《Journal of Geotechnical and Geoenvironmental Engineering》杂志刊登“改良土抗剪强度的不确定性对路堤可靠性的影响”

作者：Mohammed Salim Al-Naqshabandy and Stefan Larsson

刊物：《Journal of Geotechnical and Geoenvironmental Engineering》，139卷第4期，619–632页

关键词：地基加固；强度；系统可靠性；极限状态；路堤

摘要：石灰水泥改良土的强度可变性很高，对其进行可靠性评估也有很高的不确定性。对自然土的调查研究表明，土性质的可变性对岩土工程可靠性有着重要的影响。然而，使用石灰水泥桩进行地基加固，及其与加固强度性质相关的不确定性对工程可靠性的影响还是未知的。瑞典在一个修建在经过石灰水泥桩改良后地基上的路堤设计中，提出了以可靠性为基础的综合性设计。本文对此进行了分析。该工程提出并讨论了以触探实验的结果为基础的并与评估强度性质相关的不确定性对评估系统可靠性的影响。针对桩的抗剪强度的空间可变性，使用方差缩减对评估系统的稳定性有很大的影响。进一步研究表明，基于触探试验的测量结果带来的换算不确定性对系统可靠性的评估有很大影响，且系统可靠性不能仅通过进行大量的实验来改善。

Effect of Uncertainties of Improved Soil Shear Strength on the Reliability of Embankments

Authors: Mohammed Salim Al-Naqshabandy and Stefan Larsson

Journal:《Journal of Geotechnical and Geoenvironmental Engineering》，Volume 139, Number 4,619–632

Key words: Ground improvement; Strength; System reliability; Limit state; Embankment.

Abstract: The strength variability of soils improved by lime-cement columns is very high, and assessment of the reliability is associated with high uncertainty. Previous research on natural soils has shown that variability has a major impact on the reliability of geotechnical systems. However, concerning ground improvement with lime-cement columns, the effect of the uncertainties associated with improved strength properties on the reliability is unknown. This paper addresses the integration of reliability-based design in the design of embankments founded on soil improved by lime-cement columns by an analysis of a project conducted in Sweden. The uncertainties associated with estimating the strength property based on results from cone penetration tests and their effect on the assessed system reliability are addressed and discussed. The use of variance reduction with respect to the spatial variability of the shear strength of the columns was found to have a major influence on the assessed system reliability. Furthermore, it was found that the transformation uncertainty from measurements based on cone penetration tests has a significant impact on the assessed system reliability. System reliability cannot be improved significantly simply by performing a large number of tests.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000798