Cavity detection in urban zones of mexico city

Cavities and shallow fractures on mined regions beneath urban sites of Mexico City are a highrisk problem. Electric tomography has been applied to successively detect and map these types of structures to the western side of the city. The method developed by Loke and Barker was employed to image the real electrical distribution at depth. GPR (Ground Penetrating Radar) was also used to confirm the results obtained. The area selected possesses a high rare of population and is found in the hilly portion of the city, within the Mexican Valley. Results are very encouraging, demonstrating that a multicornponent geophysical survey help to locate and characterize areas of high risk.