List of articles (by subject) other Subjects
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Open Access Article
1 - Earthquake ground-motion prediction in the Khalkhal region, NW Iran
Akram Alizadeh Fatemeh SalehiUnderstanding seismic sources in a region help us to identify the level of ground motion. The area around Khalkhal city in the south of Ardabil province, northwest Iran, is a seismic region that is specially, complex from a geodynamic and tectonic point of view. Prevail MoreUnderstanding seismic sources in a region help us to identify the level of ground motion. The area around Khalkhal city in the south of Ardabil province, northwest Iran, is a seismic region that is specially, complex from a geodynamic and tectonic point of view. Prevailing tectonic regimes in different geologic time intervals have caused at least two deformation episodes recorded by faults, folds and other tectonic structures. These structures indicate that the dominant tectonic regimes have been compressive. Examination of the seismic power of currently active faults and software analysis of their focal mechanisms, show that major activity in the region is due to faults with trend north-south and northeast-southwest. The results of this study indicate the seismic capacity of the region and the likely occurrence of earthquakes with a magnitude greater than two on the Richter scale. Also, they show that the probability of earthquakes with magnitudes above 5.3 on the Richter scale is one in one hundred years. High a- and b-values indicate the frequency of earthquakes with low magnitude and the generally high seismicity in the region. Manuscript profile -
Open Access Article
2 - Study of development cycle of down ramp in underground metal mine
Nirlipta Nayak Harinandan Kumar Suhel AhmedMine development is the process of constructing a mining facility and supporting infrastructure. In the mining industry, operations are sequential. It means one function cannot start until its preceding operation has been completed. Hence, a delay in any operations resu MoreMine development is the process of constructing a mining facility and supporting infrastructure. In the mining industry, operations are sequential. It means one function cannot start until its preceding operation has been completed. Hence, a delay in any operations results in an overall delay for the total target. Effective underground mine planning aims at least idle & breakdown time. One such delay examined here is the cycle time for the developments in headings and drives. In this study, Blast-to-blast cycle time was evaluated in terms of productive and unproductive work in Indian underground metal mines. The actual Average Cycle Time for blast-to-blast operations was observed at 37.12 hrs, higher than the expected Cycle Time, i.e., 12.16 hrs. The variation in cycle time leads to the delay. Therefore, a study was carried out to determine the actual cause of delay through real-time analysis of all the operations during the development. The delays were breakdown, manpower idle time, shift problem, poor ventilation, water pressure problem, etc. reduced work time utilization, dewatering, and pump breakdown were observed as significant factors for cycle time delays. Effective measures were suggested to optimize the cycle time by controlling the factors responsible for the delay and improving the development cycle. Manuscript profile -
Open Access Article
3 - An experimental study on the stress memory retrieval in rocks using deformation rate analysis method
Ablodllatif Aghill Majid NikkhahKnowledge of the in situ stress state is an essential component in rock engineering, especially for underground spaces in civil, mining, petroleum geomechanics and geothermal energy projects. The most accurate methods of measuring the in situ stress of rock are direct a MoreKnowledge of the in situ stress state is an essential component in rock engineering, especially for underground spaces in civil, mining, petroleum geomechanics and geothermal energy projects. The most accurate methods of measuring the in situ stress of rock are direct and field measurement methods. However, since these methods are time-consuming and costly, indirect rock core-based methods have attracted specialists’ attention for estimating of rock stress memory. Methods based on the rock stress memory, including acoustic emission (AE) and deformation rate analysis (DRA), are among the common methods used for this purpose. In this study has been applied the DRA method to investigate rock type and its characteristic behavior in stress retrieval at different stress levels. To this end, four types of rocks (i.e., granite, zeolite, sandstone, and gypsum) with different behaviors and characteristics were used. The results show that the stress memory retrieval values in the elastic behavior region had better recognizable and higher felicity ratio (FR) for all types of rocks studied. Based on the results obtained from DRA experiments on these rocks, it can be stated that there is no logical and clear relationship between the type of physical properties of rocks and preloading stress levels and the results of stress retrieval. Manuscript profile