The pathology of active avalanche defense structures

Abstract

The safety brought up by supporting structures towards snow-avalanches has to remain total during all their life. An inquiry has shown that this was not always the case. A regular maintenance is therefore always indispensable. The main possible degradations are identified in their types (foundations, mechanics, physico - chemical) and their causes (internal or external, usual or unusual). It has been also necessary to formalize the different stages of a diagnosis process : the preparation, the evaluation and the classification of disorders, then the programming of maintenance. At last, financial aspects and the division of responsibilities of this maintenance also explain a large part of the failures observed. The role and the action of the user, of the owner, of the mayor and of the prefect are lightened. The will to prevent catastrophes must last long after the works are finished.