| Damages of earthquakes in the past indicated that post-earthquakes happened after main-earthquake. The post-earthquake can make the damage more serious, and sometimes, is the main cause of collapse of buildings. But in China, Code for seismic design of buildings and Code for earthquake disaster evaluation and its information management system, the main factor to be considered is only the single earthquake. The effects of damage, such as people death and economic loss, caused by post-earthquake have never been considered. It is important to study to what extent post-earthquakes could deteriorate the damage. The thesis is to study the damage-state of building under post-earthquakes by calculating when the damages were caused by main-earthquakes and without reparation.Firstly, in this thesis 'The Damage Assessment of Buildings' under earthquakes is introduced, studies of the damage of building under post-earthquakes in our nationwide are reviewed briefly, and the classifications of the damage index are summarized, the Park-index is chosen as the parameter that is accepted widely. Six structure models are selected from the project of damage assessment of building in Fujian province. To establish the relationships between damages of building and earthquakes, the damage indexes of building under earthquakes have been calculated in quantities, and according to the index values the damage states of the building are classified. The IDARC program has been used to analyses the elastic-plastic character of the structure under earthquakes.By calculating the damage indexes, the thesis studied damage-state of building under main-earthquakes and post-earthquakes as follows: studying the increasing of energy dissipation and damage index of the structure, comparing the damage difference of the building under different earthquake series such as: preceding-earthquake and main-earthquake series, main-earthquake and post-earthquake series, and also comparing the result of damage index between Park and Y models. Finally, a prediction model has be suggested statistically that can assess the damage state of the building under post-earthquake when there is some damages in buildings caused by main-earthquake. In the model, three factors have been included: the peak value of acceleration of main-earthquake and post-earthquake and the value of damage index of building under main-earthquake. |
