Hybrid Urban Inspection and Risk Assessment. A hybrid method for pre-earthquake seismic vulnerability assessment and post-earthquake quantitative urban inspection, linking field evidence, structural typologies and analytical models.
THEK Method
Created by Marcelo Moncayo Theurer. Its documented development brings together urban inspection, statistical typologies, structural modelling, risk scaling and pre/post-earthquake operation.
HUIRA combines empirical evidence observed in real buildings with analytical information derived from representative structural models. It is designed to operate both before and after an earthquake and to scale results from an individual building to typologies and then to a neighbourhood, sector, region or city.
The on-site survey records exterior and interior condition, cracking, buckling, collapse and the state of structural and non-structural components. Observed percentages are weighted according to component importance, so a damaged column is not treated as equivalent to a damaged window.
Dominant typologies are translated into representative models. Their seismic response is evaluated through variables such as drift, deflection, demand/capacity and dynamic characterization. HUIRA then combines this analytical response with the observed physical condition.
HUIRA organizes the building inventory, selects a sample, identifies dominant typologies and develops representative structural models before the event. Preventive field inspection may be retained with a lower weight, or the observed-damage component may be replaced by expected damage generated through SECA.
After an earthquake, assessment teams can sweep the affected area building by building. Each record feeds a quantitative index and an operational classification that supports decisions on use restriction, detailed inspection, urgent intervention and relocation.
In HUIRA Version 2.0, one documented application integrates four components: observed damage, deflection, demand/capacity and inter-storey drift. Weights are contextual and must be justified; the historical weights documented in HUIRA are treated as an initial empirical calibration derived from testing, application and professional experience.
Risk index for a specific building, obtained from inspection and/or structural modelling.
Mean risk of the buildings belonging to typology j, or the risk of the representative model when that is directly provided by the application.
Weighted integration of typologies according to their representativeness in the building stock.
The Santa Rosa application directly compared the University of Guayaquil method — the academic antecedent of HUIRA — with FEMA 154. The methods serve different levels of assessment: FEMA is highly effective as rapid visual screening, whereas HUIRA moves into deeper quantitative inspection and connects field evidence with structural models.
| Aspect | FEMA 154 | HUIRA | Complementary role |
|---|---|---|---|
| Assessment level | Rapid Visual Screening. | Quantitative interior/exterior inspection plus modelling. | FEMA screens; HUIRA deepens the assessment. |
| Main output | Score used to identify buildings that may require further evaluation. | Damage/risk indices, structural typologies and urban scaling. | HUIRA can serve as a quantitative layer after initial screening. |
| Observed damage | Global vulnerability cues. | Element-by-element quantification of structural and non-structural damage. | Higher resolution for prioritization and mitigation. |
| Structural models | Not the core of the rapid-screening procedure. | Representative models are part of the hybrid architecture. | Links observed condition to expected response. |
Recognized in the current formalization as HUIRA Version 1.0. The study represented an urban universe of 7,846 one-storey single-family houses, developed nine statistical/structural typologies, quantified field condition and produced an early model-risk formulation.
Recognized as HUIRA Version 2.0. It addressed 7,489 buildings of two to four storeys, used finite-population sampling, seven typologies and an explicit integration of damage, deflection, demand/capacity and drift. It also included a direct comparison with FEMA 154.
An application based on a severe-earthquake scenario. In the current THEK formalization, scenario construction is linked to SECA-DM, while structural and typological risk assessment is linked to HUIRA.
These applications provide cumulative evidence of applied use and validation. Full empirical validation still requires systematic comparison with observed post-earthquake damage, sensitivity analysis and recalibration.
SECA estimates the consequences of a seismic scenario; HUIRA provides the structural and typological reading of the built environment. Together, they support pre-earthquake scenario construction and faster post-earthquake interpretation.
Severe Earthquake Consequence Assessment — Global Modeling. A global route for consequence estimation based on a broad historical database.
Severe Earthquake Consequence Assessment — Discrete Modeling Method. A discrete route transferring consequences from comparable historical earthquakes to the target city.
Interprets expected damage within structural typologies, incorporates representative model response and converts the scenario into risk information for vulnerability assessment, prioritization and mitigation.
Vulnerability inventories, emergency planning, retrofit prioritization and post-earthquake assessment.
Academic applications, comparative validation, calibration, software development and joint research programmes.
Portfolio assessment, campuses, residential complexes, facilities and operational-continuity planning.
THEK Research Institute welcomes methodological licensing, joint research, technical advisory, institutional implementation and lectures on HUIRA, SECA and urban seismic resilience.