the material used, the type of structure, etc.. For example, the maximum draft of the structure with a concrete frame is 8 cm.

After gathering information on the ground,You can collect the loads directly to the foundation of a house under construction.

calculation load on the foundation ↑

To calculate the possible load on the foundation you need to know the weight of a house under construction and all operating loads.In addition, certain subject area and support its weight.Ideally, the calculation load on the foundation is an option, as they are evenly distributed over the entire area.

Example of calculating the weight of the house ↑

To properly calculate the weight of the house should have weight average values ​​of the main load-bearing structures house: roof, walls and floors.For example:

  • The proportion of 1 m2 or log bruschatoy wall is 70-100 kg / m2.
  • weight of 1 m2 of a brick wall having a thickness of 150 mm, ranges from 200-270 kg / m2.

As for the roof:

  • weight of the roof of sheet steel is 20-30 kg / m2.
  • Weight ruberoid cover ranges of 30-50 kg / m2.

The share of 1m2 or that overlap:

  • Weight attic ceiling of wooden beams with a heater will be 70-100 kg / m2.
  • Weight basement ceiling on wooden beams with a heater is about 100-150 kg / m2.

Thus, knowing these values, you can calculate the total area of ​​the roof, floors and walls of the house.After this area is multiplied by the specific weight of 1 m2 of a structural member.The result will be a constant load on the foundation of the weight of the house.

However, there are not only a constant load on the foundation, but also the time in particular on snow and wind.The average weight of snow cover is calculated depending on the region.So, to the south of our country, the figure is 50 kg / m2, and for the north - 190 kg / m2.In central share of snow is equal to about 100 kg / m2.

calculation of the weight and size of the foundation ↑

When the calculated load on the foundation, it is necessary to calculate the load on the ground that will determine the optimal area of ​​the basement.It will have to calculate the weight of the foundation, and add it to the weight of the house.

Thus, when the tab is deeply recessed strip foundation necessary to take into account the depth of frost penetration.Assume it is 1.5 m, which is added to the height of 40 cm above the ground.Final foundation height of 1.9 m. And then calculated the total length of the tape foundation, for example, it is 30 m, 24 m of which falls on the perimeter of the house, and 6 m - on the inside wall.When

foundation tape width of 40 cm, its volume will be:

30 m x 0.4 m x 1.9 m = 22.8 m3

resulting volume is multiplied by the specific weight of the material used, such as reinforced concrete.The result will be the weight of the foundation.Calculate the area of ​​the foundation is to multiply the length of its tape to its width:

3000 cm x 40 cm = 120 000 cm2

The calculation of the weight and the foundation area
Example of calculating the area of ​​the strip foundation

When laying the foundation holds many more different calculations, but the calculation loadGround and foundation of dwelling house is the basis for further calculations.

See video on how to calculate and select the preferred foundation based on calculations with a focus on economic viability.

Thus, responsible, attentive and competent approach to the collection and analysis of information on the state of the soil, the impact of external factors, the possible load on itself the ground and directly on the soles of the foundation, will lay a solid and durable basis for future residential home for the whole family.