沉入式大直径圆筒结构的动力塑性变位研究

Study on dynamic plastic displacement to large-diameter cylindrical structure

新型的无底大直径圆筒结构以其可直接嵌入地基而无需开挖的优势,在港口工程中得到广泛应用。利用有限元思想,视筒体为刚体,将筒内外土体用垂直于筒体、竖向以及法向的弹簧进行模拟,建立三维模型,进行动力计算分析。当土体发生塑性变形后,进行塑性变形累积。通过分析埋深、直径、土体重度等重要参数对塑性变位累积的影响,得出土体塑性变形累积受埋深、土体重度、孔隙比影响较大。该研究为进一步深入计算分析沉入式大圆筒结构在动力荷载作用下的力学行为提供计算模型,并为实际工程设计提供了有价值的参考。

The large-diameter cylindrical structures had been widely used in coastal engineering since it could be embedded into ground directly without excavation. The large diameter cylinder was assumed to be rigidity; soil in and outside cylinder were modeled as springs in the direction of uprightness to the surface of cylinder, vertical and tangent; a three dimension model was produced using finite element method. The plastic displacement begins to accumulate at the moment when astic displacement depth, diameter, weight density, etc. on plastic displacement were analyzed, and occurs. The effects of embedded the results showed that embedded depth, diameter, weight density and etc had a great influence on plastic displacement. The model and the research in this paper provide an analytical model of large-diameter cylinder in the condition of dynamic load for further study, and provide valuable reference for practical engineering.