In recent years, offshore wind turbines have rapidly developed, and many pile foundations installed earlier are now approaching decommissioning. Thus, the efficient removal of pile foundations has become a critical issue for the sustainable development of offshore wind energy. To address this issue, this paper systematically investigates three methods for the recovery of pile foundations using physical model experiments: water injection + lifting, air injection + lifting, and air retention + water injection. The experimental results show that the water injection + lifting method exhibits remarkable advantages in recovering large-diameter and inclined pile foundations; however, realigning inclined piles during recovery remains challenging, and a risk of pile overturning exists. The air injection + lifting method proves effective for realigning inclined piles but presents a risk of air expulsion failure, which may affect the continuity and stability of the recovery process. By contrast, the air retention + water injection method combines the characteristics of water injection and air injection techniques, effectively avoiding air expulsion failure and exhibiting pronounced displacement jumps during pile uplift. These findings provide a valuable reference for future decommissioning practices of offshore wind pile foundations, offer important engineering application value, and contribute positively to the sustainable development of the offshore wind industry.
| [1] |
CAI S, HAN D Q, CHA J R. Empirical research on vertical greening and energy saving technology in the range of architectural boundaries[J]. Journal of Southeast University (English Edition), 2023, 39(1): 33-48.
|
| [2] |
ZHANG P Y, ZHANG L Y, XIONG L C, et al. Influence of inflow conditions on the hydrodynamic characteristics of floating photovoltaic membrane structures[J]. Journal of Southeast University (English Edition), 2024, 40(4): 363-371.
|
| [3] |
ZHANG P Y, XIONG L C, LE C H, et al. Comparison analysis of the bearing capacity of rock-socketed piles and sand piles for offshore wind turbines[J]. Journal of Southeast University (English Edition), 2023, 39 (4): 384-392.
|
| [4] |
LI Z Y, DAI G L, DU S, et al. Experimental study on scour resistance characteristics of fluid cured soil for offshore wind power foundation[J]. Journal of Southeast University (Natural Science Edition), 2023, 53(4): 647-654. (in Chinese)
|
| [5] |
NIELSEN B H. Feasibility study of the complete removal of monopiles using vibratory pile removal[D]. Trondheim, Norway: Norwegian University of Science and Technology, 2022.
|
| [6] |
GE N, SUN Y, HOU C Q, et al. Model test on rooted uplift pile in sand[J]. Journal of Yangtze River Scientific Research Institute, 2019, 36(8): 146-152. (in Chinese)
|
| [7] |
SUN T T, YANG J X, ZHANG Z H, et al. Experimental study on uplift piles with different diameters and lengths in clay[J]. Journal of Highway and Transportation Research and Development, 2021, 38(10): 44-53. (in Chinese)
|
| [8] |
BEUCKELAERS W J, VANDENBOER K, VERBRAECKEN J, et al. One-dimensional finite element limit analysis for hydraulic pile extraction[J]. Computers and Geotechnics, 2021, 133: 104042.
|
| [9] |
ZHANG P Y, XIN L S, DING H Y, et al. Research on water injection demolition method for offshore pile foundation[J]. Journal of Tianjin University (Science and Technology), 2024, 57(4): 437-444. (in Chinese)
|
| [10] |
XIN L S. Study on removal technology of offshore wind power pile foundation[D]. Tianjin: Tianjin University, 2023. (in Chinese)
|
Funding
The National Natural Science Foundation of China(52171274)
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