Physical modelling of submerged groynes

Currently multiple projects investigate the effect of lowering the crest of groynes in the Dutch rivers with the aim to lower the backwater effect of groynes under high water levels. There is a major uncertainty however in the modelling of groynes, and therefore in the prediction of the effect of groyne lowering. Currently submerged groynes are...

Physical modelling of a sheetpile-vegetation system

A study carried out to understand the effects on including vegetation as an additional reinforcement to improve streambank stability.

Modeling the physics of RRAM defects: A model simulating RRAM defects on a macroscopic physical level

Resistive RAM, or RRAM, is one of the emerging non-volatile memory (NVM) technologies, which could be used in the near future to fill the gap in the memory hierarchy between dynamic RAM (DRAM) and Flash, or even completely replace Flash. RRAM operates faster than Flash, but is still non-volatile, which enables it to be used in a dense 3D NVM...

Wave overtopping and scale effects: Experimental case study New Afsluitdijk

After more than 85 years, the iconic Afsluitdijk is in need of a reinforcement. During the latest safety assessment of Rijkswaterstaat the dike did not meet the standards at two components; the amount of wave overtopping (>10 l/m/s) and armour stability. This research goes into detail about the overtopping on the Afsluitdijk. In the new...

Continuous-time System Identification: A Bilinear Optimization Approach

In the noiseless case, the identification of a grey-box model can be posed as a feasibility problem, i.e. determining if existent - and if so - finding a parameter vector such that the parametric model equals the actual model (or its associated input-output data). Being that in this thesis we are interested in continuous-time grey-box...

Numerical & experimental investigation on the effect of scour formation and protection on the monopiles behavior

Offshore wind farms are rapidly developing in Western Europe as an alternative means of clean energy. The foundation of wind-turbines in the shallow water of the Northern Sea is almost exclusively (over 87%) performed by short rigid monopiles, as an efficient and relatively cheap solution. Scour formation, meaning the soil removal around the...

Effect of irregularities in the under layer on the stability of Xbloc^Plus concrete armour unit

The Xbloc^Plus is a new type of single layer armour unit for breakwaters. The key difference between earlier single layer armour units is that the unit is not only placed in a regular grid, but also with a regular orientation. The main benefit of this is that it can directly be seen whether the unit is placed correctly. Additionally,...

Physical modelling of reflection on gentle coasts: Comparing methods to analyse long waves and optimising the lay-out for a wave absorber to minimise reflection in a wave flume

Studying mangroves in the field can be very difficult; therefore it is in some situations better to model in a flume. The question is, to what extend are the situation in the field and the situation in the flume comparable with each other? This study focusses on reflection in the wave flume. Wave energy in a flume can be damped by placing a wave...

Physical modelling of pore pressure development during impact pile driving using geo centrifuge

During the last decade, the focus of offshore activities have shifted from oil and gas production to offshore wind farm creation to reach the clean energy targets set by different nations. Foundation requirements for offshore structures have shifted because of this. The monolithic nature of windmills allows the use of a single open-ended steel...

Damage assessment of coastal structures in climate change adaptation

Coastal areas around the world have attracted settlements and human activities since the early stages of the history until nowadays. This has introduced continuous modifications to the natural characteristics of these coastal regions by means of coastal structures and engineering interventions. The design of such coastal structures has evolved...

Wave impacts on storm walls, a study on scale effects

Low-lying countries such as Belgium and the Netherlands are naturally susceptible to overtopping wave attacks. Coastal regions are therefore facing the threat of such events causing damage to dike-positioned structures and buildings. Research in this filed is often conducted using scaled-down 2D hydraulic physical models, which introduces so...

Shear strength of saturated sand-steel interfaces: Geotechnical issues found at landfall operations

Landfall operations are conducted for connecting an offshore pipeline with process facilities on the shore. During a landfall operation an offshore pipeline is pulled by means of a steel wire rope on the shore with a velocity of 7 cm/s. During this process the steel wire rope interacts with the soil located on the seabed and on the shore....

Influence of multiple thin soft layers on the cone resistance in intermediate soils

In this thesis research is presented on the influence of multiple thin soft layers on the cone resistance and an attempt has been made to develop a correction factor from numerical and physical models. The presence of thin layers causes difficulties with determination of the liquefaction potential of sand deposits containing thin clay layers...

Effectiveness of a multipurpose artificial underwater structure as a coral reef canopy: Hydrodynamic and ecological connectivity

The following research focuses on artificial underwater structures (a.k.a. artificial reefs) in a coral reef environment to mitigate the natural and anthropogenic pressures which reef systems are increasingly facing worldwide. The research question is stated as: “Establishing a method to determine if a multipurpose artificial underwater...

Experimental research on spatial distribution of overtopping

The overtopping empirical formulas calculate the discharge only at the top of the crest of a coastal protection structure. On the other hand, the tolerable overtopping discharges are defined at certain points behind the crest where the total overtopping is reduced. The scope of this thesis is to find an empirical formula to describe the...