000013670 001__ 13670
000013670 005__ 20161114170127.0
000013670 04107 $$aeng
000013670 046__ $$k2011-05-25
000013670 100__ $$aKucukcoban, S.
000013670 24500 $$aFull-Waveform-Based Inversion for Site Characterization: Theory, Numerical Simulations, and Physical Experiments

000013670 24630 $$n3.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013670 260__ $$bNational Technical University of Athens, 2011
000013670 506__ $$arestricted
000013670 520__ $$2eng$$aWe discuss recent progress in the full-waveform-based imaging of probed solids/soils, with geotechnical site characterization applications in mind. The primary goal is the reconstruction of the material profile of near-surface, arbitrarily heterogeneous formations using elastic waves as the probing agents. The problem requires efficient solutions of the forward wave simulation problem, robust strategies for tackling the inverse imaging problem, and designing of experimental protocols to best harness the limited field data that feed the imaging problem. To address the forward problem, the semi-infinite extent of the probed domains is truncated via the introduction of perfectly-matched-layers (PMLs) at the truncation interfaces. We discuss a new variational hybrid formulation for transient elastic wave simulations in PML-truncated domains that is computationally optimal when compared to competing schemes. We then discuss a full-waveformbased inversion framework driven by PDE-constrained optimization ideas: to address the imaging problem we seek to resolve simultaneously PML-endowed state and adjoint time-dependent BVPs, together with time-independent BV control problems that drive the material updates during inversion iterations. To address solution multiplicity and improve on the robustness of the inversion algorithms we deploy regularization schemes (Tikhonov and Total Variation), continuation schemes (frequency-, grid-, and regularization factor-continuations), and a new search-direction biasing scheme that seems to accelerate algorithmic convergence. We report satisfactory results with numerical experiments targeting inversion of both smooth and sharp profiles in two dimensions, and also provide examples attesting to the quality and efficiency of the forward wave modeling.

000013670 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013670 653__ $$aFull-waveform-based inversion, Perfectly-matched-layers, Site characterization, Forward transient elastic wave simulation, Mixed FEM.

000013670 7112_ $$aCOMPDYN 2011 - 3rd International Thematic Conference$$cIsland of Corfu (GR)$$d2011-05-25 / 2011-05-28$$gCOMPDYN2011
000013670 720__ $$aKucukcoban, S.$$iKallivokas, L.
000013670 8560_ $$ffischerc@itam.cas.cz
000013670 8564_ $$s1796141$$uhttps://invenio.itam.cas.cz/record/13670/files/475.pdf$$yOriginal version of the author's contribution as presented on CD, section: MS 32 Waves and Computation.
000013670 962__ $$r13401
000013670 980__ $$aPAPER