Dimensional characteristics of the system of fractures of the portuguese mainland

Abstract

The quantification of the expectable risk for works built on rock masses may be obtained on basis of the knowledge of the statistical distributions that describe the attitude of their discontinuities, the dimension of these discontinuities and the law that governs the spacing between them. This article gives reasons for the use of log-normal and exponential distributions for the last two characteristics and present studies of the system of fractures detected in the portuguese mainland by means of remote sensing. The analysis of this system of fractures confirms the applicability of those laws in spite of some limitations, which are given.