The boring log is the basic record of almost every geotechnical exploration and provides a detailed record of the work performed and the findings of the investigation. The field log should be written or printed legibly and should be kept as clean as is practical. All appropriate portions of the logs must be completed in the field prior to completion of the field exploration.
A wide variety of drilling forms are used by various agencies. The specific forms to be used for a given type of boring will depend on local practice. Typical boring log, core boring log and test pit log forms endorsed by the ASCE Soil Mechanics and Foundations Engineering Committee.
-Topographic survey data including boring location & surface elevation, and benchmark location and datum, if available.
-An accurate record of any deviation in the planned boring locations.
-Identification of the subsoils and bedrock including density, consistency, color, moisture, structure, geologic origin.
-The depths of the various generalized soil and rock strata encountered.
-Sampler type, depth, penetration, and recovery.
-Sampling resistance in terms of hydraulic pressure or blows per depth of sampler penetration. Size and type of hammer. The height of the drop.
-Soil sampling interval and recovery.
-Rock core run numbers, depths & lengths, core recovery, and Rock Quality Designation (RQD)
-Type of drilling operation used to advance & stabilize the hole.
-Comparative resistance to drilling.
-Loss of drilling fluid.
-Water level observations with remarks on possible variations due to tides & river levels.