FIRST STEP TO THE STUDY OF THE RELATIONSHIP BETWEEN SEISMIC RISK, HAZARD AND VULNERABILITY FOR THE BELGIAN BUILT ENVIRONMENT: CASE STUDY IN ATH (HAINAUT, BELGIUM)

摘要

For some years, many efforts have been made in Belgium to manage natural hazards such as karsts, flooding, etc. This information is important because they are an instrument for urban planning and preservation of cultural heritage. But some regions in Belgium are also characterized by a moderate seismic hazard (a ≥ 0.1 g for a return period of 475 years), which requires the study of its influence on built environment. Seismic risk is defined as the convolution of seismic hazard and vulnerability. Seismic hazard is a measure of the probability of earthquakes occurrence. It is determined by the historical and recent seismic activity, including the influence of the local geology. Besides, seismic vulnerability is a measure of the level of earthquakes effects on buildings and people. It includes the concepts of damages and costs. Statistical methods enable a rapid diagnosis of the vulnerability of buildings at the scale of a part of city. Such approach is based on damage inventories during past earthquakes. By combining the ground motion at local scale and the vulnerability of buildings, it is then possible to evaluate the damage rate. Our study aims first to analyze the existing relationship between ground acceleration, vulnerability of buildings and damages, then to determine a relationship according to Belgian data. A comparison between different relationships can also be dawned.