Stress Loss Analysis of a Geotechnical Prestressed Anchor under a Corrosive Environment in a Coastal Area

The corrosion of geotechnical prestressed anchor rods directly affects the safety of anchor structure engineering. To this end, an experimental device for measuring the stress loss of an anchor structure was developed, which was used to study the stress loss of a prestressed anchor structure under a corrosive environment, obtain the stress change curve of the anchor structure, and analyze the influence of a corrosive environment on the stress loss of a prestressed anchor structure in coastal areas. The final experimental results show that the degree of stress damage to bolts was determined by the cross effect of the environment and stress, and most of the stress damage occurred in the early stage after loading. The stress loss of the anchor structure resulted mainly from the bond degradation of the anchor section, and partly from the degradation of the elastic modulus of the rod body. Corrosion reduced the bonding force and bolt strength of the bolt–grouting body, and the influence of corrosion on the degradation of bonding strength of the bolt–grouting body was greater than that on the degradation of bolt strength. The maximum degree of axial stress corrosion influence on the rock–soil anchor was 11.6%. When the oxygen concentration was higher, the corrosion rate was greater. Therefore, accelerated corrosion indirectly increases the stress loss of anchor bolts.