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 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.

• Autores: Ballesteros Luna, Camilo Antonio
• 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