Earthquake fragility curves for building structures

Example: Fragility functions defining the probability of reaching or exceeding different damage states for buildings under earthquake ground shaking.

Step-by-step guidance

1. Dataset-level metadata

Select the following values when describing your dataset:

  • Risk data type: vulnerability

  • Title: “Earthquake fragility curves for [building types/region]”

  • Description: Brief description of the fragility functions, building typologies covered, and derivation method

  • Publisher: Organization or research institution that developed the fragility curves

  • License: Appropriate license

2. Resources

Add resources for your fragility function files:

  • Format: csv, json, or xlsx

  • Spatial resolution: Not applicable (functions are typically building-type specific)

  • Coordinate reference system: Not applicable

3. Vulnerability metadata

Under the Vulnerability section:

Category

  • Category: fragility

Hazard type and intensity

  • Hazard type: earthquake

  • Hazard primary type: earthquake

  • Processes: ground_shaking

  • Intensity measure: Select appropriate measure:

    • PGA:g (peak ground acceleration in g)

    • SA(0.3):g (spectral acceleration at 0.3s)

    • SA(1.0):g (spectral acceleration at 1.0s)

    • PGV:m/s (peak ground velocity)

Vulnerability functions

For each building typology, create a function entry:

Function specification:

  • ID: Unique identifier (e.g., F1_RC_lowrise)

  • Relationship: fragility

  • Function type: lognormal, beta, empirical, or hybrid

Damage scale:

  • Type: discrete or continuous

  • Damage states: List damage levels (e.g., slight, moderate, extensive, complete)

  • Number of damage states: Count (e.g., 4)

Parameters (for lognormal):

  • Median (μ): Intensity at 50% probability for each damage state

  • Beta (β): Standard deviation of logarithm

Asset taxonomy

Link fragility curves to building types:

  • Taxonomy source: GED4ALL, HAZUS, PAGER, EMS-98, or custom

  • Taxonomy code: Specific code for each building type (e.g., CR/LWAL+DNO/H:1,2)

Cost information

If economic loss is included:

  • Cost dimension: structure, content, business_interruption

  • Cost unit: Currency code (e.g., USD)

4. Spatial coverage

Define applicability:

  • Scale: global, national, or regional

  • Countries: Select applicable ISO 3166-1 alpha-3 country codes if region-specific

  • Description: Note if curves are calibrated for specific seismic regions

Example data structure

Your fragility curve file should include:

For each building type and damage state:

  • Building taxonomy code

  • Damage state name

  • Hazard intensity measure (e.g., PGA)

  • Distribution type (lognormal, beta, etc.)

  • Median value (50th percentile intensity)

  • Dispersion (beta/standard deviation)

  • Intensity units

Example CSV structure:

Building_Type,Damage_State,Intensity_Measure,Distribution,Median,Beta
RC_Lowrise_1-3stories,Slight,PGA:g,lognormal,0.15,0.45
RC_Lowrise_1-3stories,Moderate,PGA:g,lognormal,0.30,0.45
RC_Lowrise_1-3stories,Extensive,PGA:g,lognormal,0.60,0.50
RC_Lowrise_1-3stories,Complete,PGA:g,lognormal,1.20,0.55

Key considerations

  • Clearly document the derivation method (empirical, analytical, expert judgment, hybrid)

  • Specify building taxonomy codes consistently

  • Reference the intensity measure definition and units

  • Include uncertainty information (beta values for lognormal distributions)

  • Document the damage state definitions used

  • Note any regional calibration or adjustments

  • Include references to source publications or studies