Characterization of soil permeability in the former Lake Texcoco, Mexico

Abstract

The geotechnical subsoil conditions of the former Lake Texcoco represent a complex sequence of highly compressible lacustrine clays interbedded with layers and seams of harder and more permeable materials. Although the mechanical properties of these deposits have been extensively studied in the past, the information about their hydraulic properties is scarce. Currently, a comprehensive characterization of the hydraulic conductivity of this site has become necessary because of the construction of the New Mexico International Airport (NAIM). The present study describes a systematic evaluation of the hydraulic conductivity in the former Lake Texcoco through three different in-situ methods (well permeameter, LEFRANC and piezocone dissipation test). The measurements, taken from 155 locations, show a high spatial variability, with ranges spanning more than two orders of magnitude. The results also reveal that the estimated permeabilities vary significantly among methods. These discrepancies reflect the scale dependency of the hydraulic conductivity in the area caused by soil heterogeneities. A comparison of the presented results with previous studies demonstrates that piezocone tests provide representative results for the clayey formations, while LEFRANC tests better estimate the hydraulic conductivity of the permeable strata. Besides, CPTu tests yield more consistent values of hydraulic conductivity, with smaller dispersion than well permeameter and LEFRANC tests.

An effective combined framework for modelling the time-dependent behaviour of soft structured clays

“…Parameters employed are given in Table 1; they were calibrated to obtain a good agreement with experimental results. The employed initial permeability is consistent with the range of values determined from laboratory (Ovando-Shelley, 2011) and field (Lopez-Acosta et al, 2019) experiments. In addition, it is well known that the permeability of soils is a function of their void ratio (or porosity) (Chapuis and Aubertin, 2003).…”

Comparing Bioapatite and Collagen Radiocarbon Dates From a 16th Century Cemetery Context—el Japón, Xochimilco, Mexico City

“…In other geologic regions, limestone contribution to sediments and their disintegration in bodies of water are known sources of dissolved inorganic carbon that affect either bone sample preservation or 14 C age determinations of organisms procuring water or foods from bodies of water with dissolved carbon (Gustafsson et al 2011;Schulting et al 2015;Svyatko et al 2017;Hadden and Cherkinsky 2017). It is unlikely that dissolved geological carbonate played a role in carbon cycling in Lake Xochimilco because most of the Basin Mexico lies on igneous bedrock (de Cserna 1989; López-Acosta et al 2019). The soils at El Japón site where burials took place are primarily andosols with overlying technosols (McClung de Tapia and Acosta Ochoa 2015) and can be assumed to have low levels of carbonates in comparison to minerals and inclusions typical of those soil types.…”