Force-Displacement and Moment-Rotation Relationships in the Context of Dynamic Soil-Structure Interaction

Abstract

In this paper, we evaluate force-displacement and moment-rotation relationships to characterize dynamic soil stiffness and damping properties of structures subject to forced vibration loading. We first introduce a procedure to extract the necessary data to develop such relationships from forced vibration testing data. This procedure is then applied to data collected from forced vibration tests on a portable test structure at two different soil sites in California. The results show that the outlined procedure is useful in identifying soilstructure interaction characteristics and is a convenient way of presenting field performance data from forced vibration testing. For the data from the two sites collected, the derived relationships infer that rotational stiffness is more frequency dependent than the translational stiffness. Furthermore, the results suggest that the translational mode was more efficient in dissipating energy compared to the rotational mode.