Study On Changes Of Rock Surface Morphology And Strength Under Acidic Environment

Water-rock(including chemistry and mechanics function)under the action of the fractured rock mass surface morphology change,fracture failure mechanism study is a major problem in today's rock mechanics,the underground disposal of nuclear waste,underground mining and energy storage,earthquake mechanism research and the long-term stability of the geotechnical engineering evaluation facing a fundamental problem.For fractured rock mass,fracture water pressure intensifies the initiation,expansion and connection of rock mass fractures,leading to progressive instability and failure of rock mass.Hydrochemical action changes the physical state and microstructure of rock,weakens the relationship between mineral particles,and causes deformation of stressed rock mass to increase and strength to decrease.The final result of water rock action is the change of the microcosmic composition of the rock and the destruction of the original microcosmic structure.This changes the mechanical properties of the rock.This paper studies the interaction between multiple cracks in rock under water and rock action,and explores the quantification method of chemical corrosion damage caused by water chemical action,so as to provide effective solutions and analytical methods for more accurate assessment and calculation of the safety and stability of many rock engineering related to water chemistry.Based on the project supported by the national natural science foundation of China youth fund(51504220),the basic research program of Shanxi Province(2012012003)and(2015012015),this paper studies the fracture mechanical characteristics of fractured rock mass under the action of water and rock.The main work is as follows:(1)Acid environment immersion test of rock materials: three different rocks were used as comparison materials,with different pH values and soaking time to explore the water-rock interaction.(2)The influence of chemical corrosion of water and rock on rock surface morphology was studied by using ST400 three-dimensional non-contact surface topography instrument.After scanning three kinds of rock specimens with different lithology before and after hydrochemical corrosion,reasonable morphology parameters were calculated through the mathematical description of rock surface topography,and reasonable quantitative relationship between morphology parameters and corresponding physical quantities was established.The experimental results show that the height dispersion of rock surface topography,the degree of deviation from the datum level and the roughness become larger,the height distribution probability becomes more concentrated,and the height difference of rock surface decreases and becomes more coordinated.Lithologic components play a key role in hydro-lithography.(3)The surface strength of two kinds of typical rocks was tested by microcomputer controlled electronic universal testing machine,and the influence of water and rock corrosion on the surface strength was determined.Different kinds of rocks are affected by different degree of water-rock chemistry.