Study on Triaxial Compression Test and Numerical Simulation of White Sandstone under Coupled Chemical Corrosion and Temperature Effects

Abstract

: This study investigates the influence of coupled chemical corrosion and temperature on the triaxial compression mechanical behavior of white sandstone. Standard cylindrical specimens collected from Zigong, Sichuan Province, were prepared and subjected to coupled conditioning with various chemical solutions and temperatures, followed by triaxial compression tests and COMSOL-based numerical simulations. The results show that under different coupled conditions, the triaxial stress–strain curves of white sandstone generally exhibit four distinct stages: compaction, elasticity, plasticity, and post-peak failure, with a sharp drop after the peak stress, indicative of typical brittle failure. In acidic or alkaline environments, both the triaxial compressive strength and elastic modulus decrease progressively with increasing temperature. The reductions are relatively small at 0 °C, 25 °C, and 50 °C, but become substantially more pronounced beyond 75 °C. Under neutral conditions, by contrast, both parameters decrease only slightly with rising temperature and remain essentially stable. At any given temperature, the triaxial compressive strength and elastic modulus follow the same descending order: neutral > alkaline > acidic. Numerical simulations reveal that high-stress zones are concentrated at the intersections between the circular end faces and the cylindrical surface, as well as in the central region of the specimen. The simulated failure mode is characterized by brittle dilatancy, with cracks developing predominantly parallel to the axial direction. The numerical predictions are in good agreement with the experimental results.