Physical and Mechanical Properties of Transmission Line Galloping under the Action of Freezing and Thawing in Variable Temperature Range

Abstract

The western part of our country is mostly alpine regions. The rock and soil have been in a strong natural freeze-thaw environment for a long time, and their physical and mechanical properties are easily affected by external loads and external surroundings. Changes due to the influence of the environment will inevitably produce freeze-thaw cycles, damage and destruction, expansion and fracture, etc., resulting in more stable factors than usual. However, there is a lack of theoretical and practical experience in freeze-thaw rocks, especially freeze-thaw hard rocks. Therefore, studying the physical and mechanical properties and damage characteristics of rocks in alpine regions under freeze-thaw cycles has important significance. This paper uses dacite in the alpine region to carry out a freeze-thaw cycle experiment in a variable temperature range. Freezing and thawing cycle test, uniaxial compression test, triaxial compression test, and electron microscope scanning of the rock in the indoor saturated state were carried out. Combining theory with experimental mechanics, freeze-thaw mechanics, and damage mechanics, we studied freeze-thaw cycle in three variable temperature ranges (−20°C–15°C; −30°C–15°C; −40°C–15°C), along with the physical and mechanical properties and damage characteristics of freeze-thaw dacite in the alpine region under cycling. The damage curve of the final theoretical model gradually approaches 1.0 with the increase of strain during the actual test. The rock sample after the medium failure still has a certain bearing capacity, and the rock sample is often destroyed before it reaches the theoretical failure strain.