STUDY ON PROPERTIES OF LOESS SOLIDIFIED BY POLYACRYLATE SODIUM

Loess deposits are loose,collapsible,and easy eroded,which resulting in frequent geohazards such as landslides mudslides and water-soil loss in the Loess Plateau. To alleviate soil erosion and reduce the occurrence rate of geological disasters at present,this article uses sodium polyacrylate as the soil stabilizer to improve Dong Zhiyuan's remodeled loess in Gansu Province. Laboratory disintegration test,penetrant test,water erosion test,and triaxial compression test are adopted to analyze the property differences of solidified loess with different proportions. The results show that after solidification with the sodium polyacrylate mixture,the shear failure resistance and water stability performance of the soil are improved with the increase of the mixture proportion. Specially,with 3.5% of sodium polyacrylate mixture,the disintegration and erosion resistance is greatly improved. The disintegration rate is only 1.15%after seven dry and wet cycles. Compared with unreinforced soil,the principal stress difference at shear failure increases 25.29%,28.23% and 22.48%under 100kPa,200kPa and 300kPa,respectively. The penetration rate is reduced by 217.41 times. We explain the phenomenon and mechanism from the microstructure of the loess combined with the triaxial test date,size grading and field emission scanning electron microscope. The sodium polyacrylate mixture wraps and connects soil particles,which changes soil grain composition and grading,increases the cohesive force and internal friction angle between soil particles,and improves the soil shear resistance and water stability. The sodium polyacrylate mixture has a good solidification improvement effect on the loess. Our research results provide a new method for alleviating soil erosion and reducing disasters in the Loess Plateau.