Using Seismic Records to Determine the Predominant Vibration Frequency of a Tailings Dam Embankment: First Results

摘要

A large number of tailings deposits in operation, non-active, and in abandonment are located mainly in the northern and central Chile where the seismicity threatens the stability of these large and saturated geostructures. The importance of the physical stability of these deposits is relevant since it directly influences the life of mine, its closure plan, the impact on the environment, and the surrounding communities. A common practice is that tailings deposits are instrumented with different technologies to measure pore water pressure inside the wall, water levels, infiltrations, deformations, and seismic accelerations. The monitoring and understanding of the information collected is essential to ensure the stability of the deposit and its operational continuity. This work seeks to determine the predominant vibration frequency of an instrumented tailings dam embankment of 45 m height constructed from borrowed material by calculating empirical amplification transfer functions and by using the horizontal to vertical spectral ratio method (HVSR). Then, the equivalent linear wave propagation method is used to explain the observed predominant vibration frequency considering estimations of shear wave velocity profiles of the embankment dam.