Static and Dynamic behaviour of pile supported structures in soft soil

Abstract : A great amount of earthquakes have caused the collapse of important structures along the history. The design of earthquake-resistant structures depends greatly of the soil-structure interaction. This interaction implies the consideration of relative movements and load transfer mechanism simultaneously. Dealing with liquefiable soils the generation of pore pressure should also be considered.Pile system constitutes a common foundation of structures resting on soil layers of low stiffness and strength in seismic zones. More recently rigid inclusion systems were utilized. The difference is that in the rigid inclusion systems, the rigid elements are separated from the foundation slab by an earth platform that is able to transfer the surface loads and dissipate energy coming from the seismic loading.This manuscript studies the behavior, through numerical models, of inclusions systems (soil-inclusion-platform-structure) and pile systems (soil-pile-structure) considering soft soils under seismic loadings. Finite difference numerical models were developed using Flac3D. Several types of soils were utilized in drained and undrained conditions. For the undrained cases, the analyses were carrying out using dynamic coupled fluid-mechanical simulations with accuracy the behavior of soils. The Rayleigh damping approach was applied to provide additional damping in the elastic part when simple elasto-plastic constitutive models were considered.The objective of the investigation is the identification of the impact of important factors in the response of the analyzed systems. Factor such as the foundation type, the frequency of the input motion, the dynamic characteristics of the structure, the soil profile and the relative density were investigated. Considering the pile and rigid inclusion foundations, the support conditions, the pile group configuration, the pile length, the embedment of the foundation were also examined.Additional and important aspects of numerical model were also explored like the model geometry, dynamic boundary conditions, element size, interface elements, structural element types, dynamic loading.Results in terms of movements and stresses in the soil, superstructure and rigid elements were obtained. They show the great influence of some parameters in the response (accelerations, displacements, efforts, strains, pore pressure) of the evaluated systems. Others highlight the importance of a type of failure in the elements of the system.Keywords: pile; rigid inclusion; numerical modelling; dynamic analysis; soil structure interaction; liquefaction
Complete list of metadatas

Cited literature [231 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02271948
Contributor : Abes Star <>
Submitted on : Tuesday, August 27, 2019 - 1:24:07 PM
Last modification on : Thursday, August 29, 2019 - 1:02:14 AM

File

LOPEZ_JIMENEZ_2019_archivage.p...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02271948, version 1

Collections

STAR | CNRS | 3S-R | UGA

Citation

Guillermo Alfonso Lopez Jimenez. Static and Dynamic behaviour of pile supported structures in soft soil. Mechanics of materials [physics.class-ph]. Université Grenoble Alpes, 2019. English. ⟨NNT : 2019GREAI032⟩. ⟨tel-02271948⟩

Share

Metrics

Record views

242

Files downloads

163