Slide Failure Research Articles

Influence of Storm Surge on Sliding Failure Probability of Breakwater Caisson

The sliding failure probability of breakwater caisson during 50 years is computed by reliability designmethod with the assumption that the occurrence probability distribution of the extreme values ofstorm surge fits the Weibull distribution. The storm surge increases the sliding failure probability ofbreakwater caisson in surf zone, because the raise of the water level reduces the caisson weight inwater and increases the breaking wave height. On the other hand, the storm surge has little influenceon the sliding failure probability of breakwater caisson in deep water, because the caisson height islarge compared with the variation of tidal level.

The Vajont slide: Instrumentation— Past experience and the modern approach

The Vajont slide case history is reviewed from the instrumentation point of view. In the first part, the situation before the major slide of October 9, 1963 is presented, in relation to the studies made and measures adopted to control the rate of movement. The measurements which were made are then discussed with respect to the slide and the theories that were developed at the time on the failure mechanism. In the second part, the Vajont slide is considered from the modern geotechnical point of view. If engineers had had the benefit in 1960 of the knowledge we have now, over twenty five years later, what kind of instruments would they have installed and what measurements would they have made? The answers to these questions are discussed with reference to the possible prediction of the slide failure and the choice of a strategy to control the rate of failure. Some aspects of the questions raised in the geotechnical community by the Vajont slope are still unresolved today, and require further research before we can safely predict the behaviour of a slide in a condition of incipient failure when, for reasons still not fully understood, the safety factor drops far below one.