AASHTO R 13-12 (2020) PDF Download

AASHTO R 13-12 (2020) is a standard practice that provides guidelines for conducting geotechnical subsurface investigations. The standard acknowledges the complexity of these investigations and recognizes that there can be multiple techniques and interpretations involved. It emphasizes that these studies are often site-specific and influenced by geological and geographical factors, as well as the project design requirements and the expertise of the investigator.

The purpose of the standard is to establish a consistent and rational methodology for evaluating site conditions. By following standard procedures for investigation, sampling, testing, and evaluation, the practice aims to provide reliable information on subsurface materials. This information is crucial for developing transportation facilities that are safe and cost-effective.

The standard practice outlines recognized methods for determining soil, rock, and groundwater conditions. The main objective of the investigation is to identify and locate the different types of soil, rock, and groundwater present at a site, both horizontally and vertically. This is achieved through sampling and in situ testing. The standard also highlights that laboratory testing of soil and rock samples should be conducted in accordance with other AASHTO and ASTM standards.