## 3 Results
This results in the tiny particles shifting from a solid to a flocculated form and gradually dissolving in the water, which in turn increases the porosity and expands the tiny fractures. In essence, the microdamage action of soft rocks is an evolutionary process involving the dissolution and detachment of their internal soluble linkage structures. This process of the dissolution of grain boundaries is referred to as the micro-interfacial effect in red-bed soft rocks. Through the regular observation and recording of four sets of cylindrical samples sampled from the same location, the morphology of the red-bed soft rock specimens with different water saturation times was obtained. As illustrated in Figure 3, the surface of the specimen in its natural state is intact and has no directly visible pores or fractures. The slight color difference in the middle of the specimen is the result of the close association of different mineral compositions, and the specimen profile is complete. Upon reaching a saturation time of seven days, the surface of the specimen exhibited the emergence of approximately 0.3-mm-wide fractures, accompanied by the crumbling of the specimen's edge. At a saturation time of 30 days, the fractures on the specimen's surface began to extend and gradually connect from top to bottom, reaching a width of 0.5 mm. At 90 days of water saturation, the upper portion of the specimen exhibited a significant area of falling blocks, with the fractures beginning to connect with each other. The fracture width expanded from 0.5 mm to 0.8 mm. The specimen prism exhibited a collapse at the edge, accompanied by the disappearance of almost any discernible boundaries. The acquired attenuation signals of the red-bed soft rock were reconstructed in 3D using VSGStudio MAX 3.0. The 3D model of the red-bed soft rock was then quantitatively analyzed and key parameters were extracted using the 3D visualization software Avizo 2019. Figure 3: Photographs of red-bed soft rock water saturation tests. The test results indicate that the damage to the red-bed soft rock at saturation extended from the exterior to the interior. The tiny fractures in the initial water-saturated state gradually expanded into large fractures, and then the fractures were connected with each other and finally fell off in the form of flakes. Within 30 days of water saturation, the red-bed soft rock was essentially intact. At 30 days to 90 days, the sample began to display unconnected fractures, at which point it remained morphologically intact. After more than 90 days of water saturation, the specimen reached a state of basic fragmentation, no longer meeting the requisite mechanical test conditions. In the SEM water saturation process, the ionic concentration changes of Si\({}^{4+}\), Al\({}^{3+}\), Fe\({}^{2+3+}\), Mg\({}^{2+}\), Na\({}^{+}\) and Ca\({}^{2+}\) in the aqueous solution used for 1, 3, 7, 15, 30 and 90 days of water saturation in the specimens were determined using an X-ray fluorescence spectrometer. The results of the assay are shown in Table 1. Given that different ions possess disparate valences, the concentrations of ions in aqueous solutions exhibit considerable variability. The precipitation of Si and Al ions occurred first, resulting in a faster growth rate. The results demonstrated that the aqueous solution exhibited the greatest increase in content with Si ions, followed by Al ions. When combined with the aforementioned XRD test, it can be observed that the mineral elements of these two ions are the minerals with the highest content in the red-bed soft rock, as well as the important constituent elements of clay minerals. Consequently, during the deterioration and dissolution of red-bed soft rock, Al and Si ions are dissolved in the water in significant quantities, accompanied by the dissolution of other ions. This change process is illustrated in Figure 4.