Research On Key Technology Of XingFen Highway Gangue Subgrade

Coal gangue is a low carbon content and hard rock which is produced in the processingmining. For a long time the utilization of coal gangue is very low, resulting in the coal ganguepile. The exposed coal gangue will take place complex physical and chemical effect ofself-ignition, weathering and eluviating, which will result atmospheric pollution. The coalgangue exudate contains many heavy metals and pollutants which will pollute thegroundwater resources. On the other hand, the construction of highway accelerates theeconomic development which also exacerbates the land conflict. The usage of coal gangue asroad construction materials, not only can save construction costs, but also can reducepollution. So it has good economic and social benefits.This research relys on the XingFen highway of Hebei Province, mainly carrying out thefollowing research:(1) Study on the technical index systematically which the coal ganguesubgrade should meet, the coal gangue of xingtai mine indoor test was carried out. So thefeasibility of gangue rock used in subgrade of three color gangue was determined.(2) Thelaboratory tests of compaction characteristic, load-bearing characteristics and permeability ofdifferent content of P5coal gangue was carried out, systematically studied the coefficient ofthe relationship between the parameters such as maximum dry density, the best moisturecontent, CBR, the amount of flooding expansion and the permeability of coal gangue.(3)Field test are carried out for the two construction methods of vibrating roller compaction anddynamic consolidation, the variation rules of the aggregate gradation, crushing value,compaction degree, the settlement with the number of roller compaction or tamping.(4)Based on the finite element method, the differential settlement of the abutment of XingFenhighway with different coarse particle content and degree of compaction of coal ganguea arecomputed. The appropriate degree of compaction and grain composition are determined. Inthe end, the gangue backfilling control indicators are proposed.(5) From the point view ofprotecting the soil and water environment along the gangue embankment, the indoor leachingexperiment of gangue is conducted. With the help of finite element coupling model, thetransporting laws of pollution solute is simulated to recommend the reasonale thickness ofsurrounding soil of Xing Fen Expressway.(6) Based on the gangue subgrade constructionquality control methods, matters need attention, as well as quality acceptance criteriadiscussed in this paper, the construction technology and quality control standards of XingFenhighway gangue subgrade is proposed systematically.