Editorial

Abstract

Han pasado 8 años desde mi saludo y declaración de intenciones como editora, en el número 10(2) de la revista. Publicamos los correspondientes 8 volúmenes, cada uno con un numero de páginas comprendido entre 250 y 350, y un nuero de trabajos entre 20 y 27. Además, se publicaron 5 volúmenes extraordinarios. Además, durante el periodo se publicaron 5 volúmenes extraordinarios con las mismas exigencias de calidad que los ordinarios y reuniendo entre todos ellos 90 trabajos. Todo este gran volumen de obra impresa constituye una parte muy sustancial del mejor patrimonio de la Sociedad Española de Paleontología.
 Como figura en el interior de su portada, la revista es la publicación periódica científica de la Sociedad Española de Paleontología, cuyos fines principales son los de promover y difundir la actividad paleontológica en España. En cuanto a la dificultad de este periodo, no ha sido fácil para la revista y el trabajo editorial ha sido duro. Sin embargo, ha pesar de todo se ha continuado con el mismo cuidado y exigencias en cuanto a calidad de la revista.
 Desde la última Asamblea, la SEP tiene un nuevo Editor, Rodolfo Gozalo, en cuyo equipo se mantienen Sixto Fernández López y Miguel Pardo como Editores Adjuntos. El empuje y capacidad de trabajo, unidos a la experiencia previa de los Editores Adjuntos conducirán, sin duda, a una excelente gestión.

A hybrid extraction level layout design for block caving

“…The roominess increased in the Hybrid layout because of the LHD load ore from the production drift. The triangular configuration of the extraction drift decreased the span between the production and extraction drift; this is also observed in the ‘offset’ herringbone layout (Chacon 1980).…”

“…On the other hand, Table 4 shows the result of the comparison criteria (Chacon 1980). Here, it can be observed that the utilization of the area over the drawpoint increases in the Hybrid layout because of the location of the drawpoint that also decreases the layout distortion and anisotropy.…”

“…The layouts were compared in terms of development and support requirements and according to the comparison criteria proposed by Chacon (1980), which include the layout density, utilization area, sustenance, distortion, anisotropy, and roominess. Table 2 shows the input variables used for the El Teniente and the proposed layouts.…”

“…The comparison criteria used in this study are based on design aspects of extraction layouts in block caving defined by Chacon (1980) as the following: Density: Area of Influence (Ai) of each DP within an extraction layout. Utilization (Ua): The area covered by the influence of DP, regarding the area covered by the design on which the MEx is evaluated. Sustenance (S): This corresponds to the solid pillar area that remains after the excavations of the production and the extraction drifts. Distortion (DS): This is the relationship between the longest and the shortest distance between DP, measured in the direction of the extraction drift. Anisotropy (AN): Relationship between the maximum radius of influence of a DP, relative to the minimum radius of influence of the same DP, the latter generated by the distance from the DP to the edge of the neighbouring DP when there is an overlap of interaction areas. Roominess (R): The relationship between the length available for LHD equipment operation and the length of LHD equipment being evaluated. Maximum span (Smax) (additional criteria for this study) : The relationship between the excavated area in a singularity in relation to the width of the main drift generated by the excavation. Interaction IEZ (I IEZ ): This corresponds to the shared area (AO) of interaction in the DP, relative to the area generated by the diameter of the IEZ (DTI) of each DP. …”