Rocks and rock bolts that were previously unaffected by freeze-thaw cycles in northern latitudes and high elevation areas are now experiencing new forces due to rising temperatures. This study investigates the performance of rock bolts in frozen rock joints experiencing thawing and temperature changes. The objectives of these experiments are to measure and track temperature changes throughout rock joints and to identify effective ways to measure displacement and forces in rocks and rock bolts in freeze-thaw cycles. To achieve this objective, a frozen sample is created using a square 3D-printed mold. Two concrete samples with soil in between them are then frozen and then bolted together. The behavior of this sample is then recorded with two types of imaging, thermal and normal, and analyzed using 2D digital image correlation software. The experimental results found a steady increase in surface temperature over the thaw cycle. Sample temperatures range from −12.9 °C to 2.4 °C. Results from image correlation found the displacement to be highest in the unrestricted section of the sample. Strains were also found to display results similar to displacements, with highest strains in unrestricted areas of the sample. Overall, the bolts were found to limit displacement and strains by transferring stress to the bolt. Further development is required to produce more consistent displacements and strains during sample testing. This work provides important insights regarding the mechanisms and behavior of frozen rock bolts.

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Performance of Rock Bolts in Frozen Rock Joints

  • Noah Frymire,
  • Bing Li

摘要

Rocks and rock bolts that were previously unaffected by freeze-thaw cycles in northern latitudes and high elevation areas are now experiencing new forces due to rising temperatures. This study investigates the performance of rock bolts in frozen rock joints experiencing thawing and temperature changes. The objectives of these experiments are to measure and track temperature changes throughout rock joints and to identify effective ways to measure displacement and forces in rocks and rock bolts in freeze-thaw cycles. To achieve this objective, a frozen sample is created using a square 3D-printed mold. Two concrete samples with soil in between them are then frozen and then bolted together. The behavior of this sample is then recorded with two types of imaging, thermal and normal, and analyzed using 2D digital image correlation software. The experimental results found a steady increase in surface temperature over the thaw cycle. Sample temperatures range from −12.9 °C to 2.4 °C. Results from image correlation found the displacement to be highest in the unrestricted section of the sample. Strains were also found to display results similar to displacements, with highest strains in unrestricted areas of the sample. Overall, the bolts were found to limit displacement and strains by transferring stress to the bolt. Further development is required to produce more consistent displacements and strains during sample testing. This work provides important insights regarding the mechanisms and behavior of frozen rock bolts.