Bulletin of Engineering Geology and the Environment

Water generally plays a harmful role in the stability of mudstone and has induced many geological disasters in mudrock strata. To visually examine water-induced deterioration of mudstone, X-ray computerized tomographic scanning was used to detect the real-time interaction between mudstone and water. This facilitated real-time visual observations of the evolving characteristics of water-induced cracks within the samples. According to these experimental findings, assisted with scanning electron microscopy and X-ray diffraction, the water-weakening mechanisms of mudstone can be divided into the following steps: (1) micro-sized discontinuities provide an initial path for water to invade the rock; (2) the incursive water induces volumetric swelling of clay minerals and dissolution of carbonate; and (3) these effects drive the propagation and connection of cracks. This understanding of the processes of degradation provides a visual evidence for the assessment of mudrock performance with respect to the stability of landslides, debris flows, and susceptibility of subsidence in mudstone strata.