soils used as foundations of buildings and structures are divided into:
clay soils - is associated soils, for which the number of plasticity Jp greater than or equal to 0.01.On the content of the sand particles and plasticity clay soils are divided into sandy loam, clay loam, clay (tab. I).
plasticity is the difference between the moisture content at the border point and humidity on the border in the rolling unit shares.
clay soils depending on their density and moisture content may be in a different state, which is characterized by the consistencies J 1 (tab. 2).
Among clay soils should be highlighted:
- soil subsidence;
- swelling (distending) soils.
It oozes are clay soils in the early stages of its formation, formed as a structural sediment in water in the presence of microbiological processes and having a moisture content in the natural addition of excess moisture at the border point, an
Elah stand out among clay soils into a special group, since they are building against unfavorable ground, t. E. To build on them impractical.
By subsiding soils are clay soils, which are under the influence of the external load or weight sobstvennrgo soaking water provide additional draft (drawdown).
If preliminary estimates generally refer to the subsiding loess and loess soils.
Depending on the drawdown of its own weight and soaking soil subsidence are divided into two types:
type 1 - when the subsidence of its weight is less than 5 cm;
type 2 - when the subsidence of its own weight is greater than 5 cm.
By swelling (heaving) soils are: clay soils, which, when soaked in water or chemical solutions are increasing in volume.
Swelling soils as a function of the relative swelling without load in the compression device are divided into:
slabonabuhayuschie if? H 0,0404 ≤ ≤ 0,08;
srednenabuhayuschie if 0.08 silnonabuhayuschie if? H & gt;0.12.
Sandy soils - a free-flowing dry soils containing less than 50% by weight of particles larger than 2 mm and having the property of plasticity.
Depending on the particle size, they are divided into five groups tab.3.
According to the degree of humidity sandy soils are divided into three groups, Table 4.
In addition the degree of density of their sandy soils, depending on the porosity coefficient divided into three groups tab.5.
coarse soils - is unconsolidated soils containing more than 50% by weight of crystalline debris and sediment particle size greater than 2 mm.Depending on the particle size, they are divided into three groups, Tab.6.
According to the degree of humidity of coarse soils are divided into malovlazhnogo, wet, saturated water table.7.
rocky ground - this igneous, metamorphic and sedimentary rocks with tight bonds between grains (cemented and spaennye), occurring in the form of a continuous array or fractured.Rocky soils are divided into igneous, metamorphic, sedimentary tab.8.
igneous, metamorphic and sedimentary rocks cemented with siliceous cement (siliceous conglomerates, breccia, sandstone, limestone, flasks) are not soluble in water.
to soluble rocks include:
- sparingly - limestones, dolomites, sandstones and conglomerates izvestkovistnye;
- srednerastvorimye - gypsum, anhydrite, gypsum-bearing conglomerates;
- readily soluble - rock salt.
Filtration of water-soluble through cracks in the rocks, the formation of caverns.
peaty soils differ in the degree zatorfovannosti Table.9.
improve soil properties can be the following activities:
- method of compacting soil compaction rollers, machines;
- soil compaction through a variety of compactors (mechanical, electrical);
- soil compaction by vibration;
- seal soft soil deep drainage;
- strengthening the weak, including soil subsidence and other available means.