## 5 Conclusions  
At present, no substantial research has been conducted at home or abroad on the effect of corrosion of strong alkali solutions on sandstone dynamics, which is a new direction of this paper to test the research on the mechanical stability of rocks in engineering. In this paper, sandstone specimens were subjected to corrosion treatment for different time periods using a strong alkali solution with a pH value of 11. Afterward, the SHPB impact compression tests and Brazilian splitting tests were conducted on uncorroded and corroded sandstone specimens under the same air pressure conditions, and the physical and dynamic mechanical properties of sandstone specimens subjected to the strong alkali corrosion process were analyzed, and the following conclusions were drawn. 1. In the early stage of corrosion, the reaction between the solution and some components of the sandstone led to the continued expansion of the pores inside the sandstone specimen, as well as the generation of new fissures into which the solution penetrated, resulting in a faster increase in the mass increase rate and average density of the sandstone and a stabilization of the water-rock chemical reaction in the later stage, resulting in a slower increase in the mass increase rate and average density of the sandstone. 2. In the impact compression test, after different corrosion times, the sandstone dynamic stress-strain curve change law was basically the same, but the shape was different. As the corrosion time increased, the length gap between the linear elastic deformation phase curve and plastic deformation phase curve became smaller. The phenomenon indicated that with the corrosion time increasing, sandstone brittleness gradually weakened, and ductility gradually increased. 3. With the corrosion time extended, the sandstone specimens' dynamic compressive strength and dynamic elastic modulus significantly deteriorated, both of them showing two stages of rapid decline from 1 d to 14 d and a lowdown from 14 d to 28 d. The dynamic peak strain of the sandstone specimens increased as a quadratic function with the extension of corrosion time. With the corrosion time at 1 d-14 d, the sandstone specimens' \(\varepsilon_{d}\) value increased faster, and at 14 d-28 d, the \(\varepsilon_{d}\) value growth rate had a decreasing trend. The sandstone average strain rate \(\hat{\epsilon}\) and corrosion time were a quadratic positive correlation. With corrosion time increasing, the specimen impact damage degree increased \(\hat{\epsilon}\). 4. In the Brazilian splitting test, the dynamic properties of the specimens deteriorated continuously due to the corrosion of the strong alkali solution with the prolongation of corrosion time. The transmitted energy and dynamic tensile strength of sandstone specimens both showed a trend of faster decline in the early stage and a slower decline in the later stage with the prolongation of corrosion time; the dynamic peak strain of the sandstone specimens showed a quadratic polynomial positive correlation with the prolongation of corrosion time. Conceptualization, K.S. ; Data curation, C.W. ; Funding acquisition, Q.P. ; Methodology, Q.P. ; Software, C.W. ; Supervision, Q.G., K.S., Y.W. and S.W. ; Validation, S.S.; Visualization, Q.G. and Y.W. ; Writing--Original Draft, Q.P. and C.W. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China (No. 52074005, No. 52074006), Anhui Provincial Natural Science Foundation (No. 1808085 ME134), and Anhui Postdoctoral Science Foundation (No. 2015B058), Anhui University of Science and Technology Graduate Innovation Fund Project (No. 2021 CX2032). Not applicable. Informed Consent Statement: Informed consent was obtained from all subjects involved in the study. The data used to support the findings of this study are available from the corresponding author upon request.