Experimental Study on the Deterioration of Anchoring Performance of Resin Anchor Cable under Water Immersion Condition
Pre-stressed resin anchor cables are used in transportation/hydraulic tunnels,which have a complex service environment and long service life.The anchoring system in the water-rich surround-ing rock section faces long-term erosion in a humid environment.Based on the analysis of the erosion mechanism in a humid environment,indoor experiments were conducted to test the mechanical proper-ties of resin anchoring agent samples after immersion in water,and to study the characteristics of changes in anchoring performance.The results showed that resin anchoring agent samples had weak water absorption.The uniaxial compressive strength,elastic modulus and Poisson's ratio decreased to varying degrees after soaking in water.The failure modes of the samples were mainly vertically con-nected main cracks,with a large number of small cracks distributed around them,and local block-like detachment and separation on the surface.With the increase of soaking time,the pullout failure mode of samples changed from concrete splitting to the failure of resin anchoring agent-anchor bond,result-ing in the failure of the cable body to pullout.The average ultimate anchoring force decreased,and the anchoring performance of resin anchor cable gradually deteriorated.The interface between resin an-choring agent and concrete separated during samples'splitting failure.The interface between resin an-choring agent and cable slid during cable's pullout failure.The study reveals the deterioration pattern of anchoring performance of resin anchor cables in humid tunnel environment,which helps to deepen the understanding of stability changes of pre-stressed resin anchoring systems in later stages.