Wind Farm – Puebla State, Mexico

Seismic Risk Analysis

Seismic Risk Analysis for a Wind Farm in Puebla, Mexico

In light of the future construction of a wind farm in the Esperanza area in the state of Puebla in Mexico, where 63 wind turbines will be installed, DYNAMIS carried out a deterministic seismic risk analysis and the dynamic amplification of the rock spectrum on the soil deposit.

The DSHA approach is a simple process that is useful especially where tectonic features are reasonably active and well defined. The focus is generally on determining the maximum credible earthquake (MCE) motion at the site.

As recommended by the IAEA-SSG-9 guidance, the deterministic seismic hazard assessment should account appropriately for both aleatory and epistemic uncertainties at each step of the evaluation, taking into consideration that the conservative procedure to define the reference scenario has been introduced to cover uncertainties. Double counting should thus be avoided. The objective of this analysis is to quantify and propagate the uncertainties at each step of the calculation in particular, the uncertainties associated with the seismicity, local geology, tectonic processes and attenuation models will be considered using a calculation model implemented through simplified logic trees and Monte Carlo techniques.

Epistemic uncertainty is the uncertainty in a parameter or model caused by insufficient knowledge. A typical example of epistemic uncertainty is provided by the definition of alternative seismotectonic models or attenuation models for a given type of tectonic environment.

The dynamic amplification of the sand deposit is calculated from the uniform rock spectrum obtained from the deterministic seismic risk analysis.

To take into consideration the uncertainty of the properties in the site, a probabilistic analysis is carried out on 60 site profiles obtained according to the methodology proposed by Toro (1992).

DYNAMIS carried out a deterministic seismic risk analysis (DSHA) and the dynamic amplification of the rock spectrum on the soil deposit.

The client used this analysis in order to ensure the viability of the project in this location and has leaded to a safe design.