饱和粘土中挤土桩球形孔扩张的弹塑性分析

将桩体的贯入模拟为球形孔扩张过程,基于球形孔扩张理论,在大变形假定情况下,结合修正剑桥模型及水力压裂理论,由最小耗能原理从能量的角度推导出了饱和粘土中挤土按球形孔扩张后,土体整个范围内,包括弹性区、塑性区、破坏区内的应力、位移及超孔隙水压力分布的解析解,并分析了土的超固结比对结果的影响,和其他文献的比较结果证明了理论解析解的准确性。其结论可为饱和土地区的静压桩、打桩等岩土工程问题提供理论依据。

ELASTIC-PLASTIC SOLUTION OF SPHERE CAVITY EXPANSION OF SOIL COMPACTION PILE IN SATURATED CLAY

The penetration of pile is modeled as a sphere cavity expansion process. On the basis of the spherical cavity expansion theory, this paper proposes the analytical solution of the stress, displacement and excess pore water pressure in the whole field of soil around the pile. The concerned field comprises elastic zone, plastic zone and failure zone after the sphere cavity expansion in saturated clay. The solution adopts large-strain presupposition, the modified Cambridge model, and the theory of water power cracking, and follows the least consumption principle. The effect of soil’s over-consolidation ratio is investigated. The validity of the proposed solution is verified by a comparison with other references. It can provide theoretical supports for some geotechnical engineering practices in saturated soil, such as jacked pile, driving pile, and so on.