Influence of Corrosion on Anchoring Bond Behavior of Jointed Rock Mass

In order to investigate the effect of corrosion on bond behavior of anchored jointed rock masses, based on the migration law of pitting corrosion obtained by laboratory tests and the concept of strength reduction, the anchoring pull-out test of jointed rock mass was simulated by using Discrete Element Method (DEM). The results show that for uncorroded rock specimens, due to the existence of joints, there are significant differences for granular displacement and bond failure on both sides of the rock bolt during pull-out process, and phenomenon of eccentric tension also appears; for corroded rock specimens, the reduction rate of bond strength and slip ratio of single and double joint specimens decrease linearly with the increase of pitting corrosion rate. The decreasing rate gets fast with the increase of joints, but it is not a multiple relationship. Compared with the test with uncorroded specimens, when the pitting corrosion rate is 15%, the maximum pull-out load of the single-joint specimen with joint angel of 45 degrees is reduced by 1 7.8%, and the slip value is reduced by 14.6%; the maximum pull-out load of the double-joint specimen is reduced by 31.9%, and the slip value is reduced by 24.9%. The numerical test results are in good agreement with the laboratory test results. The research results can provide reference for the selection and optimization of the design parameters of anchoring support structure of jointed rock mass under the erosion environment in the future.

Automated summary

This study used the Discrete Element Method to simulate the anchoring pull-out test of jointed rock masses and investigated the effect of corrosion on the bond behavior. The results showed that corrosion significantly reduced the bond strength and increased the slip ratio of the rock specimens with joints. The research findings can provide reference for the design of anchoring support structures in eroded environments.