Geostatiscal investigations of rock masses. The sierra del medio case (Argentina)

Abstract

Este trabajo fue presentado en el V Congreso Internacional sobre "Geología Aplicada a la Ingeniería", realizado en Buenos Aires, Argentina, del 20 al 25 de Octubre de 1986. The geostatistical techniques applied for the selection of a minimum fracturation volume In Sierra del Medio allow to quantify and qualify the variability of mechanic characteristics and density of fractures and also the level of reliabllity in estimations. The role of geostatistics is discussed in this work so as to select minimum fracturation blocks as a very important site selection step. The only variable used is the "jointing density" so as to detect the principal fracture systems affecting the rocky massif. It was used on the semivariograms corresponding to the previously mentioned regionalized variables. The different results of fracturation are compared with the deep and shallow geological surveys to obtain two and three dimensional models. The range of the geostatistical techniques to detect local geological phenomena such as faults is discussed. The variability model obtained from the borehole data computations is investigated taking as basis the vertical Columnar Model of Discontinuity (fractures) hypothesis derived from geological studies about spatial behaviour of the joint systems and from geoestatistical interpretation.