Recently, due to population increase in urban areas, underground excavations increasingly influenced the development of cities, parallel with traffic organization. One of the best examples is Eger in North Hungary: several kilometer-long wine-cellars were dug over the centuries beneath the city, which influences further construction; sometimes they present a danger due to the increased weight of surface vehicles as well. Therefore, nowadays the prediction of the stability of these cellars is a question of utmost importance here. The goal of this paper is to statistically analyze the results of strength investigations of the excavated rocks, in order to predict their strength (both compressive and tensile) and Young's modulus. The results of 19 sample blocks are statistically analyzed here in different petrophysical states (air-dry, semi-saturated and fully saturated). The relationships between the different petrophysical constants are also determined and analyzed in this paper. On the basis of these correlations prediction of rock strength has become easier and faster.
Authors:Petya Kovacheva, Boyan Todorov, and Rumyana Djingova
FAO 2006: World Reference Base for Soil Resources. A Framework for International Classification Correlation and Communication. World Soil Resources Report 103. — Food and Agriculture Organization of the United Nations, Rome, 128 pp
cover 12% of the city’s built-up area, and the authorities would like to increase it to 15%, which is the minimum ratio provided by the International Organization for Standardization (ISO).
Statistical reports from the United Nations show that
Organisation (CSIRO) cells were used to measure stress change in the rock. Boreholes were drilled from the tunnel, near parallel with the tunnel axis. The CSIRO cells were installed in the boreholes in front of the advancing face to capture the entire stress