Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Apocopated forms (such as pelá instead of pelada) are frequent in oral and colloquial Chilean Spanish. Thus, the negative word nada in postverbal position (in constructions with the negative inductor no) is also attested as na’, as in no te creo na’ (‘I don’t believe you at all’). In this paper, we claim that, as regards the choice between nada and na’, a grammatical specialization can be observed: while na’ is regularly preferred for the expression of the emphatic negative marker, the interpretation of the negative word in question as an indefinite quantifier is connected whether to a moderate preference for nada, or to the absence of preference for the apocopated or the plain form. The analysis of these results let us suggest that the specialization of na’ is comparable to the grammaticalization of other negative markers in other languages.

In this paper we analyze the tradition of linguistic studies on coa (the anti-language of Chilean criminals) from a glottopolitical perspective, considering these studies as discourses that influence the configuration of regimes of normativity, not only linguistic but also social. These discourses contain ideological representations of coa and its speakers that are configured according to the modernizing project of the Chilean State and the building of the prison and police apparatuses on the basis of positivist criminological assumptions. As a result, we find that in this metalinguistic tradition persists an ideological line that presents a reductionist image of coa and its speakers, which highlights their Otherness and contributes to the naturalization and justification of their disciplining.

This study adopts an acoustic and statistical approach to investigate vowel lowering in Aymara spoken in Chile, and, if present, to determine whether it is a coarticulatory or allophonic phenomenon. The results indicate that, in line with previous research, high vowels /i/ and /u/ are articulated as [e] and [o], respectively, when they occur after uvular consonants. Additionally, according to our data, this phenomenon also occurs with the vowel /a/. The analyses support an interpretation whereby vowel lowering has an allophonic character and is not merely articulatory. For this reason, we propose adding [a̞] as an allophone of /a/ to the sound system of Aymara spoken in Chile.

The aim of this work is to estimate the compressive strength of concrete at 28 days using Gaussian Mixture Models. To carry out the work, a database of 82 dosages of different concretes and their maturity-resistance curves have been used. This database was populated with information obtained from the literature and completed with dosages carried out in the laboratory, which were monitored for 28 days. With this, a database was created with variables such as the water-cement ratio (W/C), the cement content and the temperature-resistance relationship over time. The aim is to estimate the 28day resistance value of concrete used in Engineering and Construction, in a range of compressive strengths between 15 and 45 MPa. This is intended to numerically represent the behaviour of concrete maturity over time versus the increase in compressive strength. The Gaussian mixture regression GMR model allowed the estimation of compressive strength with an error of less than 13.54%.

Dry stacking of iron ore tailings (IOTs) with cementitious materials is a viable disposal option, but its large scale implementation faces challenges. Therefore, this study investigates the key factors influencing compaction in real field conditions, including moisture content (optimum moisture content and less than optimum moisture content), vibration frequency (0 Hz and 35 Hz), and number of roller passes (4P and 6P). To achieve this objective, an experimental IOT stack was constructed in five different layers using a specific amount of Portland cement as a cementing agent (2.5% by dry solid weight). Then, laboratory tests, such as unconfined compression, splitting tensile, and ultrasonic pulse velocity (UPV), were conducted on undisturbed samples to evaluate the unconfined compressive strength (qu), splitting tensile strength (qt), and initial shear modulus (G0). Based on the laboratorytests conducted on the field-collected specimens, it was concluded that samples with moisture contents closer to the optimum moisture content (OMC), exposed to vibration, and subjected to six-roller passes exhibited superior mechanical performance. This study provides insights into optimizing the compaction process for large-scale IOT stack structures.

It is routine in geotechnical design practice to estimate the undrained strength of soils (su) using the CPTu test, based on correlations with laboratory tests. Correlations must be verified for each site with laboratory undrained triaxial tests on good qualityundisturbed samples, which is a time-consuming and sometimes difficult activity. As an alternative approach, undrained strength can be determined more efficiently using the field vane shear test (VST). However, it should be noted that some adjustment to the standard rotation rate and/or correction to the μ factor may be required for particular soils. This paper presents experimental results on the influence of VST strain rate on the estimation of undrained shear strength. The test program was carried out on lacustrine soft clays from four sites in Mexico City (CDMX), where the water content varies from 100% to 500%, and experimental results from a tailings dam in northern Mexico are also presented. Undrained triaxial, VST and CPTu tests were performed on the CDMX soft clays. The rate of rotation varied from 0.1°/s to 4°/s to evaluate the peak, residual and remolded shear strength with VST. For the soft clay, the results show that the curve versus peak resistance has a minimum value in the range of 0.2 to 0.5, which is associated with the value of the undrained resistance of the soil without viscous phenomena. Therefore, for the clayey deposits of Mexico City, it is recommended to use this range of values to ensure that the correlations used in the piezocone are reliable. In terms of soil sensitivity, the results show that it decreases with increasing speed, with a smaller decrease at greater depths. For the tailings site, similar results to those found in Mexico City were observed, but VST tests using a rotation rate varying from 0.2 to 2°/s showed that the peak resistance has a minimum value at 1°/s.

El contexto geológico y climático de Costa Rica lo hace altamente vulnerable a la ocurrencia de deslizamientos. Debido a esto es que una apropiada caracterización geotécnica es clave para la exploración y diseño de una solución. Esto implica dos aspectos: la definición del mecanismo de ruptura y su geometría, no obstante, las herramientas cualitativas y cuantitativas usualmente utilizadas como la experiencia del geólogo, geotecnista, y ensayos tradicionales como el SPT o geofísica, tienden a generar información dispersa o inconclusa, que debe ser tratada con cuidado. Bajo este escenario de incertidumbre se decide implementar el dilatómetro Marchetti DMT que es un ensayo que permite estudiar de forma directa la deformabilidad, resistencia e historial de esfuerzos del terreno, lo cual posibilita caracterizar de mejor manera el suelo e identificar la geometría de la superficie de ruptura, que a su vez facilita optimizar el diseño y la implementación de las soluciones de estabilización y reparación del deslizamiento. En este artículo se presentan tres casos de estudio donde el DMT fue implementado para definir la geometría de la superficie deruptura y desarrollar la solución del deslizamiento desde la fase de diseño hasta su construcción.

En este artículo se presenta la interpretación realizada para los resultados obtenidos en cuatro ensayos de dilatómetro plano DMT y tres perforaciones CPTu realizadas en suelos residuales en la zona central de Chile. La interpretación fue efectuada para estimar la razón de la resistencia no drenada residual (Su/σ’v0) mediante ensayos triaxiales y correlaciones existentes en la literatura para elDMT y CPTu. Dada la incertidumbre en la estimación del coeficiente de empuje lateral de tierra en reposo (K0), el cual es necesario para estimar la razón Su/σ’v0 en ensayos triaxiales, se evaluó la capacidad del ensayo DMT para estimar este parámetro. Se concluye que el ensayo DMT, en conjunto con el CPTu, permiten estimar de buena manera el parámetro K0 y, de esta forma, determinar la razón de resistencia residual mediante el ensayo triaxial. Se debe tener precaución ya que ambos ensayos in situtienen limitaciones en sus correlaciones al momento de estimar la resistencia residual no drenada.

La caracterización del suelo mediante ensayos de penetración dinámica (DPT) ha sido realizada mediante el establecimiento de parámetros geotécnicos obtenidos de la aplicación de correlaciones basadas en índices de penetración y en menor medida mediante mediciones directas. Esta característica produce una disminución en la precisión y variedad de los parámetros geotécnicos posibles de evaluar en terreno mediante DPT. El propósito de este artículo es presentar una metodologíade evaluación de la impedancia mecánica del suelo Zs mediante la aplicación de un método de desacople y reconstrucción de ondas y probar el potencial diferenciador de este parámetro entre dos tipos de arenas diferentes. Se realizaron ensayos DPT de energíavariable empleando un penetrómetro instrumentado con sensores de deformación y acelerómetro (PANDA 3) sobre especímenes de arenas Hostun HN31 y Fontainebleau NE34 reconstituidos en estado seco en una cámara de calibración ko. Los resultados mostraron que es posible la evaluación del valor de impedancia mecánica mediante la aplicación del método de desacople y reconstrucción de señales dinámicas de fuerza y velocidad en la interfaz cono-suelo para cada impacto de martillo sobre elpenetrómetro dinámico.

This paper represents a collaborative effort utilizing the finite element method to simulate the resonant column (RC) apparatus. The aim is to explore how soil dynamic properties change with varying strain levels. The RC test, renowned for its ability to analyze soil behaviour under dynamic loads, is the focus of our study. However, accurate measurement of dynamic properties using the RC can be influenced by several factors, necessitating further investigation. These factors, including strain uniformity, base fixity, strain localization, top-platen coupling, sample shape, and soil uniformity, are the key areas of our research. To gain a deeper understanding of the effects of these variables on measured shear wave velocity and damping ratio, we performed finite element analysis using Abaqus/Explicit, a commercial finite element package based on continuum mechanics. The model was based onthe specific RC setup configuration at the University of Waterloo. Initial parameters included the low strain properties of sand (shear modulus, Poisson’s ratio, damping ratio) with shear strain adjusted as a loading variable. Torsional loads were applied across shear strains from 10-5 to 10-4. The element size of the soil specimen mesh was varied to 25 mm, 10 mm, 7.5 mm, and 5 mm to observe its effect on the outcomes of the RC test. The finite element model analyzed the free vibration of the cylindrical sand sample post-forced vibration, assessing dynamic properties. Modal analysis of the RC configuration was performed to verify the primary influence of the first torsional mode. A Z-factor has been proposed as a multiplier of experimentally obtained damping ratio. Comparisons of damping ratios and resonant frequencies at various shear strains between finite element modelling and laboratory data demonstrate a strong correlation in the case of nonlinear shear strain, with differences firmly ranging from 0.50% to 3.5%.