Analysis of Rock Fall Phenomenon in Steep Wall Using Modeling by Rocfall Mass-Lump Method and PFC3D Discrete Element Method - Case Study

Document Type : Original Article

Authors

• Hadi Fattahi
• Milad Sadeghi Govari
• Hossein Ghaedi

Department of Earth Sciences Engineering, Arak University of Technology, Arak, Iran.

10.22067/jfcei.2021.69111.1026

Abstract

Rock fall is a type of slope instability that occurs in most mountainous areas and causes casualties and severe damage to facilities, residential areas, roads, farms and vehicles. Therefore, to prevent financial damage, it is necessary to predict and model the phenomenon of rock fall in steep walls to take preventive measures. In this paper, in order to assess the risk of falling rocks, first using Rocfall software, the path of rock fall of isolated blocks was analyzed individually and separately in the most critical section of the northwestern heights of Shahrood. In order to consider the interactions between particles in the path, shape, size and weight of the parts, the distinct element method PFC^3D was used. Analyzing the simulation results with the help of these two softwares, it was concluded that if the rock falls, a large number of parts will stop in the area of ​​roads and residential areas, which will result in traffic jams and financial-human risks. In other words, considering that the maximum horizontal distance traveled by the plots is 393 meters and the horizontal distance between residential areas is 340 meters, so the probability of an accident due to falling rocks is very high. In the following, suggestions such as installation of metal grids, shock absorbers, reduction of kinetic energy in the parts, change in the dimensions of the parts, change of the slope geometry to reduce the risk and damage caused by falling rock in the desired section are presented.

Keywords

• Rock fall
• Rocfall software
• PFC3D software
• Mass-lump method
• Distinct element method

20.1001.1.27832805.1400.34.1.6.8

---

References

1. 1. Azzoni, A., La Barbera, G., and Zaninetti, A., "Analysis and Prediction of Rocfalls Using a Mathematical Model", in International journal of rock mechanics and mining sciences & geomechanics abstracts 32, No. 7, pp. 709-24, (1995).
2. 2. Azzoni, A., and De Freitas, M., "Experimentally Gained Parameters, Decisive for Rock Fall Analysis", Rock mechanics and rock engineering, 28, No. 2, pp. 111-124, (1995).
3. 3. Nicot, F., Cambou, B., and Mazzoleni, G., "Design of Rocfall Restraining Nets from a Discrete Element Modelling", Rock Mechanics and Rock Engineering, 34, No. 2, pp. 99-118, (2001).
4. 4. Guzzetti, F., et al., "STONE: A Computer Program for the Three-dimensional Simulation of Rock-falls", Computers & Geosciences, 28, No. 9, pp. 1079-1093, (2002).
5. 5. Duarte, M. and Marquı́nez, J., "The Influence of Environmental and Lithologic Factors on Rocfall at a Regional Scale: An Evaluation Using GIS", Geomorphology, Vol. 43, No. 1-2, pp. 117-136, (2002).
6. 6. Chau, K. T., Wong, R., and Wu, J., "Coefficient of Restitution and Rotational Motions of Rocfall Impacts", International Journal of Rock Mechanics and Mining Sciences, 39, No. 1, pp. 69-77, (2002).
7. 7. Baillifard, F., Jaboyedoff, M., and Sartori, M., "Rocfall Hazard Mapping Along a Mountainous Road in Switzerland Using a GIS-based Parameter Rating Approach", Natural Hazards and Earth System Sciences, 3, No. 5, pp. 435-442, (2003).
8. 8. Guzzetti, F., Reichenbach, P., and Ghigi, S., "Rocfall Hazard and Risk Assessment Along a Ortattranspion Corridor in the Nera Valley, Central Italy", Environmental management, 34, No. 2, pp. 191-208, (2004).
9. 9. Chau, K. T., Tang, Y., and Wong, R. H., "GIS Based Rocfall Hazard Map for Hong Kong", International Journal of Rock Mechanics and Mining Sciences, 41, No. SUPPL. 1, (2004).
10. 10. Perret, S., Stoffel, M., and Kienholz, H., "Spatial and Temporal Rocfall Activity in a Forest Stand in the Swiss Prealps—a Dendrogeomorphological Case Study", Geomorphology, 74, No. 1-4, pp. 219-231, (2006).
11. 11. Saboya Jr, , da Glória Alves, M., and Pinto, W. D., "Assessment of Failure Susceptibility of Soil Slopes Using Fuzzy Logic", Engineering geology, Vol. 86, No. 4, pp. 211-224, (2006).
12. 12. Batterson, M., McCuaig, S., and Taylor, D., "Mapping and Assessing Risk of Geological Hazard on the Northeast Avalon Peninsula and Humber Valley, Newfoundland", Current Research. Government of Newfoundland and Labrador, Department of Natural Resources, Geological Survey, Report, No. pp. 06-1, (2006).
13. 13. Topal, T., Akin, M., and Ozden, U. A., "Assessment of Rocfall Hazard around Afyon Castle, Turkey", Environmental Geology, 53, No. 1, pp. 191-200, (2007).
14. 14. Lan, H., Martin, C. D., and Lim, C. H., "Rocfall Analyst: A GIS Extension for Three-dimensional and Spatially Distributed Rocfall Hazard Modeling", Computers & Geosciences, 33, No. 2, pp. 262-279, (2007).
15. 15. Giacomini, A., et al., "Experimental Studies on Fragmentation of Rock Falls on Impact with Rock Surfaces", International Journal of Rock Mechanics and Mining Sciences, 46, No. 4, pp. 708-715, (2009).
16. 16. Choi, Y., et al., "Engineering Geological Investigation into Rocfall Problem: A Case Study of the Seated Seokgayeorae Image Carved on a Rock Face at the UNESCO World Heritage Site in Korea", Geosciences Journal, 13, No. 1, pp. 69-78, (2009).
17. 17. Tunusluoglu, M., and Zorlu, K., "Rocfall Hazard Assessment in a Cultural and Natural Heritage (Ortahisar Castle, Cappadocia, Turkey)", Environmental geology, 56, No. 5, pp. 963-972, (2009).
18. 18. Antoniou, A. A., and Lekkas, E., "Rocfall Susceptibility Map for Athinios Port, Santorini Island, Greece", Geomorphology, 118, No. 1-2, pp. 152-166, (2010).
19. 19. Rammer, W., et al., "Evaluation of a 3-D Rocfall Module within a Forest Patch Model", Natural Hazards and Earth System Sciences, 10, No. 4, pp. 699-711, (2010).
20. 20. Huang, C.-C. and Yuin, S.-C., "Experimental Investigation of Rainfall Criteria for Shallow Slope Failures", Geomorphology, 120, No. 3-4, pp. 326-338, (2010).
21. 21. Volkwein, , et al., "Rocfall Characterisation and Structural Protection– A Review", Natural Hazards and Earth System Sciences, Vol. 11, No. 9, pp. 2617-2651, (2011).
22. 22. Spadari, M., et al., "Statistical Evaluation of Rocfall Energy Ranges for Different Geological Settings of New South Wales, Australia", Engineering geology, 158, No. pp. 57-65, (2013).
23. 23. Youssef, A. M., et al., "Assessment of Rocfall hazard at Al-Noor Mountain, Makkah City (Saudi Arabia) Using Spatio-temporal Remote Sensing Data and Field Investigation", Journal of African Earth Sciences, 101, No. pp. 309-321, (2015).
24. Keskin, B., et al., "Investigation of Rocfall Potential of Zonguldak-Kilimli Roadway (Turkey)", Arabian Journal of Geosciences, Vol. 13, No. 16, pp. 1-11, (2020).
25. 25. He, K., et al., "Failure Mode Analysis of Post-seismic Rocfall in Shattered Mountains Exemplified by Detailed Investigation and Numerical Modelling", Landslides, 18, No. 1, pp. 425-446, (2021).
26. 26. Stevens, W. D., RocFall, A Tool for Probabilistic Analysis, Design of Remedial Measures and Prediction of Rocfalls, (1998.(
27. 27. Preh, A. and Poisel, R., 3D ئodelling of Rock Mass Falls Using the Particle Flow Code PFC3D. 2007: na.
28. 28. Lee, J.-H., et al., "Evaluation of Land Subsidence Risk Depending on Grain Size and Verification Using Numerical Analysis", The Journal of Engineering Geology, 27, No. 2, pp. 133-141,(2017).