Using artificial pillars to replace the coal pillars to protect the entry gate road is one of the most effective solutions to minimize coal losses and enhance safety in mining thick seams. Currently, in Quang Ninh coal region, the biggest coal basin of Vietnam, mining operations are conducted at a depth of -350m and in the preparation for mining down to -500m. To determine the width and load-bearing capacity of the artificial pillars, it is necessary to implement further research for specific geological conditions. This paper utilizes Phase 2 numerical simulation software to analyze the relationship between the strength and compression coefficient with the width of the artificial protective pillars for entry gate roads in mining thick coal seams in Quang Ninh. The study results show that the relationship between the width of the artificial pillars and the dip angle of the seam follows the law of a linear function, with the size of the protective pillars increasing with the depth of mining. At a mining depth of -500m, the pillar size varies from 1.4 to 2.4m. Increasing the compression resistance of the protective pillars reduces their width, while larger dip angles of the seams also increase the required width of the pillars. The correlation coefficient (r) between the dip angle of the seam and the width of the pillars is strong (r = 0.621). The remaining relationship between the width of the pillars and the mining depth is directly proportional and weakly correlated (r = 0.532), and between the width of the pillars and the compression strength of the pillars is inversely proportional and weakly correlated (r = -0.177). Therefore, mining under corresponding conditions requires a selection of the appropriate size and compression resistance of the artificial pillars to ensure their load-bearing capacity.
Using artificial pillars to replace the coal pillars to protect the entry gate road is one of the most effective solutions to minimize coal losses and enhance safety in mining thick seams. Currently, in Quang Ninh coal region, the biggest coal basin of Vietnam, mining operations are conducted at a depth of -350m and in the preparation for mining down to -500m. To determine the width and load-bearing capacity of the artificial pillars, it is necessary to implement further research for specific geological conditions. This paper utilizes Phase 2 numerical simulation software to analyze the relationship between the strength and compression coefficient with the width of the artificial protective pillars for entry gate road in mining thick coal seams in Quang Ninh. The study results show that the relationship between the width of the artificial pillars and the dip angle of the seam follow the law of a linear function, with the size of the protective pillars increasing with the depth of mining. At a mining depth of -500m, the pillar size varies from 1.4 to 2.4m. Increasing the compression resistance of the protective pillars reduces their width, while larger dip angles of the seams also increase the required width of the pillars. The correlation coefficient (r) between the dip angle of the seam and the width of the pillars is strong (r = 0.621). The remaining relationship between the width of the pillars and the mining depth is directly proportional and weakly correlated (r = 0.532), and between the width of the pillars and the compression strength of the pillars is inversely proportional and weakly correlated (r = -0.177). Therefore, mining under corresponding conditions requires a selection the appropriate size and compression resistance of the artificial pillars to ensure their load-bearing capacity.
 

thick coal seam, artificial protection pillar, pillar width, compression resistance strength