Sismic Microzonation based on Site Effects in the Metropolitan Area of Mendoza

Abstract

Land-use planning in a region must consider various aspects related to the characteristics of the environment and the human habitat developed within it. In seismically active regions, potential hazards associated with seismic activity include soil liquefaction, landslides, rockfalls, and site effects, among other phenomena that may increase the vulnerability of urban areas. Local seismic response can be evaluated using theoretical and empirical methods. The former allow a more detailed analysis of the characteristics and properties of the different subsurface layers, whereas empirical methods are based on the recording of vibrations generated by earthquakes or other sources of excitation at sites with different geological and geotechnical conditions. Among the experimental techniques used to assess local effects, methods based on ambient vibration recordings have gained wide acceptance over the last decades. This study analyzes a densely populated area of the Mendoza Metropolitan Area, Argentina, with the aim of contributing to its seismic microzonation through the determination of the predominant soil frequencies using the Horizontal-to-Vertical Spectral Ratio (H/V) method. As a representative application, a West–East-oriented profile crossing different geological and geotechnical conditions of the region is analyzed in order to evaluate the ability of the method to identify variations in the local dynamic response of the soil. Based on the spatial distribution of the predominant frequencies, the study aims to identify sectors potentially exposed to seismic amplification phenomena during the occurrence of moderate- to high-magnitude earthquakes. The study is currently in its final stage of development for the entire Mendoza Metropolitan Area and will provide useful information for land-use planning, urban planning, and seismic risk management.