The New Mine Level Project is a 130 000 tonnes per day (tpd) panel caving project set to start in 2017. The high stresses, complex structural setting and high mining rates present major challenges in terms of seismicity management and rockburst hazard reduction. This paper is a case study of the calculation of the energy requirements needed to design a dynamic support system for this operation. This analysis starts with the estimation of the seismic source, forecast through the use of numerical modelling and verified with observed past data; later peak particle velocity (PPV) is calculated at the drifts using a PPV attenuation model and an amplification factor is used near the excavations. The amount of fractured rock around the drifts that could be ejected by a seismic event is calculated through numerical modelling. With the ejection velocity estimated from PPVs, energy demand is obtained. All the values resulting from numerical analysis were compared to historical data of similar mine sectors. As the results show that the methodology used in this paper agrees well with previously observed rockburst episodes, it was used to calculate the yielding support of this new deep mine project.

For the development of the pre-feasibility study for the New Mine Level Project (NML) carried out by Codelco Chile Project Corporate Vice-Presidency, it is fundamental to have numerical models that allow estimating the stress state for the various mining options under study in a quick, simple and reliable manner. For this reason, a simplified mine scale model was created to analyse geomechanical issues that go from drift scale (overbreaking), large excavations (caverns) to mine scale issues (caving front geometries, mining macro-sequences, sector interactions). The software tool preferred was Map3D (Mine Modelling Pty Ltd).The boundary conditions used as the base for the Map3D modelling tool correspond to the geometry to be analysed and the pre-mining stress state in the zone of interest. To estimate this latter condition, the Conceptual Stress Model (Karzulovic et al., 2006) information was used and originally, the stress orientation expected for that zone based on Plate Tectonics (east-west trending) was considered. To test the model's efficacy, various validation exercises were carried out: comparison of the model's results with field stress measurement for different years, between the abutment stress zone predicted by the model and the one observed in the field, and the model-predicted overbreak versus the actual overbreak obtained through field surveys.It can be concluded that the model created fulfils the reliability levels that have been historically used for mine-scale models in a pre-feasibility engineering stage. The validated and calibrated boundary conditions can be applied both for mine-scale and drift-scale models, with error values of 40% compared to stress measurements and 20% when compared to field-observed damage.

Introduction: Physical fitness may be assessed among children and adolescents in a quantitative and qualitative manner. At present, in Chile, there are no tools available to assess self-perception of physical fitness. Therefore, the purpose of this study was to develop a valid and reliable instrument that would allow to assess selfperception of physical fitness among adolescents and propose standards for age and sex. Material and methods: A survey was administered among adolescent students from six public schools in the Maule Region, Chile, selected in a probabilistic (stratified) fashion. To measure self-perception of physical fitness, a qualitative instrument was developed: the Self-Perception of Physical Fitness Scale (EAPAF, escala de autopercepción de la aptitud física), which is made up of four dimensions and 18 questions. The LMS method (L: Box-Cox coefficient, M: median curve, and S: variation coefficient) was used to establish percentiles and propose references by dimension, age and sex. Results: A total of 3060 adolescents (1702 boys and 1358 girls) aged 11.0 to 18.9 years old were included. The factor analysis evidenced four factors. Saturation values were above 0.40. The percentage of instrument explanation reached 54.24%. In terms of reliability, the 18 questions reflected that Cronbach's alpha was between 0.82 and 0.85. Percentiles (p15, p50 and p85) were developed to classify self-perception of physical fitness by dimension, age and sex. Boys showed higher scores in the self-perception of physical fitness scale when compared to girls (p < 0.001). Conclusion:The instrument developed in this study was valid and reliable. In addition, the standards proposed may become a useful tool to classify adolescents in relation to their selfperception of physical fitness.

El texto propone un esquema conceptual que sistematiza la jurisprudencia del Tribunal Constitucional chileno en materia del derecho a la tutela judicial y al debido proceso. Tomando en consideración la doctrina reciente, el texto elabora categorías dogmáticas para diferenciar las potestades y componentes del derecho a la tutela judicial del debido proceso. Los autores concluyen que ambos derechos son de creciente desarrollo conceptual por la jurisprudencia constitucional chilena y que su sistematización dotaría de mayor certeza jurídica a las decisiones del Tribunal Constitucional.

El texto aborda la penetración de nuevas tecnologías en el profesión legal chilena, para explicar la innovación curricular del minor en inteligencia artificial y derecho (IA+D), conforme a sus resultados de aprendizaje. A partir de ello, examina cada asignatura que compone el minor IA+D, desde un doble punto de vista: el de la justificación de su inclusión y la estructuración orientada al cumplimiento del perfil esperado con la aprobación de todas las asignaturas del minor. Tras esta revisión, el texto concluye con los desafíos de la implementación de un programa curricular de esta naturaleza en el pregrado.

El vertiginoso avance de la ciencia y tecnología, sumado al afán de proteger los derechos de las personas, han llevado a un grupo de senadores a iniciar mociones sobre materias relacionadas con los nuevos neuroderechos. En concreto, los honorables senadores señor Girardi, señora Goic y señores Chahuán, Coloma y De Urresti, han presentado, por un lado, un Proyecto de reforma constitucional que modifica el artículo 19, número 1°, de la Carta Fundamental, para proteger la integridad y la indemnidad mental con relación al avance de las neurotecnologías (Boletín Nº 13827-19); y, por otro, un Proyecto de ley sobre protección de los neuroderechos y la integridad mental, y el desarrollo de la investigación y las neurotecnologías (Boletín Nº 13828-19). Ambos documentos de los congresistas datan del 7 de octubre de 2020, pasando en misma fecha a la Comisión de Desafíos del Futuro, Ciencia, Tecnología e Innovación, la que a fines de noviembre del mismo año ha dado respaldo a las ideas matrices.

Resumen: El presente trabajo analiza el itinerario de cambio constitucional propuesto por la Presidenta Michelle Bachelet. Junto con una descripción del mismo, se discuten, críticamente, varias de sus etapas. En lo principal, se objeta el conjunto de cerrojos institucionalmente vigentes que harían imposible, al menos desde una perspectiva teórica, hablar de un proceso genuinamente constituyente. El trabajo ofrece, al mismo tiempo, una lectura democráticamente adecuada para que el proceso permita un diálogo entre la institucionalidad que se pretende abandonar y el mecanismo con el que se busca el cambio constitucional, sin que las primeras limiten al segundo.Palabras clave: cambio constitucional -proceso constituyente -poder constituyentecerrojos institucionales -Chile. Abstract: This work analyzes the itinerary for constitutional change that PresidentMichelle Bachelet recently announced. Along with a presentation of the process, this work critically assesses some of its stages. It mainly contends that the set of institutional regulations it assumed−regulations that were taken from current constitutional rules−makes it impossible to talk, at least from a theoretical perspective, of a genuine constituent process. This work also offers a democratically adequate reading for the process, so that it will make possible a dialogue between the current institutions sought to be replaced and the mechanism for constitutional change, without subjecting the latter to the former.

The New Mine Level Project is a 130,000 tonnes per day (tpd) panel caving project set to start in 2017. The high stresses, complex structural setting and high mining rates presents a major challenge in terms of seismicity management and rockburst hazard reduction. This paper is a case study of the calculation of the energy requirements needed to design a dynamic support system. This analysis starts with the estimation of the seismic source forecasted through the use of numerical modelling and verified with observed past data, later peak particle velocity (ppv) is calculated at the drifts with a ppv attenuation model, and an amplification factor is used near the excavations. Finally, the amount of fractured rock around the drifts that could be ejected by a seismic event is calculated through numerical modelling. With the ejection velocity estimated from ppvs, energy demand can be obtained. All the values resulting from numerical analysis were compared to historical data of similar mine sectors. The results shown that the methodology used in this paper agrees well with previously observed rockburst episodes, therefore it was used to calculate the yielding support of this new deep mine project. The method used to calculate yielding support is based on the steps proposed in the Canadian Rockburst Research Project (Kaiser et al., 1996): 1. Estimation of the most likely location and the maximum magnitude of future events. 2. Estimate ground motion decay from the source to each of the drifts. 3. Estimate the amplification factor in the broken rock mass surrounding the drifts.