Some aspects of andesitic Bimrock characterisation

Abstract

This paper describes an approach applied in the design and construction of one cut at section km 23+200 - km 23+400 from the expressway A4, section Stip – Radovish, part of the Macedonian road network in construction. The cut is constructed in volcanogenic rock mass of andesitic type, with different zones within the massif. It is specific, because of different phases of extrusions along wider fault zones, rock mass has typical composition of block - in -matrix (BIM) rocks. In the frame of this article, the approach based on the integral application of empirical – analytical, and observational methods during the design and construction is presented. Some results from investigations and correlations between the investigated parameters necessary to define optimal slope protection elements are also given. One attempt is done to prepare a simple tool for characterization of BIM rocks initially named as BIMSI (Block In Matrix Strength Index), based on a combination of Volumetric Block Proportion and Strength Ratio of significant blocks and matrix. This idea requires further study. Finally, some elements of applied solution for slope protection are presented.