Resistance Factor of Caisson-Tip with Internal Fillet for Suction Caissons Penetrating into Clay

• Published in: China ocean engineering 2023-06, Vol.37 (3), p.525-532
• Main Authors: Wu, Yu-qi, Li, Da-yong, Zhang, Yu-kun, Zhang, Yu, Li, Shan-shan
• Format: Article
• Language: English
• Subjects: Caissons; Centrifuge model; Centrifuges; Clay; Coastal Sciences; Engineering; Failure mechanisms; Fillets; Finite element method; Fish fillets; Fluid- and Aerodynamics; Limit analysis; Marine & Freshwater Sciences; Numerical and Computational Physics; Oceanography; Offshore Engineering; Penetration resistance; Resistance factors; Seafoods; Simulation; Vertical forces
• ISSN: 0890-5487; 2191-8945
• DOI: 10.1007/s13344-023-0044-0

This paper presents failure mechanisms of the soil at the caisson-tip with fillet during suction-assisted penetration of suction caissons in undrained clay. Theoretical solutions of resistance factor N c of the caisson-tip are obtained in terms of the caisson-tip geometry ratio of the flat section of the caisson-tip to the caisson wall thickness m/t and adhesion factors α i along inside of caisson wall and α b at the base of the caisson-tip. It is indicated that the factor N c increases with the increase of m/t, α i and α b . The resistance factors N c for the rough base ( α b =1) are larger by 0.57 than that for the smooth base ( α b =0). Besides, the factors N c of caisson-tip with flat base ( m=t ) are larger by 1.14 than that with full internal fillet ( m =0). The required suction to penetrate suction caissons with various fillets is obtained in terms of the force equilibrium in vertical direction. The finite element limit analysis and centrifuge model test results are used to verify the rationality of the presented failure mechanisms and theoretical predictions.