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Item type:Publication, Access status: without files , Multikriterielle und topologische Optimierung im Grundbau(2020-03); Der vorliegende Beitrag zeigt die Anwendung von Mathematischen Optimierungsmethoden im Grundbau. Zum einen wird die Topologieoptimierung präsentiert, die es ermöglicht eine Art der Gründung zu finden, die die Lasten bei minimaler Verformung in den Boden abtragen kann und das völlig losgelöst von herkömmlichen Gründungsstrukturen. Zum anderen wird die Dimensionierung vorgestellt, die mit der Methode der multikriteriellen Optimierung umgesetzt wird, um einen geotechnischen Entwurf hinsichtlich vielfältiger Kriterien zu optimieren.Publicationtype: Conference Paper69 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Zur Topologieoptimierung von geotechnischen Strukturen und zur Tragfähigkeitssteigerung des Baugrunds durch Scherfugenverfestigung(Technische Universität Hamburg, Institut für Geotechnik und Baubetrieb, 2020); Publicationtype: Doctoral Thesis160 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Numerical modelling of limit load increase due to shear band enhancementStrengthening of just the shear bands is a patented idea to prevent a critical failure mechanism in order to increase the capacity of a geotechnical system with a minimum of material. Numerical modelling is used to examine this proposed method for limit load increase. Two basic geotechnical systems are analysed using OptumG2 for finite element limit analysis (fela): a shallow foundation with bearing failure and a retaining wall with horizontal wall movement resulting in the active earth wedge. An automated procedure identifies and enhances the shear band using a coupling of OptumG2 with MATLAB. The fela is performed with OptumG2 and run from a MATLAB script, which identifies the shear band based on the simulation result, sets the area of shear band enhancement and reruns the fela. The numerical simulations show that the shear band enhancement leads to a capacity increase for a simple geotechnical system. © 2018 Taylor & Francis Group, London, UK.Publicationtype: Conference Paper158 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A three-dimensional topology optimization model for tooth-root morphology(2018-01); ; To obtain the root of a lower incisor through structural optimization, we used two methods: optimization with Solid Isotropic Material with Penalization (SIMP) and Soft-Kill Option (SKO). The optimization was carried out in combination with a finite element analysis in Abaqus/Standard. The model geometry was based on cone-beam tomography scans of 10 adult males with healthy bone-tooth interface. Our results demonstrate that the optimization method using SIMP for minimum compliance could not adequately predict the actual root shape. The SKO method, however, provided optimization results that were comparable to the natural root form and is therefore suitable to set up the basic topology of a dental root.Publicationtype: Journal Article177 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Advances in numerical modelling of different ground improvement techniquesCommon ground improvement techniques like deep vibration compaction, vibro replacement stone columns, dynamic compaction or vibratory rolling are still a subject of research. Research fields are for example optimized layouts or estimation of main influencing parameters. A lot of successful scientific research is conducted on piles and piling using various numerical methods. Therefore, it is assumed that numerical models can be used to improve ground improvement methods. In this contribution, different ground improvement techniques and numerical models to simulate the influence of these techniques on the surrounding soil are presented. Furthermore, optimization methods and potentials of ground improvement techniques are shown.Publicationtype: Journal Article183 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Three-dimensional topology optimization for geotechnical foundations in granular soil(2016-12-01); This article presents three-dimensional structural optimization in geotechnical engineering for foundations in granular soil. The general design (topology) of a shallow foundation is optimized with respect to its deformational behaviour within the service limit state. The SIMP (solid isotropic material with penalization) method is applied to optimize the distribution of foundation material. The soil is modelled as a hypoplastic material with a constitutive model suitable for optimization using finite element analysis. Two load cases are examined. The optimized topology is validated against two-dimensional optimization and 1g-model test results. The present study proves the applicability and shows the potential of topology optimization in geotechnical engineering.Publicationtype: Journal Article53 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Topology optimization in geotechnical engineering: Application to foundations and validation(2016-03-01); ; This article presents the application of structural optimization in geotechnical engineering. The general design (topology) of a foundation strip is optimized with respect to its deformation behaviour within the service limit state. The SIMP-method is applied for the topology optimization. Hence, a finite element analysis with Abaqus is combined with an adequate optimization algorithm. A hypoplastic constitutive model for modeling material transitions is used for finite element analysis. Four load cases will be examined. The optimized topology design will be reproduced for the following validation with 1 g physical models. A comparison of the load deformation behavior with non optimized foundations with equal volume is carried out. The presented study shows the applicability and potential of topology optimization in geotechnical engineering.Publicationtype: Journal Article88 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Interpretation of CPT data for pile loading behavior - Inverse estimation of void ratio over depth(Australian Geomechanics Society, 2016); ; ; Cone penetration tests are often used for geotechnical site investigation before pile installation. Usually the measured data for cone and shaft resistance are roughly interpreted and applied for the design of the pile resistance. This paper presents an approach for soil modelling included in numerical simulations of pile loading behavior which employs the CPT data directly. Considering the material properties to be known, e.g. from laboratory tests which have been performed on bore hole excavations, state variables such as void ratio distribution and in situ stress state need to be determined to model an accurate initial state. This paper proposes an inverse determination of these unknown variables with mathematical optimization using an evolutionary algorithm to minimize the difference between measured CPT data and simulation results obtained from FEM. The obtained initial state variable distribution for void ratio for a given stress state may then be used to simulate the pile loading behavior without the need of prior interpretation of CPT data. The solution of the proposed inverse problem will be compared to the determination of state variables for a fictitious problem, in which the initial state is known.Publicationtype: Conference Paper49 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Optimization of geotechnical structures for states of serviceability and ultimate loadsIn geotechnical engineering we usually think in typical structure elements like plates, piles, walls and anchors. But this is in general not the optimal structural set-up with regard to the necessary construction material and costs. Two approaches to geotechnical optimization will be presented in this paper: (1) the topological optimization to find the structural set-up which is able to reduce the system’s deformation and (2) the enhancement of geotechnical systems within the shear zones in order to increase the capacity. The first approach is conducted numerically using the SIMP-method for optimization in combination with finite element analysis in Abaqus/Standard. 1 g-model tests are used to prove the optimization results obtained from numerical analysis. The second approach is the patented idea to strengthen just the shear zones e.g. by jet grouting. This leads to a relatively best capacity increase with a minimum of material. This idea has already been investigated in first model tests. Up to now the numerical simulation is still in progress. The work is part of two projects: “Finite-Element based multicriterial numerical optimization of geotechnical structures in the service limit state” (GR 1024/9-3) and “Increase of bearing capacity for geotechnical constructions through shear zone enhancement” (GR 1024/23-1), which are both funded by the German Research Foundation (DFG).Publicationtype: Conference Paper64