The largest infrastructure project ever undertaken in Gothenburg, the Västlänken tunnel project, brings new geotechnical challenges when a 6 km long train tunnel is to be built underneath the city. The several deep excavations supported by retaining walls needed in the soft Gothenburg clay raises the question: Which retaining wall design method is the most accurate?
The aim of this thesis is to compare the forces and deformations measured at a multi-anchored sheet pile wall, installed during the construction of Götatunneln with similar conditions, to the results of different calculation methods. The calculation methods are hand calculations, the one-dimensional finite element software Novapoint GS Supported Excavation and the Mohr-Coulomb, Hardening Soil and Hardening Soil with small strain stiffness constitutive models in the two-dimensional finite element software PLAXIS 2D.
The different models were created based on previously conducted investigations of the soil, evaluation of CRS and triaxial tests and blueprints of the sheet pile wall and its anchors. A parametric study was also performed to see how the different models reacted when varying certain parameters and assessing the importance of investigating these parameters.
The results show that the PLAXIS 2D models give the best results, with the Hardening Soil model being the most accurate. Another advantage with the Hardening Soil model is that it provides the possibility of validating the model by comparing the stress paths obtained from triaxial tests to simulated tests in PLAXIS SoilTest.
The parametric study showed that if no triaxial tests are available, the Mohr-Coulomb model can give fairly accurate results as well, using empirical correlations to evaluate the stiffness. It also showed that basing a Hardening Soil with small strain stiffness model on empirical correlations for small strain stiffness should not be done, since there are different methods of correlating these parameters which give different results.
Keywords: Sheet pile wall, Multi-anchored, Deep excavation, Finite element, Novapoint GS Supported Excavation, PLAXIS 2D, PLAXIS SoilTest, Mohr-Coulomb, Hardening Soil, Hardening Soil with small strain stiffness, Geotechnics
Details
| Title | Modelling of a Deep Excavation in Soft Clay - A Comparison of Different Calculation Methods to In-Situ Measurements |
| Pages | 99 |
| Language | English |
| Format | |
| Size | 6 MB |
| Download Method | Direct Download |
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The post Modelling of a Deep Excavation in Soft Clay – A Comparison of Different Calculation Methods to In-Situ Measurements appeared first on Civil Engineering Community.
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