Belgorod State University, Belgorod, Russia:

E. V. Leontieva, Associate Professor, Candidate of Geographical Sciences, leonteva@bsu.edu.ru

EuroChem Project LLC, Saint-Petersburg, Russia:

R. Yu. Sapachev, Chief Specialist

Belnedra LLC, Belgorod, Russia:

V. N. Kvachev, CEO, Candidate of Engineering Sciences

Solution of any problem of hydrogeology, especially pit wall slope stability design, needs information on groundwater levels in different phases of open pit mining. The groundwater level is mostly determined from the numerical modeling of fluid flows. The unsteady fluid flow modeling is a labor-consuming process and it often involves 3D methods of finite elements, finite volumes and finite differences, which requires much time and is sometimes impossible because of the lack of the source data. The fastest way of determining groundwater levels and fluid flow parameters in wanted directions at different times of open pit mining is the solution of 2D nonstationary problem of hydrogeology using the finite element method. The problem solving details are insufficiently described in technical literature, and the present authors instantiate the process by comparing the Rocscience Slide 2 application with the analytical solutions. The 2D unstable groundwater flow in the pit wall was modeled for 5 time periods: open pit mine life for 1460 days; every year until termination of open pit mining; time of the steady-state flow setting 25 years long. The modeling domain is found based on the open pit mine geometry, topography and impact radius. The impact radius is 1357 m. The model identifies a single aquifer with the permeability of 0.69 m/day. The model groundwater level deviates from the in-situ measurements taken in observation wells at a distance of 23 m by 2.5 %.

1. Leontieva E. V., Sapachev R. Yu., Kvachev V. N. Real-time prediction and assessment of hydrogeological conditions in pit wall rock mass using advanced computer technologies. Gornyi Zhurnal. 2021. No. 8. pp. 57–61. DOI: 10.17580/gzh.2021.08.11
2. Martin D., Stacey P. Guidelines for Open Pit Slope Design in Weak Rocks. Leiden : CRC Press/Balkema, 2018. 416 p.
3. Anderson M. P., Woessner W. W., Hunt R. J. Applied Groundwater Modeling: Simulation of Flow and Advective Transport. 2nd ed. London : Academic Press, 2015. 564 p.
4. Singh V. P. Handbook of Applied Hydrology. 2nd ed. New York : McGraw Hill Education, 2017. 1440 p.
5. Cheskidov V. V., Lipina A. V., Melnichenko I. A. Integrated monitoring of engineering structures in mining. Eurasian Mining. 2018. No. 2. pp. 26–31. DOI: 10.17580/em.2018.02.05
6. Eremenko V. A., Neguritsa D. L. Efficient and active monitoring of stresses and strains in rock masses. Eurasian Mining. 2016. No. 1. pp. 21–24. DOI: 10.17580/em.2016.01.02
7. Dassargues A. Hydrogeology: Groundwater Science and Engineering. Boca Raton : CRC Press, 2018. 492 p.
8. Musin R. Kh., Khramchenkov M. G. Introduction of geo-permeation to digital modeling : Educational and teacher edition. Kazan : Izdatelstvo Kazanskogo universiteta, 2019. 41 p.
9. Slide 2. Rocscience Inc., 2021. Available at: https://www.rocscience.com/software/slide2 (accessed: 15.06.2021).
10. Beale G., Read J. Guidelines for Evaluating Water in Pit Slope Stability. Collingwood : CSIRO Publishing, 2013. 615 p.
11. Maksimov V. M. (Ed.). Reference book of hydrogeologist. In two volumes. Leningrad : Nedra, 1979. 810 p.
12. Mironenko V. A., Fisenko G. L., Norvatov Yu. A., Bokiy L. L. Drainage of open pit mine fields. Leningrad, 1965. Iss. I. 79 p.
13. Sindalovskiy L. N. Hydrogeological computations in ANSDIMAT. Saint-Petersburg : Nauka, 2021. 891 p.
14. Kresic N. Hydrogeology and Groundwater Modeling. 2^nd ed. Boca Raton : CRC Press, 2006. 828 p.
15. Vasilev S. V., Verigin N. N., Razumov G. A., Sherzhukov B. S. Weepage from water reservoirs and ponds. Moscow : Kolos, 1975. 303 p.