5.1 Whether for the sake of simplicity or because of a lack of information, geotechnical engineers regularly assume that soil and rock properties are the same throughout a particular location, even though they realize that the use of averaged parameter values can result in soil parameters that are significantly different from the actual parameters.

5.2 Considering the spatial distribution of soil and rock mass properties, the use of geostatictics in site investigations should be considered as it will provide a more accurate estimation of the soil and rock properties based on the available input information.

5.3 This guide is intended to encourage consistency in the analysis, interpretation, and modeling of spatial variation in geostatistical site investigations.

5.4 This guide should be used in conjunction with Guides D5549, D5923, and D5924.

1.1 This guide covers recommendations for analyzing, interpreting, and modeling spatial variation of regionalized variables in geotechnical and environmental site investigations.

1.2 The measures of spatial variation discussed in this guide include variograms and correlograms; these are fully described in Refs. (1-4).2

1.3 This guide is intended to assist those who are already familiar with the geostatistical tools discussed herein and does not provide introductory information on the analysis, interpretation, and modeling of spatial variation.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.