A Three-Dimensional Analysis of Inclined Conical Anchors in Silty Sand

This study uses the sand strain hardening-softening and volumetric dilatancy model (SHASOVOD) in conjunction with FLAC3D software to perform a three-dimensional analysis of inclined conical anchors in silty sand, with field test results verifying the accuracy of the numerical analysis. The anchorage capacity of the inclined conical grouted anchor mainly comes from friction, with the contribution of end bearing force being relatively small. In silty sand with a relative density of Dr = 30%, the displacement required to achieve peak friction is approximately 50% of the anchor top diameter (Dt), while the displacement needed to reach the residual friction is about 100% of Dt. The end bearing force does not exhibit an obviously peak value, and from the definition of the yielding end bearing force, it is found that the displacement required to mobilize the yielding end bearing force Qqy is approximately 25% of Dt, and is not significantly influenced by the bottom diameter or the inclination angle of the anchor. Increasing the overburden depth, free length, fixed anchor length, or bottom diameter can all enhance the anchorage capacity of the anchor, with increasing the anchor length proving to be the most effective in improving anchorage capacity. Additionally, when site constraints prevent increasing the anchor length, the anchorage capacity can be enhanced by increasing the bottom diameter of a conical anchor. From the soil yielding process around the anchor shaft, it is observed that the soil at the anchor bottom reaches yielding first due to decompression. Then, he soil approximately 1.5 to 2 times the anchor top diameter ahead of the anchor shaft yields. The soil above the anchor shaft yields before the soil below it, and the yielding range above the anchor shaft is larger than that below. The overall yielding range forms an elliptical shape.