JOURNAL OF ROCK MECHANICS

JOURNAL OF ROCK MECHANICS

Numerical Modeling of Evaluation The Stability of The Rock Pillar of The Nakhlak Underground Lead Excavation Network By Sublevel Stoping Method

Document Type : Original Article

Authors
Mohammad Mehdi Chehrepak 1
Hamed Molladavoodi 2
1 Department of Mining Engineering, Amirkabir University of Technology, Tehran, Iran.
2 Associate Professor of Rock Mechanics, Department of Mining Engineering, Amirkabir University of Technology, Tehran, Iran.
10.22034/IRSRM.2024.432158.1061
Abstract
Today, due to the development of underground excavations, access to mineral resources is very common through tunnel excavation. In this regard, Due to the wide variety of underground mining methods, it is necessary to choose the suitable drilling method for the mining conditions and in order to achieve higher efficiency by reducing the cost. Designing the choice of mining method requires a systematic method based on the slope, size and shape of the mineral material. Sublevel Stoping Method from subgrades has a special place among underground methods from the economic point of view, conditions of use and production capacity. In this method, the mineral material is divided into separate layers, and in the surrounding of the mining Stope, the layers of the mineral material are considered as a Pillar to maintain the roof, walls and Footwall. In this research, In this research, the stability of the middle Rock Pillar of the two northern and southern Stope with the excavation of the southern Stoping up to level914 (-125 meters) of the new underground lead mine of Nakhlak in zone 35 and 36 has been investigated using FLAC3D finite difference numerical modeling. The Sublevel Stoping method is as drilling method and Mohr-Columb continuous behavioral model. In order to evaluate the numerical results and the stability of the Rock Pillar, Sakurai's criterion was used. According to the results, the maximum amount of total displacement caused by the excavation of the southern Stoping is equal to11.47 cm. The degree of displacement of the Z and Y axes is 5.36 and 9.59 cm, respectively, and the maximum induced stress is 19MPa. From the results, it can be seen that the amount of induced stresses around the access tunnels, Rock Pillar and the southern Stoping did not exceed the Strength of the rock mass, so failure did not occur. Also, the maximum amount of displacement obtained from the excavation of the southern Stoping is between the maximum and minimum limits of the Sakurai standard, and it is possible to understand the necessary stability of the 12meter wide Rock Pillar after the excavation of the southern Stoping.
Keywords
Stability Analysis
Nakhlak Underground Lead Mine
Sublevel Stoping Method
Finite Difference Numerical Method
Sakurai Method
Subjects
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JOURNAL OF ROCK MECHANICS
Volume 7, Issue 4
Winter 2024
Pages 27-39