ABSTRACT
This paper describes and analyzes several aspects observed during the exploration of mine tailings deposits in Mexico using the CPTu_∆u, test: high ground temperatures, interstratification, chemical reaction, dissipation curves with negative pore pressure, and S-wave profile. It was observed that the use of sensors with temperature compensation for the q T and f s measurements produces satisfactory results if temperature changes are not abrupt. For the case of the dynamic pore pressure sensor u 2 , where no temperature compensation was made, the measurements are within the range mentioned in the standard except in the case when the temperature increases to values of 50°C or higher. The presence of high interstratification between thin layers of hard and soft soils, with different degrees of saturation, leads to errors in the measurement of the tip resistance and can produce deviations from the verticality of the cone, making it necessary to carry out corrections. The different types of dissipation curves observed in the tailings dams studied, where the soils are partially saturated, are generally the same as those described by Sully et al. (1999), with the particularity that in some cases, the equilibrium pressure reaches negative values. Finally, the S-wave profile obtained with correlations reproduces the general trend of the measured S-wave profile. Nevertheless, it was not possible to capture the variations in this type of deposit. In the case history described in this paper, the maximum values were not reproduced. Therefore, in this type of deposit, it is advisable the direct measurement of the shear wave and to use the smaller intervals of measurement according to the technique used.
