Testing Study On Saline Wind Erosion Of Earthen Sites In The Arid Region Of Northwest China

Saline wind erosion, which is defined as the salinized deterioration of the rock-mass and soil-body exacerbating their loss of wind erosion, is a universal damage effect in nature, and has a particularly great significance on the earthen sites of the arid area in northwest China. The roots of the site accumulate variety of salt, when soil moisture changes in the body, causing salt crystallization-dissolution-recrystallization, it can result in deterioration of soil structure, along with weakening resisting ability of wind erosion. And it is easy for the site roots to form recesses at the roots which would cause instability and collapse of the dumping site, and even devastating damage if it has a long-term development. Therefore, to commence the study of saline wind erosion of the site, and analyze the internal and external factors that led to the destruction, can provide a theoretical basis for the scientific formulation of the effective protection measures.In this paper, based on a comprehensive understanding of the occurrence environment physical and mechanical properties of the site, laboratory tests are carried out on the factors such as salts, sediment-laden wind and wet and dry cycles which affect saline wind erosion. Choosing site soil of Ming Great Wall in Shandan, Gansu Province, as testing soil sample, desalt and then mix it with salt of specific categories and contents and make it into reshaped soil samples. Maintain the samples by simulating the natural cycle of wet and dry conditions, and then carry out acoustic testing and wind tunnel test. Aided by the soil microstructure SEM image analysis, a preliminary analysis is made of saline degradation and wind erosion loss of the site soil.The results show that, in the process of soil erosion effect of saline site, the salt category and content serves as internal deterioration factor, the sediment-laden wind as dynamic mechanism, and dry-wet cycle as external power. Different categories and content of salt varies on the impact of saline deterioration and loss of wind erosion of the site soil., as the samples with complex salt of NaCl and Na2SO4 have significant impact on the saline deterioration and wind erosion, followed by samples with Na2SO4, the minimum sample containing NaCl. Wet and dry cycle accelerates soil structure deterioration, and effects much on the surface layer of the samples where the maximum concentration of salt crystals occur, thus making the soil particles of the surface layer more prone to wind erosion damage.