Analysis of the variation of the compressibility index (Cc) of volcanic clays and its application to estimate subsidence in lacustrine areas
Por:
Carreón-Freyre D., González-Hernández M., Martinez-Alfaro D., Solís-Valdéz S., Vega-González M., Cerca M., Millán-Malo B., Gutiérrez-Calderón R., Centeno-Salas F.
Publicada:
1 ene 2015
Resumen:
An analysis of the deformation conditions of lacustrine materials
deposited at three sites in the volcanic valley of the Mexico City is
presented. Currently geotechnical studies assume that compressibility of
granular materials decreases in depth due to the lithostatic load. That
means that the deeper the sample the more rigid is supposed to be, this
assumption should be demonstrated by a decreased Compression Index (Cc)
in depth. Studies indicate that Mexico City clays exhibit brittle
behaviour, and have high water content, low shear strength and variable
Cc values. Furthermore, groundwater withdrawal below the city causes a
differential decrease in pore pressure, which is related to the physical
properties of granular materials (hydraulic conductivity, grain size
distribution) and conditions of formation. Our results show that Cc for
fine grain materials (lacustrine) can be vertically variable,
particularly when soils and sediments are the product of different
volcanic materials. Lateral and vertical variations in the distribution
of the fluvio-lacustrine materials, especially in basins with recent
volcanic activity, may be assessed by Cc index variations. These
variations can also be related to differential deformation, nucleation
and propagation of fractures and need to be considered when modelling
land subsidence.
Filiaciones:
Centro de Geociencias de la UNAM Juriquilla, Queretaro, Mexico
Centro de Evaluación de Riesgos Geológicos CERG, Iztapalapa, Mexico City, Mexico
Posgrado en Ciencias de la Tierra, UNAM Juriquilla, Queretaro, Mexico
Centro de Física Aplicada y Tecnología Avanzada, UNAM Juriquilla, Queretaro, Mexico
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