钉形搅拌桩扩大头直径与其承载机理关系研究

钉形搅拌桩是通过将普通搅拌桩上部桩身直径扩大而形成的一种类似＂钉子＂形状的复合地基新技术,已在我国地基处理工程界中得到普遍认同。但其在实际工程中的相关设计参数多取决于经验并无可靠的理论依据。本文通过现场静载试验所得数据整理分析钉形搅拌桩扩大头直径与其承载机理的关系,并根据试验所得桩身轴力值、附加应力值,变截面轴力骤减值、集中应力与桩顶应力比等参数,结合试验曲线得出钉形搅拌桩扩大头直径的合理建议值D=1 m。从而为钉形桩地基处理的设计与施工提供参考。

Study on relation between expanding head diameter of T-shaped mixing pile and its bearing mechanism

T-shaped mixing pile is a new technique of composite foundation descend from common mixing pile by expanding the diameter of its upper pile body so as to form a kind of T-shaped mixing pile,which technique has been generally accepted by engineeing world of ground treatment in our country. But the relative design parameters are mainly depend on experience and have not credible basis of theory in practical engineering. This paper analyzed the relation between expanding head diameter of T-shaped mixing pile and its bearing mechanism by the data from field static load test. According to the parameters such as saxial force,additional stress,collapse value of axial force of variable cross-section and the ratio of concentration stress and pile top stress which were gotten from test and combined the test curve,it got a reasionable suggestion value of expanding head di-ameter of T-shaped mixing pile which was one meter so as to provide reference for design and construction of the method.