The success of a drainage system depends not only on the design of the system and the characteristics of the soil and its cover; In addition, it depends on the soil moisture level during installation, how the trench is filled and the general quality of the operation. Manual installation of drains and the use of excavators in small drainage projects is the right choice. Excavators dig deeper trenches than drainage machines commonly used in large projects. These machines are also used for wide and deep drilling to install large collectors. Drainage machines are also used to construct narrow trenches in which drains are placed (trenches); They can also install drains directly underground (trenchless). Turners dig the trench with rotating blades or chains. The range of changes in the depth and width of the trench drills is very different. Installation of drains using labor or conventional drilling machines involves a series of sequential activities, including trenching, pipe installation, application of cover materials, and return of soil to the trench. This operation is performed by turners simultaneously. Trench filling is sometimes done separately by an auger or blade located on a tractor. Filling the trench can also be done using the device installed on the trench, when the machine returns to dig a new trench.
Today’s drainage machines are equipped with laser slope control system, which has a significant effect on increasing the efficiency and accuracy of underground drainage installation. At the same time, the maximum drilling speed must be in line with the speed of the hydraulic system used to automatically adjust the installation depth. Otherwise, the accuracy of the operation will be reduced. Although deviation from the design slope is somewhat acceptable, it should not be more than half the diameter of the pipe. Further deviation causes air to be trapped at higher points and sedimentation at lower points, blocking the flow of water through the pipe. Also, a negative slope in the installed drains is not acceptable.
2- In installing drainage pipes of UPVC type that do not have artificial filters, after confirming the depth, width and slope of the trench of filter materials (granulated sand) as a natural filter under the supervision of a consulting engineer and monitoring device It is poured into the trench as the first layer and then after the end of the pipe installation operation, the trench is filled by embankment operation.
3- Excavation and digging of trenches should always be done according to the type of soil in the area, the type of drainage and taking into account the depth, width and slope.
4- The ends of UPVC drainage pipes should be connected to each other by means of a connection or connection (without glue) and the trench should be filled with the specified materials as a natural filter. (The area around the pipes should be surrounded by sand) and then covered with excavated soil.
5- The thickness of the natural filter layer (sand) around the pipe is usually 10 cm and sampling and granulation tests of the natural filter around the pipe should always be done and in accordance with the desired specifications.
6- During the whole installation operation, either manually or using special drainage equipment, care must always be taken not to collide with equipment, machinery and any severe impact that causes breakage and separation of pipe connection points.
7- In order to have the desired result and also high efficiency in drainage by special drainage pipes of UPVC type, it should always be ensured that the holes on the pipe are not blocked. For this purpose, using suitable artificial or natural filters, the entry of mud and sludge, which causes blockage of holes, is prevented. To use natural filters (granulated sand) and mix with excavated soil, soil sampling is done at the desired depth for application and then the type and size of sand (granulated) is determined. And is used in the project.
8- In the world, artificial filters for underground drainage have been used successfully for years and are a very good alternative to natural filters (granulated sand). These materials replace the soil around the pipe and in terms of high water permeability compared to the soil and natural filters around the pipe, water drainage is done with higher efficiency. Depending on the type of soil where UPVC drainage pipes are installed, such filters with different permeability (can be produced based on the size of the soil around the pipe) prevent the entry of particles and thus block the holes around the pipe. Polypropylene artificial filter cover on UPVC drainage pipe has a very high efficiency due to the investment. Synthetic filter coating of this type causes much better drainage of water, the need for less washing inside the pipe compared to other filters and having a very long life is a very good choice for natural filters. PVC drainage pipes with synthetic filter coating (PP) can be applied directly without the need for natural filters (granulated sand) and in terms of very low weight and low shipping costs compared to moving and access to sand and Suitable sand is a very good alternative in any area. Due to the very high installation speed, the overall costs of the project are much lower and can be done in a large area in less time.