竖向荷载下裙式吸力基础周围土体变形研究

对饱和细海砂中传统吸力基础与裙式吸力基础开展了竖向单调加载试验和有限元模拟的对比研究,获得了基础周围砂土的变形规律及基础破坏形式,讨论了"裙"结构对基础周围土体变形的影响。研究发现:极限状态下,传统吸力基础周围土体变形范围小于裙式吸力基础周围土体变形范围,减少幅度为31%~55%,说明裙式吸力基础调动了较大范围土体发挥作用以提高其水平承载力。裙宽会引起土体的变形增大,而裙高可以对周围土体进行约束;裙宽相同时,土体变形范围随裙高的增大逐渐减小。在竖向压力荷载作用下,传统吸力基础与裙式吸力基础在砂土中的破坏形式符合Prandtl整体剪切破坏。

Sandy soil deformation behavior around skirted suction caisson under vertical compression load

Sandy soil deformation and foundation failure are studied by using model tests and the finite element method to explore the behaviors of traditional suction foundation and skirted suction foundation in saturated fine marine sand under vertical monotonic loading. The effects of the skirt structure on sand deformation are discussed. The results show that the range of soil deformation caused by traditional suction foundation is smaller than that of skirted suction caisson by 31%~35%, which illustrates that the skirted suction caisson could make more soil to support the horizontal bearing capacity. The skirt width could increase the soil deformation, and the skirt height has a restraint function on the soil. Under the same skirt width, the soil deformation area decreases with increase of the skirt height. The failure modes of suction caissons in saturated sand are in accordance with Prandtl’s whole shear failure.