Item: THE EFFECT OF PROPAGATION SAW TEST GEOMETRIES ON CRITICAL CUT LENGTH
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Title: THE EFFECT OF PROPAGATION SAW TEST GEOMETRIES ON CRITICAL CUT LENGTH
Proceedings: International Snow Science Workshop Proceedings 2023, Bend, Oregon
Authors:
- Bastian Bergfeld [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Karl Birkeland [ Birkeland Snow and Avalanche Scientific, Bozeman, Montana ]
- Valentin Adam [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ] [ Institute of Structural Mechanics and Design, Technical University of Darmstadt, Darmstadt, Germany ]
- Philipp L. Rosendahl [ Institute of Structural Mechanics and Design, Technical University of Darmstadt, Darmstadt, Germany ]
- Alec van Herwijnen [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
Date: 2023-10-08
Abstract: Information on failure initiation and crack propagation is essential for assessing avalanche triggering potential. The Propagation Saw Test (PST) is a field test that provides valuable data on the propensity of crack propagation. The first PSTs were performed about 20 years ago and standards have been established. However, there are still differences in how the PST is performed. Standards in North America require the column ends to be cut vertically, whereas in Europe they are typically cut at a normal angle. In this study, we investigate the effect of these different column geometries on the cut length. To this end, we carried out field tests. In total, we conducted 28 pairs of PST experiments, each pair consisting of one PST with normal cut ends and one PST with vertical cut ends. Our experiments showed that PSTs with normal cut ends have shorter critical cut lengths (up to 50% shorter). The influence of the different column geometries on the cut length depends on the slope angle and the slab. We have also developed a model to convert critical cut lengths into both, slab normal and slab vertical PSTs. In addition, we interpret our results with a modern fracture mechanics model that reproduces our measured data. For uniform slabs both models were in excellent agreement. For layered slabs the model predictions suggest that the simplified model also provides a reliable approximation. This study is intended to make practitioners and researchers alike aware of the influence that the geometry of field tests and the slope angle of the field site have on test results. It also shows that only accurately prepared field tests can be reliable and therefore meaningful.
Object ID: ISSW2023_P3.20.pdf
Language of Article: English
Presenter(s): Bastian Bergfeld
Keywords: stability test, Propagation Saw Test, edge effect, failure initiation
Page Number(s): 1358 - 1363
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