For providing country houses with water their owners usually drill on sites of the well. Depth and diameter of the last can be different. But in order that the well smoothly functioned for many years, around it the caisson is without fail equipped.
Caissons call the special tanks intended for protection of wells against adverse environmental factors and installation of the water giving equipment. The owner of country house if desired and independently can make such hermetic device around casing pipe.
Options of caissons
Before starting mounting of the similar device the hands, the owner of residential building or giving should decide on its look, of course. The caissons differing on can be established over heads of wells of country houses:
- to form;
- to the material used for production;
- to the sizes.
In form the caissons most often are cylindrical or cubic. Advantage of tanks of the first version is that they are capable to resist pressure of surrounding soil very well. First of all refer simplicity of their mounting to pluses of cubic caissons.
Similar borehole devices are classified by production material on:
- metal;
- plastic;
- reinforced concrete.
Simplicity of installation and resistance to corrosion are considered as the main advantages of plastic caissons. Metal tanks of this type are appreciated first of all durability large-scale. Pluses of reinforced concrete caissons, according to most of owners of country houses, are the durability, low cost and relative simplicity in mounting.
What can be dimensions
Having decided on form and material of caisson, it is necessary to think of what it will have the sizes also. It is the best of all to be guided when choosing dimensions of such capacity by the existing industrial standards and standards.
Metal caissons, for example, usually have such sizes:
- 2000:1200:1200 mm at thickness of steel of 3-10 mm;
- diameter is 1000 mm with height of 2 m and wall thickness in 3-8 mm;
- 4000:1500:2400 mm at wall thickness in 3-10 mm.
Diameter of the working chamber of plastic tanks is most often equal to 955 or 1270 mm. Concrete caissons usually bury in soil at 2 meters and do by 1000:1000 mm in size.
Working procedures
Borehole caissons in several stages are mounted:
- Around head of the well the ditch is dug out. Its depth have to be 40 cm more than height of future caisson.
- The trench under water supply system is dug out.
- The geological research of bottom of hitch is made. If there is probability that in the spring underground waters will rise above its level, waterproofing works are carried out.
- On bottom of hole sand by layer approximately in 10-15 cm is filled.
- Over sand on bars 3-4 cm thick the mesh reinforcement is established.
- Filling of bottom is made by cement slurry. Thickness of concrete layer at the bottom of hole has to be not less than 5-8 cm.
After the ditch is completely ready, the casing pipe is cut off so that its rest towered over concrete bottom approximately on 30 cm.
Mounting of steel caisson
Devices of this version usually do by the hands of sheet steel 4-6 mm thick. Make metal protective capacity for the well as follows:
- from steel weld cube;
- attach to it bottom with the sleeve which is welded in in it which diameter has to exceed diameter of casing pipe a little;
- weld mouth with the hatch;
- weld in the ventilating nipple;
- on sidewalls equip nipples under cable and pipe.
At the next stage the caisson is established in hole. Further the operations procedure has to be such:
- the caisson is welded on the cut-off casing pipe;
- the return dumping of capacity is made by sand or soil.
To prolong caisson life cycle, before installation in hole it is desirable to waterproof it two layers of bituminous mastic on outer side. If desired to warm metal capacity, it is necessary to weld on it in advance in addition special hooks under plates of mineral wool.
How to make reinforced concrete caisson
For filling of protective capacity of this type the wood form is used. Mounting of reinforced concrete caissons as follows is made:
- by means of struts at distance approximately in 10-20 cm from walls of ditch the timbering is established;
- between walls of hitch and timbering the mesh reinforcement is mounted;
- concrete placement is made.
It is possible to remove timbering from the caisson which is filled in thus approximately after day. Of course, in one of walls of concrete capacity it is necessary to build in branch pipes under water pipe and cable. At the final stage over the ready device it is necessary to establish plastic or the warmed cover welded from metal on loops.
Caisson from the reinforced concrete rings
Capacity of this version it will also be excellent to protect the well and besides will serve very long. However, as reinforced concrete rings weigh much, for their installation in hitch it is necessary to employ special equipment. In this case the owner of the well when mounting caisson will need to perform the following operations:
- to cut off from the first ring after its installation in ditch by means of the Bulgarian fixing loops;
- on the upper edge of ring to lay concrete mix 1.5 cm thick;
- after installation of the second ring and cover to close up slot between them construction foam.
Independent mounting of plastic caisson
Capacity of this version to make with own hands it will turn out hardly. Plastic caissons usually just get from suppliers in already ready look. In this case mounting will consist only actually in installation of capacity in the dug-out ditch with the bottom which is filled in with concrete. Also it will be necessary for preparation of caisson for operation:
- to cut in its day opening under casing pipe;
- to establish in opening and to pressurize the coupling.
It is necessary to mount plastic capacity in the dug well so that her mouth acted over the surface of soil a little. If this condition is not met, in the spring the melt water will surely be poured into caisson.
Helpful advice
It is desirable to dig out ditch under caisson of any version not symmetrically, and with small shift in one party. Such device of caisson in the subsequent will allow to arrange more ergonomically in it the borehole equipment.
How to stretch water supply system
Trench under pipe to caisson dig lower than the level of freezing of soil. Stack the highway not directly on its bottom, and on previously filled sandy pillow 10 cm thick. For bigger reliability it is desirable to warm external water pipe in addition with use mineral or glass wool.
The cable for connection of the borehole equipment can be passed directly on the same trench. In this case the warmed water pipe keeps within previously the last. Then the highway is powdered with the earth layer approximately in 20 cm with tamper. Further on trench the pipe PND with the cable stretched in it is laid. At the final stage everything is filled up with soil up to the top.
Installation of equipment
After the caisson is established, and the water supply system and cable are laid, it is possible to start installation of the pump. Lower this borehole unit to the mine on rope. At the same time previously according to the instruction from the producer attach water delivery pipe and cable to it. The rope to pumps usually fastens through special ears.
It is necessary to stop immersion of the unit to the mine right after it reaches depth in 1 m over its bottom. After installation of the pump the upper part of the well should be closed head.