Jürgen Grabe

Jürgen Grabe
Technische Universität Hamburg | TUHH · Institute of Geotechnical and Construction Engineering

Univ.-Prof. Dr.-Ing.

About

531
Publications
49,966
Reads
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2,352
Citations
Citations since 2016
137 Research Items
1601 Citations
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
Introduction
Current research interests: soil mechanics, unsaturated soils, particle-fluid-structure interactions, computer tomography, foundation engineering, marine geotechnics, optimization of topology, mechatronics and numerical methods like FEM, MPM, SPH, DEM and CFDEM
Additional affiliations
September 1998 - present
Technische Universität Hamburg
Position
  • Head of Department

Publications

Publications (531)
Article
For an economic design against stability failure of double-T pile of combined sheet pile walls, it is necessary to consider the resistance of the soil to twisting or buckling. Results from in situ tests are already presented in Part I of this publication [1] for the determination of lateral and rotational spring properties to represent the pile-soi...
Article
The main part of the load transfer of combined sheet pile walls is performed by the king piles embedded in the soil. At present, however, the calculation for combined walls in the final state is carried out without considering the resistance of the soil to twisting or buckling of the king piles. With attention to the valid standards, the considerat...
Conference Paper
Current design practice simplifies complex loading scenarios, i.e. highly cyclic loads from varying direction offshore, using classification methods by combining different cycle packages with constant frequency, mean load level and amplitude. This procedure assumes the resulting accumulated deformation in the soil to be independent of the ordering...
Conference Paper
One of the main reasons for damage to embedded offshore infrastructure is anchor penetration. Sea cables, for example, are harmed either by direct anchor contact or by additional pressure caused by anchor dragging above the cable. A sufficient permanent burial depth is required to minimize the risk of failure due to anchor penetration. This work pr...
Conference Paper
Floating offshore wind turbines (FOWTs) are moored, e.g., by anchor chains connecting the anchorage in the seabed and the floating unit. At various marine foundation infrastructures, erosion has occurred along the anchoring system, reducing soil resistance. This reduction is assumed to be caused by the anchor chain movement. Numerical simulations i...
Conference Paper
Full-text available
The capillary collapse is an irreversible reduction in volume of partially saturated soils caused by the provision of water at essentially unchanging total vertical stress. Despite extensive research, however, the processes involved are still not fully understood and will therefore be investigated in more detail as part of the project. As a special...
Conference Paper
During the construction of the new ship lift in Niederfinow (Germany), the lower outer harbours bank walls are to be rear-anchored with driven steel piles. The characteristic pile shaft resistance is calculated using empirical values for the preliminary design according to the Recommendations of EA-Pfähle (2013). These are in the range of typical e...
Conference Paper
With offshore wind turbines being constructed in water depths greater than 40 m, floating offshore wind turbines (FOWT) become more cost-effective than conventionally founded alternatives. However, sea bed anchoring of such floating bodies is yet not well understood, and deeper insights into the anchor-soil-interaction are crucial for the operation...
Conference Paper
Im Zuge der Errichtung des neuen Schiffshebewerks Niederfinow werden die Uferwände des unteren Vorhafens mit Stahlrammpfählen rückverankert. Zur Vorbemessung wurden Bruchwerte der Mantelreibung basierend auf Erfahrungswerten unter Berücksichtigung der anstehenden Bodenarten abgeschätzt. Diese lagen im Bereich üblicher Werte für Rammpfähle gemäß den...
Conference Paper
Submarine landslides can entail a substantial hazard for offshore infrastructure as they are capable of triggering tsunamis and may develop into highly mobile turbidity currents capable of breaking seabed cables. Despite considerable research activity, the trigger mechanisms for such landslide events cannot be clearly defined. Recently, marine gas...
Article
Full-text available
A numerical model based on the finite element framework was developed to predict the seismic response of saturated sand under free-field conditions. The finite element framework used a non-linear coupled hypoplastic model based on the u-p formulation to simulate the behaviour of the saturated sand. The u-p coupled constitutive model was implemented...
Article
Full-text available
Gauging the mechanical effect of partial saturation in granular materials is experimentally challenging due to the very low suctions resulting from large pores. To this end, a uniaxial (zero radial stress) compression test may be preferable to a triaxial one where confining pressure and membrane effects may erase the contribution of this small suct...
Article
The destructive potential of submarine landslides for populated coastal areas and maritime infrastructure has been described many times. However, the geological processes that can trigger such landslide events have not yet been fully established. In order to be able to conclusively assess the trigger potential of these processes, a quantification o...
Technical Report
The overall objective of the research project is the optimization of design procedures of combined steel sheet pile walls used in quay wall construction for the protection of terrain jumps. First, the basic principles were determined in a parameter identification in the research project. For this purpose, common quay wall projects were analysed reg...
Article
Vibroflotation is an established ground improvement technique for granular materials. It densifies loose sands by means of shear and compressive deformation processes imparted by the horizontal vibrations of a vibrator probe at the required soil depth. The field experience and empirical relations used for the design of vibroflotation processes prom...
Article
Vibroflotation is one type of ground improvement technique used for liquefaction mitigation in saturated sand. In order to study the feasibility of vibroflotation for liquefaction mitigation, two numerical models were created in the finite element framework. A nonlinear, coupled, hypoplastic u-p formulation was developed to simulate the behaviour o...
Article
de Während des Kaimauerbaus ist die plangenaue Installation der Träger herausfordernd und zugleich unabdingbar, um die Zwischenbohlen kombinierter Stahlspundwände einbringen zu können. Die Doppel-T-Träger haben profilbedingt, im Vergleich zu einem Rundrohrstahl, eine geringe Biegesteifigkeit um die schwache Achse und eine geringere Torsionssteifigk...
Article
In diesem Beitrag wird ein dynamisches Modell einer Offshore‐Windenergieanlage mit Schwerpunkt auf der numerischen Modellierung der Boden‐Struktur‐Interaktion vorgestellt. Das entwickelte Modell basiert auf einem zweidimensionalen FE‐Modell eines auf Federn gebetteten Euler‐Bernoulli‐Balkens. Die Pfahl‐Boden‐Interaktion bzw. das Last‐Verformungsver...
Article
Offshore wind is a key part of the change toward renewable energy sources. Offshore wind farm developments are moving to sites that are characterized by increased water depths and layered soil profiles, e.g., in the North Sea. Suction caisson–based jacked structures are expected to be increasingly used to support wind turbines at such sites. Experi...
Article
The pore-water pressure generated by intermittent dynamic vehicle loading under various saturation states is recognized as a critical factor influencing the behaviour of permeable pavement structures, especially the behaviour of UGB layer. However, the underlying mechanisms of hydro-mechanical interaction in the UGB layer and the influence on the p...
Article
Vibroflotation includes densification of loose sands by means of shear deformation processes imparted by horizontal vibrations of vibrator probes. 1g model tests replicating the vibroflotation process were conducted using a model vibrator to identify online compaction control parameters. The effectiveness of the compaction was evaluated by means of...
Article
Full-text available
Rising world trade and the following consolidation of material flows cause a growing need for bigger bulk carriers. Therefore, the quay walls of the harbours need to be adjusted to realize the depth of the channels. Combined sheet pile walls are used to build quay walls. They consist out of up to 45 m long H-shaped beams and Z-shaped intermediate p...
Article
Full-text available
Combined walls are built out of heavy king piles and lighter sheet piles to protect site jumps up to 30 m of quay walls. Few recommendations exist on how to install the king piles so that the sheet piles can absorb the deformations coming from the location slippage of the king piles. As such the installation process of king piles needs to be regula...
Chapter
There is an increasing interest to utilise suction caissons as foundations for offshore wind turbines. Significant research has been devoted to developing penetration prediction methods and to understand the in-service response under cyclic loading. However, the effect of the installation process on the state of the surrounding soil is less well un...
Conference Paper
Rising world trade and the following consolidation of material flows cause a growing need for bigger bulk carriers. Therefore, the quay walls of the harbours need to be adjusted to realize the depth of the channels. Combined sheet pile walls are used to build quay walls. They consist out of up to 45 m long H-shaped beams and Z-shaped intermediate p...
Conference Paper
Combined walls are built out of heavy king piles and lighter sheet piles to protect site jumps up to 30 m of quay walls. Few recommendations exist on how to install the king piles so that the sheet piles can absorb the deformations coming from the location slippage of the king piles. As such the installation process of king piles needs to be regula...
Article
The Hypoplastic model is introduced and the procedure to determine the model parameters along with intergranular strain parameters is discussed in detail. Static trial tests and load/displacement controlled oedometer tests are performed to determine the hypoplastic model parameters. The dependence of the hypoplastic model parameters on initial dens...
Conference Paper
Offshore wind turbines supported by suction caisson jackets transfer the loading to the foundation primarily through a vertical push-pull mechanism. This leads to the foundation performance under vertical cyclic loading to be a critical design aspect, with recommended design practice usually limiting the tensile capacity in sandy soil to the draine...
Article
de Ein Anwendungsgebiet von Stabilisierungssäulen (STS) stellt die Baugrundverbesserung für großflächige, setzungsempfindliche Strukturen, wie (faser‐)bewehrte Bodenplatten von Logistikzentren und anderen Hallenkomplexen dar. Zur wirtschaftlichen Optimierung der Bodenplatte (Dicke und Bewehrung) wird häufig eine Lastverteilungsschicht (LVS) oberhal...
Article
Offshore wind turbines are considered as an integral part of renewable energy. Dense sand often characterises the sea bed and suction caisson foundations are increasingly used to support offshore wind turbines at North Sea sites. Significant experience with this technology exists in the oil and gas industry, although these platforms are typically l...
Conference Paper
Full-text available
Offshore wind is increasingly utilised as a renewable energy source. A growing number of bottom fixed wind turbines installed offshore are supported by suction caisson foundations. The suction-assisted installation remains a source of uncertainty towards the in-service performance due to the unknown post-installation soil plug state. Cone penetrati...
Article
Full-text available
Granular soils subjected to flow through their soil skeleton can show a behaviour in which fine particles migrate through the pore space between coarser particles. This process is called internal instability or suffusion. This contribution deals with the numerical analysis of the migration of fine particles in a soil column subjected to fluid flow...
Article
The use of field experience and empirical relations for the design of a vibro-compaction encourages the development of the understanding of vibratory compaction for granular material. Field measurements are difficult to conduct in homogeneous loose sands, and there is a lack of adequate control of the test conditions in the field. Hence, a model vi...
Article
Permeable pavements have been widely used as an effective means to improve hydrological characteristics and the ecology of the urban environment. This study aims to investigate the response of fully permeable pavement (FPP) subjected to dynamic loading under dry and saturated conditions. A full-scale test track topped with polyurethane bound permea...
Article
Spatial variations of soil properties occur even within nominally homogeneous soil layers. Therefore, to achieve a reliable geotechnical design, it is necessary to consider local variations of soil properties. Varying soil stiffness leads to spatially variable settlements, implying increasing dynamic forces on passing vehicles. Higher dynamic force...
Article
de Die lagegetreue Installation kombinierter Stahlspundwände ist weiterhin eine Herausforderung. Deformierte oder von ihrer geplanten Lage abweichende Tragbohlen können zu einem Systemversagen führen. Es gibt nur vereinzelt Empfehlungen, wie das Einbringgerät und die Rammführung passend zum Boden und der einzubringenden Tragbohle zu wählen ist. Zus...
Article
Permeable pavements represent an effective approach to optimize the conventional sealed pavement infrastructure. Compared to sealed pavement structures, the porous pavement structure allows fluids to pass through it freely, reducing and controlling runoff in the surrounding area. The stress state of this pavement system under different saturation c...
Conference Paper
Offshore wind turbines supported by suction caisson jackets transfer the loading to the foundation primarily through a vertical push-pull mechanism. This leads to the foundation performance under vertical cyclic loading being a critical design aspect. Recent research of suction caissons under cyclic vertical loading into tension in uniform soil pro...
Article
Full-text available
The development of debris flows and turbidity currents in the course of a submarine slope failure event can cause major damage in offshore infrastructure. Additionally, the tsunamogenic potential of large slope failures at continental margins poses a direct threat to coastal communities. Therefore, the trigger mechanisms of submarine slope failures...
Conference Paper
Use of High Speed Camera Videos to derive the movement of a king pile during its installation process.
Article
Submarine slope failures pose a direct threat to seafloor installations and coastal communities. Here, we evaluate the influence of free gas on the soil's shear strength and submarine slope failures in areas with gassy soils based on an extensive literature review. We identify two potential destabilization mechanisms: gas bubbles in the pore space...
Article
Full-text available
The static axial pile bearing capacity depends mainly on the developed pile–soil interaction. Hence, to determine a realistic and reliable ultimate pile bearing capacity, the pile–soil interaction needs to be identified and described precisely. One relevant field for this application is dynamic load tests (DLTs). During a DLT, the pile bearing capa...
Conference Paper
Full-text available
Die Computertomografie (CT) ist ein bildgebendes Verfahren, das für medizinische Anwendungen entwickelt wurde, aber inzwischen mehr und mehr in der materialwissenschaftlichen Forschung eingesetzt wird. Mithilfe der CT können zerstörungsfrei räumliche Momentaufnahmen von Materi-alproben gewonnen werden, wobei im Postprocessing mikroskopische Struktu...
Conference Paper
Full-text available
A numerical model is set up to simulate the densification of dry sand using the vibrocompaction method. This compaction method includes densification of loose sands by means of shear deformation processes imparted by horizontal vibrations of vibrator probe at the required soil depth. A cylindrical stay-tube and vibrator probe assembly are numerical...
Conference Paper
Full-text available
Gathering insights on materials at pore scale using digital imaging techniques, such as X-ray computed tomography (CT), gains more and more attention in various fields of engineering disciplines. The better understanding of material properties, internal structures, and material behaviour has generated many scientific and industrial advances. Invest...
Conference Paper
Full-text available
The installation of shallow foundation systems for offshore wind turbines like gravity foundations requires the excavation of the weak top soil of the seabed to place the structure on more stable ground. This excavation can be done through suction dredging resulting in a pit. Different slope angles of this pit can be realized using this technique....
Article
In the last years, X-ray computed tomography (CT) has been found to be a valuable tool to visualize and analyze structures in granular media from a microscopic point of view. With a sufficient resolution (voxel size) and a sequence of images over time, CT-images also allow to visualize processes in unsaturated soils, where microscopic features, suc...
Article
Constant urban and infrastructural growth leads to increased sealing of areas in municipal areas. This surface sealing results in distortions of the natural water cycle, which again can lead to noticeable changes in the natural ecosystem. To counteract the effects of surface sealing, innovative permeable road structures provide a promising environm...
Article
Floating offshore structures can be founded on submerged foundations such as anchor plates. Their extraction resistance is of major importance during and at the end of the lifetime cycle. During their lifetime cycle, the foundation is suspended to complex loading conditions due to waves, tidal currents and wind loads and its resistance has to be kn...
Article
de Im maschinellen Tunnelbau mit Schildvortrieben mit Erddruck‐ oder Flüssigkeitsstützung stellen die Verklebungen von Schneidrad und Abbaukammer sowie der Verschleiß der Schneidwerkzeuge nach wie vor ein Problem dar. Infolge Verklebungen kommt es trotz verschiedener Prognoseverfahren anhand der Plastizitäts‐ und Konsistenzzahl für weiche Böden noc...
Conference Paper
Full-text available
Granular soils subjected to a flow through their soil skeleton can show a behavior in which fine particles migrate through the pore space between coarser particles and hence changing the decomposition and the mechanical behavior of the soil skeleton. This process is called internal instability or suffusion and can occur in geotechnical structures s...
Conference Paper
Full-text available
This paper presents numerical models in Abaqus/CEL and MPM for dynamic compaction. Both methods are capable of treating large deformations and therefore combine the advantages of the Lagrangian and Eulerian approaches. Nevertheless there are significant differences in both methods. While in CEL the simulation is divided into Lagrangian and Eulerian...
Conference Paper
Full-text available
Dynamic compaction, pile installation, sub-surface explosions are examples of geotechnical applications for which it is important to capture the generation and propagation of dynamic waves in saturated soils. This paper presents a verification of the two-phase formulations implemented in Anura3D. A column of saturated material is instantly loaded a...
Chapter
Mit dem Begriff „Marine Gründungsstrukturen“ seien alle Gründungsstrukturen bezeichnet, die an der Küste, an Tideästuaren, im Hafen und im Meer errichtet werden. Es handelt sich beispielsweise um Gründungen für Ufereinfassungen, Seeschleusen, Kajen, Leuchttürme, Öl‐ und Gasplattformen, Versorgungsleitungen sowie Bauwerke zur Nutzung der regenerativ...
Conference Paper
Full-text available
The prediction of the bearing capacity of shallow foundations is subject to countless numerical simulations in geotechnical applications. It is widely known that the solution of this specific problem depends on the characteristics of the respective finite element mesh-especially in small deformation based calculations. Since large deformation metho...
Conference Paper
FOSTA Projekt Optimized design of combined steel sheet pile walls for the installation process and the final state (P 1327) Combined steel sheet pile walls built of H shaped king piles and Z-shaped intermediate piles are used to ensure the function of quay walls in seaports and are characterized by high slenderness The key question is the loading...
Article
Zusammenfassung Geomechatronik bezeichnet das Zusammenspiel von Geotechnik, Maschinenbau, Mess-, Steuerungs- und Regelungstechnik. Durch ein verbessertes Verständnis der Prozesse in der Geotechnik kann es gelingen, den Prozess und die Baumaschinen zu optimieren und den Herstellungsprozess durch Kennwerten zu charakterisieren. Diese Messwerte können...
Article
Static load tests (SLTs) are rarely performed on offshore piles, instead relying on dynamic load tests (DLTs). Evaluation techniques for DLTs were developed originally for solid piles, and caution is needed in applying the techniques directly to open-ended piles, particularly for the large-diameter monopiles used for offshore wind turbines. Centrif...
Conference Paper
Full-text available
Installation effect of encased sand columns on virgin soil and surrounding columns is an important field in geotechnical research domain. Numerical simulations of a step of the installation process of geosynthetic encased sand columns (GEC) in soft soils in the Coupled Eulerian Lagrangian (CEL) framework is performed. Installation of 400 mm diame...
Article
The material point method (MPM), which is a combination of the finite element and meshfree methods, suffers from significant computational workload due to the fine mesh required in spite of its advantages in simulating large deformations. This paper presents a parallel computing strategy for the MPM with multiple Graphics Processing Units (GPUs) to...
Article
A numerical model to predict the displacement of piles under cyclic lateral loading using a new type of spring element is demonstrated. The formulation of the numerical model is based on the subgrade reaction method and allows for modelling of a limited number of cycles. To accurately represent the soil behaviour, the spring elements are establishe...
Conference Paper
Full-text available
In general, the determination of soil hydraulic parameters given by drainage and imbibition paths in the water-retention curve is of major interest to predict hydraulic and mechanical responses of porous media. This study focuses on the estimation of drainage and imbibition paths of different water-permeable pavement materials based on an alternati...
Conference Paper
Full-text available
In this contribution an experimental method is presented which allows to investigate transient effects of cyclic drying and wetting paths on the soil-water characteristic curve (SWCC) of sandy soils. The idea of transient effects and a way for their experimental investigation may be new and an enhancement to the state of the art, in which mainly eq...
Article
If the bearing capacity of the soil is not sufficient an improvement method has to be considered. In case of soft and cohesive soils the vibroreplacement technique can be used. This paper describes the numerical simulation of a group of encased granular columns under an embankment based on a real life project situated to the north of Hamburg, Germa...
Conference Paper
Strengthening of just the shear bands is a patented idea to prevent the critical failure mechanism in order to increase the capacity of a geotechnical system with a minimum of material. 1g-model tests are used to examine the proposed method for limit load increase. Therefore the failure mechanisms and bearing loads of a geotechnical system without...
Conference Paper
Full-text available
The deep vibration compaction method includes densification of loose sands by means of shear deformation processes imparted by horizontal vibrations of vibrator probe. Model tests are conducted using a mini vibrator in order to study the physical processes the granular material undergoes during deep vibration compaction. Tests were performed in tes...