The accumulation of soil is the process of increasing its volume due to the freezing of moisture in the soil. This phenomenon occurs in various types of soil to varying degrees, and in some it is absent altogether. During construction, this must be taken into account, since a significant increase in volume can crush the foundation or violate its integrity. Therefore, foundations on heaving soils should be selected and built with particular care. Read more about their device.
Types of soil
Soil is a rock located in the upper layers of the earth's crust. By strength and size of their constituent particles they are divided into the following types:
- Half-run - refer to cohesive soils. They differ in their compaction ability (marls, mudstones, siltstones, etc.), as well as non-water-resistant rocks (gypsum-bearing conglomerates, gypsum).
- Sand are small particles of rocks that are not interlinked, and do not have plasticity.
- Coarse fragments consist of unconnected pieces of semi-rock and rock, containing more than half of the fragments having a size of more than 2 mm.
- Clay soils are composed of small particles less than 0.005 mm in size.
- Rock - moisture resistant solid rocks that are practically not compressible.
More often, construction is carried out on clay, coarse, semi-rock, sand and sand-clay rocks.
Foundations on heaving soils. How to counteract heaving
To reduce heaving and increase the strength of the foundation, it is necessary to replace the problematic soil with sand. To do this, excavate a pit deeper than the level to which the soil freezes at the construction site. Then the resulting reservoir is covered with sand, which is an excellent base for arranging the foundation of the house. It passes moisture well and can withstand significant loads. Sand should be compacted, and then proceed with the construction of the foundation.
It is possible to lay horizontal thermal insulation of soil along the perimeter of the structure. This method is suitable for small houses with a shallow foundation.
Foundations on heaving soils can be arranged below the level to which the soil freezes. However, freezing affects the walls of the foundation, it can harm the design of the house. Therefore, this method should not be used in the construction of prefabricated and wooden houses with a lightweight tape base. However, for houses made of reinforced concrete and brick, it is quite suitable.
Installing a drainage system will help remove excess moisture from the soil. To do this, use perforated pipes and lay them in a specially prepared ditch at a small angle of inclination at a distance of half a meter from the foundation. Pipes are wrapped with filter cloth and covered with non-porous soil (gravel, sand). Water accumulating in the ground freely enters the pipes and flows into a well or other reservoir.
Foundations on heaving soils. Summarizing
It should be borne in mind that the choice of a specific method of counteracting heaving depends on the size and depth of the foundation, on the materials used. Of great importance is also the size and weight of the building.