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

Abstract

: This study aims to investigate the coupled effects of chemical corrosion and temperature on the uniaxial compression mechanical behavior of white sandstone. Specimens were prepared from white sandstone sourced from Zigong, Sichuan Province, and subjected to various coupled chemical and thermal conditioning regimes prior to uniaxial compression testing and COMSOL-based numerical simulation. The results show that, regardless of the coupled conditions, the stress–strain curves consistently exhibit four distinct stages, namely compaction, elasticity, plasticity, and post-peak failure, with a sharp stress drop after the peak, indicative of typical brittle failure. In acidic or alkaline environments, both the uniaxial compressive strength and elastic modulus tend to decrease progressively with increasing temperature. The reductions are relatively modest at 0 °C, 25 °C, and 50 °C, but become substantially more pronounced beyond 75 °C. Unde r neutral conditions, both parameters decline only slightly with rising temperature and remain essentially stable. At any given temperature, both the uniaxial compressive strength and elastic modulus decrease in the order of neutral > alkaline > acidic. Stress concentrations are observed at the junctions between the specimen end faces and the cylindrical surface, as well as in the central region, with the specimens exhibiting barrel-shaped failure. The numerical predictions are in good agreement with the experimental measurements.