Experimental Research On The Interaction Between Geosynthetic And Fine Grain Tailings And Its Application

To apply reinforcement technology to the tailings dam and improve the stability of the dam, pull-out test has been performed in this paper by using geobelts (or geogrids) and tailings soil from Longdu tailings dam of Dahongshan copper mine in Yunnan province. The interface properties between fine grain tailings and reinforcement have been investigated. The experiment results are applied to the analysis of the stability of tailings dam.The experiment shows that the curve of pull-displacement can be distinctly divided into three sections, namely the static friction, the sliding friction and the remnant sliding friction periods.The qualitative analysis based on test results shows that the greater the density and the compactness of tailings are, the larger the virtual coefficient between tailings and reinforcement; the higher the water content in tested tailings, the smaller the virtual coefficient.The virtual coefficient is quantitatively calculated through the application of the friction reinforcement principle and the apparent coherence principle. Compared with other types of engineering soil, the virtual coefficient between tailings and reinforcement is not bigger than 0.25, while that of other kinds of soil usually exceeds 0.25.The calculation analysis about the stability of reinforced and non-reinforced tailings dam of Longdu, at Dahongshan copper mine in Southwest China's Yunnan province is made. Calculation results show that the current tailings dam, non-reinforced, is safe. But with the height of tailings dam increasing, it will tend to become unsafe and need reinforcing. In this paper, in addition that the stability of reinforced tailings dam is analyzed in a convention way, a new idea is first put forward that the reinforcement can be used to counteract a portion of quake force in analysis of the stability of tailings dam, the result of which approximates to that of the previously calculated.It is the first time to apply reinforcement technology to improving the stability of tailings dam through experiment research using fine grain tailings as fill-soil, which further enriches the reinforcement theories, widens its scope of use and proves valuable both in theory and in practice.