Braced excavation in soft soil incorporating bottom jet grout slab: Analysis considering the consolidation effects
DOI:
https://doi.org/10.14195/2184-8394_118_4Keywords:
Braced excavation, Soft soil, Bottom slab, Jet grouting, ConsolidationAbstract
Using a numerical model based on the finite element method, a bottom-jet-grout-slab-reinfor ced braced excavation in soft soil is analysed. The numerical model incorporates the Biot consolidation theory (coupled formulation of the flow and equilibrium equations) with constitutive relations simulated by the p-q-θ critical state model. The importance of the jet-grout slab construction in order to increase stability against bottom heave failure is particularly assessed. Special emphasis is given to the analysis, during and after the construction period, of the pore pressures, shear stresses, stress levels and displacements in the ground, as well as strut compression forces, wall displacements and bending moments, pressures on the wall and jet-grout slab compression forces and bending moments.
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References
Borges, J. L. (1995) – Aterros sobre Solos Moles Reforçados com Geossintéticos. Análise e Dimen sionamento. Dissertação de Doutoramento, Faculdade de Engenharia, Porto.
Borges, J. L.; Cardoso, A. S. (1998) – Simulação numérica do modelo de estados críticos (p,q,θ) em aterros sobre solos moles. Revista Geotecnia, nº 84, pp. 39-63.
Borges, J. L.; Cardoso, A. S. (2000) – Simulação numérica dos processos de consolidação em aterros sobre solos moles. Revista Geotecnia, nº 89, pp. 57 75.
Britto, A. M.; Gunn, M. J. (1987) – Critical State Soil Mechanics via Finite Elements. Ellis Horwood Limited, England.
Costa, P. (2005) – Escavações escoradas em solos argilosos moles. Análise do comportamento considerando os efeitos da consolidação. Dissertação de Mestrado, FEUP, Porto.
Eide, O.; AAS, G; Josang, T. (1972) – Special application of cast in place walls for tunnels in soft clay in Oslo. Proc. 5th Europ. Conf. Soil Mech. Found. Eng., Madrid, Vol. 1, p. 485 498.
Finno, R. J.; Harahap, I. S.; Sabatini, P. J. (1991) – Analysis of Braced Excavations with Coupled Finite Element Formulations. Computers and Geotechnics, Vol. 12, Nº 2, pp. 91 114.
Lewis, R. W.; Schrefler, B. A. (1987) – The Finite Element Method in the Deformation and Consolidation of Porous Media. John Wiley and Sons, Inc., New York.
Matos Fernandes, M. (1983) – Estruturas Flexíveis para Suporte de Terras. Novos Métodos de Dimensionamento. Dissertação de Doutoramento, FEUP.
O’ Rourke T. D. (1992) – Base Stability and Ground Movement Prediction for Excavations in Soft Clay. Proc. International Conference on Retaining Structures, Cambridge, UK.
Pinto, R. G. (2008) – Sistemas Construtivos de Estruturas de Contenção Multi Apoiadas em Edifícios. Dissertação de Mestrado em Engenharia Civil, FEUP.
