Assessing the effectiveness of toe buttressing on slope stability through monitoring and numerical modelling in a quarry in Germany

Bulletin of Engineering Geology and the Environment, vol. 85

Abstract

Abstract Slope instability poses significant challenges in geotechnical engineering, necessitating effective mitigation strategies. Among these strategies, toe buttressing has emerged as a prominent method, involving the strategic placement of materials at the base of unstable slopes. However, the efficacy of toe buttressing remains insufficiently explored in scientific literature, particularly through the integration of real-time monitoring and numerical modeling. This paper explores the effectiveness of toe buttressing as mitigation measure for slope stability without the influence of additional stabilization methods. Through a combination of field monitoring, laboratory testing, and the finite element analysis, we assess the influence of toe buttressing on slope dynamics and stability under varying environmental conditions. The study site, located in a basalt quarry in Nentershausen, Germany, experienced a landslide, with the sliding plane located at the interface between basalt formations and the underlying clay layers. Our monitoring results demonstrate that the placement of a 10 m thick toe buttress effectively halted the movement of a 295,000 m³ landslide. Additionally, we investigated the impact of different buttress configurations and groundwater levels on the factor of safety (FoS) using a 2D finite element model. The results clearly show the important role that toe buttresses play in strengthening slope stability. Our study emphasizes the need for more detailed case studies focusing solely on toe buttressing as a means of stabilization. Such research is essential to develop statistical models that can determine the necessary buttress volume and height to support/stabilize different landslide scenarios. Additionally, we discuss the broader implications of our study and future research for slope management applications and underscore the need for interdisciplinary approaches to address the complexities of slope stability in a changing environment.

Authors 10

1. Emilie Lemaire corresponding Aachen Institute of Engineering Geology and Hydrogeology

   RWTH Aachen University

   Affiliation as printed

   Institute of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany

2. Anja Dufresne Aachen Institute of Engineering Geology and Hydrogeology

   RWTH Aachen University

   Affiliation as printed

   Institute of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany

3. Pooya Hamdi Aachen Institute of Engineering Geology and Hydrogeology

   RWTH Aachen University

   Affiliation as printed

   Institute of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany

4. Ansgar Wehinger
   Affiliation as printed

   State Office for Geology and Mining Rhineland-Palatinate, Mainz, Germany

5. F M Wagner Aachen Geophysical Imaging and Monitoring

   RWTH Aachen University

   Affiliation as printed

   Geophysical Imaging and Monitoring, RWTH Aachen University, Aachen, Germany

6. Frieder Enzmann

   Johannes Gutenberg University Mainz

   Affiliation as printed

   Institute of Geosciences, Johannes Gutenberg University, Mainz, Germany

7. W. Fein
   Affiliation as printed

   Geotechnik-Team Mainz GmbH, Mainz, Germany

8. Teemu Hagge-Kubat
   Affiliation as printed

   State Office for Geology and Mining Rhineland-Palatinate, Mainz, Germany

9. Gerd Mathes

   Technische Universität Braunschweig

   Affiliation as printed

   Herbert Mathes & Sons GmbH, Braunfels-Tiefenbach, Germany

10. Florian Amann Aachen Institute of Engineering Geology and Hydrogeology

    Fraunhofer Research Institution for Energy Infrastructures and Geotechnologies IEG · RWTH Aachen University

    Affiliation as printed

    Fraunhofer Research Institution for Energy Infrastructures and Geotechnologies IEG, Aachen, Germany

    Institute of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany