(Special session) Temperature- and heat-related rock engineering

[3306-11-02] [Student presentation: Master’s course]Numerical simulation of the physical and mechanical response of Noboribetsu welded tuff under different freeze-thaw actions

○Mingwei Gang¹, Jun-ichi Kodama¹, Dai Nakamura² (1. Hokkaido University, 2. Kitami Institute of Technology)

Chairman:Yoshiaki Fujii (Hokkaido University)

Keywords:Freeze-thaw action, Welded tuff, Numerical simulation, Uniaxial compresion test

The freeze-thaw damage of rock is one of the most significant durability issues in cold regions, and freeze-thaw action varies with rock structure. Temperature changes may come from only one direction or from different directions at the same time. Hence, the mechanical response of rocks undergoing different freeze-thaw actions was investigated by numerical simulation and experimental analysis. In this study, a simulation method for the damage of rocks after different freeze-thaw actions was proposed. In this way, rock specimens were simplified as different mineral particles, water particles and pores. The volume of water particles and mineral particles changed with temperature. The change characteristics were determined by the relationship between the thermal expansion coefficient and the temperature. Different temperature transmission ways were realized by heat transfer command, and the diameter of water particles increases with the decrease of temperature. The effectiveness of this approach was demonstrated by comparing the simulation results with the experimental results. The numerical and experimental results show that the uniaxial compressive strength decreases after experiencing freeze-thaw action. And the reduction of uniaxial compressive strength after undergoing tri-directional freeze-thaw action is larger than that after experiencing unidirectional freeze-thaw action. In addition, the results further show that the porosity of rocks subjected to tri-directional freeze-thaw action changes more. Therefore, it can be inferred that the tri-directional freeze-thaw action has greater damage to the rock.