Soil: types of soils. Characteristics of soils

Many are accustomed to perceive the soil precisely in the form in which it is represented now. However, nature has been engaged in its formation for millions of years. Initially, the surface was a rock. Over time, it was exposed to erosion, the influence of rain and minerals. The remains of the first and subsequent plants enriched the soil with humus. Thanks to these metamorphoses, the upper layer increased, becoming better in composition and structure. For geological reasons, mechanical and chemical characteristics vary on the entire surface. Soil - soil, all variety of rocks, man-made formations. All this for a long time was the scope of engineering and economic activities of man.

Classification

There are several basic types of soil. In particular, they include:

• Monolithic rock and semi-rock with rigid structural connections.
• Dispersed, separated-granular without strong structural joints. Connected - clayey, unconnected - coarse-clastic.

The soil is applied in the construction of the base of buildings, in engineering structures, as well as in covering roads, embankments and dams. Well suited for the creation of underground channels: tunnels, storage and other. Soil science is a science, the field of study of which is the soil.

Types of soils and their properties

To build a reliable foundation, it is necessary to take into account the physical qualities of the soil that is in the basement. The basic information is contained in the soil table. Before starting work, earth resistance calculation must be carried out. In assessing its technical suitability, aspects such as:

1. Uniformity of composition.
2. In consideration should be taken and the coefficient of friction of parts of the ground mass against each other.
3. The maximum amount of water absorption, as well as its initial availability.
4. The ability of the ground to retain the liquid absorbed by it, despite the efforts made to remove it.
5. Washability and solubility in water, compressibility, looseness, plasticity and the like.
6. Coupling, as well as the shape and size of the particles. In this case, the strength of the bonds that the soil possesses is implied.

Types of soils are divided into two large categories, which are different in structure, physical properties and methods of development. Intermediate groups of rocky, destroyed rocks are also implied. They consist of unrelated or interconnected stones. The latter are called conglomerates.

Loose structures

This group consists of sandy types of soils that do not lose their volume when dried. In pure form, they have an almost insignificant connection between the particles. Also included here are clay. It is able to increase its volume when wet and, depending on humidity, can have good connectivity. Sands do not have plasticity. After the use of force, they instantly contract, but do not retain the shape attached to them. But clay is very easily amenable to modification. She under the influence of an external force rather slowly, but strongly compressed.

Rock structures

It is cemented and welded to each other. Outwardly, these structures represent a continuous array or a fractured layer. Saturated with water, they show a high percentage of compressive strength. These structures are readily soluble and soft in water. They are well suited as a foundation for the foundation due to their strength, resistance to compression and frost. The undoubted advantage of these structures is also the fact that they do not require additional opening and penetration.

Conglomerates and non-scaffold structures

Most of them are uninforced crystalline and sedimentary coarse clastic rocks. These structures are able to withstand buildings in several floors. On these soils, a ribbon foundation is laid, the depth of which is not less than half a meter. On the territory of the Russian Federation there are many varieties of rock carvings, which have a wide variety of physical properties.

Loose structure

It should be said that the soil-sand is considered a fairly common structure. What is this category? The composition of the soil includes a loose mixture of grain quartz, as well as other materials that appeared due to weathering of very small rock particles. These structures are divided into several subgroups. This, in particular, gravelly, medium and large, silty rocks. All these structures are easily developed, are highly water-permeable, pressurized well. When laying sand in a uniform layer in terms of density and volume, a good basis can be laid for subsequent construction. Use of its maximum characteristics will occur if the freezing level is above the groundwater. All this depends on the characteristics of the region in which construction takes place. Compression of sand occurs in a short time, which means that the sludge of such a structure does not take much time. Its size is directly proportional to the ability to withstand loads. The particle size of dust sand varies from 0.005 to 0.05 mm. It will not be a good basis for construction, because it does not cope with high loads. Sandy ground is able to sag under pressure. Also it almost does not freeze and easily passes water. If the foundation is based on such soil, then it should be laid at a depth not exceeding 70 cm, but not less than forty centimeters.

Plastic structures. Subcategories

The plastic characteristics of soils allow them to be divided into several subgroups. Consider the main ones. Bulk structures, in the content of which 5-10% clay, are called sandy loam. Some of them, when diluted with water, become fluid, similar to a liquid. Because of this, such a ground is also called a melt. Such structures are unsuitable for founding foundations. Loams in their composition have from 10 to 30% clay. There are they are light, medium and heavy. These indicators provide an intermediate position of such soils between clay and sand.

Natural material for the foundation

The physical characteristics of soils are of great importance in the construction of structures. Not every rock can build a building. Unlike the loose structure, clay has a high compressibility. At the same time, under the load, the compaction process is rather slow. Accordingly, and the draft of buildings on such a soil will take more time. Combined soil layers - from rock and loose structure - do not have resistance to liquefaction. Because of this, they have low load-bearing capacity. The composition of the soil includes the smallest particles, the size of which does not exceed 0.005 mm. This structure also contains a small amount of particulate matter. Clay is easily compressed and washed. Over the years, this structure will serve as an excellent basis for laying the foundation of the house. However, there are a number of reservations, because in the natural state of clay is almost impossible to find dry.

The fine structure of the rock contributes to the formation of a capillary effect. It leads to a constant wet clay condition. But the disadvantage of this kind of structure is not in its moisture, but in heterogeneity. She misses the water well. Because of this, the liquid is spread through various ground impurities. At low temperatures, the clay begins to sample to the building, which leads to its swelling. This helps raise the foundation. Clay humidity is uneven. In turn, this means that it will rise in each place in different ways. All this leads to the destruction of the building. In some places it is stronger, in others it is insignificant, but on the whole surface the foundation is affected by the soil. Types of soils, depending on the properties, affect the foundations in different ways.

Macroporous structures

This is a separate category, which is formed by clay soils. Their name is macroporous due to the presence of large gaps between the particles. Pores are visible even to the naked eye. In review, you can see that they significantly exceed the skeleton of the soil. Loessial rocks belong to this structure. They contain more than 50% of dust particles. These structures are widespread in the south of Russia and the Far East. Under the influence of moisture, such a rock razmokaet and loses its stability. If the initial stage of clay soils was formed due to structural precipitation in water, in which microbiological processes were present, it is called mud. They are most often found in swampy and wetlands and in the peatland. If the foundation is erected in a territory where there is a high probability of loess and silty soils, then the necessary measures should be taken to strengthen the building.

Determination of consistency at the site

The structure of clay soils is determined by the development of a shovel visually. For example, a plastic mixture will adhere to the tool. In a completely different way, a firm ground will behave. Types of soils are determined by rolling them into a cord or rubbing them with palms. So you can appreciate their plasticity. Clay soils are well compressed, blurred and bloated when freezing. These structures are among the most fastidious and unfavorable for erecting a foundation. On such an area, the foundation must be laid on the entire depth of freezing. Evaluation of soil composition on the site is performed by means of a watering can. Record the time of water absorption from the surface. If the absorption takes place within a second, the structure is rocky or sandy. Pretty quickly takes water and a damp peat. But on the surface of the clay soil, the liquid is delayed.

After that, draw a little wet layer and squeeze it in the palm of your hand. If the structure has broken up into grains or has seeped through the fingers, then it is a rocky or sandy rock. The clay is easily compressed and fixed in the form of a lump. It feels rather slippery. If the soil seems soapy, silky and does not shrink so much, then, most likely, it is silty or loamy. Peat structure is similar to a sponge.

How to determine the structure at home?

A full tablespoon of soil is placed in a glass with clear water. It must be mixed and left. After a few hours you can see the result. If a layered sediment is at the bottom, and the water itself is relatively clean, then you have added loamy soil. Sand, stones on the bottom and clean liquid - this is another structure. Most likely, this is a rock. In particular, it can be sandy or stony soil. Grayish water and whitish grains character for limestone structure. Peaty soil will make the water turbid. On the surface, in this case, thin and light fragments will float, and a small precipitate will appear on the bottom. If there is mud and silt in the water, then it will become cloudy. At the same time, a fine precipitate forms on the bottom.

PH level

The soil can be subdivided depending on the degree of acidity. So, according to the pH of the structure there are weakly acidic, neutral or slightly alkaline. In the latter, the soil acidity level varies from 6.5 to 7.0. It is excellent for garden plants, including vegetables, contributes to their faster growth and development. Acidic soil has values from 4.0 to 6.5, but from 7.0 to 9.0 - this is an alkaline structure. In addition to these, there are extreme points of the scale - from 1 to 14, but in practice, European gardening, they almost never occur. Knowledge of these data is necessary for the correct selection of plants for planting. The acidity of the soil can be reduced by mixing the structure with lime. Increase the pH level will help organic air conditioners. However, the latter process is quite expensive. In this regard, in areas with alkaline soil can be grown acidophiles in containers and tubs, which are filled with acidic structure.

Cultivation of plants

When choosing the soil for planting, it is necessary to emphasize such points as:

• The field of its application. There is a primer for flowers, seedlings, as well as garden and universal. There is an opportunity to purchase peat. All this depends on what soil is needed for, what cultural or ornamental plantations on it will be grown.
• Types of plants. If you are going to grow representatives of one category, then the best choice will be a special primer for him. But if more than one, the universal one will do.
• Consumed volume.

To make the soil mixture more loose, use vermiculite. To ensure that the roots do not rot from stagnant water, a drainage layer is placed on the bottom during planting. For cacti and a number of other plants, the soil is mixed with a loose structure. If planting occurs in infertile places, its quality will help improve peat. Hydrogel improves the moisture and air exchange processes. Charcoal is used to reduce the pH. It is added to the soil for flowers (for example, for orchids) and other plants.

Useful impurities

Vegetative soil structures are mainly used in landscape works. But the field of application of structures with various "useful" impurities is much wider because of the inclusion of stones, clay and other components in the composition. What is the percentage of necessary useful ingredients? Typically, fertile soil is a combination of 50% peat, 30% chernozem and 20% sand. Thus, its composition includes an increased content of organic compounds and minerals. The soil is fertile with high water resistance. Such a structure ensures complete nutrition of cultivated plants, regardless of the stage of their growth.

At agricultural enterprises, farms, as well as on private plots, the fertile soil is used quite actively. He copes well with the tasks that are put in the process of cultivating cultural plantations. Of particular importance is that it contributes to the improvement of soil structure, increases yield. In addition, such a mixture does not need additional fertilizer use.

How to improve the structure of the soil?

For poor stony and sandy soils, rotted manure mixed with straw is used. It is better to give preference to horse than to cow. It promotes retention of moisture and useful components in the root system of plants. But fresh manure can not be added. For the same purposes, garden compost can be used. A mixture of repulsed horse manure, lime and peat is called a mushroom compost. If in neutral soils it is necessary to create a weakly alkaline reaction, then such a mixture will perfectly suit. Leaf humus is suitable for plants that need acidic soil, that is, for hygrophilous acidophiles. Conditioners, mulches and acidifies the earth. For the same purpose, wood chips and sawdust can be used. Peat is used to oxidize the soil. It quickly decomposes, but practically does not contain nutrients. In winter, you can use bird feathers, which are rich in phosphorus. They are also added to the areas where the planting of potatoes is expected. To improve water permeability and structure of clay soils, use chopped wood. The bark is also used for mulch, due to appearance and qualities. It is desirable to use the air conditioner at the same time or instead of applying organic fertilizers. Soil plots that are only planned to be sowed are dug up and mixed with them a few months before the planting starts. To fertilize already planted plants, the soil is enriched with a layer of mulch from conditioning organic materials with fertilizers at the very beginning and end of the season.