Seasonal and locational variation in the flexural strength of lake ice in Saimaa area

Inland waterways offer a sustainable and efficient way to transport goods and people. The vessel design for winter conditions require knowledge about the mechanical properties of ice from the planned operational area. To gather knowledge about the mechanical properties of ice, and seasonal and locational variation in the properties in Saimaa area in Finland, three measurement campaigns were planned that covered different parts of Northern and Southern Saimaa in January, February, and March in 2021.
This paper studies the measured seasonal and locational variation in the mechanical properties of ice in the Saimaa area. The measurements include the flexural strength and strain modulus determined from the 3-point bending tests. The measured flexural strength and strain modulus did not have any clear trend along the season and the variation between the location is negligible. However, the study indicates the bottom of the ice to be slightly stronger than the surface, except in one occasion. The average measured flexural strengths were 0.8 MPa, 1.0 MPa, and 1.3 MPa for the top, middle and bottom layers, respectively. The corresponding average strain modulus were 3.7 GPa, 4.7 GPa, and 4.5 GPa. The measured ratio between the strain modulus and flexural strength varied between 2000 and 9500, the average being around 5000.