Seismic response of hunchbacked block type gravity quay walls

Earthquakes near major cities may cause big social and economic impacts. Damages to port facilities may cripple the economy. The past twenty years' experience has proven the high vulnerability of the port facilities. This fact, along with the economic importance of port structures, indicates the need for better seismic design approaches for berth structures and cargo handling facilities. In the recent decades, there have been many incidences of failure of gravity type quay walls. These failures have stimulated research interest in the development of performance-based design methods. In this paper, two different hunchbacked block type quay walls with different back face shape were studied. A series of 1-g shaking tank tests was performed using a 1/10 scaled block type quay wall with gravel backfill materials on firm non-liquefiable sea bed conditions subjected to different harmonic loads. The shaking tank tests provided insight into the wall displacements and the total dynamic pressures by analyzing pressure components at the contact surface between the saturated gravel backfill soil and the wall. It is concluded that the back-face shape of the walls is an important factor and the larger positive slope of the wall improves the overall seismic stability

Stability of high density cube armoured breakwaters

The performance of high-density cubes in the armor layer of a breakwater was investigated through an experimental study. For this purpose, two different cross-sections, one with a conventional cross-section and one with a berm, were modelled in a wave flume. A total of ten tests were performed for both cross-sections. Different concrete densities of cubes and different placement methods were applied. The dimensions of the cubes with two different densities were the same for all tests to avoid potential scale effects caused by the dimensions of HD cubes. The experimental study showed that HD cubes were more stable than ND cubes; the characteristic wave height for HD cubes was 1.5 times higher than that of the ND cubes. The use of HD cubes may provide economic efficiency and enables a significant reduction of the concrete volume, transportation of material, and reduction of required construction area for manufacturing, etc. HD cubes in a single layer turned out to be very stable. However, only using HD cubes in a part of the armor layer or only used on the second (upper) layer caused a decrease in the stability of the armor layer, especially in comparison to the armor layers that fully consist of HD cubes. The performance of HD cubes was also evaluated by comparing the experimental results with the Van der Meer (1988) formula and the suitability of the stability number for HD cubes was discussed.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Coastal Engineerin