Horizontal drainage pipes

Horizontal drainage pipes

Drainage pipes (drains) are the key and principal element of the drainage system. Up until the 1990s, drainage pipes were mainly made of clay (tile) and asbestos-cement. Laying of such drains used to take long time, because it required preliminary preparation: in asbestos-cement pipes, numerous slits were made and holes were bored. Drain tiles were connected with each another by means of filter couplings (rarely) or laid butt-to-butt (more often) with protection of the butt connection by moss, straw, and later by glass cloth. Water inflown to a field tile through joints (pipe length is 33 cm, 5 joints per running meter). In addition, the tiles were often clogged up, which was the reason for frequent rinsing and short service life of them. The joints of drain tiles are protected by using geotextile.

Source: Wikipedia

Drainage pipes are a component of the structure of closed horizontal drainage (CHD), performing the function of a water-intake and water diversion element. They differ in terms of such parameters as length, water-intake design, material, diameter, wall thickness, durability, weight, shape, butt joint design, etc.

Short-length (0.33-1.0 m), medium-length (4.0-8.0 m) and long-length (coiled) pipes are used for construction of closed horizontal drainage. In the first case, water intake is executed through the gaps at joints; in the second and third cases, through perforation holes of round or rectangular (slots) cross section in the pipe walls. Depending on the properties drained materials and material of the filter, the size of the gaps in the joints and perforation holes vary from 1 to 4 mm.

When developing new lands in Uzbekistan, pipes from different materials, ceramic (clay), plastic, concrete, polymer-concrete, reinforced concrete, etc., underwent test in production conditions.

Among the advantages of ceramic pipes are age resistance, sustainability in corrosive environment, wearing resistance, and smooth interior face; among their disadvantages are brittleness, which requires being particular careful at loading/unloading operations and transportation.

Of ceramic pipes, inserted-joint (socket) pipes with an internal diameter of 100, 150 and 200 mm and length of 600 mm are commonly used. Asbestos concrete pipes were used mainly for assembling the outfall parts and mouth of a drain.

Plastic drainage pipes, supplied as a rule in coils, distinguish in comparatively low weight, their enabling laying drains in a continuous line, etc. Among their disadvantages are susceptibility to low and high temperature, exposure to solar radiation which negatively affects its endurance capability.

Corrugated pipes made from polyethylene also gained widespread use. Industrial process of production of filled-polyethylene pipes of 90 mm was tested in experimental production conditions of the Special Design Bureau of the Scientific-and-Production Implementation Company “Soyuzvodpolymer” (Latvia).

In many foreign countries, when constructing drainage system they used conventional (ceramics, concrete, asbestos concrete, etc.) and new synthetic (plastic) materials. In the USA, for example, ceramic and concrete pipes of standard and high quality as well as for especially hard conditions were produced. In terms of the design of the butt joint, pipes were made with straight (flat) face, bell mouth and collars for their grooved-and-tongued connection.

For especially hard conditions, they used metallic corrugated pipes made from bituminized fiber with perforation holes on the muff joints as well as asbestos concrete, plastic, etc.

They have experience in making multilayer design of drainage pipe with metal framework. In Great Britain, Germany, and other countries, they proposed a design of ceramic pipes with external grooves for increasing water intake as well as concrete filtering pipes with gaps and half-grooves.

Being inferior to plastic pipes in terms of laying technology, cost and other showings, ceramic pipes are distinguished, in addition to high resistance to corrosive environment, for age resistance: with high quality of making and construction, they can serve for 100 and more years. Therefore, with the development of plastic drainage, it is recommended to keep constructing drains from ceramic and polymer pipes, haydite concrete and other piped filters.

Source: Beglov, F.F. Study of the technology of closed horizontal drainage construction
in an irrigated zone and development of measures to improve it. Tashkent, 2012

To install drains, they use non-metallic non-pressure pipes. The pipe materials are required to have such properties as durability under agricultural machines moving across the field, resistance to corrosive environment, and sufficiently long service life (50 years at least). Closed drains are made from ceramic (clay), asbestos concrete, polymer, and porous-concrete pipes.

Ceramic pipes are most commonly used for construction of drainage. They have the following advantages: long service life (there are cases when such pipes served for more than 200 years); simple technology of their production and cheap local raw materials (clay). Ceramic pipes are made of round and polyhedral shape, 33 and 50 cm in length, and with internal diameter of 200-250 mm. Permeable plastic unions/sockets are convenient for fixing pipes. The pipes are laid on the trench bed end to end with their connection space of 0.5-2 mm. Ceramic pipes have the following disadvantages: hardly transportable because of their brittleness; heavy weight; incomplete mechanization and low productivity of ceramic drainage system construction.

Pipes from polymer materials (plastic, high and low-density polyethylene, PVC, etc.) can be used at soil water permeability of over 0.1 m/day. They are made smooth-bored and corrugated with walls 1-3 mm thick, 40-125 mm in diameter, with ready filters from synthetic protective materials. They have the following advantages: light weight; resistance to corrosive environment; well transportable; complete mechanization; and high productivity of drainage construction. Among disadvantages of them are: high cost and insufficient durability of pipes.

Source: Land reclamation / Golovanov, A.I., Aydarov, I.P., Grigorov, M.S. et al.
Edited by Golovanov, A.I. moscow, «Kolos» Publishing House, 2011, 824 p.