Detección de zonas de fracturamiento en áreas urbanas mediante el método capacitivo de tomografía eléctrica

Abstract

Within the metropolitan area of Mexico City; affectations are commonly observed in buildings structures, and in some cases fractures, subsidence and collapses have become one of the major risks in the current urban sprawl. Iztacalco municipality is located northeastward of the city. Surrounding municipalities are Venustiano Car- ranza and Cuauhtémoc to the north; Benito Juárez to the west; Iztapalapa to south and Nezahualcóyotl to east. Several areas are influenced of disruption in their hous- ing units, such as Barrio de Santiago and “Infonavit” (Institute of the National Housing Fund for Workers). Damage to the units are related to the presence of fractures in the subsurface under structures, weakening or altering their basements underground and causing structural damage. In order to characterize the observed fracturing, geophysical surveys were carried out in two critical areas of these resi- dential buildings; consisting of four surveys of Electrical Capacitive Tomography (ECT) in each site. A preferential NW-SE direction of fractures inferred in the sub- surface in both study areas were found. Such directions have a remarkable correla- tion with previous studies near this area. 

In the same manner, the acquired data using the ECT method with the Omh Mapper (Geometrics) instrument, are noisy because the shallow variations of elec- trical resistivity; in order to minimize such noise, the data were processed and in- verted separately and display clear the resistivity anomalies observed in the profiles.