Subsurface exploration for foundation design

The purpose of subsurface exploration is to provide knowledge of the ground conditions for safe and economical foundation design and potential problems that may be encountered during construction. The subsurface exploration should extend beyond the expected depth of the foundation, but to determine the depth of the foundation is one of the purposes for subsurface exploration. A well-planned and executed subsurface exploration assures that the necessary geotechnical design parameters are obtained with reasonable efforts and cost. The chapter introduces the general procedure and items to be considered in the planning of a subsurface exploration program. It describes available techniques and tools for drilling and sampling related to subsurface exploration. The chapter also describes commonly used in-situ testing methods, their operations, and interpretation of the test data as they relate to foundation designs. It presents the basic techniques of a few geophysical testing methods commonly used in subsurface exploration.