Grunts filtrācijas īpašību uzlabošanas iespējas Pļaviņu HES apkārtnē, pielietojot elektroosmozes metodi

Abstract

Bakalaura darbs ir veltīts grunts elektroosmotiskajai apstrādei, tās filtrācijas īpašību uzlabošanai. Elektroosmoze ir fizikāla grunts nostiprināšanas (nosusināšanas) metode, kuru inženierģeoloģijā parasti pielieto mālu gruntīm, iedarbojoties uz tām ar elektrisko lauku. Šī darba ietvaros elektroosmoze tika pielietota, lai laboratorijas apstākļos izmainītu smiltsiežu filtrācijas īpašības. Grunts paraugu apstrādei ar elektroosmozes metodi tika izmantotas speciālās ierīces – permeametri. Paraugu elektroapstrādē tika veikta pēc trīs dažādām apstrādes shēmām, kas savā starpā atšķīrās ar sprieguma lielumu, filtrāta padeves spiedienu un filtrāta sastāvu. Pētījuma laikā noskaidrojās, ka visizdevīgāk grunti apstrādāt, par filtrātu izmantojot kalcija hlorīda šķīdumu nevis destilētu ūdeni un pēc elektroosmotiskās apstrādes palielinās smilšaino grunšu porainība, un līdz ar to arī uzlabojas filtrācijas īpašības. Pasaules praksē nav daudz līdzīgu piemēru šādiem darbiem, jo nav izstrādāta un aprobēta standartizēta metodika elektroosmozes pielietošanai. Tā kā elektroosmoze ir viena no lētākajām metodēm, kas ļauj izmainīt grunts īpašības, papildus pētījumi šajā jomā veicinās metodes attīstību un plašāku pielietošanu gan Latvijā, gan ārpus tās.

Bachelor thesis is entitled "Increasing of soil permeability in the area of Plavinas HPP using electro-osmosis". Electro-osmosis method is based on applying electric field to soil. It produces so called "osmotic flow" of the water molecules from one electrode to the other. The work is based on the results of the laboratory tests and field experiment. The structure of the soil samples, used in the laboratory tests, was undisturbed (like in soil massive). This point was achieved by special "monolith" sampling technique. Soil samples were tested in the laboratory by using special equipment (permeameters), where electric field and water flow were generated through the soil sample. Water flow was generated by pressured water from one side of the ground sample, so the water is relished from the other side of the sample as far as water have got through it. The electric field was generated by applying the electrodes to the both sided of the soil sample (which is already in the plastic tube). The next values have been controlled during soil sample testing: power, voltage, the water quantity relished through the ground sample. Before and after the tests in permeameters, other tests were made to determine specific values and characteristics of the ground sample, such as grading composition, moisture, coefficients of porosity, friction angle, and others. The point was to determine the differences before and after the application of the electro-osmosis method in the ground sample. According to the laboratory test results the method application in the field was developed. As the result of applying the electro-osmosis the filtration and resistance characteristics of the ground sample and ground massive raised up. Putting this method in practice could increase the debit of the relief wells, improve weak soils, and decrease the groundwater level in the defined territory.