Underground rock is often subjected to the coupled action of acid sulfate, chloride ion corrosion, and external dynamic disturbance: the degree of corrosion and dynamic load can significantly affect the pore structure and mechanical behavior of rock. To quantify the microscopic pore structure changes and macro-dynamic behavior characteristics of acidified corroded sandstone, first, a mixed acidic solution of NaHSO₄ and HCl with different pH values was used for immersion corrosion of sandstone; second, the pore structure of sandstone before and after corrosion was quantitatively evaluated by nuclear magnetic resonance (NMR), dynamic loading tests of corroded sandstone were conducted on an SHPB experimental system and scanning electron microscopy (SEM) was used to observe the morphology of corroded sandstone section; and finally, the mechanism of water–rock interaction and damage and fracture of acid-corroded sandstone were analyzed. The results show that, after acidizing corrosion of sandstone, the macropores increase significantly in number and volume, the boundary of the pore structure tends to be fuzzy; the effective porosity, the number of effective pores, and the total porosity increase significantly; the residual porosity, the number of residual pores, and T₂ cut-off value decrease. The proportion accounted for by the elastic stage in stress–strain curves of corroded sandstone is lowered; the proportion accounted for by the plastic yield stage is increased; and post-peak rebound is diminished. With the decrease of pH value, the peak stress on acid-corroded sandstone decreases and the peak strain increases. The peak stress on corroded sandstone is negatively correlated with effective porosity and the number of effective pores, but positively correlated with residual porosity, the number of residual pores, and the T₂ cut-off value. The reaction of acidic solution with sandstone minerals causes the free fluid space to increase, the bound fluid space decreases, and the number of pores increases, resulting in a decrease in the dynamic strength of acidified sandstone. The fracture of original sandstone after impact failure has no obvious directionality, and the failure mode of grain is the coexistence of intergranular fracture and trans-granular fracture. The fracture of sandstone after acidizing corrosion is obviously directional after impact damage, and the fracture form is single, which is intergranular fracture. The research results can provide a certain reference for the protection of rock engineering under acidic water chemical environment.

地下岩石经常受到酸性硫酸盐、氯离子腐蚀和外界动力扰动的耦合作用：腐蚀程度和动载荷对岩石的孔隙结构和力学行为有显着影响。为了量化酸化腐蚀砂岩的微观孔隙结构变化和宏观动力学行为特征，首先，NaHSO ₄的混合酸性溶液使用不同pH值的HCl对砂岩进行浸泡腐蚀；其次，通过核磁共振（NMR）定量评价腐蚀前后砂岩的孔隙结构，在SHPB实验系统上对腐蚀砂岩进行动态加载试验，并利用扫描电镜（SEM）观察腐蚀后的形貌。砂岩段；最后，分析了酸蚀砂岩的水岩相互作用及损伤断裂机理。结果表明，砂岩酸化腐蚀后，大孔隙数量和体积显着增加，孔隙结构边界趋于模糊；有效孔隙率、有效孔隙数和总孔隙率显着增加；残余孔隙率、残余孔隙数、₂截止值减少。腐蚀砂岩应力-应变曲线中弹性阶段所占的比例降低；塑性屈服阶段所占比例增加；峰后反弹减弱。随着pH值的降低，酸蚀砂岩的峰值应力减小，峰值应变增大。腐蚀砂岩上的峰值应力与有效孔隙度和有效孔隙数呈负相关，与残余孔隙度、残余孔隙数和T ₂呈正相关。截止值。酸性溶液与砂岩矿物发生反应，使自由流体空间增大，束缚流体空间减小，孔隙数量增多，导致酸化砂岩的动态强度降低。原始砂岩冲击破坏后的断裂没有明显的方向性，晶粒的破坏模式为沿晶断裂和穿晶断裂并存。酸化腐蚀后的砂岩断裂冲击损伤后具有明显的定向性，断裂形式单一，为沿晶断裂。研究结果可为酸性水化学环境下岩石工程的防护提供一定的参考。