Abstract: The underground support structure is frequently subjected to harsh conditions including high temperature,high humidity,and chemical erosion,which lead to recurrent corrosion failures and pose a significant threat to the stability of road way surrounding rock.To investigate the damage evolution law of mine pipe-seam anchor bolts in corrosive environments,indoor salt-spray accelerated corrosion tests and mechanical property tests were conducted to examine the effects of different tempera tures (30,35,40 ℃) and pH values (3,4,5) on the corrosion damage of the bolts,with particular focus on the apparent cor rosion characteristics,mass loss rate,corrosion rate,and fracture load loss.The test results show that:① Both the corrosion rate and the degree of mechanical property degradation decrease gradually with increasing pH value.The corrosion rate and fracture load loss rate at pH=3 are 1.24 times and 2.5 times those at pH=5,respectively.② The influence of temperature on the mass loss rate and fracture load loss rate is not consistent:the mass loss rate increases monotonically with rising temperature,whereas the fracture load loss is most severe at 35 ℃.③ At pH=3,the effects of 30 ℃ and 40 ℃ on the mechanical properties are not notably different,and 35 ℃ results in only 1.3 times the fracture load loss of the other two temperatures;thus,the acidic envi ronment is the dominant factor controlling corrosion.However,as the acidity weakens,the effect of temperature variation on fracture load loss becomes more pronounced.

Key words: pipe-seam anchor bolt,corrosion,temperature,pH value,damage deterioration,breaking load