Research On Characteristics And Stability Of Guizhou Manganese Slag Roadbed Filling Engineering

Manganese slag is a kind of industrial waste produced by electrolysis production of manganese metal.The traditional method of slag storage not only causes waste of resources but also causes environmental pollution.Finding harmless,effective and economical disposal technology of manganese slag has gradually become the hot spot and difficult point in electrolysis manganese industry and environmental protection field.In this paper,relying on the science and technology project of Guizhou Provincial Department of Transportation and taking the manganese slag in Songtao City,Guizhou Province as the research object,we consider the manganese slag as the roadbed filling according to local conditions,carry out a more systematic test analysis and numerical simulation,and study and summarize the key technology of the manganese slag roadbed filling in mountainous areas.(1)The physical and chemical properties such as particle composition,chemical composition,X-ray diffraction,scanning electron microscope,limit water content and leaching toxicity of manganese slag in Songtao area were studied.The mechanical properties of manganese slag were studied by compaction test and load-bearing ratio test.The results show that the manganese slag without curing treatment can not meet the standard of subgrade filling and environmental protection requirements,and electrolytic manganese slag can not be directly used as subgrade filling.(2)According to the technical requirements of environmental protection and road performance,the leaching toxicity test and road performance index test were carried out.The results showed that when adding 10% quicklime into the manganese slag,the soluble manganese in the leaching solution decreased to 0.009mg/L and the ammonia nitrogen decreased to 11.67mg/L,which reached the national standard.The results of column leaching test show that the solidified manganese slag meets the long-term environmental protection requirements.The engineering characteristic test of quicklime solidified manganese slag shows that quicklime solidified manganese slag is a kind of subgrade filling material with high strength,small deformation and good water permeability.The CBR value and rebound modulus value are obviously higher than the standard of subgrade filling stipulated in the code,and it has great shear strength.The permeability coefficient is similar to that of fine sand,and it has better drainage performance.The stress-strain curve is of strain softening type.(3)The slope stability and deformation characteristics of solidified manganese slag embankment with different slope heights and different slope ratios were calculated and analyzed by Geostudio2018 software.The results show that solidified manganese slag embankment with 10% quicklime is better than ordinary soil embankment with the same geometric size in slope stability,horizontal and vertical deformation.Lime solidified manganese slag embankment can be designed according to conventional soil embankment.(4)By establishing the finite element model manganese slag embankment slope under the condition of rainfall,considering different rainfall intensity and rainfall patterns on manganese slag is finite element simulation of seepage and stability of subgrade slope,considering the spatial variation of soil properties at the same time,using monte carlo method of slope reliability and failure probability calculation,for the design of the manganese slag embankment slope under the condition of rainfall and management to provide technical support.