Rock Mechanics
Pankaj Bhatt; Anil Kumar Sinha; Mariya Dayana P J; Murtaza Hasan; Parvathi Geetha Sreekantan
Abstract
The rapid development of road networks needs huge construction materials. Mining and industrial wastes can be used as sustainable road construction materials and will be alternatives to fulfill the huge demand in road construction. Zinc tailing is one such mining waste and has the potential for road ...
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The rapid development of road networks needs huge construction materials. Mining and industrial wastes can be used as sustainable road construction materials and will be alternatives to fulfill the huge demand in road construction. Zinc tailing is one such mining waste and has the potential for road construction. This material was collected from Zawar mines (Rajasthan), and characterization was carried out for embankment/subgrade applications. A physical model test was conducted in the laboratory to examine the stress-settlement behaviour. To improve the modulus value of tailing, it was reinforced with geogrid in two different laying patterns, viz. layer/loop and stress-settlement behavior was studied. Different parameters were studied: reinforcement depth, layer of reinforcement, number of loops, and depth of loop of reinforcement. The experimental result was validated with the numerical finite element method (SoilWorks). Tailing comprises fine-grained silt-size particles (61%) with no swelling behavior and non-plastic nature. It has values of MDD and OMC as 1.86 g/cm3 and 11%, respectively. It has a higher value of CBR (12%) and internal friction angle (34.6o) with cohesionless nature. The variation of settlement with stress is linear for reinforced and unreinforced tailing fill. As the depth of reinforcement increases, settlement increases in both layer and loop reinforcement. The settlement trajectory obtained from a numerical method closely resembles that of a laboratory physical model, particularly when the applied stress is up to 600 kPa. The modulus of elasticity of tailing was significantly improved with the introduction of geogrid reinforcement either in layer or loop.
Rock Mechanics
Praveena Das Jennifer; Porchelvan P
Abstract
This paper presents a comprehensive study on the stability of the deep underground closed Kolar Gold Fields mine (3.2 km deep) under varying seismic loading conditions. The study utilized the Finite Element Method (FEM)-based Midas GTS NX software tool to conduct numerical simulations of seismic loads ...
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This paper presents a comprehensive study on the stability of the deep underground closed Kolar Gold Fields mine (3.2 km deep) under varying seismic loading conditions. The study utilized the Finite Element Method (FEM)-based Midas GTS NX software tool to conduct numerical simulations of seismic loads of varying intensities under multiple conditions of water level in the mine voids. The seismic loads applied were equivalent to the intensity of maximum mining-induced seismicity experienced in the mine. The study also examined the influence of the Mysore North Fault and its effects on the surface above the mining area. A seismic hazard vulnerability map of the mining area was developed based on the results for all simulated numerical model combinations. The results inferred that for a seismic load of PGA, 0.22 g, for fault and actual water level combination, very strong shaking and moderate potential surface damage were observed at vulnerable zones with a maximum PGA of 0.196 g and Peak Ground Velocity (PGV) of 0.49 m/s. The study highlights the importance of monitoring post-mining induced seismic activities using a dedicated microseismic monitoring system with sensors placed at the most vulnerable zone locations assessed from the numerical modelling studies carried out. Remedial measures suggested include regular dewatering of mine workings based on water accumulation and backfilling of mine voids with suitable fill material. The dynamic modelling approach using Midas GTS NX was found to be a more reliable, feasible, efficient, and simple method for assessing the stability of closed mines.
