Back analysis of a shoring system at the excavation site of M4 subway, Budapest

Abstract

The paper focuses on the numerical back analysis of the monitored deep excavation of II. János Pál pápa square of Budapest Metro Line 4. Inclinometric measurement of diaphragm wall deformations has been compared to numerical results derived by PLAXIS using HSsmall soil model. Considering the influence of small strain stiffness of plastic soils, good fit of measured and calculated deformations could be observed. Parametric analysis were carried out to observe influence of the following inputs on the numerical results: Construction time and sequence Consolidation effects Small strain stiffness parameters A detailed evaluation is given about the results of parametric analysis, considering the inherent errors of the inclinometric measurements, as well.

Two- and Three-dimensional Numerical Back-analysis of Deep Excavation Case Studies from Budapest, Hungary

“…Looking for the answers the following calculation models were built to back analyze the introduced case studies: 2D subgrade reaction (Winkler-type) models by PARIS software of Soletanche Bachy, 2D FEM models by PLAXIS 2D and 3D FEM models by PLAXIS 3D for project "C" and "D". All the finite element models were built up with "hardening soil model with small strain stiffness" (HSS) soil model considering hardening behavior and small strain stiffness as previous studies ([ [6][7][8][9][10][11][12]) proved its general appropriateness. "Plastic" type calculations were done excluding direct consideration of time dependency.…”

“…• 2D and 3D back analysis of single projects in Budapest [6][7][8][9][10][11] to answer principal questions on soil models and 3D model settings. • Parametric comparison of 2D and 3D calculation results for the typical deep excavation solutions in Budapest [12] following the concept of studies of [13] and [14].…”