Failure analysis and remedial measures applied to a RC water tank

This paper presents an analysis of the failure of a 150,000 m3 reinforced concrete drinking-water tank built on a hillside. The facility, close to a town of 63,000 inhabitants, was taken out of service soon after being filled for the first time after excessive movement was detected in its retaining walls, which threatened collapse. After several field visits to assess the damage “in situ”, a diagnosis was made which permitted the causes of the failure to be established. These included an analysis of the stability of the retaining walls by the finite element method considering both the whole soil-structure system and the construction process. The paper also describes the solution chosen to stabilize the tank, the tests carried out on the full tank to check the effectiveness of the solution and the lessons that have been learned from the experience.