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| Titel |
Verification of the GIS-based Newmark method through 2D dynamic modelling of slope stability |
| VerfasserIn |
A. Torgoev, H.-B. Havenith |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059488
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| Zusammenfassung |
| The goal of this work is to verify the simplified GIS-based Newmark displacement
approach through 2D dynamic modelling of slope stability. The research is applied to a
landslide-prone area in Central Asia, the Mailuu-Suu Valley, situated in the south of
Kyrgyzstan. The comparison is carried out on the basis of 30 different profiles
located in the target area, presenting different geological, tectonic and morphological
settings. One part of the profiles were selected within landslide zones, the other part
was selected in stable areas. Many of the landslides are complex slope failures
involving falls, rotational sliding and/or planar sliding and flows. These input data were
extracted from a 3D structural geological model built with the GOCAD software.
Geophysical and geomechanical parameters were defined on the basis of results
obtained by multiple surveys performed in the area over the past 15 years. These
include geophysical investigation, seismological experiments and ambient noise
measurements.
Dynamic modelling of slope stability is performed with the UDEC version 4.01
software that is able to compute deformation of discrete elements. Inside these
elements both elasto-plastic and purely elastic materials (similar to rigid blocks) were
tested. Various parameter variations were tested to assess their influence on the
final outputs. And even though no groundwater flow was included, the numerous
simulations are very time-consuming (20 mins per model for 10 secs simulated
shaking) – about 500 computation hours have been completed so far (more than 100
models).
Preliminary results allow us to compare Newmark displacements computed using
different GIS approaches (Jibson et al., 1998; Miles and Ho, 1999, among others) with the
displacements computed using the original Newmark method (Newmark, 1965, here
simulated seismograms were used) and displacements produced along joints by the
corresponding 2D dynamical models. The generation of seismic amplification and its impact
on peak-ground-acceleration, Arias Intensity and permanent slope movements (total and slip
on joints) is assessed for numerous morphological-lithological settings (curvature, slope
angle, surficial geology, various layer dips and orientations) throughout the target area. The
final results of our studies should allow us to define the limitations of the simplified
GIS-based Newmark displacement modelling; thus, the verified method would make
landslide susceptibility and hazard mapping in seismically active regions more reliable. |
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