SOIL SAMPLING

To provide accurate knowledge of the subsurface conditions, as well as the physical and engineering properties of the foundation materials, soil sampling operations are routinely conducted to determine those conditions that affect the safety, cost-effectiveness, and design of a proposed engineering project. This manual presents a summary of commonly accepted soil sampling practices and procedures to assist geotechnical personnel performing actual field studies. It provides both technical guidance for conducting soil sampling operations, and the best methods for handling and storage of samples obtained in support of geotechnical investigations. The principles, equipment, procedures, and limitations for obtaining, handling, and preserving soil samples are discussed. Since the highest quality samples are often obtained at the least cost by using a variety of equipment and techniques, this manual surveys the different devices and techniques that have been developed for drilling and sampling geotechnical materials ranging from soil to rocks. The manual further suggests the various types of sampling devices best suited to obtain samples of various soil types encountered during geotechnical investigations. Contents cover: sampling requirements; drill rigs and appurtenant equipment; drilling fluids; equipment and procedures for undisturbed soil sampling in borings; equipment and procedures for disturbed soil sampling in borings; sampling frozen soils; underwater sampling of soils; sampling from test pits, trenches, accessible borings, or tunnels; sampling from stockpiles and bins, transportation units, or conveyor belts; handling and storage of samples and sampling records; and backfilling boreholes and excavations.