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| Titel |
Modeling root reinforcement using a root-failure Weibull survival function |
| VerfasserIn |
M. Schwarz, F. Giadrossich, D. Cohen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 11 ; Nr. 17, no. 11 (2013-11-06), S.4367-4377 |
| Datensatznummer |
250085984
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| Publikation (Nr.) |
 copernicus.org/hess-17-4367-2013.pdf |
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| Zusammenfassung |
| Root networks contribute to slope stability through complex interactions with
soil that include mechanical compression and tension. Due to the spatial
heterogeneity of root distribution and the dynamics of root turnover, the
quantification of root reinforcement on steep slopes is challenging and
consequently the calculation of slope stability also. Although considerable
progress has been made, some important aspects of root mechanics remain
neglected. In this study we address specifically the role of root-strength
variability on the mechanical behavior of a root bundle. Many factors
contribute to the variability of root mechanical properties even within a
single class of diameter. This work presents a new approach for quantifying
root reinforcement that considers the variability of mechanical properties of
each root diameter class. Using the data of laboratory tensile tests and
field pullout tests, we calibrate the parameters of the Weibull survival
function to implement the variability of root strength in a numerical model
for the calculation of root reinforcement (RBMw). The results show that, for
both laboratory and field data sets, the parameters of the Weibull
distribution may be considered constant with the exponent equal to 2 and the
normalized failure displacement equal to 1. Moreover, the results show that
the variability of root strength in each root diameter class has a major
influence on the behavior of a root bundle with important implications when
considering different approaches in slope stability calculation. Sensitivity
analysis shows that the calibration of the equations of the tensile force,
the elasticity of the roots, and the root distribution are the most important
steps. The new model allows the characterization of root reinforcement in
terms of maximum pullout force, stiffness, and energy. Moreover, it
simplifies the implementation of root reinforcement in slope stability
models. The realistic quantification of root reinforcement for tensile, shear
and compression behavior allows for the consideration of the stabilization
effects of root networks on steep slopes and the influence that this has on
the triggering of shallow landslides. |
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