3D Numerical Analysis Of Cellular Steel Sheet Pile Structure

As harbor engineering comes towards to the deep water, more complex hydrogeological conditions have been emerging in recent years. Cellular steel sheet pile structure is a type of structure suitable for complex hydrogeological conditions with less construction time. However, in China, there is rarely engineering application of cellular steel sheet pile structure as well as no full-fledged design and calculation method available, which still remain to be solved. Consequently in this paper, these following researches on cellular steel sheet pile structure have been completed based on a practical project of artificial island cofferdam.(1) A 3-D rigid finite element model has been established based on the numerical methods and models of cellular steel sheet pile structure. The soil's plastic deformation, the sliding and tension fissure on the surface between the soil and structure as well as the characteristics of the soil pressure variation with structure deformation have been considered in the numerical model.(2) Basing on the project of artificial island cofferdam, the numerical model is used to analyze the stability of cellular steel sheet pile cofferdam, the location of rotation point, the distribution of soil pressure inside and outside the structure as well as the circumferential tension of the structure. Compared with the results obtained by the existing calculation methods recommended in the design codes, the model has been verified.(3) A series of analyses about the effects of different buried depth and soil properties on the stability of the structure have been completed. They included these specific effects on the ultimate bearing capacity, the location of obvious inflexion point on the P-S curve and the location of the rotation point of the structure. With these analyses, the existing calculation methods are assessed and new design basis are provided to improve the existing calculation method and propose new methods.(4) On the condition that the rotation point is inside the structure when the structure is damaged, the stability of the structure, the location of rotation point, the distribution of soil pressure inside and outside the structure as well as the circumferential tension of the structure have been analyzed and compared with the condition that the rotation point is underneath the structure.(5) A new method to simulate the flexibility of the structure using anisotropic material has come up. Moreover, the selection of the flexibility parameters and the way that the model is built with ABAQUS has been thoroughly demonstrated.(6) A flexible numerical model has been established on the basis of the rigid one. The stability of cellular steel sheet pile structure, the location of rotation point, the distribution of soil pressure inside and outside the structure as well as the circumferential tension of the structure have been analyzed and compared with the results of the rigid one.