Rahul Shakya; Manendra Singh; Narendra Kumar Samadhiya
Abstract
An earthquake is a random occurrence that can happen anytime in highly seismic active areas. Therefore, it might happen even when the metro-train is moving. In such a scenario, the vibrations produced by the dynamic loading of a moving metro-train and the dynamic loading due to an earthquake will impact ...
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An earthquake is a random occurrence that can happen anytime in highly seismic active areas. Therefore, it might happen even when the metro-train is moving. In such a scenario, the vibrations produced by the dynamic loading of a moving metro-train and the dynamic loading due to an earthquake will impact the dynamic response of underground metro-tunnels. In this work, an effort is made to comprehend how the Delhi Metro's underground tunnels will respond to the combined dynamic loading from the earthquake and the running train. Therefore, the dynamic response of underground metro-tunnels is primarily influenced by the vibrations generated due to the dynamic loading of a running metro-train and the dynamic loading due to an earthquake. Both these loadings cause vibrations at the ground surface and the tunnel utilities. In this paper, an attempt is made to understand the response of Delhi metro-underground tunnels to the combined dynamic loading due to the earthquake and the train's motion. Two-dimensional and three-dimensional finite element analyses are carried out using the Plaxis software. The research work finds that the overall response at the ground surface increases due to the combined dynamic loading of the train and earthquake compared to the train's or the earthquake's sole dynamic loading. Maximum displacements in the soil-the tunnel system and forces in RC liners are found to be more significant for the combined loading of the earthquake and the train motion than those due to individual loadings.
R. Koner
Abstract
The Wardha valley coalfields, situated in the western part of India, contribute to more than 7% of the national coal production. The open-pit mining methods are the modes of exploitation of coal in the majority of the mines in the area. Due to the increased depth of working and higher stripping ...
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The Wardha valley coalfields, situated in the western part of India, contribute to more than 7% of the national coal production. The open-pit mining methods are the modes of exploitation of coal in the majority of the mines in the area. Due to the increased depth of working and higher stripping ratio, the output of waste overburden is increased. The challenges are the scarcity of the available land for dumping waste overburden geo-material safely. Optimization of the mine dump slope geometry is the only available alternative in the hands of the management in order to increase the life of the projects and continue the production of coal. This investigation specifically addresses this issue, and proposes a combination of the optimum geometric configurations of the dump slope. This work utilizes the computational power of the numerical modeling technique in order to solve a large number of alternatives and zero them down to the optimum combination. The numerical modeling is considered as a major external factor that contributes to the mine dump's instability. This work shows an 18% increase in the dumping waste material volume in the present condition. This investigation also reveals that double stage dumping is comparably better in optimizing the dump slope configuration.
