Effect of obliqueness, short-crested waves and directional spreading, report on additional tests

Based on a database of laboratory data on wave overtopping (around 10,000 tests) a neural network technique is used for producing a generic prediction method. In the first database (around 7,000 tests) the following white spots were detected where additional tests could improve the generic prediction method. This report deals with the laboratory...

Reshaping breakwater tests, additional tests

Tests have been performed with low steepness and reshaping breakwaters at Ghent University and Aalborg University respectively. The reshaping breakwater is a type of breakwater where the information on overtopping is very limited. The additional tests are described in the following four reports: .. D24 – Part A: Effect of obliqueness, short...

Berm breakwaters: Hydraulic response of roundheads and trunks exposed to oblique waves

As a part of the MAST II Berm Breakwater Structures, existing data from conducted laboratory tests have been reanalised. The objective was to evaluate the effect of the longshore transpsort on both the roundhead and trunk, the ht.u,er exposed to both head-on waves and oblique inegular waves varying from 15 to 30 degrees angle of incidence. 3...

Delos final report

Summary of all results of the Delos (Environmental design of low crested structures) project. Objectives of Delos were (1) to provide an inventory of Low Crested Structures (LCS), (2) analyse LCS hydrodynamic an stability and their effects on morphology (3) investigate impacts of LCS (4) develop methodology for Integrated Coastal Zone Management...

Quantification of measurement errors, model and scale effects related to overtopping

CLASH is concentrating on investigations of wave overtopping for different structures in prototype and in laboratory. The model investigations have focussed on wave overtopping and the comparison of overtopping results from small-scale model tests and prototype measurements. Possible differences in the results from small-scale tests and...

Berm breakwater structures: Final report: Research summary

A research project on berm breakwater structures was carried out with the overall objective of arriving at a better design basis. Eight European organisations from Denmark, The Netherlands, United Kingdom, Norway, Italy and Iceland participated in the joint research project co-sponsored by the European Commission under the second research and...

2-D model test of Dolosse Breakwater

The rational design diagram for Dolos armour should incorporate both the hydraulic stability and the structural integrity. The previous tests performed by Aalborg University made available such design diagram for the trunk of Dolos breakwater without superstructures (Burcharth et al 1992). To extend the design diagram to cover Dolos breakwaters...

Rubble mound breakwater failure modes

The RMBFM-Project (Rubble Mound Breakwater Failure Modes) is sponsored by the Directorate General XII of the Commission of the European Communities under the Contract MAS-CT92- 0042, with the objective of contributing to the development of rational methods for the design of rubble mound breakwaters. 11 institutes from the European Union...

Design of rubble mound breakwaters

This rapport includes two main topics for designing a rubble mound breakwater: 1. Geometrical properties and durability of rock materials 2. Structural integrity of concrete armour units Included in this rapport are some design diagrams for Dolos of different waist ratios.

Reliability evaluation of a structure at sea

In general a safety factor or a conventional partial coefficient is used for the design of structures at sea. These methods are classified as Level I (deterministic) methods. However, such approaches do not allow the determination of the reliability (or the failure probability) of the design, and consequently it is neither possible to optimize,...

Design formula for tetrapod breakage

The paper presents a design formula for Tetrapod armour on a 1:1.5 slope exposed to head-on random wave attack The formula predicts the relative number of broken Tetrapods as function of: the mass of the Tetrapods, the concrete tensile strength and the wave height in front of the structure. Thus, the formula addresses the observed problem of...

Wave basin experiment Delos

Low-Crested stmctures (LCS's) are typically built in shallow water as detached breakwaters for coastal protection purposes. The structures are usually parallel to the shoreline with wave attack almost perpendicular to the structure. However under special enviromnental conditions more oblique waves can occur. Groin systems or breakwaters for...

On the stability of berm breakwaters roundheads and trunk erosion of oblique waves

The stability of a berm type breakwater (sacrificial breakwater) was tested in a 3-dimensional model at rhe Hydraulics Laboratory, Department of civil Engineering, university of Aalborg. The object was to study the stability/erosion of the breakwater head and the trunk, the latter exposed to both head-on and oblique irregular waves. To avoid too...

The Application of load-cell technique in the study of armour unit responses to impact loads

The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an inbalance between the strength (structural integrity) of the units and the hydraulic stability (resistance...