DYNAMIC DAMAGE ANALYSIS OF EXTENDED PILES OF BRIDGE STRUCTURES UNDER SEISMIC LOADING
Journal
World Conference on Earthquake Engineering proceedings
Journal Volume
2021
ISSN
30065933
Date Issued
2021
Author(s)
Fu Y.W.
Abstract
Piles are a type of deep foundations, commonly used in bridge structures. When an earthquake occurs, piles may sustain inertial forces transferred from the structure as well as kinematic loading caused by ground movement. In this study, we perform dynamic analysis to investigate the development of damage of an extended pile of a bridge structure caused by inertial and kinematic ground movement effects during earthquakes. The analysis model combines a structure-pile-soil interaction model and a ground movement model. In the structure-pile-soil interaction model, beam elements are used to simulate the pile, soil springs are used to simulate the soil reaction, and a lumped mass is used to simulate the deck. In the ground movement model, a series of shear springs are used to simulate soil layers at different depths subjected to horizontally upward shear waves. In addition, plastic hinges are placed in the beam elements to simulate the nonlinear flexural behavior of the pile. Through a series of numerical analyses, effects of ground motions of different characteristics, and effects of ground movement and inertial loading on the development of plastic zones in the pile are explored. From this study, the consideration of ground movement appears to increase the inertial forces in the pile and may further increase the range of the plastic zone. The maximum range of the plastic zone occurs when the directions of the inertial and kinematic loading are out of phase. Seismic design for pile foundations only considering inertial loading may be unsafe, and therefore the ground movement effect needs to be included for more rational design.
Subjects
inertial loading
kinematic ground movement
plastic hinges
structure-pile-soil interaction
Publisher
International Association for Earthquake Engineering
Type
conference paper