Cordilleran Section - 108th Annual Meeting (29–31 March 2012)

Paper No. 6
Presentation Time: 16:10

INSTRUMENTATION SYSTEM FOR IN SITU MONITORING OF GROUND DEFORMATION IN IZTAPALAPA, MEXICO CITY


CARREON-FREYRE, Dora1, BARRIENTOS-GARCÍA, Bernardino2, GUTIERREZ-CALDERON, Raul3, MARES-CASTRO, Carlos2 and CERCA, Mariano4, (1)Geociencias, UNAM, Campus Juriquilla, Queretaro, 76230, Mexico, (2)Centro de Investigaciones en Optica, A.C, Loma del Bosque #115 Col. Lomas del Campestre, Leon, Guanajuato, 37150, Mexico, (3)Delegacion Iztapalapa, Gobierno del Distrito Federal, Aldama No. 63. Col. Barrio San lucas. Iztapalapa, Mexico City, 09000, Mexico, (4)Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Blvd. Juriquilla 3001, Queretaro, 76230, Mexico, freyre@geociencias.unam.mx

We present a methodology to study the mechanisms of fracturing that affect the urban infrastructure in Iztapalapa, Mexico City. This methodology has been developed during the last years, mapping of fracturing and its classification by generating mechanisms permitted to asses the geological hazards related to subsoil deformation. Considering causes and not only the effects of these phenomena has aided advising in making decisions on risk issues.

Based on the fracture analysis we have designed a measurement system of surface deformation distributed on the Iztapalapa area. The system includes: monitoring sites of surface deformation (EMDS, Estacion de Monitoreo de Deformacion Superficial), an optical array of monitoring (SODS, Sistema Óptico de Deformación Superficial), and a network of georeferred leveling sites. Five EMDS have been placed during 2011 in fractured sites, which include mechanical instruments using either a micrometer to measure moderate displacements in vertical and horizontal directions (3D); and an angular instrument that consists of a lever arm of 5 m in length with an angle amplifier (1D). Continuous measurement of the deformation generate reliable information to correlate deformation with geological and/or anthropogenic triggering mechanisms. The SODS is a recent technological development, robust and low cost, used to monitor widespread deformation in approximately 2500 m2 areas that includes a programmed camera, two laser devices and a mirror to asses 3D deformation with a milimetric resolution.

The in situ monitoring system are being complemented with remote sensing studies and topographic leveling in selected sites in order to asses the local and regional deformation processes. Iztapalapa is the first entity in Mexico with a deformation monitoring system, the continuous measurements will support the diagnosis of stability of the subsoil to establish mitigation measures or preventive actions at different scales.