The impact of temperature on soil dynamics has long been a topic of widespread interest. However, the effects of high-temperature environments caused by phenomena such as wildfires and tunnel fires on soil remain poorly understood. This study, using purple soil from Chongqing, China as a representative, investigates the effects of high-temperature conditions on the mechanical properties and microstructure of this soil type. The results show that unconfined compression strength, deformation modulus, and strain energy density at peak of purple soil tend to increase with the increase of the treatment temperature from 20 degrees C to 1000 degrees C. This enhancement becomes pronounced when the temperature exceeds 600 degrees C. The physical and chemical changes are employed to elucidate the evolution of mechanical properties, and significant reinforcement effect primarily attributed to the 'welding action' of clay minerals. The variation in pore size distribution becomes significant when the treatment temperature approaches 800-1000 degrees C, and soil samples become vesicular structure at 1000 degrees C. These transformations depend on the decomposition of CaCO3, as well as the redistribution and confining effects of melted illite. Therefore, following high-temperature treatment, purple soil exhibits the capacity to alleviate environmental degradation from the perspective of mechanical properties. Purple soil exposed to temperatures between 800 and 1000 degrees C exhibits properties akin to those of clay bricks, making it a viable material for construction purposes. This research holds substantial significance for environmental engineering, geological engineering, and the development of construction materials following thermal treatment.

来源平台：CHEMICAL ENGINEERING JOURNAL