离岸深水全直桩码头承载特性与简化计算方法

全直桩码头是一种新型高桩码头结构型式，在离岸深水海域得到越来越广泛的应用。该结构的承载机理、破坏模式及设计计算方法等与传统高桩码头结构存在较大差异，目前研究尚不完善。采用ABAQUS建立全直桩码头结构-地基相互作用三维弹塑性有限元模型，研究水平荷载作用下码头的承载变形特性及破坏模式。明确了对于水平荷载作用下的离岸深水全直桩码头，基桩的塑性破坏是结构失稳的控制因素，地基土体的承载力对结构水平极限承载力不起决定性作用。在此基础上，采用经典的P-y曲线，建立了全直桩码头水平向承载力简化计算方法。该方法可以计算出桩身任意位置的内力及变形，且适于大、小位移情况。并提出了以“塑性铰”作为简化计算方法中水平极限承载力的判断标准。通过与有限元计算结果进行对比，验证了所建立简化计算方法的正确性。

Bearing behavior and simplified calculation method of all-vertical-piled wharf in offshore deep water

All-vertical-piled wharf is a new type of high-pile wharf suitable for offshore deep sea. However, its bearing behaviors, failure modes and design and calculation methods are quite different from those of the traditional one. The purpose of this paper is to carry out researches so as to solve the above problems. By use of the 3D elastoplastic finite element model for the all-vertical-piled wharf and soil foundation based on ABAQUS, the bearing behaviors and failure modes under horizontal loads are studied. It can be concluded that when the all-vertical-piled wharf in offshore deep water is under the horizontal loads, the plastic failure of pile foundation is the key to the buckling damage, while the bearing capacity of foundation soil is not a decisive factor. After these analyses, a simplified calculation method for the horizontal bearing capacity is established based on P-Ycurves. The internal force and deformation at any position of piles can be calculated by means of this method. Moreover, the simplified method is suitable for both large and small displacements. The “plastic hinge” is used as the criterion of horizontal bearing capacity in the simplified calculation method. In comparison with the finite element model, the proposed method is proved to be reliable.