Seismic IDA and Fragility Curves
Budget: ₹600 – ₹1,500 INR
I need a full workflow carried out for a high-rise reinforced-concrete building located in Seismic Zone V of Assam. The core of the assignment is an Incremental Dynamic Analysis (IDA) in which ground-motion selection is handled with great care—records must be spectrum-compatible for the local soil class and scaled through collapse.
The numerical model must capture soil–structure interaction and all three layers of non-linear fidelity I specify: material nonlinearity (Mander or Kent–Park concrete, steel B–H curves), geometric nonlinearity (P-Δ, large-displacement effects) and a detailed element mesh that resolves plastic hinge formation in beams, columns and shear walls. Any platform is acceptable—ETABS + PERFORM-3D, OpenSees, SAP2000 nonlinear, or Abaqus—so long as the results can be cross-checked and exported.
From the IDA, generate fragility curves at Immediate Occupancy, Life Safety and Collapse Prevention, then translate those into a fragility-based vulnerability assessment for the entire Zone V region. The final document must end with clear design recommendations indicating how drift limits, ductility detailing and foundation options change the probability of exceedance.
Deliverables
• Calibrated 3-D nonlinear model (input and runnable file)
• Set of selected and scaled ground motions with justification sheet
• IDA plots and tabulated Sa-Δmax data
• Fragility curves for IO, LS, CP (PDF + Excel)
• Written report summarising methodology, vulnerability metrics and design recommendations
Acceptance will be based on:
1. Matching target spectrum within ±5 % for 0.2–2 s period band.
2. Convergence of IDA strips up to global drift > 10 %.
3. R² ≥ 0.95 for lognormal fragility fitting.
The numerical model must capture soil–structure interaction and all three layers of non-linear fidelity I specify: material nonlinearity (Mander or Kent–Park concrete, steel B–H curves), geometric nonlinearity (P-Δ, large-displacement effects) and a detailed element mesh that resolves plastic hinge formation in beams, columns and shear walls. Any platform is acceptable—ETABS + PERFORM-3D, OpenSees, SAP2000 nonlinear, or Abaqus—so long as the results can be cross-checked and exported.
From the IDA, generate fragility curves at Immediate Occupancy, Life Safety and Collapse Prevention, then translate those into a fragility-based vulnerability assessment for the entire Zone V region. The final document must end with clear design recommendations indicating how drift limits, ductility detailing and foundation options change the probability of exceedance.
Deliverables
• Calibrated 3-D nonlinear model (input and runnable file)
• Set of selected and scaled ground motions with justification sheet
• IDA plots and tabulated Sa-Δmax data
• Fragility curves for IO, LS, CP (PDF + Excel)
• Written report summarising methodology, vulnerability metrics and design recommendations
Acceptance will be based on:
1. Matching target spectrum within ±5 % for 0.2–2 s period band.
2. Convergence of IDA strips up to global drift > 10 %.
3. R² ≥ 0.95 for lognormal fragility fitting.