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This paper gives a brief mining and geological description of the Yakovlevo deposit of rich iron ores of the Kursk magnetic anomaly (Russia), which is one of the largest by explored reserves of high quality ores (9.6 billion mt) with iron content up to 69%. For the assessment of physical and mechanical properties of ores and enclosing rocks, a testing procedure was developed, and a non-linear geomechanical model for the assessment of stress-strain state of rock ore and rocks masses around workings was proposed on the basis of the study. Tangential stress concentration coefficients on working's contour were calculated and zones of rock ore mass's limit state were identified. The calculation data agree with those found by experiment, giving ratios between working's breadth and roof arch height. Stress criterion for assessment of mine rocks around workings was developed, expressing the ratio of calculated stresses and calculated strength of rock mass, and recommendations were given on choosing kinds and parameters of supports for various stability categories of mine rocks outcroppings on workings' contours.Key words: Iron ore, mines, mine rocks properties, geomechanical model, assessment of stability.Basic resources of Russia's iron ore are concentrated within the Kursk magnetic anomaly 1 . 90.5% of rich Kursk Magnetic Anomaly's (KMA's) ores by A+B+C 1 categories and 96.9% by A+B+C 1 +C 2 categories are concentrated in the Belgorod iron ore zone. It includes deposits of rich ores, unique in reserves and quality: Yakovlevo (9.6 billion mt), Gostischevo (10.9 billion mt), Bolshetroitskoye (1.5 billion mt), Razumnoye, etc. Average iron content in ore exceeds 60%. Deposits of rich iron ores of the Belgorod ore zone of the KMA are 500-1,000 m deep.The Yakovlevo deposit is one of the largest deposits of high quality ores by discovered reserves with the highest iron content and the lowest harmful impurities (sulfur, phosphorus, etc.). Maximal depth of iron ores from the daylight surface exceeds 500 meters. Slope angles of ore bodies vary within 65-75°; in the northern part of the deposit they do not exceed 50°. Thickness of ore chute near lying side of banded iron formations is 20-30 m, in middle part and hanging side it increases up to 100-200 m. Besides hat-shape rich iron ore occurrence, the ores forming V-shaped and sheetlike bodies going rather deep are developed in the deposit.The highest iron content is seen in ironmicaceous ores. In martite-hydrohematite and hydrohematite ores the iron content is lower. The iron content depends on the thickness of ore chute -increasing thickness, as a rule, causes iron 2880 TRUSHKO & PROTOSENYA, Biosci., Biotech. Res. Asia, Vol. 12(3), 2879-2888 (2015) content in ore to grow. In upper layers of deposits in the zone from several to 20-40 m thick, the iron content varies from 45 to 60%. The zone from 10-20 to 200-250 m in the middle area of the Yakovlevo deposit contains up to 60% of iron. In the footwall, on the border with banded iron formation 0.5-12 m thick, the iron content ...

This article discusses possible variants of underground parking lot in complex engineering and geological environment of St Petersburg, namely: soil excavation in open pit and excavation with solid supports. These methods were analyzed with regard to reasonability for preset construction conditions. A series of predictions were performed using Plaxis 2D software, two variants were described in this article: excavation with the bottom elevation of +0.560 m and excavation with the bottom elevation of -2,500 m and adjacent building (at the distance of 2.5 m). The formulated problems were solved using 2D models. The model was based on the Mohr–Coulomb theory which facilitated estimation of geotechnical environment in the vicinity of the construction. Predictions of retaining wall according to the two considered variants have demonstrated that maximum soil settlement near the excavation is 20 mm and the maximum additional settlement of building at the distance of 2 m from the excavation is 30 mm, which in both cases corresponds to predetermined specifications.

The article presents an analytical review of the current state of the iron ore base of the ferrous metallurgy of Russia and the world, identifies the largest iron ore provinces and iron ore producers. The promising directions of development and improvement of the quality of the iron ore base of Russia and the features of the development of new deposits of rich iron ores are identified. Effective technologies for the development of rich iron ores deposits that ensure an increase in production volumes are proposed. The geomechanical justification of rational technological parameters that are easily adapted to changes in mining and geological conditions has been performed. Based on the results of field studies, the use of an elastic-plastic model with the Coulomb – Mohr strength criterion for modeling changes in the stress-strain state of an ore rock mass during mining operations is justified and recommendations for ensuring the stability of mine workings are developed. Effective engineering and technical solutions for the complex development and deep processing of rich iron ores with the production of fractionated sinter ore, which increases the efficiency of metallurgical processes, the production of high-grade iron oxide pigments and iron ore briquettes, which increase the competitiveness of iron ore companies and the full use of the resource potential of deposits, are presented.

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