Performance and mechanism of bolt and slurry bonds in anchor systems for earthen sites

Fully grouted anchor systems have been widely used for stability control at earthen sites. The bond performance between the bolt and the slurry, which is determined from the bolt type, bolt diameter, slurry thickness and bond length, has an important influence on the anchor performance and working mechanism of the anchor system. This paper considers three anchor systems consisting of different types of bolts and modified glutinous rice slurry. To test the relevant physical and mechanical indexes of the soil for a site, the slurry and bolts, in situ anchor, pull-out tests and stress–strain monitoring of the bolt–slurry interface are conducted for anchor systems in terms of the bolt diameter, slurry thickness and bond length. The influence of various parameters on the bond strength between the bolt and the slurry is quantitatively analysed based on the test results, while the distributions of the bond stress between the bolt and the slurry along the bond length are qualitatively analysed. The bond mechanisms between the bolt and the slurry for different bolt types with the anchor systems are discussed, and optimal matching values for the anchor parameters with each bolt type are proposed.