叶片可伸缩钢管螺旋桩结构的承载特性及设计方法

摘要

In order to realize the integration characteristics of structure and function for steel screw piles,and further improve the extensive application in the actual projects,a kind of steel screw pile structure with telescopic blades is proposed in this paper due to the better mechanical construction characteristics.The effects of the blade extension length and the layout on the downward and uplift bearing characteristic of the steel screw piles are numerically investigated by means of the nonlinear finite element analysis using Abaqus.Research results show that when the pile diameter is a constant,the bearing capacity of the steel screw piles will be improved with the increase of the blade extended length.The layout of the full projection blade is better than that of the trefoil pile.Moreover,the interaction rules between the screw pile structure and soil under the uplift loadings are also discussed in detail by analyzing the stress diffusion of the soil retractable blade.These researches will provide theoretical guidance on the multifunctional design and its bearing capacity evaluation of screw pile structures.%为了实现钢管螺旋桩结构和多功能一体化,进一步提升其在实际工程中的应用,提出了一种具有良好机械施工性能的叶片可伸缩钢管螺旋桩装置.利用非线性有限元软件Abaqus,研究了叶片外伸长度和叶片布置方式对钢管螺旋桩下压和上拔承载特性的影响.研究结果表明:在桩身直径不变的前提下,叶片外伸长度越长,其承载性能越好;全投影型叶片的布置方式要优于三叶型布置方式.同时,通过分析桩体可伸缩叶片周围土体的应力扩散,具体讨论了上拔载荷作用下螺旋桩-土相互作用规律.该研究将对螺旋桩结构的多功能化设计及其承载特性评估具有理论指导意义.