The AASHTO Manual on Subsurface Investigations was first published in 1988, based on a National Cooperative Highway Research Program initiative (NCHRP 20-07, Task 30). Since then, the practice of subsurface investigation has evolved as reflected in engineering practice, as well as in the project development and delivery processes. Proposed updates to this manual of fundamental geotechnical subsurface investigation guidance will provide the latest in cost-effective geotechnical design and construction solutions. The AASHTO manual is used by many state and local highway agencies as the authoritative guidance manual for developing scopes of work and conducting subsurface investigations.
The objective of this research was to propose revisions to the AASHTO Manual on Subsurface Investigations by synthesizing current practices and advancements for geotechnical subsurface investigations, including methods to assess the relative value of these investigations with respect to project and program risks, costs, and life-cycle performance.
The research agency’s final report that documents the entire research effort is available as NCHRP Web-Only Document 258: Manual on Subsurface Investigations provides an update to the American Association of State Highway Transportation Officials (AASHTO) at: https://www.trb.org/Publications/Blurbs/178722.aspx
