Comparison analysis of numerically calculated slip surfaces with measured S-wave velocity field for Just-Tęgoborze landslide in Carpathian flysch

Abstract

The article presents the comparison analysis between deformation field from numerical model and shear wave (S-wave) velocity field obtained from seismic interferometry (SI). Tests were conducted on active Just-Tęgoborze landslide. Geologically, the study area lies in Magura Nappe in the Outer Carpathians. The landslide’s flysch bedrock is covered by Quaternary colluvium built of clays and weathered clayey-rock deposits. During geotechnical investigation, properties of landslide body were established and failure surfaces were distinguished. In order to obtain S-wave velocity models, one-hour of ambient seismic noise was recorded by 12 broadband seismometers. As a result of data processing with SI method, Rayleigh surface wave propagation was reconstructed. The analysis of dispersion curves allowed to estimate a two dimensional S-wave velocity field. The deformation field were calculated assuming an elastic-plastic Coulomb-Mohr strength criterion. Images of shear strain increment, and values of factor of safety of the slope were obtained as a result of calculation. The comparison of the results indicates the similar characteristic features in the S-wave velocity field and the field of deformation calculated numerically.

Dynamic numerical modelling of co-seismic landslides using the 3D distinct element method: Insights from the Balta rockslide (Romania)

“…Flysch can be classified as highly anisotropic sedimentary rock, composed of alternating layers of hard (limestone, sandstone or siltstone) and weaker (claystone, mudstone or marl) materials, which increases the complexity for geotechnical parametrisation (cf., Marinos and Hoek, 2001). Stability analyses of flysch slopes have been presented by several authors, e.g., Baron et al (2005); Berti et al (2017); Kogut et al (2018); Krawiec and Harba (2019), testing rock strength and joint conditions in 2D. In general, numerical analyses of natural slopes have been largely presented in the two-dimensional domain; however, three-dimensional analyses of natural slope behaviour are rather scarce, especially in a seismic context.…”