Upper Bound Solution for Ultimate Uplift Bearing Capacity Analysis of Suction Caisson Foundations Based on the Reverse Meyerhof Failure Mechanism[J]. Chinese Journal of Geotechnical Engineering. DOI: 10.11779/CJGE20241185
Citation:
Upper Bound Solution for Ultimate Uplift Bearing Capacity Analysis of Suction Caisson Foundations Based on the Reverse Meyerhof Failure Mechanism[J]. Chinese Journal of Geotechnical Engineering. DOI: 10.11779/CJGE20241185
Upper Bound Solution for Ultimate Uplift Bearing Capacity Analysis of Suction Caisson Foundations Based on the Reverse Meyerhof Failure Mechanism[J]. Chinese Journal of Geotechnical Engineering. DOI: 10.11779/CJGE20241185
Citation:
Upper Bound Solution for Ultimate Uplift Bearing Capacity Analysis of Suction Caisson Foundations Based on the Reverse Meyerhof Failure Mechanism[J]. Chinese Journal of Geotechnical Engineering. DOI: 10.11779/CJGE20241185
Offshore wind power generation is the core of the national wind power energy strategy, and the suction cylinder foundation is expected to become one of the main foundation forms for offshore wind power generation structures by virtue of its good load-bearing performance, recyclability and environmentally friendly advantages. Under the action of large uplift velocity, the foundation damage mode of the deep-sea floating platform based on suction cylinder is overall shear damage, and the limit analysis upper limit method is adopted to study the suction cylinder foundation under this damage mode, which can reasonably and economically select the foundation size under the premise of ensuring the safety of the platform. In this study, based on the reverse Meyerhof damage mechanism, combined with the non-homogeneous characteristics of saturated marine clay, an improved upper limit analysis method is proposed. By introducing the linear gradient effect of undrained shear strength with depth and establishing the virtual work balance equation, the analytical solution of the upper limit of the pullout capacity under the overall shear damage of the suction cylinder foundation is deduced. Comparison is made with model tests and some traditional theories to verify the reasonableness and validity of the derived upper limit solution formula for the uplift bearing capacity, and further through the parameter sensitivity study, the influence of geometrical parameters such as the cylinder length-to-diameter ratio on the bearing capacity coefficient Nc is systematically revealed, and the influence effect of each factor is clarified by combining with the normalisation process of the bearing capacity. The results show that there is a positive correlation between the upper limit solution F and each parameter; when the length-diameter ratio is changed by changing only the radius of the suction cylinder or only the length of the suction cylinder, the normalised load carrying capacity coefficient Nc shows a different trend with the change of the length-diameter ratio. The derived analytical theoretical formulas are closer to the results of the model tests than the traditional theories, indicating that the upper limit analytical formulas are reasonable within the error tolerance and have certain potential for application.