Investigation of the load-bearing capacity of suction caissons used for offshore wind turbines

2017 ◽  
Vol 67 ◽  
pp. 148-161 ◽  
Author(s):  
Pouyan Bagheri ◽  
Su Won Son ◽  
Jin Man Kim
Author(s):  
Yuqi Wu ◽  
Qing Yang ◽  
Dayong Li ◽  
Yu Zhang

Suction caissons supporting offshore wind turbines are exposed to great horizontal loading above the soil surface, which may lead to overturning failure of the caisson. This paper presents a modified three-dimensional failure mechanism to analyze the anti-overturning bearing capacity of suction caissons. The modified failure mechanism is composed of meniscus-conical wedge having meniscus shape at the soil surface and scooped shape. The analytical solution to the anti-overturning bearing capacity of suction caisson is deduced in terms of the limit equilibrium method, following by a parametric study of wedge depth ratio (c) to optimize the critical failure mechanism that satisfies both the force and moment equilibriums. Thus, the methodologies are relatively easy to implement in traditional spreadsheets and the analyses tend to perform very fast. Meanwhile, the effects of gap formation at the rear side of the caisson, loading eccentricity and adhesion factor at caisson-soil interface on anti-overturning bearing capacity are investigated. Comparing with finite element limit analysis results, experimental data and existing theoretical solutions, it is proved that the presented limit equilibrium analysis can satisfactorily predict the anti-overturning bearing capacity of suction caissons with low aspect ratios for offshore wind turbines in uniform and linearly increasing strength clays.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ruiqing Lang ◽  
Run Liu ◽  
Jijian Lian ◽  
Hongyan Ding

Because offshore wind turbines are high-rise structures, they transfer large horizontal loads and moments to their foundations. One of the keys to designing a foundation is determining the sensitivities and laws affecting its load-bearing capacity. In this study, this procedure was carried out for a new high-rise cap pile group foundation adapted to the loading characteristics of offshore wind turbines. The sensitivities of influential factors affecting the bearing properties were determined using an orthogonal test. Through a combination of numerical simulations and model tests, the effects of the inclination angle, length, diameter, and number of side piles on the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity were determined. The results indicate that an increase in the inclination angle of the side piles will increase the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity. An increase in the length of the side piles will increase the vertical bearing capacity and bending bearing capacity. When the length of the side piles is close to the central pile, the increase is more apparent. Finally, increasing the number of piles will increase the horizontal bearing capacity; however, the growth rate is small because of the pile group effect.


Author(s):  
Wen-Gang Qi ◽  
Jing-Kui Tian ◽  
Hong-You Zheng ◽  
Hai-Yan Wang ◽  
Jing Yang ◽  
...  

2018 ◽  
Vol 151 ◽  
pp. 1-11 ◽  
Author(s):  
Nan Jia ◽  
Puyang Zhang ◽  
Yonggang Liu ◽  
Hongyan Ding

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