This discussion notes that while modeling requires simplifying assumptions, oversimplification may detract from the information available sufficiently to mask the correct solution and mislead or misinform the designer. This discussion focuses on the mass and stiffness parameters, their computation and effect on the dynamic properties of the foundation. The six characteristics frequencies and mode shape of the foundation are primarily a function of the foundation stiffness as expressed by matrix and the mass matrix containing values of mass and mass moment of inertia corresponding to the linear and rotational degrees-of-freedom, respectively. Soil moving in phase with piling constitutes a "virtual mass" effect. This mass must be approximate in computations and tests used for verification. Computation of the foundation stiffness first requires modeling and calculation of the stiffness of each pile. Once the pile's stiffness is computed in its own or local axes it may be transformed to account for rotation and translation of axes to be coordinates of the foundation. The choice of pile model and the computations are discussed.

Media Info

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Filing Info

  • Accession Number: 00193595
  • Record Type: Publication
  • Report/Paper Numbers: ASCE 13158
  • Files: TRIS
  • Created Date: Jun 13 1979 12:00AM