Item: MEASURING SNOW PRESSURE FORCES ON SUPPORTING STRUCTURES USING LOW-COST STRAIN GAUGES
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Title: MEASURING SNOW PRESSURE FORCES ON SUPPORTING STRUCTURES USING LOW-COST STRAIN GAUGES
Proceedings: International Snow Science Workshop 2024, Tromsø, Norway
Authors:
- Joël Borner [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ] [ Climate Change, Extremes and Natural Hazards in Alpine Regions Research Centre CERC, Davos, Switzerland ]
- Patrik Rusterholz [ FERUGEN GmbH, Bubikon, Switzerland ]
- Stefan Margreth [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Perry Bartelt [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ] [ Climate Change, Extremes and Natural Hazards in Alpine Regions Research Centre CERC, Davos, Switzerland ]
Date: 2024-09-23
Abstract: Predicting snow pressure forces exerted by the snow cover on structures on sloping terrain remains a challenging task. Especially with the increasing interest in alpine solar parks with little financial margin for safety, the demand for monitoring systems as well as accurate prediction models for snow pressure acting on slender supports is higher than ever before. This paper presents an experimental setup for measuring the reaction forces of the snow cover on various support and pressure bars of an snow supporting structure made of steel using strain gauges. In combination with the material properties and the entire static system of the structure, we can back calculate the pressure exerted by the snow cover. In order to interpret the measured forces correctly, additional field campaigns in winter are important to determine the local snow distribution, the snow temperature and the density of the snow cover. We extensively address challenges encountered during the measurement campaign, including eliminating temperature-induced strain, amplifying the signal in low strain ranges, handling combined bending and restraint stresses, and protecting sensors and cables against settlement and creep forces. Having overcome these challenges, the key advantages of using strain gauges are that the system is cost effective and non-invasive and therefore allows rapid installation on a large number of sections of interest. We discuss results obtained from the first winter of the campaign (2023/2024). The high measurement frequency of one measurement every five minutes provides an insight into the daily cycle of the forces. Most notably, on warm spring days with cold nights, we observed a continuous increase in forces starting at sunset, peaking at sunrise, followed by a rapid decline thereafter. The measurement data can be used to calibrate newly developed viscoelastic 3D snow creep models with various constitutive laws for the prediction of creep and glide forces on supporting structures. These models as well as the presented experimental setup show great potential to further optimise the design of supporting structures and installations of alpine solar parks.
Object ID: ISSW2024_P8.11.pdf
Language of Article: English
Presenter(s):
Keywords: strain gauges, snow pressure monitoring, supporting structures
Page Number(s): 1127 - 1132
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