Development and validation of predictive model to describe the growth of concrete water tank vulnerability with time

Abstract

IntroductionThe Algerian heritage of drinking water storage tank has almost 40,000 tanks and is mostly built of reinforced concrete. The average age of the national heritage of concrete tanks is about forty years. The feedback from nearly half a century of management has highlighted a great disparity in the behaviour of these structures, expressed by several pathologies [1]. The lack of maintenance of these tanks, directly exposed to natural threats (snow, earthquakes, winds), accelerates the ageing process. In consideration to this, in recent years, civil engineering activity is repositioning primarily in the life cycle of existing structures operation rather than in the design and construction of new structures. Therefore, we note a great interest in the scientific community to risk analysis. Many methods have been developed by several authors intended to structure managers in order to assess the structural performance, to make risk analysis or programming maintenance actions for hydraulic structures, harbour structures and buildings. We mainly cite the reliability approach, the approach using physical models and expertise approach.The reliability approach based on probabilistic analysis has its limitations when the data is in insufficient quantity and in poor quality. Probability calculations become quickly complicated or impossible and their validity becomes difficult to demonstrate. We are then in the presence of the concept of imprecise probabilities. The interested reader by further details can consult the reference [2]. This latter provides an overview on developments which involve imprecise probabilities for the solution of engineering problems. Evidence theory, probability bounds analysis with p-boxes, and fuzzy probabilities are discussed with emphasis on their key features and on their relationships to one another. In the case where the structure is badly known and where the available data are of poor quality, the deterministic method using physical models; which consists of a recalculation of the structure; is difficult to implement. So, the simplest way to assess the future development of damages is to examine the evolution laws of existing structures of same design that have similar mechanisms, based on the experience feedback. This method is known as the expert approach that will be discussed in this paper.

Seismic Vulnerability Analysis of Steel Clarification Tank

“…Ye et al [5] calculated the various susceptibility parameters of the tank to derive the damage curve to analyze the low failure probability values. Aliche et al [6] used the concept of natural hazard vulnerability based on the vulnerability index (I-V) assessment to predict the possible degradation and aging of the tank structure. Wei et al [7] analyzed the form of the relationship between seismic acceleration and the degree of damage to the storage tank by using probabilistic estimation.…”