Gravitational water level in the first surface of the earth, are ever-present in the aquifer - is groundwater.They differ in that they have a free surface, and above it there is a continuous roof of waterproof rocks.They are located in weak and loose rocks.Can fill the cracks in the cemented sedimentary, metamorphic and igneous rocks, and occur in the Quaternary sediments.Groundwater under its bedding are classified into several types: reservoir, fractured and porous.Their formation is due to the infiltration of surface water and precipitation.FIELD their presence often coincides with the spread of the aquifer, the capacity of which is not constant, but depends on the supply intensity, the distance to the area of discharge water containing rocks, etc.
Groundwater possess the main characteristics that distinguish them from artesian, deeper waters - lack of pressure.They are influenced by weather conditions: temperature, pressure and precipitation, evaporation, etc.Also has important influence of human activities: pumping water from oil and mineral resources, construction of irrigation and drainage and hydraulic structures, fertilizer / agricultural land, mining and others. In addition, the hydraulic conditions are important: changing the mode of draining, feeding and surface water bodies.
In construction the groundwater damage, a harmful effect on concrete and other building materials.Before you start designing facilities necessary to carry out the study area, with a special attention is paid to the existence, nature, chemical composition (aggressiveness) of groundwater, as well as the expected water production.Aggressiveness determine the solubility of calcium carbonate and evaluate the following degrees: obschekislotnaya, leaching, magnesia, sulphate and carbon dioxide.
for the national economy, these waters are of great importance as a source of water supply of settlements, industrial facilities, etc.They are produced by drilling wells and wells with gravel backfill, combining with grids woven braid.What are they dangerous?The presence of groundwater restricts the realization of individual construction processes, for example: the choice of foundation, the existence of a ground floor, basement, cellar or a septic tank.
Ground water in the basement slow down the process of excavation, as they erode the soil and do not allow to carry out construction.The walls lose their load-bearing capacity due to the fact that the caissons basements and cellars affects hydrostatic pressure tightness is lost.Ground water in the basement significantly affect the strength of the foundation, and in addition, require additional protective measures: insulation against capillary moisture at ground level, protection of double wall daubing resin on plaster, hot bitumen, or mixed with cement mortar with the addition of gidrozita.From the pressure of water protection buildings is carried out drainage and water intake, as well as through the creation of a waterproof membrane walls and basement floor.
Defining the groundwater level starts with finding the aquifer.On a flat surface or a portion of it is the same everywhere, and at the level of irregularities in the high passes above and below the ground - in the lowlands.Typically, they are located at a distance of 20 m in wetlands - 1 m. If the water fills in the territory of fine recesses, its level is above the ground surface.In rainy weather, their level increases, and the drought - reduced.
Determining the level of groundwater is of paramount importance for the construction and laying of the foundation.From this will depend on soil bearing capacity.If the level is too high, fill the foundation is strictly forbidden to produce.
