管桩地基顶升复位的试验研究

Experimental Study on the Foundation Res by Jacking of Steel Pipe Pile

本文结合某实际工程,研究和开发了地基处理新技术——桩式托换和柱基顶升复位。文中对这种新方法的可行性进行了论证,给出了合理的施工方案和托换的基本原则;结合压桩过程,对静压钢管桩的沉桩机理、阻力特性,以及钢管桩的闭塞效应对单桩承载力的影响进行了理论分析和探讨,得出了一般规律;在现场单桩静载试验的基础上,讨论了单桩的极限承载力和容许承载力,给出了容许承载力的取值方法;通过实测桩身的应变,得出了单桩轴向力和摩阻力的分布规律;文中还研究了厂房整体空间效应对顶升的影响,给出了预估荷载时采用的空间效应系数的建议值。实践证明,本方法适合于产生了较大不均匀沉降或倾斜的建(构)筑物的地基事故处理。

Based on the practical engineering, a new technique in the soil treatment that is jacking foundation was studied and developed. The foundamental principle and the feasibility of this method have discussed. In this paper the analyses of the soil cork ef- fect in the steel pipe piles, pile safe bearing capacity were carried out, and the law of soil cork, determine method of pile safe bearing capacity were given. Based on the field load- ing test, the distribution of the pile axial force and the fractional resistance along the pile has analysed. As jacking foundations the influnce of the space interraction is considered. It is proved that the new underpinning can be applied to the engineering.