# The Bearing Characteristics of Sand Anchors under Vibrating Load
## 3 Results and Analysis
### Study on the Bearing Characteristics of Anchor Rods under a Vibration Load
#### 3.2.3 Effect of Vibration Amplitude on the Bearing Capacity of Anchor Rods under Vibration Load  
As shown in Figure 12, the bearing capacity-displacement curves of anchor rods under different amplitude vibration loads of the same diameter are shown. An anchor solid of 100 mm diameter was used for the test. The amplitude of the vibration load was changed under the same moisture content condition, and three amplitudes of 30% F1, 40% F1, and 50% F1 were set. To keep the vibration frequency consistent, the vibration frequency was set to 5 Hz when the vibration load was applied. In the state of sand soil moisture content of 10%, first, loading took place at the rate of 6 mm/min to 65% of the ultimate pullout resistance (F1) under the action of anchor static load, and this load value is approximately 1.22 kN, which is the peak of this vibration load. The valley value is 35% of the ultimate pullout resistance under the action of anchor static load, with a load value of approximately 0.66 kN. The amplitude of the vibration load is 30% F1, its value is approximately 0.56 kN, the average load is 50% F1, and the number of vibrations is 1000. As seen in Figure 12a, the anchor solid produced a displacement of 0.75 mm at the initial stage of loading, which is a small displacement. After the application of the vibration load, the anchor solid produced an upward displacement of approximately 1.8 mm, and it did not fail. In the later destructive testing phase, the anchor solid produced a 3 mm displacement, and its remaining bearing capacity was approximately 1.41 kN, with a 24.6% reduction in bearing capacity. The above operation is repeated to change the amplitude of the vibration load. The amplitude of the vibration load is 40% of F1, and the load is 0.74 kN. The peak is 70% of the ultimate pullout resistance, and the load is 1.31 kN. The trough is 30% of the ultimate pullout resistance, and the load is 0.56 kN. The displacement of the anchor solid at the initial stage of loading is 0.79 mm, which is small. After the application of vibratory loads, the anchor solid produced an upward displacement of approximately 2.06 mm, and it did not fail. In the later destructive testing phase, the anchor solid produced a displacement of 3.47 mm, and its remaining bearing capacity was approximately 1.28 kN, with a 31.6% reduction in bearing capacity. The amplitude of the vibration load is 50% of F1, which is 0.93 kN. The peak of the load is 75% of the ultimate pullout capacity, which is 1.4 kN, and the trough is 25% of the ultimate pullout capacity, which is 0.47 kN. The displacement of the anchor solid at the initial stage of loading is 0.82 mm, which is small. After the application of the vibration load, the anchor solid produced an upward displacement of approximately 2.14 mm, and it did not fail. In the later destructive testing stage, the anchor solid produced a 2.6 mm displacement, and its remaining bearing capacity was approximately 1.1 kN, with a 41.2% reduction in bearing capacity. In the state of 12% moisture content of sand soil, first, loading took place at the rate of 6 mm/min to 65% of the ultimate pullout resistance (F1) under the action of anchor static load, and this load value is approximately 1.11 kN, which is the peak of this vibration load; the valley value is 35% of the ultimate pullout resistance under the action of anchor static load, and this load value is approximately 0.59 kN; the amplitude of vibration load is 30% F1, and its value is approximately 0.52 kN, the average load is 50% F1, and the number of vibrations is 1000. The above Figure 12b shows that the anchor solid produces a displacement of 0.57 mm at the initial stage of loading, which is a small displacement. Figure 12: Load-bearing capacity–displacement curve under different amplitude vibration loads (f = 5 Hz). (a) R = 100 mm, w = 10%, F = 30% F1, 40% F1, 50% F1; (b) R = 100 mm, w = 12%, F = 30% F1, 40% F1, 50% F1; (c) R = 100 mm, w = 14%, F = 30% F1, 40% F1, 50% F1.