Seismic Imaging of a Dam-Rock Interface with Elasto-Acoustic Wave Propagation Models
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In this talk we are interested in reconstructing the interface between the concrete structure of a hydroelectric gravity dam and the underlying rock, using Full Waveform Inversion. Indeed, it appears that the roughness of the dam-rock interface has an effect on the sliding stability of gravity dams (see, e.g., Saichi et al 2019). We minimize a regularized misfit cost functional by computing its shape derivative and iteratively updating the interface shape by the gradient descent method. At each iteration, we simulate time-harmonic elasto-acoustic wave propagation models, coupling linear elasticity in the solid medium with acoustics in the reservoir. Numerical results using realistic noisy synthetic data demonstrate the method ability to accurately reconstruct the dam-rock interface with a limited number of measurements.