Seismic risk mapping for Germany

International audienceThe aim of this study is to assess and map the seismic risk for Germany, restricted to the expected losses of damage to residential buildings. There are several earthquake prone regions in the country which have produced Mw magnitudes above 6 and up to 6.7 corresponding to observed ground shaking intensity up to VIII?IX (EMS-98). Combined with the fact that some of the earthquake prone areas are densely populated and highly industrialized and where therefore the hazard coincides with high concentration of exposed assets, the damaging implications from earthquakes must be taken seriously. In this study a methodology is presented and pursued to calculate the seismic risk from (1) intensity based probabilistic seismic hazard, (2) vulnerability composition models, which are based on the distribution of residential buildings of various structural types in representative communities and (3) the distribution of assets in terms of replacement costs for residential buildings. The estimates of the risk are treated as primary economic losses due to structural damage to residential buildings. The obtained results are presented as maps of the damage and risk distributions. For a probability level of 90% non-exceedence in 50 years (corresponding to a mean return period of 475 years) the mean damage ratio is up to 20% and the risk up to hundreds of millions of euro in the most endangered communities. The developed models have been calibrated with observed data from several damaging earthquakes in Germany and the nearby area in the past 30 years

Fluessigkeitsgefuellte Stahlbetonbehaelter unter Erdbebeneinwirkung

Available from TIB Hannover: RO 6928(9) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Influence of reservoir and foundation on the nonlinear dynamic response of concrete gravity dam

The dynamic analysis of a concrete gravity dam is a reasonably complex problem. The response of a dam subjected to dynamic loading is a combined effect of the interaction among dam, reservoir and foundation systems. The profile of the Koyna dam has been adopted for the study of this investigation. Nonlinear concrete properties have been taken into account through concrete damaged plasticity model to simulate the damage induced in the dam body under a real-time earthquake motion. The study indicates that tensile damage of the dam structure occurred during the earthquake motion. Parametric studies, while varying the height of the reservoir and the foundation modulus values, have been conducted to show the influence of reservoir and foundation material on the dynamic response of concrete gravity dams

Influence of site and source dependent ground motion scenarios on the seismic safety of long-span bridges in Cologne, Germany

An overlap in frequency between the 1D resonance frequency of sediments and the vibrational frequencies of long-span bridges might lead to a strongly increased structural response of the latter. Interference of surface waves caused by reflections at dipping interfaces may introduce additional unfavourable amplifications. Therefore, the vulnerability of two bridges crossing the Rhine River in Cologne, Germany, was assessed using ground motion scenarios computed for four profiles crossing the Lower Rhine Embayment. Due to their vibrational frequencies being in the vicinity of resonant peaks in the response spectra, the Severinsbridge showed critical loading and the bridge Cologne-Deutz even exhibited grave failure according to the dynamic FE-simulations