Study On Test Of Dynamic Characteristics Of Tailings Sand Under Different Saturation

In China, a large part of tailings reservoirs are woring in unsafe state, that is, they exist a major health hazard. Thus it is prone to liquefaction which may lead to dam failure in the event of dynamic loads like earthquakes. In recent years, China’s demand for mineral resources is growing along with fast ecnomic growth, and, numbers of tailings dams are also increasing year by year. Under this background, how to prevent effectively the occurrence of dam break accident as well as enhance the security index of tailings reservoirs has becoming a major topic. In this paper, dynamic characteristics of tailings sand obtained from a tailing dam in Liaoning province were studied using dynamic triaxial test, the main achievements are as follows:1. By means of consolidated quick shear test, compression test and grain size composition analysis test, the basic physical and mechanical properties of tailings sand were studied, obtaining particle composition rules, compression properties and strength properties.2. A series of dynamic characteristics test were carried on saturated tailings sand using DSC2000 triaxial apparatus, thus the dynamic strength and deformation of saturated tailings sand were studied. Dynamic shear strength index and relationship between shear modulus, damping ratio and dynamic shear strain were obtained; the development process of pore pressure during the test was analyzed. Parameters in pore pressure-stress model and pore pressure-strain model were modified and the modified parameters seemed have a better reflect on the increasing model of pore pressure.3. A series of test on tailings sand with two kinds of different saturation were carried, thus the dynamic strength, pore pressure and dynamic deformation of unsaturated tailings sand were studied. Besides, the effects of different saturation on the dynamic strength and deformation of tailings sand were studied.4. Three typical models of viscoelastic theory were introduced in detail. By the analysis and calculation of the dynamic triaxial test data, finding that equivalent linear model can better reflect stress-strain relationship of tailngs sand and the relevant parameters of equivalent linear model under dynamic load were obtained...