To study the anchoring performance of a self-drilling anchor in sandy gravel strata, the influence of different anchoring lengths on the ultimate pull-out resistance of the self-drilling anchor was carried out through field tests, and the load-displacement curve was obtained. Based on this, combined with the indoor grouting test, an indoor orthogonal test scheme in line with the construction technology of the self-drilling anchor was designed, and the effects of different fine particle proportions, grouting pressures, and water-cement ratios on the pull-out peak, ultimate displacement, anchor diameter, and equivalent bond strength were analyzed. The results indicate a critical value of the self-drilling anchor in the sandy gravel strata. In the field test and indoor test, the failure mode of the bolt is the failure of the interface between the anchor body and the soil, and the trend of the load-displacement curve of the bolt is the same. Through an orthogonal test, it was found that the proportion of fine particles has the greatest influence on the anchorage performance of the self-drilling bolt. With the increase in the proportion of fine particles, the peak value of pull-out decreases, indicating that the self-drilling bolt exhibits better anchorage performance in soft soil layers, such as sandy gravel strata.
Liu et al. (Sat,) studied this question.