Back analysis of Budapest Rákóczi square metro4 station deep excavation

Abstract

The construction monitoring of Ráckóczi square metro station of Budapest Metro Line 4 offered a great opportunity to back analyse the braced deep excavation in the building period. Building movements, strut forces and wall displacement measurements have 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 the measured and calculated movements could be observed and the strut forces could be calculated reasonable. Curve characteristic of surface settlements was explored, as well. Analysis were carried out to observe influence of the following inputs on the numerical results: soil material model; consolidation effects, boundary conditions. A detailed evaluation is given about the results of parametric analysis.

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].…”