Closure to 'Assessing Overconsolidation Ratios in Soil with Piezocone: Referencing Soil Index Properties' by Steven R. Saye, Alan J. Lutenegger, Jorge Santos, and Bryan P. Kumm

摘要

The writers would like to thank the discusser for his insightful comments regarding the paper. As the discusser pointed out, the approach presented in the paper by the writers is a total stress approach whereas the approach presented by the discusser in the numerous publications cited is an effective stress approach. As might be expected, both approaches will essentially lead to similar results if properly used with reference testing. The writers' approach requires only basic soil characteristics, which practitioners can easily obtain, whereas the approach presented by the discusser and his colleagues requires the determination, or at least an estimation, of a number of soil properties, many of which are not necessarily easy to obtain by practicing engineers. The paper cited by the discusser was not available to the writers at the time of preparation of the paper, and it may be of some value to consider this review. As previously reported, the cone penetration test (CPT) material index, I_c, may be useful in helping to refine empirical correlations using CPT results and it may be that for saturated fine-grained soils, I_c may embody the subtle differences in behavior resulting from differences in composition, plasticity, and consistency. Further correlation data in highly plastic clays and organic soils over a range of overconsolidation ratio values are merited to extend the discusser's approach where the writers identify high exponent m_(CPTu) values. The use of basic soil characterization parameters, such as plasticity index and liquid limit, in differentiating soil behavior from both a total stress and effective stress approach has been a part of geotechnical practice and research for the last 60 years and is a simple, expedient approach that provides both an alternative and a confirmation to other more intricate approaches described by the discusser.