Parametric analysis in deep urban excavations using fully coupled flow-deformation analysis

Currently, the implementation of advanced methods for the analysis of deep urban excavations such as the Fully coupled flow-deformation analysis that enables to simultaneously calculate stress, deformations and pore water pressures in a time dependent process and can take into account partially drai...

Full description

Autores:
Ballesteros Luna, Camilo Antonio
Tipo de recurso:
Fecha de publicación:
2019
Institución:
Universidad Nacional de Colombia
Repositorio:
Universidad Nacional de Colombia
Idioma:
spa
OAI Identifier:
oai:repositorio.unal.edu.co:unal/76579
Acceso en línea:
https://repositorio.unal.edu.co/handle/unal/76579
http://bdigital.unal.edu.co/73119/
Palabra clave:
Excavations
Fully coupled flow-deformation analysis
Excess pore water pressures
Alpha parameter
Hydraulic conductivity
Excavation rate
Partially drained conditions
Numerical modeling
Deformations
Excavaciones
Análisis completamente acoplado flujo-deformación
presiones de poros en exceso
conductividad hidráulica
tasa de avance de excavación
condiciones parcialmente drenadas
Rights
openAccess
License
Atribución-NoComercial 4.0 Internacional
Description
Summary:Currently, the implementation of advanced methods for the analysis of deep urban excavations such as the Fully coupled flow-deformation analysis that enables to simultaneously calculate stress, deformations and pore water pressures in a time dependent process and can take into account partially drained conditions are easily available in several programs for numerical simulation, however, there is not a clear definition about the necessary conditions for its correct implementation. This research work present a method to define the drainage condition that most likely will take place during an excavation process. Guidelines to define the applicability of fully drained and undrained cases are presented. Special focus is given to define the cases were the implementation of fully coupled flow-deformation analyses is essential for an accurate modeling of excavation in soft to medium fully saturated clays. This research work is believed to be the first attempt to employed advanced finite element modeling of a generalized excavation where soil consolidation and non-linear soil behavior were simulated via fully couple flow-deformations analyses along with the advanced hypoplasticity clay model that accounts for stress history and small strain behavior. The proposed design charts are based on a parametric study conducted to evaluate the effects on excess pore pressures and ground surface settlements of variations in excavation rates, hydraulic conductivity of the soil, excavation geometry and support system stiffness. The proposed method is validated against field performance data (i.e. ground surface settlements and excess pore water pressures) collected from 11 different excavation case histories around the world.