Well drilling
The well construction is the building of structures for the promotion and monitoring of the groundwater. These structures usually include wells and groundwater monitoring wells.
The following types are used:
Dug wells
By manual or mechanical excavation a vertical shaft is built up in the body of groundwater. As part of the Deep exceeding the shaft is secured with masonry or precast concrete, which were prefabricated concrete from (steel). The inflow of groundwater to the wells is carried out by the bottom of the well and / or a vertical filter section. The method is suitable only for shallow depths ( generally much less than 40 m).
The establishment of a well shaft is usually carried out in a simple design for small depths and individual properties as follows (this work is dangerous and should be performed by a specialist company ):
- There are concrete manhole rings ( eg, diameter 1.000 mm ) was used.
- A small amount of excavation, on which the first shaft ring (without crampons ) touches down exactly horizontal. This first ring can be fitted at the bottom with a steel blade.
- The ground under the first shaft ring is lifted, the shaft ring sinks, more manholes may be placed. A special form of the shaft Brunnes is the Kanat.
Piling and driven wells
A tube with top and bottom arranged filter section (open part of the tube ) is advanced into the ground by ramming. This method is used especially by hobby machine operators in small plants and shallow depths. The Bore is also called Abessinierbrunnen or " Norton Fountain ". Advantage: easy to erect. Disadvantage: keeps depending on groundwater quality sometimes only about 5 years.
Artesian well
A hole is driven into the aquifer. In the area of the aquifer, a filter circuit is provided. The filter section is usually formed by the gravel, which can be performed at cased and uncased hole. Often there is a single or multi-stepped bed, with the largest grain size is applied directly to the filter tube. Even when drilling in hard rock gravel is often introduced, but here especially with a support function and preventive in terms of erosion. This method can be used to great depths ( over 1,000 m).
Sickerrohrleitungen
In order to develop flat-lying and low- powerful, but extensive aquifers used horizontal Sickerrohrleitungen, originally developed from open seepage ditches. These well filter pipes are used in at least 4 to 5 meters depth usually formed on the length and girth completely permeable.
Source versions
One potential source is to be protected as possible at the exit point, from contamination, taken without a damming. Source versions are often problematic in terms of hygiene.
Horizontal well
Starting from a shaft horizontal wells with filter sections are driven into the groundwater body ( horizontal wells ). These wells allow large quantities removal. The wells are to be secured by a cover and a side sealing of the shaft or the bore to the surface against the ingress of contaminants.
The water supply can be done by sucking pumps or submersible pumps and submersible pumps. The water withdrawal depends on the fertility of the ground water occurrence and the performance of the filter section, which has to avoid washing out of the soil into the well.
Water surface and fountains
The suction lift a pump corresponds known to the air pressure of the atmosphere. The same is adequate pressure from a 10.33 m high water column. For this reason, can be a suction pump theoretically promote only water from a depth of 10.33 m, after deduction of all losses only from a depth of 7-8 meters. For promotion from greater depths underwater pumps are necessary.