Forces on plunge pool slabs: Influence of joints location and width

The hydrodynamic pressures due to jets impinging on plunge pools must be taken into account in the stability design of pool floor concrete slabs. The contraction joints between slabs are normally sealed with waterstops, which prevent the transmission to the foundation of the pressures applied on the upper faces of the slabs. However, a waterstop failure will allow pressure transmission to the foundation, inducing uplift forces on the slabs. The use of open joints might also become a feasible solution for the lining of plunge pool floors if the pressure field that develops around each slab could be adequately evaluated. This paper presents an analytical model and experimental research developed to assess the forces on plunge pool slabs, considering either open or closed. The influence of the relative width of the contraction joints and the joint between the slabs and the foundation is analyzed. The mean value and standard deviation of the hydrodynamic vertical force are determined based on point pressure measurements, and their relative importance is discussed.