When you want to build an agricultural irrigation pool, irrigation canal or irrigation pond, you will research and see that reinforced concrete pools can no longer hold water due to cracking and water leakage problems. For this reason, you can also see that geomembrane coatings, which have been accepted by the State Hydraulic Works and have been emphasized for about 10-12 years, give the best results in water retention. After the decision is made in this direction, geological and geotechnical examinations of the application area should be made. Type of soil (soil, clay, rock, loam) Structure of the soil Presence of voids (calcareous rocks or soils) Height and variability of the groundwater level Presence of gases in the soil (organic substances) Risk of differential settlement (volcanic soil, backfilling, etc.) Risk of internal erosion (karst soil, filling lands) In all conditions, the rules of soil mechanics must be followed in order to obtain a solid and stable base and consequently durable waterproofing. In this way; Agricultural irrigation ponds, Fish ponds, Irrigation canals, Decorative ornamental ponds, Fire ponds, Artificial pond applications are covered with geomembrane. Geomembrane selection is determined as a result of life, functionality, quality and economic evaluations. Each membrane type has different properties. In other words, the elongation and stretching coefficient, response to hot and cold changes, UV resistance, compressive strength, chemical resistance and costs are all different from each other. The types you can use in geomembrane selection are homogeneous PVC geomembrane, reinforced PVC geomembrane, EPDM geomembrane, HDPE geomembrane can be used for water retention.
Application Site Preparation;
After all kinds of ground investigation and improvement of the application area according to the required improvement methods are completed, excavation is carried out according to the desired project. The base and lateral slope slope dimensions to be formed in the excavation should be selected by considering the project and application. In order to help the drainage (gas-water) systems to be built and to make pond maintenance easier, the base slope is preferred between 2% and 5%. The lateral slope should be maximum 50% for the works to be carried out during the application. It is important that your pool or pond has a slope; both to prevent a possible landslide and collapse (the soil will become more unstable and will want to flow with the effect of precipitation) and to collect more tonnage of water. There should be no sharp stones, iron pieces etc. on the ground that can damage the membrane. If there is such a situation, it should be intervened immediately. If you already have a reinforced concrete pool and there is water leakage due to cracks, you can proceed starting from geotextile felt application.
Geotextile Felt Application;
After the necessary preparations for the pool & pond are made, geotextile felt is selected in weight suitable for the characteristics and structure of the soil. Geotextile felt should not be less than 250 g/m2. Geotextile felt is overlapped and geotextile laying is completed. If deemed necessary, geotextile felt can also be sewn. After geotextile felt application, geomembrane laying can be started.
Geomembrane Application;
Geomembranes are brought to the application site in coils. In accordance with the pool project, the wings are overlapped on top of each other (minimum 35 mm – 50 mm) and welded with a thermal automatic welding robot. All welds made are specially controlled. Geomembrane Locking; It is done in order to prevent the membrane laid on the pool & pond surface from moving downward with water pressure. At the upper level of the pond embankment; the locking channel through which the geomembrane will be passed is opened along the perimeter of the pond. The channel through which the geomembrane is passed is backfilled (by filling sacks with soil or gravel) to create pressure on the geomembrane. The geomembrane is locked due to the pressure caused by the weight of the backfill.
Geomembrane Protection;
In order for the applications to be long-lasting, it is necessary to take protective and preventive measures against external mechanical influences. These factors are mainly; – Human Factor: Angling, desire to swim, desire to drink water, etc. – Animal Factor: Animals entering the pond for water needs, especially in summer due to the effect of hot weather, etc. It has become a legal obligation to close it with a wire fence to prevent human and wild animals from entering the pond area. (It is prohibited based on Article 66 of the Provincial Administration Law No. 5442 and Article 32 of the Misdemeanor Law No. 5326). – Nature Factor: Landslides, excessive wind, etc. Measures should be taken against these effects. In order to prevent rock fragments breaking off from the slope from damaging the membrane application on the surface of the pond, an energy-breaking set, i.e. gabion, can be built on the edge of the embankment. If your pool or pond will be empty for a while, the geomembrane on the empty pond surface may swell and tear with the effect of wind. Sand bags are prepared to prevent this effect. Sandbags prepared to be placed on the surface of the pond to be emptied are placed on the upper elevation of the pond at certain intervals.
Conclusion and Evaluation;
We make pool and pond applications using all geomembranes. However, EPDM membrane waterproofing material has the highest elasticity among geomembranes, provides the best resistance to climatic conditions and temperature changes, and has the longest life. EPDM geomembrane provides waterproofing for a long time without the need for maintenance.
