جستجوی مقالات مرتبط با کلیدواژه « soil stabilization » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Nowadays, the destructive phenomenon of desertification and wind erosion is one of the most important environmental crises in the world, which are serious challenges to sustainable production and agricultural land management. In the present study, the effect of microbial precipitation of calcium carbonate has been studied as a biological reformer and compatible for controlling wind erosion and soil stabilization. For this purpose, erosion rate of bio-cemented samples was investigated through ….in a wind tunnel under the condition of wind velocity of (0 to 98 km hr-1) in two soil types with sandy and silty texture in a completely randomized design in three replications. Investigation of the threshold velocity of soil particle movement revealed that air dried soil particles begin to move at the velocity of 8 and 10 km hr-1 in the silty and sandy soils respectively, however, in all biological samples (MICP) particles did not move at 97 km.hr-1. The results also indicated that the weight loss of all MICP treatments at different wind velocities were significantly reduced as compare to the control. The amount of the soil loss among biological cemented samples and control treatments were dramatically different at higher velocities. So that, at velocities more than 57 km/h, soil losses indicated significantly enhancement in control, whereas in the soils which are treated by bacteria, soil losses were insignificant and approximately 2.5 kg.m-2.hr-1. The results also showed that the equal's amount of calcium carbonate and the penetration resistance of the soil surface increased significantly in MICP treatments as compare to control treatments, this event indicated the formation of a surface-resistant layer on bio-treated cement samples. In this study, the comparison of used bacteria also showed that Bacillus infantis and Paenibacillus sp3 have high efficiency in controlling wind erosion. Therefore, it seems that cementation by biological methods could be an effective way to stabilize surface particles and control soil erosion.

Application of chemical polymers is one the effective methods for stabilization of soils. In this research, the effects of Polyvinyl Acetate Polymer on stabilization of soils and erosion control has been investigated. To do this, three different soils types were treated with five levels of Polyvinyl-Acetate emulsion and cured for three ages. Thus, considering three replication for each samples totally 135 specimens were prepared and tested for determination of their compressive strength. Statistical analysis of the results showed that the adding of polymer increases the compressive strength of the samples significantly, where the rate of increase depends on soil texture and varies from 15 % in clayey samples to 400 % in sandy soils. Furthermore, the compressive strength of the samples significantly affected by the age of the samples and deacreased upto 15 and 28 percet after 3 and 6 months respectively. Also based on durability tests, addition of polymer to the samples makes the sandy samples durable but has no effect on the durability of clay samples. Finally, application 25 g of polymer per square meter of soil was determined as the optimal treatment to stabilize the studied soil.

Mulch is one of the most common materials for soil stabilization which prevents wind erosion and dust emissions. In this respect, the sustainability of mulches against corrosive environmental factors is important for selection. In this study, the resistance of some abiotic mulches was examined in simulated desert conditions against pressure by pocket penetrometer at different temperatures. Also, to evaluate the amount of surface leaching, the mulches were tested against spraying water as well. Treatments include 13 types of mulches, nano-polymer mulch, sand, stone powder, sludge and clay soils. Two types of eroded soils including moderate and severe soil erosion and three levels of temperature including ambient temperature, 50 ºC, 60 ºC all of them with three replications were studied. The results showed that sprayed polymers on severe soil erosion and under both 50 ºC and 60 ºC temperatures had the maximum compressive strength. Also the results of spraying water on the treatments showed that polymeric mulch was more resistant against leaching than others.