Dissolution Alters Failure in Rock-Like Specimens Under Uniaxial Compression

Increasing dissolution weakened rock-like specimens and shifted their failure under uniaxial compression from rapid coalescence of one dominant crack to progressive, mixed tensile-shear damage involving multiple defects. Experiments on specimens prepared at dissolution degrees of 0%, 5%, 10%, 15%, and 20% showed clear declines in four measured mechanical properties, alongside changes in acoustic emission and surface strain measured by digital image correlation.

The study used a mechanical-acoustic-optical system to combine mechanical loading with acoustic emission monitoring and digital image correlation. Mechanical measurements quantified compressive strength, elastic modulus, peak axial strain, and deformation modulus. Acoustic emission tracked activity associated with cracking during loading, while digital image correlation mapped the evolution of strain across the specimen surface. Together, the methods characterized the specimens’ overall mechanical response, fracture activity, and spatial strain patterns.

From the least to the most dissolved specimen, compressive strength decreased by 36.45%, elastic modulus by 27.01%, peak axial strain by 17.25%, and deformation modulus by 41.28%. The largest relative change was therefore in deformation modulus, while peak axial strain showed the smallest decrease. These measurements indicate that increasing dissolution affected both the load-bearing and deformational behavior of the rock-like material.

Acoustic emission also changed in timing and distribution. At low dissolution, activity was concentrated near peak strength and accompanied the rapid coalescence of a single controlling crack. At higher dissolution, acoustic activity began earlier and continued throughout loading, expanding the pre-peak damage interval. Digital image correlation showed a corresponding progression from small-scale microcracking to the propagation and coalescence of larger cracks. Instead of primarily axial tensile splitting, the more dissolved specimens developed multiple shear strain concentration zones and progressive mixed tensile-shear failure. The results provide experimental evidence about how dissolution-related defects can alter rock-like material under controlled uniaxial compression, with direct relevance to stability assessment and disaster mitigation in karst underground engineering.

Subject of Research: Effects of dissolution on the mechanical, acoustic, and optical failure behavior of rock-like specimens under uniaxial compression

Article Title: Mechanical-acoustic-optical response properties in uniaxial compression failure of rock masses with different dissolution degrees

Article References: Luo, W., Guo, J., Chen, F., Chen, T., & Wang, Y. (2026). Mechanical-acoustic-optical response properties in uniaxial compression failure of rock masses with different dissolution degrees. PLOS One, 21(10), e0360540. https://doi.org/10.1371/journal.pone.0360540

Image Credits: AI Generated

DOI: 10.1371/journal.pone.0360540

Keywords: rock dissolution, uniaxial compression, rock-like specimens, acoustic emission, digital image correlation, compressive strength, crack coalescence, mixed tensile-shear failure, progressive damage, karst engineering, Mechanical-acoustic-optical, response