To manage China’s growing demands of electricity, more and larger dams could be a part of the solution. It is important to evaluate and perform safety analysis for existing dams, in order to improve our understanding and knowledge about future dams. In this master thesis, a safety research of Longtan Dam on the Hongshui River in China was analysed. The main objectives in this research were to construct a 3D model and determine the critical points of large stress, strain and yield area in the dam for different cases.The factor of safety for sliding when primary loads were acting on the dam was calculated to be 0.50 for the non-overflow section of the dam and 0.48 for the overflow section. A safety factor against overturning was also calculated for the non-overflow and overflow section to 2.24 and 1.96 respectively. The results showed that the dam was safe from both sliding and overturning. The numerical results for distribution of stress, strain and yield area were simulated in 3D models by using ANSYS, a finite element program. Several cases for non-overflow and overflow sections of Longtan Dam were analysed for different heights and load combinations. For the first three cases where only self-weight was applied on the dam, high impacts of stress and strain were located at the dam heel, toe and at the largest maintenance tunnel of the dam. Appearance of plastic strain was also found around these areas. However, when primary loads were applied to the dam sections, the values of stress and strain became larger, especially in the toe area. In the last case when the dam was subjected to seismic activity, the distribution of stress and strain along the z-direction (along the dam) showed an uneven distribution, hence showing the importance of simulation in 3D.

The construction of Songlin rock-filled concrete gravity dam, located in the Yunnan province, China began in the end of 2015. In this master thesis the finite element method (FEM) based software Abaqus has been used to perform a computational analysis on tension stresses, compression stresses and sliding stability for static conditions. One overflow section and one non-overflow section of the dam have been analysed. The results of the analysis have been evaluated by comparing with Chinese standards for dam safety and is intended to help engineers with making decisions in the construction process of the dam. The measured compressive stress values of both the overflow and non-overflow section are not evaluated to be within safe levels, further evaluation is required to ensure the safety of the dam. The dam is considered to be safe from vertical tension in the analysed region, however an extended evaluation including the whole dam base is recommended. The analysed cross-sections for sliding stability can be considered safe, but further analysis is required to make a conclusion of the sliding stability of the full dam base.

Hydroelectric power is a commonly used alternative source of energy in developing countries. In this regard, concrete gravity dams are the most preferred dam type especially with the developments in the engineering industry. Roller compacted concrete became more popular in dam construction due to its advantages of speed and economy. Several methods are used for the design of concrete gravity dams by analyzing the dam response under static and dynamic loads. This study provides three dimensional linear dynamic analysis of roller compacted concrete gravity dam with a complete dam-foundation-water interaction by using EACD-3D-08 program. Foundation flexibility was included with damping and mass using boundary elements. Three dimensional solid elements were used for the idealization of the dam and water with using finite element methods. Compressibility of water with reservoir absorption was studied. In the light of USACE, performance criteria of linear analyses were assessed. Parametric study was conducted to determine the most influential parameters on the dam response. The importance and necessity of three dimensional analyses were investigated by comparing with linear two dimensional analyses. Linear analyses were then compared with three dimensional nonlinear analyses. In conclusion, the realistic dam seismic response can only be obtained by using three dimensional linear analyses with full interaction of dam-foundation-water.

The Diploma thesis deals with the assessment of global and local stability of the masonry gravity dam Pastviny, for two load conditions. The first part consists of a present state review describing selected masonry dams in the Czech Republic and abroad. Further on a conceptual and mathematical formulation of the seepage flow and strain-stress problem are stated. The case study is focused on the practical application of formulated problems on the Pastviny dam. Firstly the available data have been assembled and processed. Global and local safety of the dam was assessed for the selected most vulnerable profile of the dam body. In the final chapters 5, 6 and 7, the seepage flow, stress and strain have been calculated and graphically displayed. Finally global and local stability have been assessed and completed with final summary of the results and concluding remarks.