Commercial graphites are used for a wide range of applications. For example, Gilsocarbon graphite is used within the reactor core of advanced gas-cooled reactors (AGRs, UK) as a moderator. In service, the mechanical properties of the graphite are changed as a result of neutron irradiation induced defects and porosity arising from radiolytic oxidation. In this paper, we discuss measurements undertaken of mechanical properties at the micro-length-scale for virgin and irradiated graphite. These data provide the necessary inputs to an experimentally-informed model that predicts the deformation and fracture properties of Gilsocarbon graphite at the centimetre length-scale, which is commensurate with laboratory test specimen data. The model predictions provide an improved understanding of how the mechanical properties and fracture characteristics of this type of graphite change as a result of exposure to the reactor service environment.

Rubble mound coastal structures typically contain granular filters in one or more layers. These filters are normally geometrically tight (to prevent material washout), often difficult to realize in the field, and expensive. An alternative is a geometrically open filter. A geometrically open filter has a large ratio of the size of toplayer material and underlayer material and is designed in such a way that it fulfills its filter functions with only minimal base material loss or settlement. Potential applications of open filters include bed protections and toe & slope configurations of coastal structures. Proper guidelines on the design of open filters under wave loading could lead to significant cost and material savings, and to a more practical application of filters in the field. Physical model tests were conducted in a wave flume. These tests focussed on granular open filters on a 1:7 sand slope under wave loading. The analysis of the tests has led to guidelines on the amount of erosion of the sand underneath a granular filter and of the sand accretion within a granular filter.

The stability of rock slopes with a horizontal berm has been studied by means of physical model tests. This paper is focussed on the rock slope stability of the slopes above and below the berm. By applying a berm the rock size can be reduced compared to the required rock size for a straight slope without a berm. This reduction can be significant for the slope above the berm. The influence of the slope angle (1:2 and 1:4), the width of the berm, the level of the berm, and the wave steepness have been investigated. Based on the test results prediction formulae have been derived to quantify the required rock size for rubble mound breakwaters with a berm.

The stability of rock slopes subject to breaking waves over a shallow foreshore is addressed in this paper. Physical model tests have been conducted on a 1:100 foreshore slope with a wide range of wave conditions including single and double peaked spectra and severely breaking wave conditions. The measured damage levels are compared to the Van der Meer design formulae, which were developed for conditions with no breaking on the foreshore. It has been found that the results of the design formulae are sensitive to the choice of input parameters (H1/3 or Hm0 and Tm or Tm-1,0) and that the inclusion of the reduction factor for breaking waves (H2%/Hs) in the design formulae should be applied only with caution, depending on the choice of input parameters. These results apply for the conditions tested and should be verified for other foreshore configurations before a definite recommendation pertaining to the use of the Van der Meer formulae for shallow foreshores can be given.