基于离散元法的密砂中螺旋锚安装扰动及其对抗拔能力的影响

Rong Chen¹, Hu Liu¹, Dongxue Hao^1,*, Zhaoguo Liu² and Chi Yuan³

¹ School of Civil Engineering and Architecture, Northeast Electric Power University, Jilin 132012, China;

20112384@neepu.edu.cn (R.C.); lhu0221@163.com (H.L.)

² China Energy Engineering Group Heilongjiang Electric Design Co., Ltd., Harbin 150090, China;

zgliu0019@ceec.net.cn

³ College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 110124, China;

yuanc@emails.bjut.edu.cn

Abstract: Helical anchors have been extensively employed as foundation systems for carrying tension loads due to their installation efficiency and large uplift capacity. However, the installation influences of helical anchors are still not well understood, especially for multi-helical anchors. The matrix discrete element method was used to model the process of helical anchor penetration and pull-out in dense sand to investigate the effects of the anchor geometry and advancement ratio (AR, the relative vertical movement per rotation) on soil disturbance, the particle flow mechanism, and the uplift capacity. For shallow helical anchors, the overall disturbance zone is the shape of an inverted cone after installation, while for deep helical anchors, it is funnel-shaped. The advancement ratio has significant effects on the soil particle movement and uplift capacity of helical anchors. The soil particle flow mechanism around helical plates has been identified for single-helix anchors at various advancement ratios, and for double-helix anchors, the influence of the top plate on particle movement during installation was investigated. The uplift capacities of both single- and double-helix anchors increase with the decrease in the AR (AR = 0.5~1), and the influence decreases with the anchor embedment ratio. The efficiency of double-helix anchors induced by installation is close to 1 at pitch-matched installation (AR = 1), indicating that the impact of the top plate during installation is minimal in this case.

Keywords: DEM; helical anchor; installation effect; particle movement; uplift capacity

Figure 2. Soil and anchor model diagram.

Figure 6. Displacement nephogram during installation for different AR: (a) L = 3 d_w, (b) L = 6 d_w, (c) L = 9 d_w, (d) L = 12 d_w (unit: m).

Figure 8. Soil particle displacement nephogram of double-helix anchors with different relative helix spacing at AR = 0.5. (a) Vertical displacement, (b) lateral displacement (unit: m)

Figure 14. Schematic diagram of particle motion for different ARs. (a) Single-helix anchor. (b) Double-helix anchor

Figure 22. Displacement nephogram of double-helix anchor with S/dw = 4.5,(a) AR = 0.5, (b) AR =1;

Chen R, Liu H, Hao D, et al. Installation Disturbance of Helical Anchor in Dense Sand and the Effect on Uplift Capacity Based on Discrete Element Method[J]. Journal of Marine Science and Engineering, 2024, 12(3): 422.