Construction of the foundation

Cost of construction of foundations, usually about 20% of the value of the house. But not only this fact determines the most thorough, thoughtful manufacturing base. No need to explain what cracks, distortions and other deficiencies that arise as a result of mistakes made, how it will affect the rest of the house construction, how difficult it is to eliminate the marriage and to repair the foundation. Therefore, the calculation, the selection and construction of the basement should be under your closest attention. Design, material and depth of laying of foundation depends on the size and nature of acting on the foundation loads of capital and the design features of the house and the natural conditions of the site (depth of soil freezing, the nature of their occurrence, the presence of groundwater, etc.). On the reliability of the bases to a large extent depend on the operational quality of the building, its capital, and durability. First, you need to figure out on what ground or grounds will be home: the depth of laying the foundation depends on the type of soil, its depth of freezing, the groundwater level. Distinguish the following primers: the rocky soil - reliable, sturdy, not shrink, not blurred and not freeze. Laying the groundwork can be directly on its surface; gristly soils (gravel, stone breakup) - not compressed and not blurred. Should lay the foundation at a depth of not less than 50 cm, regardless of the depth of soil freezing, sandy soils - easy to remove, a good pass water, greatly compacted under load and slightly frozen. You can lay the foundations at a depth of 40 to 70 cm, clay soils - are able to shrink, blur and freezing, distend. On a humid area with clay soils should lay the foundation for the calculated depth of freezing; loam and sandy loam - a mixture of sand and clay particles. Loam containing from 10 to 30% clay particles, fine sandy loam - 3 to 10%. Both of these soil occupies an intermediate position between the clay and sand. In wet soils laying depth of foundation shall not be less than the calculated depth of freezing. Soils can be divided into poor, satisfactory and good for construction. Forest soil, garden and marsh land - poor soil, clay, loam, sand, gravel - satisfactory, the best soil - virgin sand and gravel soil, completely untouched rocky soil (thickness of a meter). To make a conclusion on the ground of your site, and simultaneously determine the level of groundwater at the site, enough to dig a pit-pit depth 2-2,5 m (of course it is. Done with an eye to the future - or it will subsequently be part of the foundation, or a well ). After some time, measure the groundwater level. Depth of soil freezing usually find out from local builders. The mean values ??of the depth of freezing on various regions of the CIS are as follows: 100 cm - Astrakhan, Rostov-on-Don, Odessa, 120 cm - Kiev, Volgograd, Kursk, Pskov, Smolensk, Minsk, 140 cm - Moscow, St. Petersburg, Novgorod, Tver , Voronezh, 150 cm - Nizhny Novgorod, Vologda, Kostroma, Penza, Saratov, 170 cm - Kazan, Izhevsk, Samara, Ulyanovsk. The most dangerous forces acting on the foundation of low-rise buildings are the forces of frost heaving. In severe heaving soils (in these soils are water-saturated clay, loam, sandy loam) the maximum pressure of these forces is equal to 150 kPa. The vertical displacement of the surface layer of soil when it is freezing to a depth of 1-1,5 m reach 0.15 m. Skewed walls of the houses - often the forces of frost heaving (less ~ - lowering the basement to the ground). Avoid the impact forces of frost heaving is not always possible only by increasing the depth of the basement below freezing (frost heave forces act not only lower, but the side - the tangential force). To avoid the action of tangential forces, the base of the foundation makes an extended (ground-anchor, which prevents the expulsion of the foundation for frost heaving). Inside lay a foundation reinforcing cage that protects it from breaking in layers. Foundation of stone. Bricks (without internal reinforcement) are doing with tapering upwards flanks. In addition, we recommend covering the side surfaces of the foundation of a sliding layer (waste oil, plastic film). Depth of the foundation depends on the depth of soil freezing (see Table .. 5), as well as the groundwater level. Minimum embedment foundation base from ground level at any ground shall not be less than 0,7 m. Installation of foundation are necessary as the correct choice of depth burial, breakdown of competent, quality work in the installation of foundations, the use of quality building materials and the correct selection of the construction of the foundation. Before you decide to choose the type of foundation, you need to know on what ground it will be installed, as well as the design resistance of the soil. These values ??contain Tables. 6. Table 5. Depth of laying foundations Table 6. Types of soils and their calculated pressure drag on the ground at a certain bearing surface foundation shall not exceed the design resistance of soil, and the total load acting on the sole of strip foundation, will be equal to the sum of loads from the fallen and the snow lying on the roof, the roof, attic floors, exterior walls home, sex, and the very foundation. Approximate the total load can be calculated using Table. 7, 8 and 9. Table 7. Load of 1 m2 of wall