Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
ENERGY TRANSFER IN COMPOUND FOUNDATIONS FOR ARBITRARY BONDING CONDITIONS
Submission Author:
Luis Filipe do Vale Lima , SP
Co-Authors:
Pérsio Leister de Almeida Barros, Josue Labaki, Luis Filipe do Vale Lima, EUCLIDES MESQUITA
Presenter: Josue Labaki
doi://10.26678/ABCM.COBEM2019.COB2019-1747
Abstract
This work discusses energy transfer in a piled raft foundation problem for different bonding configurations found in practice. The surface raft is modeled as circular rigid plate, the pile is modeled as an elastic bar embedded in perfectly bonded contact within the soil, which in turn is modeled as a viscoelastic, transversely isotropic, homogeneous half-space. Traction distribution between plate and soil and between pile and soil is written as piece-wise constant boundary elements. Coupling between the foundation and the soil is obtained via direct equilibrium and kinematic compatibility at the interfaces. The system is under time-harmonic, external vertical loads uniformly distributed on the surface of the plate, or vertically- propagating, time-harmonic seismic pressure waves. A Winkler layer of stiffness Kw is added throughout the plate-soil interface, and an additional spring Kp is added at the plate-pile contact point. Arbitrary bonding conditions between plate-soil and plate-pile can be obtained by varying Kw and Kp. A parameter α varying from 0 to 1 is defined in order to make the bonding conditions easier to interpret. The limiting condition in which all energy is transferred from the plate directly to the pile, and then to the soil, is represented by α=1, and arbitrary values of Kw and Kp. The other limiting condition in which all energy is transferred from the plate directly to the soil is represented by α=0, and different values of Kw and Kp. The article discusses the appropriate description of α in terms of Kw and Kp to represent all bonding cases in between. A parameterized foundation model is also used in this study. This model is obtained by directly adding together the complex spring constant of plate-soil and pile-soil interaction. This parameterized model disregards energy transfer from the plate to the pile through the soil. The present model contributes to our understanding of energy transfer between different parts of compound foundations with different bonding conditions.
Keywords
Dynamic soil-foundation interaction, Raft Foundations, Pile Vibration, Coupled Foudation
