1.Xi ''an University of Architecture and Technology;2.Xian University of Architecture and Technology
Project funded by China Postdoctoral Science Foundation(2020M673525)；National Natural Science Foundation of China (41172237); Science and Technology R&d Project of China Railway 20th Bureau Group Co., LTD in 2020 (YF2000SD01A)
To study the relationship between the microstructure and the macroscopic mechanical parameters of the acid-corroded sandstone, the mass and mechanical parameters of sandstone corroded by hydrochloric acid were monitored based on the physical property test and the uniaxial mechanical test. The characteristic parameters and the fractal dimension of the pore structure were obtained with SEM-EDS. The chemical damage variable based on porosity was established and the constitutive model of the corroded sandstone was derived based on the extended Lemaitre strain equivalence principle. The results show that the mass loss of sandstone immersed in hydrochloric acid at pH = 1, 3 and distilled water with pH = 7 for 180 days increased by 1.22%, 1.08%, and 0.57%, respectively. The uniaxial compressive strength decreased by 51.93%, 41.91%, and 27.11%, respectively. It has obvious time effect. The average pore size and the fractal dimension of pores of the acid corroded sandstone increase with increasing the corrosion time; The macroscopic mechanical parameter deterioration degree of sandstone is correlated with the mass loss rate and the microscopic porosity of sandstone The rationality of the model is verified by calculation and test results.