## 1 Introduction
Their findings indicate that with successive wetting-drying cycles, these properties tend to increase, whereas the mass and both longitudinal and transverse wave velocities decrease. In addition, the hydrochemical coupling effect has a significant impact on the degradation of the mechanical properties of porous rock masses. [PERSON] [19; 20] revealed through wetting-drying cycle tests of shale with a single fracture of different dip angles that as the number of cycles increased, the peak strength, cohesion, and internal friction angle of the specimens decreased by 19.8%, 22.4%, and 14.3%, respectively, and the regulatory effect of the structural plane dip angle on the mechanical parameters showed a significant attenuation trend. [PERSON] [21] carried out wetting-drying cycle tests on jointed sandstone to explore the fracture evolution and fracture criteria of jointed sandstone under wetting-drying cycles. [PERSON] [22] used digital image correlation technology (DIC) to quantitatively characterize the damage evolution process of fractured mudstone. It was found that when the loading angle increased from 30\({}^{\circ}\) to 60\({}^{\circ}\), the peak load increased by 38.7%, but after 10 wetting-drying cycles, this parameter decreased by 24.3%, confirming the coupling degradation effect between moisture migration and the stress path. [PERSON] [23] found through uniaxial compression tests of karst-fissured limestone that when the water-rock contact area increased from 12.5 cm\({}^{2}\) to 50.2 cm\({}^{2}\), the wetting-drying damage degree linearly increased from 0.18 to 0.47 (R\({}^{2}\) = 0.93), and the shape of the karst fissures guided the crack propagation path through stress redistribution. [PERSON] [24] found through multi-axial tests that the regulation of joint density on damage evolution was confining-pressure-dependent. Under uniaxial conditions, when the number of joints increased from 1 to 3, the damage degree increased by 64.3%, while when the confining pressure was 10 MPa, the increase rate decreased to 27.5%, revealing that the confining pressure had a significant inhibitory effect on joint activation. The grouted fractured rock tests by [PERSON] [25] showed that after 15 wetting-drying cycles, the attenuation rate of the elastic modulus of the specimens decreased from 12.3% at the fifth cycle to 6.8%, revealing that the degradation effect of moisture migration had the characteristic of time-dependent attenuation. The shear test data of [PERSON] [26] further confirmed that wetting-drying alternation caused a discrete decrease of 18.2-32.4% in the shear strength of the fracture surface and a regular degradation of 23.1 \(\pm\) 2.7% in the shear strength of the anchorage interface. It is worth noting that the erosion of chemical solutions will exacerbate the damage of water-rock interaction to the rock mass structure. [PERSON] [27] obtained a 41.2% decrease in the elastic modulus in a sandstone test in a sulfuric acid solution with pH = 2.5, which was significantly higher than the 12.5% in a neutral environment, confirming the strengthening effect of H+ ions on the dissolution of silicate minerals. [PERSON] [28] constructed an acid-based sensitivity ranking of the shear strength degradation rate through multi-field coupling tests--acidic environment (42.3%)? alkaline environment (28.7%)? neutral environment (12.5%)--and its mechanism was closely related to the differences in mineral solubility at different pH values. In addition, [PERSON] [29] found through X-CT scanning that the porosity of sandstone under the action of a 1.0 mol/L NaCl solution increased by 64.8% compared with the 0.1 mol/L condition, and the expansion stress of 9.8 \(\pm\) 1.3 MPa generated by salt crystallization was the key inducement for the increase in pore connectivity. [PERSON] [30] found in an acid-etching test of deep-seated sandstone that the gypsum precipitation generated by the reaction of sulfuric acid with carbonate minerals could reduce the local porosity by 18.7%.