[an error occurred while processing this directive]

Coal Engineering ›› 2026, Vol. 58 ›› Issue (7): 55-65.doi: 10.11799/ce202607008

Previous Articles     Next Articles

Corrosion fatigue design and service life prediction of rock bolts in deep mine environments#br#

  

  • Received:2025-10-22 Revised:2026-01-20 Online:2026-07-15 Published:2026-08-03

Abstract:

The support structures of deep mine tunnels are subjected to harsh service conditions such as high ground stress, strong corrosion, and frequent dynamic disturbances. Under long-term cyclic loading, the anchor rod body is susceptible to corrosion fatigue failure, leading to deformation and instability of the surrounding rock of the galleries. 1. Taking deep coal mine support anchor rods as the research object, analyzing the factors inducing corrosion fatigue of the rod body and the fatigue failure theory, revealing the mechanism of corrosion fatigue failure of the rod body; 2. Carrying out indoor accelerated corrosion tensile tests on rod materials, the results show that corrosion leads to a decrease in yield strength and ultimate strength. Combined with theoretical analysis, it is found that the decrease in yield strength and ultimate strength leads to a reduction in fatigue limit; 3. Based on the theory of finite fatigue life design of metals, introducing the influence factor of corrosion degradation strength, a calculation model for the corrosion fatigue life of anchor rods is proposed; 4. Based on the calculation model of anchor rod corrosion fatigue life, the factors influencing corrosion fatigue life are studied from three levels: corrosion degradation, energy release from strata movement, and rod material. The results show that corrosion degradation reduces service life and has a significant impact on low-cycle fatigue loads. An increase in energy release from strata movement and stress concentration factor decreases the corrosion fatigue life of anchor rods, while an increase in surface coefficient and dimension coefficient increases the corrosion fatigue life of anchor rods; 5. Taking Zhaolou coal mine as the engineering background, combined with microseismic data and indoor test results of anchor rod materials, corrosion fatigue life calculations are performed on four types of anchor rods: 335MPa, 400MPa, 500MPa and 600MPa. The results show that 335MPa and 400MPa anchor rods cannot meet service requirements, 600MPa anchor rods have excessively conservative service life, and 500MPa anchor rods can meet the requirements for corrosion fatigue durability.

CLC Number: