Structural Earthquake Response Analysis

Doktorsavhandling, 2007

Abstract Earthquakes are one of the most dangerous natural phenomena causing damage to buildings and other structures as well as injury and death of people. These destructive processes can never be prevented to happen, but their impact on the structures can be minimized. Structures with improved earthquake resistance can be designed using optimization techniques together with realistic modelling of the structure, the soil-structure interaction and the earthquake excitation. The present research work consists of structural earthquake response analysis and design using developed tools based on the finite element method together with global and local optimization techniques and stochastic simulation methods. The developed tools have been tested on different types of 3D structures subjected to earthquake excitation. The objective has been to reduce vibrations either for the whole structure or for a selected part, such as a vibration-sensitive room. Optimized design variables are: structural dimensions and soil-structure interaction parameters (Paper A), optimal numbers, locations and parameters of viscoelastic passive dampers (Paper B), optimal parameters and location of viscoelastic passive dampers between adjacent structures (Paper D). Further, since earthquake excitations have random properties, stochastic linear and nonlinear response of a large structure (Paper C) has been evaluated using finite element and stochastic simulation methods (Paper E). The results of this thesis indicate that structures subjected to earthquakes can be efficiently designed against earthquakes by integration of finite element, optimization and stochastic simulation methods.