K.W. Pilarczyk

Bio: K.W. Pilarczyk is an academic researcher from Rijkswaterstaat. The author has contributed to research in topics: Revetment & Perspective (graphical). The author has an hindex of 5, co-authored 13 publications receiving 118 citations.

Design of low-crested (submerged) structures - an overview -

Abstract: Low crested and submerged structures (LCS) such as detached breakwaters and artificial reefs are becoming very common coastal protection measures (used alone or in combination with artificial sand nourishment). Their purpose is to reduce the hydraulic loading to a required level that maintains the dynamic equilibrium of the shoreline. To attain this goal, they are designed to allow the transmission of a certain amount of wave energy over the structure by overtopping and also some transmission through the porous structure (exposed breakwaters) or wave breaking and energy dissipation on shallow crest (submerged structures).

Design of revetments

Abstract: The use of revetments, such as riprap, blocks and block mats, various mattresses, and asphalt in civil engineering practice is very common. The granular filters, and more recently the geotextiles, are more or less standard components of the revetment structure (PIANC, 1987,1992). Within the scope of the research on the stability of open slope revetments, much knowledge has been developed about the stability of placed (pitched) stone revetments under wave load (CUR/TAW, 1995) and stability of rock under wave and current load (CUR/CIRIA, 1991, CUR/RWS, 1995). Until recently, no or unsatisfactory design tools were available for a number of other (open) types of revetment and for other stability aspects. This is why the design methodology for placed block revetments has recently been extended in applicability by means of a number of desk-studies for other (open) revetments: • interlock systems and block mats; • gabions; • concrete mattresses; • geosystems, such as sandbags and sand sausages; and other stability aspects, such as: flow-load stability, soil-mechanical stability and residual strength.

Wave forces and structure response of placed block revetments on inclined structures

Abstract: A summary of the theoretical and empirical knowledge of the stability of block-revetment structures under wave attack is given. This has been accomplished by selecting the very essence of the design formulas from (CUR/TAW, 1992/1994) and completing it afterwards with a database of results of large-scale model studies from all over the world. Furthermore, the additional filter criteria and geotechnical criteria will be presented. For each of these mechanisms easy to use design formulas are given. Finally, the specific design considerations related to block revetments will be discussed.

Hydraulic and coastal structures in international perspective

Abstract: The objective of this paper is to bring some international perspectives on the policy, design, construction, and monitoring aspects of Hydraulic and Coastal Structures in general, and whenever possible, to present some comparison (or reasons for differences) between the experiences of various countries and/or geographical regions. This chapter reviews the trends of our hydraulic/coastal engineering profession and presents an overview of miscellaneous aspects, which should be a part of the entire design process for civil engineering structures. This overview ranges from initial problem identification boundary condition definition and functional analysis, to design concept generation, selection, detailing an costing and includes an examination of the construction and maintenance considerations and quality assurance/quality control aspects. It also indicates the principles and methods, which support the design procedure making reference as appropriate to other parts of the chapter. It must be recognized that the design process is a complex iterative process and my be described in more than one way. Some speculation on the possible future needs and/or trends in hydraulic and coastal structures in the larger international perspective is also presented briefly.

Hard Structures for Coastal Protection, Towards Greener Designs

Abstract: Over recent years, many coastal engineering projects have employed the use of soft solutions as these are generally less environmentally damaging than hard solutions. However, in some cases, local conditions hinder the use of soft solutions, meaning that hard solutions have to be adopted or, sometimes, a combination of hard and soft measures is seen as optimal. This research reviews the use of hard coastal structures on the foreshore (groynes, breakwaters and jetties) and onshore (seawalls and dikes). The purpose, functioning and local conditions for which these structures are most suitable are outlined. A description is provided on the negative effects that these structures may have on morphological, hydrodynamic and ecological conditions. To reduce or mitigate these negative impacts, or to create new ecosystem services, the following nature-based adaptations are proposed and discussed: (1) applying soft solutions complementary to hard solutions, (2) mitigating morphological and hydrodynamic changes and (3) ecologically enhancing hard coastal structures. The selection and also the success of these potential adaptations are highly dependent on local conditions, such as hydrodynamic forcing, spatial requirements and socioeconomic factors. The overview provided in this paper aims to offer an interdisciplinary understanding, by giving general guidance on which type of solution is suitable for given characteristics, taking into consideration all aspects that are key for environmentally sensitive coastal designs. Overall, this study aims to provide guidance at the interdisciplinary design stage of nature-based coastal defence structures.

Risk-based design of large-scale flood defence systems

Abstract: On the basis of quantitative reliability analysis of flood defence systems, two design methods are developed. The first is reliability-based design, where the optimal geometry of a flood defence system is obtained by minimising the cost of construction under a constraint on the probability of flooding of the protected area. Reliability-based design is an integral part of the second design method, risk-based design. In risk-based design, the appropriate flooding probability of a protected area is obtained by comparing the cost of protection with the risk reduction that is obtained. A case study illustrates the application of both methods. INTRODUCTION The Netherlands is a low-lying country that depends on an extensive system of flood defences for its existence. Clear defined design requirements for the flood defence systems are necessary. Since 1956, the design requirements are given as prescribed exceedance frequencies of the water level in front of the structure (Delta Committee, 1961). At the time, this approach revolutionised the design and safety evaluation of flood defences in the Netherlands. With the statistical analysis of observed water levels, elements of probabilistic methods entered hydraulic engineering in the Netherlands for the first time. Since the Delta Committee, probabilistic methods have been further developed. The fundamentals were developed by Turkstra (1962). Today, a number of tools for reliabilitybased design are now available to the hydraulic engineer (see Oumeraci et al, 2001 for an overview). As a result of the development of probabilistic methods, it is now recognised that: 1 Risk analysis specialist, ARCADIS, Postbus 220, 3800 AE, Amersfoort, The Netherlands, H.G.Voortman@arcadis.nl 2 Assistant professor of probabilistic design, Delft University of Technology, Faculty of Civil Engineering and Geosciences, Stevinweg 1, NL-2628 CN, Delft, The Netherlands, P.H.A.J.M.vanGelder@ct.tudelft.nl 3 Professor of hydraulic structures and probabilistic design, Delft University of Technology, Faculty of Civil Engineering and Geosciences, Stevinweg 1, NL-2628 CN, Delft, The Netherlands, J.K.Vrijling@ct.tudelft.nl