The foundation of any home is the foundation. Not only the longevity of the entire building, but also comfort for living depends on its strength and stability. An untrained person may think that the foundation of the house serves only as a construction "site" for the foundation of the walls, but this is not so.
Thanks to the foundation, the entire huge load that the house imparts to the soil is evenly and accurately distributed over the entire surface of the soil, which prevents the structure from sagging and falling apart due to seasonal heaving of the earth. However, the pillows are much more reliable in this regard.
Over millennia of construction practice, many generations of builders have developed a huge number of techniques for the proper construction of such structures. Using the accumulated knowledge, you can build a house even in the conditions of
permafrost, but we will not enter such difficult areas. It will be enough to discuss the question of what pillows are foundation.
Most often in our area they use convenient and versatile strip foundations. Their disadvantage is that there are often situations when they distribute pressure on the soil unevenly. To avoid many unpleasant consequences, the foundation of the house has to be put on a solid concrete slab. If you have great doubts about the quality of the soil, you have to additionally fix the base under the slab using piles driven into the ground.
It should not be thought that
foundation pillows are used only in the tape variety. Often it is necessary to install such a pillow under the columnar base, which is used in the construction of small cottages. It saves the building from "swims" that can happen on unstable types of soils.
By the way, we’ll immediately determine what should be understood by the term “foundation pillows”: GOST has one definition, but it often causes difficulties and confusion even among professional builders. As a rule, they believe that this should be called a well-compacted layer of clay, gravel or even sand. This should be considered a gross mistake, since in fact the foundation pillow is a powerful solid cast concrete slab, although there may be exceptions.
So, sand is acceptable, but its minimum thickness should be at least a meter. Concrete is used much more often, and it is not always used when the soil is unsatisfactory: it often happens that unnecessarily narrow load-bearing walls of buildings are erected on such a basis. It should also not be considered that it must necessarily be monolithic, since often builders use prefabricated structures from several plates at once. We will provide the simplest information on which the foundation pillow is calculated , the dimensions of which are used in construction.
We take random values as the initial data. We have that 15 meters of the wall weigh 25 tons, while the soil has a bearing capacity of 4 kg / cm. The calculations themselves are carried out in this case as follows: we translate tons into kilograms, distributing them over the area. We get 250 kg / cm, which must be divided by soil characteristics (4 kg / cm
2 ), we get 62.5 cm as a result. We align all the numbers to the right of the comma in the direction of their increase. Watch for the multiplicity, which should be equal to a hundred. Thus, we got a value of 625 mm, which we round to 700 mm. Such pillows foundation will be as reliable as possible, but for even greater reliability they should be reinforced.