一种新型桩基框架式海堤结构分析与优化

Structural analysis and optimization for a new pile-frame sea dike

桩基框架式海堤是一种适用于深水软土地基的海堤结构,该结构具有断面小、施工机械化程度高、砂石材料需求少等优点。但该结构在软土地基中的受力机理复杂,目前尚缺乏成熟的设计方法。以上海地区某圈围工程为例,采用有限元法分析了桩基框架式海堤结构的受力变形特点,揭示了堤身和桩基的沉降、应力变化规律。研究结果表明,将前后排桩基设计成不等长度,既可以控制沉降差,又能达到节约投资的目的。研究结论为桩基框架式海堤的推广应用提供了理论依据。

Pile -frame sea dike is a new dike structure suiting for deep offshore and soft soil foundation, which possesses the advantages of small cross -section, high mechanization and low sand and stone demands. However, there lacks of mature design methodology for this new structure due to complex force condition in the soft soil foundation. We analyze the stress and deforma- tion features of the pile - frame sea dyke used in a tidal flat reclamation project in Shanghai by FEM, and illustrate the settlement as well as stress variation law of dike body and pile foundation. The results show that optimization goal of both settlement control and investment reduction can be achieved through arranging different lengths respectively for the rear and front piles. The re- search results provide a theoretic basis for application of this new pile - frame sea dyke.