Effekter på befintlig fyllningsdamm vid dammsäkerhetshöjande anläggningsarbeten : Analyser med finita elementprogrammet PLAXIS

This Master’s thesis comprehends simulations of planned dam safety measures of a hydropower dam in Sweden with the aim to show effects the work will exert on the dam. The simulations have been carried out in the finite element programme PLAXIS 2D, where three different sections have been analysed concerning deformations and stability. The planned measures include excavations and new berms, according to the following list:•Section A: A new drainage trench is to be constructed, since the existing drainage system is deemed as not functioning based upon observations of increased pore water pressures at the downstream side of the dam. •Section B: In this section a new toe berm is planned, since the dam should be able to divert leakages according to design requirements. •Section C: A new toe berm is planned for this section. Due to space limitations a retaining wall is to be constructed. Before the retaining wall is constructed, an excavation is to take place at the toe berm. Effects of the excavation on the dam body are assessed. The simulations have resulted in deformations of acceptable magnitudes and factors of safety that indicate stable conditions for the planned dam safety measures. Though, it is not concluded that the factors of safety represent conditions of sufficient safety. Conclusively, this is up to the dam owner to decide. Monitoring of the deformations can be performed during the construction work, in order to reassure that the magnitudes are within reasonable limits, which can be done by utilising the results from the finite element simulations to determine alarm values. Additional verification computations have been performed in order to achieve a higher reliability of the numerical simulations.Validerat; 20151022 (global_studentproject_submitter