Abstract
Abstract
Two concrete cooling towers were designed and built during the British Mandate in Haifa Bay in late 1930s. The towers were in constant use as part of an industrial power plant for approximately 78 years, until decommissioning in 2016. In May 2020, a large hole appeared in the upper part of one of the cooling towers, and approximately two weeks later, the entire upper part of the tower suddenly failed while collapsing and buckling. This paper investigates the possible causes of the structural failure in the tower, general design criteria for cooling towers, and era-specific design codes and material properties from the years the towers were constructed. A detailed nonlinear Finite Element Analysis was performed on the towers in its various structural stages: as built and then with the large hole. Various design loads including seismic loads and combinations were applied on the tower models to investigate the tower response using modern design techniques that were not available at the time of the tower’s design and construction. Stresses in reinforced concrete were compared to limit values for compression and tension, and conclusions about excessive tension forces in the shell structures were revealed. Advanced concrete spalling and oxidization of steel rebar is clearly visible and is suggested as the initial cause of tower degeneration.