Geotechnical Foundation Systems - CEE Continuing Education Course

Geotechnical foundations are paramount for supporting structural loads of buildings, bridges, towers, walls, poles, and other civil engineering works. The loads must somehow be transmitted to the underlying natural geomaterials (soils and rocks) using a foundation system that is safe, stable, and economical. Since site-specific information is required for each particular structure, an emphasis is made on the use of geotechnical in-situ testing for a rational and proper assessment of the ground, particularly strength and stiffness. This course reviews analytical procedures for the evaluation of shallow foundation systems (spread footings, structural mats/rafts) and deep foundations (driven piles, augered and bored piles, drilled shafts). Methods cover ultimate bearing capacity from limit plasticity solutions and load-displacement behavior as represented within the framework of elastic continuum solutions, whereby soil stiffness is represented by an equivalent modulus (Es) and Poisson's ratio. For deep foundation systems, considerations for evaluating side resistance are examined by effective stress approaches (ß method). Direct and indirect methods from in-situ testing are discussed. Case studies are intermingled throughout the course to illustrate applications in practice. The small-strain stiffness (Gmax) is shown to be relevant to all types of foundation systems.