The Experimental Study On Interface Properties Between Geogrid And Grain Tailing And Numerical Analysis

Tailings is a special kind of soil, structured with single granule and beehive, and it differs greatly from common sandy soil used for engineering purpose in composition and physical and mechanical properties. Common soil is strengthened by putting high tensile strength geosynthetics into it to form composite soil, or called reinforced soil.Reinforcement technology has been widely applied to various engineering fields including hydraulic building, road and railway construction, coal mining and architecture etc, because of its contribution to the improvement in soil strength and stability. In recent years, although there have been many engineering practices and some theoretical progresses in reinforcement technology, few research results about its use in tailings dams have been reported as yet.Geo-grid is a new type of geosynthetics with more advantages over previous ones including uniformity, high deformation module and tensile strength, great toughness, light weight, corrosion-proof, great interaction with soil grains and instantaneous reinforcement effect etc. In view of these mentioned characteristics, it has been considered the main reinforcement material among others. This paper deals mainly with the interface interaction properties of tailings of Longdu tailings pool, Dahongshan Copper Mine, Yunnan province with geo-grid through pull-out tests, reinforcement theories discussion and numerical simulation of the interaction between geo-grid and tailings. Research results of this paper may be summarized as below.(1) The friction reinforcement mechanisms and pseudo cohesion theory were theoretically discussed.(2) Pull-out tests were performed on two types of steel-plastics composite geo-grid to study their interaction properties with tailings using a self-made apparatus. Interaction parameters between geo-grid and tailings were measured and factors affecting them were also discussed. These data may be referred to for project designs and numerical analysis.(3) The ANSYS software was employed to numerically simulate the interaction between geo-grid and tailings, which led to the isoline diagrams of stress, strain, shear stress and strain for fine-grained tailings as well as von miss stress and strain diagrams for geo-grid. On the basis of numerical simulation, the interaction between tailings and geo-grid was extensively investigated.