Multi-scale Analysis Of Mechanical Properties Of Textile Geotextiles Reinforced Tailing Sand

With the continuous exploitation of mineral resources and the continuous discharge of tailing sand,the requirements for the capacity of tailings ponds continue to increase.In order to increase the storage capacity of tailings ponds,the tailings dams have been heightened step by step,thus ensuring the safety and stability of tailings dams.As geosynthetics have good engineering application performance,more and more geosynthetics are applied to reinforced slope engineering at present.However,the interaction mechanism between various geosynthetics and fillers with different mechanical properties is relatively complex,and relevant research needs to be further strengthened.The paper ains at studying the mechanical properties of the interface between textile geotextile and tailing sand,laboratory pull-out tests and discrete element numerical simulation pull-out tests between geotextile and tailing sand were carried out.Laboratory tests show that the order of influence of vertical pressure,pull-out rate and moisture content of tailing sand on peak shear stress is: vertical pressure > moisture content > pull-out rate;The peak shear stress increases linearly with the increase of vertical pressure;With the increase of pull-out rate,the peak value of interfacial shear stress increases slightly,the apparent cohesion increases first and then decreases,and the interfacial friction angle decreases slowly and then increases rapidly;With the increase of moisture content in tailing sand,the peak value of interfacial shear stress decreases obviously,when the moisture content is 1.2%,the value is 1.5 times as high as when the moisture content is 8.4%,With the increase of moisture content,the apparent cohesion increases first and then decreases,and the interfacial friction angle decreases quickly and then slowly.The correctness of meso-parameters in PFC numerical simulation is very important,currently,the trial algorithm is usually used to select meso-parameters.The macro-meso parameter correlation of PFC linear contact model is studied through numerical triaxial tests,meso-parameters mainly include normal contact stiffness,stiffness ratio and friction coefficient,and the shear mechanical parameters mainly include the peak value of principal stress and its corresponding strain,cohesion and internal friction angle.The meso-parameters of tailing sand are calibrated and the numerical pull-out test is carried out.The results show that: when the friction coefficient of geosynthetics decreases,the peak pull-out force and its corresponding pull-out displacement will both decrease,and a stronger reinforcement effect can be obtained by increasing its friction coefficient;Geosynthetics have the strongest reinforcement effect when the aperture ratio is around 5.0.Therefore,appropriate reinforcement materials should be selected in engineering application.This paper has 79 pictures,21 tables and 72 references.