eesti teaduste
akadeemia kirjastus
Estonian Journal of Engineering

Risk assessment of seismic impact on the roof and pillars stability in Estonian underground; 325–333

Full article in PDF format | doi: 10.3176/eng.2008.4.04

Sergei Sabanov, Jyri-Rivaldo Pastarus, Oleg Nikitin, Erik Väli

The processes of immediate roof exfoliation and pillars collapse is accompanied by significant subsidence of the ground surface. Ground surface subsidence causes soil erosion and flooding, swamp formation, agricultural damage, deforestation, changes in landscape, ground water level decreasing and the formation of unstable cavities. For the last four years a new blasting technology with great entry advance rates (EAR) has been introduced in an experimental mining block. By improved blasting technique the EAR reached 4 m; it is twice greater in comparison with usual technology, but emulsion explosive volume is twice higher and explosion occurs for 4.5 seconds (about 15 times longer than with the old technology). As a result of such greater advance rates, unsupported room lengths up to 5.5 m with decreasing stability of the immediate roof (IR) can be expected. In this paper the analysis of the IR stability using the deformation criteria for a new room-and-pillar mining technology with modern machinery at “Estonia” mine is presented. The analysis of the IR stability is based on the on-site underground testing by using benchmark stations and convergence measurements. The target of this study is to determine the impact of the vibration on the roof and pillars stability using the risk assessment method. Risk analysis on the basis of available earthquake data is also carried out.


  1. Nikitin, O., Sabanov, S. and Pastarus, J.-R. Analysis of earthquakes available influence on “Estonia” mine underground construction stability. In Proc. 6th International Scientific and Practical Conference “Environment. Technology. Resources” (Noviks, G. and Moro­zov, V., eds.). RA Izdevnieciba, Rezekne, Latvia, 2007, 78–84.

  2. Nikitin, O. Immediate roof stability analysis for new technology with great advance rates at Estonia mine. Reports of the department of development (Nikitin, O., ed.). AS Eesti Põlevkivi, Jõhvi, 2004–2005 (in Estonian).

  3. Andreev, V., Reinsalu, E., Djachenko, Z. and Toomik, A. Experimental working in under­ground mines for technological suggestion elaboration. Reports of IGD Skochinski A. A., No. 0103018100, 1987, Jõhvi (in Russian).

  4. Seleznev, N., Zarkov, S. and Kuznetsov, S. The main parameters determination for the main and immediate roof stability estimation for Estonian oil shale new excavation technologies. Reports of VNIMI, St. Petersburg, 1961 (in Russian).

 5. Nikitin, O. and Sabanov, S. Immediate roof stability analysis for new room-and-pillar mining technology in "Estonia" mine. In Proc. 5th International Scientific and Practical Conference "Environment. Technology. Resources" (Noviks, G. and Morozov, V., eds.). RA Izdevnieciba, Rezekne, Latvia, 2005, 262-269.

  6. Reinsalu, E., Toomik, A. and Levin, A. The analysis of harmful geological influences during the oil-shale mines “Estonia”, “Ahtme”, “Viru”, “Tammiku” exploitation. Reports of IGD Skochinski A. A., No. 0192066000, 1987, Jõhvi (in Russian).

  7. Djachenko, Z. K., Cheshin, А. J., Bolotov, N. and Toomik, A. The research of oil-shale bed full exploration by longwall mining. Reports of the Oil Shale Institute. Kohtla-Järve, 1985, No. 0112411104 (in Russian).

  8. Shirokov, A., Lider, V. and Pisljakov, B. Calculation of Anchor-bolt for Different Application Conditions. Nedra, Moscow, 1976 (in Russian).

  9. Fadeev, A. B., Glosman, L. and Kartuzov, M. I. Seismic control of mine and quarry blasting in the USSR. In Proc. 6th International Congress of Rock Mechanics. Montreal, 1987, 617–619 (in Russian).

10. Singh, S. P. and Narendrula, R. Assessment and prediction of rock mass damage by blast vibrations. In Proc. Conference on Mine Planning and Equipment Selection MPES. Wroclaw, 2004, 317–322.

11. Тalve, L., Samlan, J., Reinsalu, E. and Petrov, R. Investigation of different variants of the room and pillars method. Reports of the Oil Shale Institute. Kohtla-Järve, 1964, No. 0112411106 (in Russian).

12. Seismic velocity of Narva Pit. Optimum fleet recommendation, OFR service. Hyd. Excavator & Global Sourcing Marketing Unit Komatsu Europe International n.v. (Koji Ito), KEHG02-2068. Narva 2003.



15. Tomberg, T. The analysis of blasting vibration in oil shale mining. Tallinn University of Technology, Master thesis. Tallinn, 1998 (in Estonian).

Back to Issue