Full Name

AASHTO R13 – Standard Practice for Conducting Geotechnical Subsurface Investigations


This standard practice identifies recognized methods by which soil, rock, and groundwater conditions may be determined.

The objective of the investigation should be to identify and locate, both horizontally and vertically, significant soil and rock types and groundwater conditions present within a given site area and to establish the characteristics of the subsurface materials by sampling and in situ testing.

Laboratory testing of soil and rock samples is governed by other AASHTO and ASTM standards.


explorations; feasibility studies; field investigations; foundation investigations; geological investigations; geophysical investigation; groundwater; hydrologic investigations; maps; preliminary investigations; reconnaissance surveys; sampling; site investigations; soil surveys; subsurface investigations