Hazards for and their Impact on Urban Areas

Transcription

1 Hazards for and their Impact on Urban Areas Ingo Müllers Anne Kleemann Thursday, 7 April 2016

2 Risk analyses Objective: Description or calculation of risks Basis for further decisions Descriptive Wind Snow Earthquake Car impact Explosion Plane Impact B&C attack Fire arms Tragwerk Infrastruktureinrichtung Gebäudefassade Gebäudeeinrichtung (Möbel, EDV, Ausbauelemente usw.) Server Haustechnik (Heizung, Elektrotechnik, Telefon, Internet usw.) (Semi-) Quantitative Gefährdungsszenario Bewertung Überschwemmung Brand einer Erdbeben Sturm / Hagelsturm Blitzschlag Extremer Schneefall infolge Starkregen Büroetage Schutzgutwert Gefährdungswert Verwundbarkeitswert Relatives Risiko Schutzgutwert Gefährdungswert Verwundbarkeitswert Relatives Risiko Schutzgutwert Gefährdungswert Verwundbarkeitswert Relatives Risiko Schutzgutwert Gefährdungswert Verwundbarkeitswert Relatives Risiko Schutzgutwert Gefährdungswert Verwundbarkeitswert Relatives Risiko Slide 2

3 European Seismic Hazard Map Source: EU Project SHARE Slide 3

4 Response Spectra Analysis Basic idea: It exists a group of eigenmodes which is dominant and other eigenmodes can be neglected. 1 st step: Calculation of eigenmodes 2 nd step: Choice of the dominant eigenmodes 1 st Eigenmode, T 1 = 3.3 sec 2 nd Eigenmode, T 2 = 2.9 sec 5 th Eigenmode, T 5 = 0.54 sec 6 th Eigenmode, T 6 = 0.49 sec Slide 4

5 Response Spectra Analysis 3 rd step: Calculation of the reactions due to certain eigenmodes 4 th step: Superposition of reactions of different eigenmodes Slide 5

6 Push-over analysis Displacement-based nonlinear static calculation method Pushover-curves describe the correlation between the displacement of the top floor and the horizontal base shear force Slide 6

7 Push-over analysis Final evaluation by spectral acceleration spectral displacement diagram Slide 7

8 Comparison of both methods Example asymmetric wall structure Response spectra: a g = 3.0 m/s² Push-over: a g = 4.8 m/s² Slide 8

9 Explosion Process of an explosion: Much energy abruptly gets free Explosion results in a blast wave (shock front) Blast wave consists of a positive and a negative pressure Slide 9

10 Far field vs. close field detonation Differentiation through distance and mode of failure: Scaled distance Z: Z = R 3 W Close field range: Z 0.5 Far field range: Z > 0.5 Far field detonation: Global failure Big distance - bending failure peak pressure: MPa Close field detonation: Local failure Short distance punching failure peak pressure: MPa (hurricane = 0.001MPa) Slide 10

11 Design concept far field detonation Software developed in house by EMI: Blast properties vs. blast resistance of structural members SDOF model builds the basis to derive an iso-damage curve in a pressure-impulse diagram Two areas in this curve (above: damaged, below: undamaged) m E u r( u) p( t) Generated iso-damage curve for a structural member Slide 11

12 Design concept close field detonation Hydrocodes Fraunhofer EMI Necessary for the simulation of scenarios like: o Blast, impact or crash o High-dynamic processes with extreme distortions o Consideration of high-dynamic material behavior (strain rate effects) Based on conservation equation for mass (M), impulse (I) and energy (E) Explicit time integration as solution method Slide 12

13 ELASSTIC design Case bomb in the lobby Case bomb in the hotel lobby of Ribbon 1 Slide 13

14 ELASSTIC design Case Bomb in the lobby Bomb is placed between two columns (1.0 x 1.0 m) Significant damage at the bottom of column A and the ceilings Concrete is destroyed and the reinforcement gets exposed Collapse of the column is expected, but no progressive collapse Slide 14

15 Conclusion Try to anticipate all possible hazards Use risk analyses to focus on the main hazards Think of earthquakes as an important hazard in Europe Apply different methods to design new or existing buildings for earthquakes Think of possible explosion scenarios and use expert knowledge to design your structure for explosions Slide 15

16 Coordination: Project Team: End of presentation This project has received funding from the European Union s Seventh Framework Programme for research, technological development and demonstration under grant agreement no This project has received funding from the European Union s Seventh Framework Programme for research, technological development and demonstration under grant agreement no