Using topology optimization in tunnel reinforcement design
PhD Thesis
Title | Using topology optimization in tunnel reinforcement design |
---|---|
Type | PhD Thesis |
Authors | |
Author | Nguyen, Tin |
Supervisor | Ghabraie, Kazem |
Institution of Origin | University of Southern Queensland |
Qualification Name | Doctor of Philosophy |
Number of Pages | 162 |
Year | 2015 |
Abstract | In tunnel reinforcement design, having a suitable tool which is able to capture complex ground material and various tunnelling conditions is definitely significant. Since early stages of tunnelling engineering, empirical approaches using rock mass classification and accumulated experiences have been commonly used. Nevertheless, as developed from long-term accumulated knowledge in older projects, it is not always applicable to new ground conditions and also hardly guarantees a In spite of effectiveness of topology optimisation theory, which is proved to work effectively in a broad range of engineering disciplines, its applications in geotechnical This thesis explores the incorporation of topology optimisation methods in tunnel reinforcement design. The main focus of the study is to improve some critical As the first step in this study, material nonlinearities are accounted for in optimization techniques to improve the linear elastic material model assumption of previous studies. Practical behaviours of material, hence, can be captured. The Bidirectional Evolutionary Structural Optimisation (BESO) method is extended to consider nonlinear material behaviour. An elastic perfectly-plastic Another serious shortcoming of the previous studies is that reinforced areas were modelled as homogenised isotropic elements. Optimisation results, therefore, do not clearly show reinforcement distributions, leading to difficulties in explaining the final outcomes. In order to overcome this deficiency, a more advanced modelling technique in which reinforcements are explicitly modelled as truss elements In reality, minimisation of certain displacements such as heave issues or ground displacements in shallow tunnel is sometimes of concern. Extending optimization methods to capture these objective functions is crucial. A general displacement-based objective function is introduced with a constraint on a bolt volume. Sensitivity analysis is conducted and details on identification of necessary parameters are provided. Using the presented optimisation algorithm, an example on optimizing bolt layout to minimise a heave function is performed. It is shown that the This study focuses on applying topology optimisation in tunnel reinforcement design to take advantage of both numerical analysis and optimisation methods. The presented techniques are applicable to any material models of host ground and reinforcements and provides clear and practical final outcomes. Using the proposed methods, all significant factors including geological conditions, construction sequences and tunnel characters can be taken into account to obtain an optimised reinforcement distribution. It is also demonstrated that various objective functions can be employed and usefully optimised by the methods. The obtained results proves that the optimisation techniques presented in this thesis are promising tools to reinforcement design of underground excavations. |
Keywords | tunnel reinforcement; tunnel reinforcement design; tunnels; design; topology optimisation |
ANZSRC Field of Research 2020 | 400502. Civil geotechnical engineering |
400505. Construction materials | |
490304. Optimisation | |
Byline Affiliations | Computational Engineering and Science Research Centre |
https://research.usq.edu.au/item/q30xw/using-topology-optimization-in-tunnel-reinforcement-design
Download files
1867
total views386
total downloads0
views this month0
downloads this month