Introduction to Seismic Essentials in Groningen Lateral Load - PowerPoint PPT Presentation

Introduction to Seismic Essentials in Groningen

Lateral Load Resisting 5.3 System Design – Part 2 By Prof Joop Paul MSc PhD – TU Delft / Arup

Seismic Design Principles 1. Use ductile materials 2. Connect all the building elements 3. Minimize mass and mass/strength ratio 4. Minimize eccentricities and plan irregularities 5. Minimize discontinuities and vertical irregularities 6. Ensure energy absorption by designing for ductile failure mechanisms 7. Design multiple lateral load paths

Use ductile materials Brittle materials Ductile materials Member size bigger smaller Failure mode sudden not sudden Energy absorption limited significant Example masonry steel

Connecting all building elements Friction connections Positive connections Design connections member connection Sliding off possible No separation possible Connection is stronger • • • than incoming members

Minimize mass and optimize vertical mass distribution water storage separation walls roofs facade floors storage

Minimize mass Optimize strength/mass ratio Strength/mass ratio Steel Timber Concrete Masonry

Minimize eccentricities Centre of mass

Minimize eccentricities Centre of resistance

Minimize eccentricities Torsional shaking shaking in x-direction shaking in y-direction y y CoR CoR e y x x CoM CoM F x F y e x Torsional moment =

Minimize eccentricities Designing for torsion not good ok better

Minimize plan irregularities CoM CoR

Minimize discontinuities Discontinuity in stiffness h h h h h h not good ok

Minimize discontinuities Discontinuity in mass and stiffness h h h h h h 1,5h h h not good not good ok

Minimize discontinuities Discontinuity in mass and stiffness not good not good ok

Minimize discontinuities Podium buildings pinned on separation of tower flexible tower and columns podium podium not good ok ok

Ensure energy absorption Predictable ductile failure mechanisms mechanism 1 mechanism 2 mechanism 3 weak beam strong column affected = affected = not affected = not good not good good

Ensure energy absorption Design of “plastic” fuses excentric portal braced frame braced frame F F local bending local axial local bending + deformation deformation shear deformation

Ensure energy absorption Design of “plastic” fuses excentric portal braced frame braced frame detail detail detail F F moment capacity axial capacity shear capacity

Design multiple lateral load paths not redundant redundant more redundant = not good = good = better

Design multiple lateral load paths not redundant redundant more redundant = not good = good = better

Seismic Design Principles 1. Use ductile materials 2. Connect all the building elements 3. Minimize mass and mass/strength ratio 4. Minimize eccentricities and plan irregularities 5. Minimize discontinuities and vertical irregularities 6. Ensure energy absorption by designing for ductile failure mechanisms 7. Design multiple lateral load paths

Thank you for your attention!

References and further reading 5.3 Charleson, A. (2008). Seismic Design for Architects - outwitting the quake. Published by Routledge – Architectural Press.