Examing The Seismic Behaivor And Liquefaction Stability Of Tailing Dam Using Dynamic Centrifuge Tests

China is a country rich in mineral resources.Most of the energy and raw materials required for the development of our country come from the utilization of mineral resources,which produced a huge amount of tailings at the same time.A large number of tailings reservoirs have been built in China in order to store the tailings.There are three common types of tailings reservoirs called upstream tailings reservoir,midline tailings reservoir and downstream tailings reservoir.For economic and convenience considerations,upstream tailings reservoir were widely used.However,upstream tailings reservoir has many disadvantages,including low structural strength,high infiltration line,and poor dynamic stability,which will lead to liquefaction and destruction of tailings reservoirs during the earthquake.To further explore the seismic behaivor and liquefaction stability,a series of model tests have been carried out.The main works and results of this dissertation are as followsThe types and characteristics of tailings dams are systematically introduced.The factors that may affect the dynamic stability of the tailings dam are sorted and classified in detail by sorting out and analyzing the tailings accidents in historyThe dynamic response of the tailings dam on soft ground is studied based on the dynamic centrifugal model test.The acceleration,settlement displacement and pore water pressure of the tailings dam have been focused during the test.The effect of heightening and consolidation on the seismic response was discussed by comparing the test results of different working conditions.The results show that the soft soil foundation is less than the initial dam.Meanwhile,the acceleration amplification of the heightened and expanded dam is the most obvious.The pore water pressure in the the tailings dam and foundation has increased slightly in the test.In terms of deformation,when the earthquake is weak and the soil is well consolidated,the deformation mode of the tailings dam is seismic settlement,and when the earthquake is strong and the degree of consolidation of the soil is poor,the deformation mode is that the deformation of the tailings in the horizontal direction causes the uplift of the downstream soilIn order to examine the failure process of tailings dam with relatively impermeable thin layers,dynamic centrifuge model tests were carried out using an advanced centrifuge shaking table.The development of pore pressure in tailings,the mechanisms of liquefaction and the influence of relatively impermeable layers on the liquefaction process were investigated.The tests successfully simulate the dam breach behavior of tailings dam under seismic loading.The dam breach is mainly induced by the local liquefaction caused by the continuous pore pressure generation in tailings during shaking,while there is minor damage on the starter dam.The relatively impermeable thin layers can inhibit dissipation of excess pore pressure and then lead to accumulation of excess pore pressure beneath those layers,making tailings more prone to liquefaction.