《Journal of Geotechnical and Geoenvironmental Engineering》杂志刊登“喷射注浆法地基加固分析”

作者：Giuseppe Modoni; Joanna Bzówka

刊物：《Journal of Geotechnical and Geoenvironmental Engineering》，2012年12月，138卷第12期，1442–1454页

关键词：旋喷桩；直径；强度；现场试验；变异性；概率分析

摘要：本文研究了旋喷桩法增加基础承载力，降低基础沉降量的作用。其目的是通过理论分析与现场观测相结合的方法提出一个完整的设计步骤。基于文中给出的试验结果表明：旋喷桩能够将较高的垂直荷载转移到周围土壤，同时由于截面的突然缩小或较弱的土壤胶结作用，也会在局部出现结构性塌陷。为了研究旋喷桩的特性及其与周边土壤的力学作用，进行了足尺试验并对试验结果进行分析。分析结果构成了用于模拟群桩支撑下垂直承载筏基响应的数值方法的基础。采用荷载传递曲线法来模拟轴向承载桩的非线性荷载-沉降响应，并将其用于解释旋喷桩形状的不规则性。通过考虑桩和上部混凝土筏基的相互作用，完成了对整个基础的进一步分析。通过对现场试验的结果进行统计，可以估计桩性质的变化，并将蒙特卡洛模拟技术引入模型模拟的计算中。本文所提出的方法的主要优点是基础设计极限荷载可用容忍破坏概率的方式表示，且可以对旋喷过程中出现的不确定性进行试验量化并合理的引入到分析中。最后将提出的方法应用到一个实例研究，并讨论了用旋喷桩进行加固的优缺点。

Analysis of Foundations Reinforced with Jet Grouting

Authors: Giuseppe Modoni; Joanna Bzówka

Journal: Journal of Geotechnical and Geoenvironmental Engineering, Volume 138, Issue 12 (December 2012), 1442–1454

Key words: Jet grouting columns, Diameter, Strength, Field trial, Variability, Probabilistic analysis

Abstract: The use of jet grouting columns to increase the bearing capacity and reduce the settlements of foundations is dealt with, the aim being to formulate a complete design procedure where theoretical analyses and site observations are combined. The study is based on experimental results reported in the literature, which show that jet grouting columns are able to transfer high vertical loads to the surrounding soil but also that structural collapse may locally occur because of a sudden narrowing of their cross sections and/or poor soil cementation. Noticeable attention has been then given to these aspects by interpreting the results of full-scale tests specifically performed to investigate the characteristics of jet grouting columns and their mechanical interaction with the surrounding soil. The results of this analysis form the basis of a numerical method developed to simulate the response of vertically loaded rafts supported by arrays of columns. The nonlinear load-settlement response of axially loaded columns is modeled with the load-transfer curves method customized to account for the irregular shape of jet grouting columns. Extension of the analysis to the whole reinforced foundation is accomplished by considering the mutual interaction between the columns and the upper concrete raft. The variation of column properties is statistically evaluated from the results of field trials, simulated with probabilistic models and introduced into the calculation with a Monte Carlo simulation technique. The main advantages of the proposed method is that the design limit load of the foundation can be expressed in terms of acceptable probability of failure and that the uncertainty arising from the jet grouting process can be experimentally quantified and rationally introduced in the analysis. Benefits and limitations of reinforcement with jet grouting are finally discussed by applying the proposed method to a case study.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000718