FHWA Soils and Foundations Reference Manual A comprehensive geotechnical reference manual geared towards transportation applications but relevant to all aspects of geotechnical engineering.
Geotechnical Publications based on Subject Geotechnical Info .Com has several publications, free by downloading from the links in the site or many more publications are referenced as well.
Download Site Investigation Manual Manual on Subsurface Investigations
National Highway Institute
Publication No. FHWA NHI-01-031
Geotechnical Site Characterization
July 2001
Download Trenching and Shoring Manual The Manual is devoted to the analysis of trench and excavation earth support (shoring) systems and retaining walls.