Krukovska V.V., Krukovskyi O.P. Numerical simulation of coupled processes at blasting explosive charges towards compensation borehole

Details
Parent Category: Geo-Technical Mechanics, 2018
Category: Geo-Technical Mechanics, 2018, Issue 143

Geoteh. meh., 2018, 143, 102-109

https://doi.org/10.15407/geotm2018.143.102

NUMERICAL SIMULATION OF COUPLED PROCESSES AT BLASTING EXPLOSIVE CHARGES TOWARDS COMPENSATION BOREHOLE

1KrukovskaV.V., 1KrukovskyiO.P.

1Institute of Geotechnical Mechanics named by N. Polyakov NAS of Ukraine

UDC 622.26:622.235.001.57

Language: Russian

Annotation.

The study of the stress-strain state of rocks in the roadway face is of great importance for determining rational parameters for drilling-and-blasting operations and increasing rates of the working drivage. A certain layout of blastholes and compensation boreholes in the roadway face can be substantiated by mathematical modelling. In this article, a mathematical model is presented, which describes coupled processes of changing of the rock stress state during explosion of the concentrated charges with taking into account weight of overlying rocks and unsteady, nonlinear filtration of gaseous detonation products. With the help of finite element method, stress field, zones of inelastic deformations and gas pressure were calculated for different schemes of the charge layout in the face of the preparatory roadway with and without pilot compensation borehole. It is shown that the edge rocks are unloaded from rock pressure during drilling blast-holes and installing explosive charges. The presence of a pilot borehole increases depth of the unloaded zone in the roadway face. As a result of the explosion, the stress distribution is changed in the roadway face: zones of completely destroyed and disturbed rocks and with increased fracturing are formed around the charges, and explosive charges are surrounded by an inelastic deformation zone. In case of no compensation borehole, this zone of inelastic deformation does not reach the face surface.  In the roadway face with compensation borehole, zone of inelastic deformation around the charges is connected with the face surface when two charges are exploded. When four explosive charges are exploded in the plane of the longitudinal section of the roadway, zone of inelastic deformations — the fractured rocks — extends from charges to the surfaces of the borehole and roadway face. The calculation of the fracture cavity size during the explosion of charges confirms the findings. In order to achieve the same effect without compensation borehole, it is necessary to increase radius of the charges. Therefore, use of the pilot compensation borehole ensures the roadway face drivage with a lower explosive charge power.

Keywords:

stress state of rocks, drilling-and-blasting operations, numerical simulation of coupled processes.

References

1. Kiyashko, Yu.I., Krukovskaya, V.V., Krukovskiy O.P. and Ischenko, K.S. (2013), “Modelling of geomechanical processes in the rock massif in the blast-hole charge explosion on the compensation well”, Izvestiya vyisshih uchebnyih zavedeniy. Gornyiy zhurnal, no. 7, pp. 75-79.

2. Boiko, V. and Remez, D. (2014), “Mathimatical simulation of millisecond-delay blasting for curry out spectrum of fluctuations”, Suchasni resursoenerhozberihaiuchi tekhnolohii hirnychoho vyrobnytstva,  no. 1/(13), pp. 33-40.

3. Krukovskaya, V.V. (2015), “Simulation of coupled processes that occur in coal-rock massif during mining operations”, Geo-Technical Mechanics, no. 121, pp. 48-99.

4. Krukovskaya, V.V., Krukovskiy O.P. and Ishchenko, K.S. (2011), “Analysis of changes in the rocks stress state in the working face in the for-mation of cut cavities”, Vzryivnaya tehnologiya. Empirika i teoriya. Dostizheniya. Problemyi. Perspektivy: Materialy Mezhdunarodnoy nauchno-prakticheskoy konferentsii [Explosive technology. Empiricist and theory. Achievements. Problems. Prospects: Materials of the International science-practical conference], TulGU, Tula, RU, pp. 44-50.

5. Borovikov, V.A. and Vanyagin, I.F. (1990) Modelirovanie deystviya vzryiva pri razrushenii gornyih porod [Design of action of explosion at destruction of mine rocks], Nedra, Moscow, SU.

6. Zienkiewicz, O.C. and Taylor, R.L. (2000), “The finite element method”, Butterworth-Heinemann, Vol. 1..

7. Zorin, A.N., and Kolesnikov, V.G. (1978), Upravlenie dinamicheskimi proyavleniyami gornogo davleniya [Control  by the dynamic displays of mine pressure], Nedra, Moscow, SU.

8. Linkov, A.M., Petuhov, I.M. and Sidorov, V.S. (1977), “About growth of cracks in a preparatory stage and at the front of the troop landing”, Trudy VNII surveyor institute, no. 106, pp. 46-55.

9. Krukovskiy, A.P. (2011), “Simulation of stress-strain state of marginal rock massif at the start of exca-vation face motion”, Problemi obchislyuvalnoi mekhanIki I mItsnostI konstruktsIy, no. 17, pp. 175-181.

10. Hutton D.V. (2004), Fundamentals of Finite Element Analysis, McGraw-Hill.

About the authors

Krukovska Viktoriia Viktorivna, Doctor of Technical Sciences (D. Sc), Senior Researcher, Senior Researcher in Department of Control of Dynamic Demonstrations of Rock Pressure, Institute of Geotechnical Mechanics by N. Pjlyakov of the National Academy of Sciences of Ukraine (IGTM, NASU), Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it. .

Krukovskyi Olexandr Petrovych, Corresponding Member of NAS of Ukraine, Doctor of Technical Sciences (D. Sc), Deputy Director of the institute, Institute of Geotechnical Mechanics by N. Pjlyakov of  the National Academy of Sciences of Ukraine (IGTM, NASU), Dnepr, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it. .