# The Bearing Characteristics of Sand Anchors under Vibrating Load
## 5 Conclusions  
For the study of the bearing characteristics of sandy soil anchor rods under vibration loading, this paper uses the self-developed indoor anchor-pulling system to conduct anchor-pulling tests and investigate the effects of changes in sandy soil moisture content, vibration amplitude, and vibration frequency on the bearing characteristics of sandy soil anchor rods. Based on a basic theory, this paper uses an indoor model test to further analyze the damage mode during the specimen-pulling process. The main conclusions are as follows:  
1. Under the condition that the vibration frequency, vibration amplitude, and vibration number are certain, the ultimate pullout capacity of anchor solids decreases with the change in moisture content of sand and soil, and the decrease is large. This is because as the water content becomes higher, the cohesive force of sand and soil decreases, the ultimate pullout resistance of anchor solids decreases rapidly after vibration load disturbance, and most anchor solids exhibit fatigue failure. 2. The ultimate pullout capacity of anchor solids did not change significantly under the condition that the vibration amplitude and the number of vibrations were constant when vibration loads were applied to anchor rods of the same diameter at different vibration frequencies. When the vibration frequency was 5 Hz, the anchor solid bearing capacity changed significantly after the vibration load disturbance and it decreased significantly; when the vibration frequency was increased to 8 Hz, the anchor solid bearing capacity changed less after the vibration load disturbance and decreased slightly; when the vibration frequency was increased to 10 Hz, the anchor solid ultimate bearing capacity remained the same compared with that under static load. 3. The ultimate pullout resistance of anchor solids changes significantly under the condition that the vibration frequency and the number of vibrations are certain when vibration loads are applied to anchor rods of the same diameter at different vibration amplitudes. With a vibration amplitude of 30% F1, the change in the ultimate pullout resistance of the anchor solid is small; with the increase in vibration amplitude to 40% F1 and 50% F1, the ultimate pullout resistance of the anchor solid decreases significantly after the vibration load disturbance, and the bearing capacity decreases rapidly. 4. In terms of ultimate pullout bearing capacity, anchor solids are sensitive to changes in the water content of sandy soil. By analyzing the anchor solid with a 100 mm diameter, it turned out to be sensitive to both vibration frequency and vibration amplitude after vibration load disturbance, but the correlation was not significant. 5. In this article, the model test limited by the model box lacks microscopic study. A dynamic strain collector should be added to collect the stress-strain at the anchor-soil interface. Add microscopic analysis of the anchor-soil damage interface. Conceptualization, S.Z. ; methodology, S.Z. and J.D. ; validation, J.-L.H. and Z.-H.W. ; formal analysis, Y.-C.W., S.-W.C., S.Z. and J.-L.H. ; investigation, J.D. and J.-L.H. ; resources, S.Z. and Z.-H.W. ; data curation, S.Z., Y.-Q.L. and Y.-C.W. ; writing--original draft preparation, S.Z. and S.-W.C.; writing--review and editing, Z.-H.W. and Y.-Q.L. ; funding acquisition, J.D. All authors have read and agreed to the published version of the manuscript. The research described in this paper was financially supported by the Natural Science Foundation of China (NO. 51878242), the Natural Science Foundation of Hebei Province of China (NO. E2020404007), the Doctoral Research Start-up Fund Project (B-202101), the Research Project of Basic Scientific Research Business Fund for Higher Education Institutions in Hebei Province(2021 QNJS07), and the Research Project on Basic Research Funds for Higher Education Institutions in Hebei Province (2021 QNJS02). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.