Caracterização geomecânica de um maciço rochoso em corte de estrada no município de Boa Viagem - CE

Abstract

Road cut slopes are common works on the various roads and highways in Brazil. These cuts, on many occasions, are performed on rocky structures and are carried out through mechanical rock dismantling or with the aid of explosives and, over time, these remaining rock masses tend to undergo changes in their stability due to to the appearance or alteration of discontinuities. In this way, the analysis of the stability of these slopes is of paramount importance for the safety of those who travel close to them, because, depending on their geomechanical conditions, wedge, planar, overturning or circular failures may occur. For this analysis, field investigation of these structures present in the rock mass is necessary, with the aid of equipment such as a geological hammer and compass and, with the collection of these data and foundation in the literature, the rock mass can then be classified geomechanically. This work aims to geomechanically classify a rocky mass of slope in a road cut located in the municipality of Boa Viagem, State of Ceará, aiming at determining its stability, and recommending supports in cases of unfavorable results. To this end, based on the characteristics of its discontinuities, such as roughness, spacing of fractures, presence of water, resistance to compression of the walls and orientation, data obtained in the field using compasses, geological hammers, measuring tapes and GPS, it was possible to classification according to Q-Barton, RMR and SMR methodologies. By RMR, areas 1 and 2 obtained a value of 71, being classified as good, area 4 with a value of 80 also classified as good, and area 3 with a value of 85 considered very good, following the Q-Barton description obtained by the method for area 1 was 22.5 describing the massif as of good quality, area 2 with a value of 1 being a massif of poor quality, area 3 with a value of 2 also being described as massif of poor quality and area 4 with a value of 8, thus being described as a massif of regular quality. For the SMR according to the characterization, a value of 54 was obtained for areas 1 and 2, being then classified as partially stable, thus the suggested stabilization measures are protection and reinforcements, for area 3 with a value of 68 considered stable, it is not it is necessary to use stabilizing measures, in area 4 with a value of 63 being considered stable, the recommendation is the use of protections and for area 5 considered unstable, re-sloping is necessary, due to the instability of the slope. Therefore, the recommended measures aim to prevent the fall of blocks from interfering with road traffic, it is expected that with the implementation of these treatments, possible incidents and accidents related to ruptures in these slopes will be avoided.