Peer-reviewed articles 17,970 +



Title: SLOPES STABILITY STUDIES EXCAVATED IN A ROCK MASSES. CASE OF AHMED EL-HADJ QUARRY (LAFARGE)

SLOPES STABILITY STUDIES EXCAVATED IN A ROCK MASSES. CASE OF AHMED EL-HADJ QUARRY (LAFARGE)
Mohamed Fredj; Riadh Boukarm; Abderrazak Saadoun; Radouane Nakache
10.5593/sgem2023/1.1
1314-2704
English
23
1
•    Prof. DSc. Oleksandr Trofymchuk, UKRAINE 
•    Prof. Dr. hab. oec. Baiba Rivza, LATVIA
The study of the effect of blasting on bench stability is indispensable for the overall mine’s safety, in this perspective, we conducted a study in the limestone quarry, which is characterized by a highly fractured rock mass. While the quarry presents a steep topographic profile, the extraction is carried out on a single operating edge. The blasting operations in the quarry offer an unsatisfying fragmentation (high percentage of oversized boulders), important overbreak, and deformation to the bench’s face; these irregularities are problematic, and their continuity may cause serious instability to the system benchquarry slope.
The study concerns several benches located on different levels of the quarry and aims to evaluate the extent of the blast-induced effects beyond the intended fragmentation section and to assess the bench stability under the blast effects. Then, propose practical solutions to limit the unwanted effects, starting by determining a more suitable blast design that allows a higher bench stability, and assures, at the same time, a satisfying and accurate rock mass fragmentation.
The work is divided into two parts: First, a comparative study between two fragmentation analysis methods; a prediction and analysis of the fragmentation using the Kuz-Ram model, to assess the efficiency of blasts by the quarry’s current blast design. Then, by variating, some settings in the blast design, which serves as input for the Kuz-Ram model, we obtain, after a series of simulations, different predictions for the fragmentation. Subsequently, the design that presents improvements compared to the currently used design, in both fragmentation quality and bench stability, is chosen for application. Afterward, a digital image processing of the fragmentation, using the WipFrag software, is carried out for, both, the design obtained by the Kuz-Ram study and the precedent blast design. This method of analysis, contrary to the Kuz-Ram model procedure that presents as results of a prediction of the fragmentation, offers an actual and practical estimation of the fragmentation process. This technique consists in taking many digital images of the muck pile after each blast. These images are, then, processed by the WipFrag software, which estimates the average size of the fragments. Afterward, a general mean value of the average size of the material is estimated for all the blasts. Lastly, we compare the results obtained by the digital image analysis to those predicted by the first method. In the second part of this paper, a numerical modeling approach is adopted, by employing the Finite Element Method (FEM) and through the “Phase2” software. At this point, we perform simulations, in the static and dynamic conditions, on a numerical model of the quarry’s profile, the goal is to observe the various problems that could possibly occur during the blast excavation process and the permanent deformations that the rock mass might be subject to. The simulations in the dynamic conditions are carried out using the new proposed blast design.
[1] Saadoun A., Fredj M., Boukarm R., Hadji, R., Fragmentation analysis using digital image processing and empirical model (KuzRam): a comparative study. Journal of Mining Institute, 2022, 257, pp 822-832. DOI:10.31897/PMI.2022.84.
[2] Hosseini M., Namvar Z.N. The Design of the Large Blastholes Pattern by Analyzing of Fragmentation of Blasted Rocks in Sarcheshmeh Copper Mine. Geotechnical and Geological Engineering, 2017, vol. 35, pp 395-402. DOI: 10.1007/s10706-016-0115-6
[3] Djoudi M., Bensehamdi S., Fredj M., Study of blasting effect on bench stability. IOP Conf Ser Earth Environ Sci. 2021, 833:012196. DOI:10.1088/1755-1315/833/1/012196
[4] Agyei G., Owusu-Tweneboah M A., Comparative Analysis of Rock Fragmentation using Blast Prediction Results. Ghana Mining Journal, 2019, vol. 19, n 1, pp 49-58. DOI: 10.4314/gm.v19i1.6
[5] Ren Yue-long., Cai Qing-xiang., Shu Ji-sen., Zhou Wei., Han Liu., Influence of blasting vibration and structural plane progressive failure on slope stability [J]. Journal of Mining & Safety Engineering, 2014, (31) 435.
[6] Verma H K., Samadhiya N K., Singh M., Goel R K., Singh P K., Blast induced rock mass damage around tunnels. J. Tunneling and Underground Space Technology. 2018, 71, pp 149-158.
[7] Ning J., Yang J., An X.M., Ma G.W., Modelling rock fracturing and blast induced rock mass failure via advanced discretisation within the discontinuous deformation analysis framework [J]. Comput Geotech. 2010, (38) 40.
[8] Hartman H.L., SME mining engineering handbook Britton S.G., Mutmansky J.M., Gentry D.W., Schlitt W.J., M Karmis., Singh M.M. Eds Denver: Society for Mining, Metallurgy, and Exploration. 1992, vol.2.
[9] Fredj M., Hafsaoui A., Khadri Y., Boukarm R., Influence of the failure surface choice on the safety factor value during slope stability studies. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu. 2018, pp 30-35. DOI:10.29202/nvngu/2018-3/3
[10] Cunningham C.V.B., The Kuz-Ram fragmentation model–20 years on Brighton conf. proc. European Federation of Explosives Engineers, 2005, England pp 201-210.
[11] Mutinda E.K., Alunda B.O., Maina D.K., Kasomo R.M., Prediction of rock fragmentation using the Kuznetsov Cunningham-Ouchterlony model. Journal of the Southern African Institute of Mining and Metallurgy. 2021, vol. 121, n.3, pp 107-112. DOI: 10.17159/2411- 9717/1401/2021
[12] Maerz, N.H., Palangio, T.C., Franklin, J.A., WipFrag image based granulometry system. Proceedings of the FRAGBLAST 5 Workshop on Measurement of Blast Fragmentation, Montreal, Quebec, Canada, 23-24 Aug. 1996. pp. 91-99
[13] Kanungo D.P., Pain A., Sharma S., Finite element modelling approach to assess the stability of debris and rock slopes: a case study from the Indian Himalayas. Natural Hazards. 2013, 69 1, pp 1–24.
[14] Jimeno E.L, Jimeno C.L., Carcedo A., Drilling and Blasting of Rocks CRC Press, 1995.
conference
Proceedings of 23rd International Multidisciplinary Scientific GeoConference SGEM 2023
23rd International Multidisciplinary Scientific GeoConference SGEM 2023, 03 - 09 July, 2023
Proceedings Paper
STEF92 Technology
International Multidisciplinary Scientific GeoConference-SGEM
SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci and Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts and Letters; Acad Fine Arts Zagreb Croatia; Croatian Acad Sci and Arts; Acad Sci Moldova; Montenegrin Acad Sci and Arts; Georgian Acad Sci; Acad Fine Arts and Design Bratislava; Russian Acad Arts; Turkish Acad Sci.
233-242
03 - 09 July, 2023
website
9017
blasting, bench stability, Kuz-Ram, WipFrag, fragmentation, uniformity index