Evolution Of Anchorage Performance Of Resin Anchored Bolt Influenced By Polyester Film

Polyester film as the packaging material of resin anchoring agent,in the process of the bolt installation do not eliminate sexual and after the bolt anchorage solubility,make its long-term exists in anchor solid,led to the decrease of the quality of the anchor rod anchor,which affect the stability of the bolt support system,therefore,the research on the rules of polyester film affect the performance of anchor rod anchor is of great significance.In this paper,polyester film,the outer coating of resin anchoring agent,was taken as the research object,and theoretical analysis,laboratory test and numerical simulation were comprehensively used to study the evolution law of anchor bolt anchoring performance under the influence of polyester film.The following results and conclusions were mainly obtained:(1)The occurrence conditions,failure states and failure causes of three failure modes of bolt slippage are summarized.Through the analysis of polyester film after the destruction of the anchor in the solid form distribution,found in the anchor solid polyester film has two basic form and two kinds of compound existence form of existence and the four basic modes of distribution and six kinds of special distribution,and the four basic modes of distribution result in bolt anchorage failure reason is analyzed.(2)Based on the pull-out test of the bolt with sheet polyester film,the damage law of the size of sheet polyester film on the interface between the bolt and resin anchoring agent and the distribution position along the anchoring section on the anchoring force of the bolt was studied.The results show that when the length of sheet polyester film is constant,the farther the distance from the initial end of anchoring,the less the anchoring force loss of the bolt,and the less the influence on the anchoring performance of the bolt.When the flake polyester film from anchorage distance between a certain,its length,the greater the bolt anchoring force loss,the more the greater the effect on the performance of anchor rod anchor.(3)The influence of the distribution position of the agglomerated polyester film in the cavity between the bolt and the coal rock mass(steel pipe)on the anchorage performance of the bolt was studied by the pull-out test of the load-measuring bolt with agglomerated polyester film.At the same time,numerical simulation software is used to simulate the drawing test process,and the test is supplemented and verified.The results show that with the increase of the distance from the initial anchoring end,the influence of the agglomerated polyester film on the anchoring performance of the bolt increases firstly and then decreases.