THE EFFECT OF VERTICAL GROUND ACCELERATIONS ON THE DYNAMIC STABILITY OF SIMPLE STRUCTURES

摘要

Based on current research, it appears that there is some disagreement as to whether vertical accelerations have a significant impact on the lateral response of a structure in a seismic event. Some research indicates that vertical accelerations are significant and other research indicates the opposite. Furthermore, most research on vertical accelerations has focused on specific buildings, thus it is not clear which types of structures would be influenced by vertical accelerations. The authors sought to determine the types of structures that might be sensitive to vertical accelerations using Single Degree of Freedom (SDOF) models with bilinear force-deformation relationships. The SDOF model parameters varied were stiffness (period of vibration), post yield stiffness ratio, yield strength, and geometric stiffness (P-Delta effects). Additional parameters allowed to vary in the study related to the ground motions were earthquake ground motion, lateral ground acceleration intensity, and vertical ground acceleration intensity. Considering both structural parameters and earthquake parameters, seven independent parameters were varied.