The structural integrity of water pipelines by considering the different loads

The objective of the study was to analyse the structural integrity of water pipelines. The analysis shows how large the discrepancies in structural integrity of water pipelines can be, depending on the method used to calculate loads acting on the pipes. Factors affecting changes in the size of loads of water pipelines were introduced based on the analysis of causes of several failures of water pipelines analysed by the authors and several field measurements performed by them. The article discusses the impact of different loads on strength changes in water pipelines. The two methods used in the case study differ in the assumptions concerning the determination of the size of loads acting on the pipes. The results of the case study indicate to what extent different loads influence the amount of stress in a pipeline. The discussion indicates that it is advisable to perform detailed studies of soil parameters around the pipes because they have a very significant impact on the dead loads and the selection of correct live loads. Depending on the assumptions made, the total stresses in the pipeline can vary up to several times. Therefore it is justified to consider, in failure models and life time prediction models of long operated water pipelines, the actual loads acting on the pipes taking into account changes of their quantity that occurred during their exploitation to-date.