Study Of Slope Stability Affected By Ionic Rare Earth In-situ Leaching In Gannan Area

Ionic rare earth is one of the dominant mineral resources in Ganzhou city, as well as the exploitable resource which has been protected by our nation. The in-situ leaching mining technology of ionic rare earth is the newest technology of the rare earth ore mining at present. This technology has been generalizing for more than ten years and has been the first selection of ionic type rare-earth ore leaching technology of hydrometallurgy, without excavating mountains、destroying surface vegetations or discharging solid waste residues, eliminating pool leaching and heap leaching process so called “mountain movement”. With the continuous exploitation of ionic rare earth, in-situ leaching mining technology on the mountain slope destruction is becoming more and more serious. Hundreds of mountain collapses have been caused by in-situ leaching mining according to the recent years’ data. So, the research on how in-situ leaching mining impacts on slope stability got its importance.In-situ leaching mining slope stability is mainly affected by internal and external factors, but the external factors of human engineering activities(grouting strength, grouting time) are the principal elements triggered landslides. This paper focuses on the influences of different grouting strengths on rare earth slope stability, mainly for the following work:(1) In view of the field investigations on Dingnan、Longnan and Xinfeng counties, 890 locations’ data of in-situ leaching mining landslides(hidden troubles) have been analyzed to research the basic characteristics, landslide types, spatial and temporal distribution characteristics, and the law of development and evolvement of in-situ leaching mining landslide.(2) Survey and research the influence factors of in-situ leaching mining landslide stability. According to the influence factors of affecting in-situ leaching mining landslide stability, using orthogonal experiment design method and combining with the software of Geo-studio to study the seven factors including slope Angle, slope height, grouting strength, internal friction angle and cohesive force of clay layer and weathered deposits, and to conduct sensitivity analysis and sorting, to find out the most sensitive factors.(3) Set the typical Muzi mountain rare earth mine in Dingnan county as the research object, combined with Geo-studio numerical simulation software to analyze the law of pore water pressure and slope safety factor changes of rare earth side slope in the different grouting strength of 0.6m3/day, 0.9m3/day, 1.2m3/day, 1.5m3/day, 1.8m3/day.