Study Of Key Technologies Of Highway Fly Ash Embankment

Both the production and consumption of China’s coal resources ranks first in the world. A quarter of the world’s raw coal is from China every year, of which76%is consumed as energy.About34%of China’s electricity is generated by the coal-fired power plants. Although they have provided a lot of energy for China, they have also produced lots of industrial wastes such as the fly ash.lt is estimated that the power plants emission up to three billion tons of fly ash every year in China, which will cause serious pollution and hazards to our environment if not handled properly.As a very important power output in China’s strategic deployment of the power transmission from west to east, the coal-fired power industry has grown so fast in Guizhou Province, but the fly ash has not been used effectively, which has restricted Guizhou’s economic development to some extent and hindered the construction of sustainable development of society and the achievement of energy-saving and emission reduction targets.Relying on the research project "Research on the comprehensive utilization technology of fly ash of Guizhou highway" of Guizhou Province Science and Technology Commission, this article has studied the material properties and applicability in embankment filling of the fly ash produced by the coal-fired power plants along the Zunyi Bijie highway and also the fly ash embankment construction technology so that it can provide actual reference for Guizhou’s wide use of the fly ash.First of all, the article has analysed the research and application of the fly ash’s usage in the road construction at home and abroad and also expounded the application of the fly ash produced by the coal-fired power plants along the Zunyi Bijie highway so that the significance of this study can be explored further.Secondly, the article has studied the physical and chemical properties and mineral composition and also analysed the engineering characteristics of the fly ash, especially the maximum dry density, optimum moisture content, shearing strength, modulus of resilience and compression characteristics and so on.We have drawn the preliminary conclusion that the fly ash produced by the coal-fired power plants along the Zunyi Bijie highway can meet the relevant provisions of the specification for road in our country and thus has higher use value.Thirdly,choosing the fly ash produced by the five typical coal-fired power plants along the Zunyi Bijie highway as the study subject,we have done the numerical simulation analysis of the stability, stress and deformation of the fly ash embankment using the finite element software PLAXIS,based on which we studied the applicability in embankment filling of the fly ash. We have come to the conclusion that the embankment filled by the fly ash exhibites good mechanical properties,which can meet the requirements of strength and stability of the subgrade and also reduce the settlement and deformation of it effectively. This has important implications for highway construction in Guizhou Province.Finally, through the study of the construction process of fly ash embankment and analysis of the construction preparation, embankment base treatment, transportation, paving and rolling of the fly ash and environmental pollution control,we further summarize the construction method and key points of the fly ash embankment based on field tests and will provide reference for road construction in the future.