THE USE OF DYNAMIC PILE TESTING TO INTERPRET SOIL SET-UP. IN: CURRENT PRACTICES AND FUTURE TRENDS IN DEEP FOUNDATIONS

Dynamic pile testing involves the recording of stress and velocity time histories during pile driving, using strain transducers and accelerometers attached on opposite sides of the pile near the top. The soil resistance to driving is estimated using the Case-Goble formulation, assuming a damping coefficient that is a function of soil type. A signal-matching program, such as the Case Pile Wave Analysis Program (CPAWAP), is used to estimate the distribution of the soil resistance to driving along the length and at the toe of the pile. Dynamic pile testing permits an interpretation of soil set-up that was not possible by simply counting hammer blows especially when the pile driving hammer is not large enough to overcome the long-term static capacity.