## Long-term pull-out resistance and material properties of geogrids

- Geogrids, which are installed to prevent sliding failure on long and steep slopes, have to be safely anchored. The design and calculation of the anchorage is based on simple design rules. Basically, it is assumed that the pull-out resistance is proportional to the soil shear strength, the vertical load and the anchoring length and that the soil-reinforcement coefficient of proportionality as determined in pull-out tests is typically in the range between 0.5 and 1. Based on an extended version of a model for the soil-geogrid interaction, which was described by Ziegler and Timmers (2004) and Sieira et al. (2009), the physical assumptions and limitations of these rules are discussed. For those geogrids, for which the passive thrust mobilization of earth pressure by the displacement of the transversal or bearing force grid elements substantially contributes to the pull-out resistance, the mechanical strength of the junction between longitudinal and transversal elements is of crucialGeogrids, which are installed to prevent sliding failure on long and steep slopes, have to be safely anchored. The design and calculation of the anchorage is based on simple design rules. Basically, it is assumed that the pull-out resistance is proportional to the soil shear strength, the vertical load and the anchoring length and that the soil-reinforcement coefficient of proportionality as determined in pull-out tests is typically in the range between 0.5 and 1. Based on an extended version of a model for the soil-geogrid interaction, which was described by Ziegler and Timmers (2004) and Sieira et al. (2009), the physical assumptions and limitations of these rules are discussed. For those geogrids, for which the passive thrust mobilization of earth pressure by the displacement of the transversal or bearing force grid elements substantially contributes to the pull-out resistance, the mechanical strength of the junction between longitudinal and transversal elements is of crucial importance. The relation between mechanical properties of the junction, the flexibility of the longitudinal grid elements, the surface friction and the finally achieved pull-out resistance is exemplarily shown by a model calculation. It is included, that due to aging and creep the short-term junction strength may be significantly lower than the long-term strength. There is a certain critical pull-out resistance and an associated critical anchorage length. Both are determined by the strength of the junction embedded into the soil and are independent from the actually installed anchorage length. For a safe design it is not allowed to go beyond that limit. This requirement restricts the range of application of the common design rules. It follows that not only the long-term strength of the longitudinal elements has to be considered and quantified by reduction factors but also the long-term strength of junctions. These limitations have to be observed to achieve a safe design of the anchorage. Preliminary design rules are discussed.…

Autoren/innen: | Werner Müller |
---|---|

Persönliche Herausgeber/innen: | M. Ziegler, G. Bräu, G. Heerten, K. Laackmann |

Dokumenttyp: | Beitrag zu einem Tagungsband |

Veröffentlichungsform: | Verlagsliteratur |

Sprache: | Englisch |

Titel des übergeordneten Werkes (Englisch): | 10th International conference on geosynthetics (Proceedings) |

Jahr der Erstveröffentlichung: | 2014 |

Organisationseinheit der BAM: | 4 Material und Umwelt |

4 Material und Umwelt / 4.3 Schadstofftransfer und Umwelttechnologien | |

Herausgeber (Institution): | Deutsche Gesellschaft für Geotechnik e.V. (DGGT) |

Erste Seite: | 1 |

Letzte Seite: | 8 |

Freie Schlagwörter: | Anchoring; Geogrid; Junction strenght; Junctions; Sliding failure |

Veranstaltung: | 10th International conference on geosynthetics |

Veranstaltungsort: | Berlin, Germany |

Beginndatum der Veranstaltung: | 21.09.2014 |

Enddatum der Veranstaltung: | 25.09.2014 |

ISBN: | 978-3-9813953-9-6 |

Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |

Datum der Freischaltung: | 20.02.2016 |

Referierte Publikation: | Ja |

Datum der Eintragung als referierte Publikation: | 09.10.2014 |