Abstract:
Pre-stressed anchor rods,existing in complex underground environments for long periods,experience performance degradation due to long-term tensile stress and corrosion infiltration. While existing research often focuses on the corrosion of anchor rods under pure environmental factors,there is relatively little analysis on the degradation of mechanical properties under the coupling of stress and corrosive media. This study selects commonly used HRB400 threaded steel anchor rods in engineering as the research object,using the C-ring method constant deformation test to explore the morphological failure characteristics of anchor rod materials under stress-corrosion environments. Additionally,using independently developed stress-corrosion test equipment,the degradation law of the tensile performance of anchor rods under constant prestress and chloride corrosion is investigated. Furthermore,combined with numerical analysis,the study further explores the impact of long-term chloride corrosion environments on the pre-stressed anchor rods for slope support and slope stability. The research results show that in chloride corrosion environments,the surface of the anchor rod body exhibits small cracks and pitting corrosion,with localized accelerated corrosion areas. With the passage of time or the increase of stress,these corrosion pits become more pronounced.Under the combined action of constant prestress and chloride corrosion,although the tensile strength of the anchor rod is slightly reduced,it still meets the specification requirements. However,it is worth noting that the elongation of the anchor rod body after tensioning decreases significantly,approaching the lower limit specified in the standards. Through numerical simulation analysis,it is found that the degradation of the mechanical properties of the anchor rod leads to an increase in slope displacement,tension failure at the top of the slope,and gradual expansion of the shear failure zone. With the increasing degree of corrosion,a slip-through surface may form,significantly reducing the stability of the slope.