Abstract:

Nowadays, many underground coal mines in Quang Ninh, Vietnam have been exploiting coal seams located below the mining waste dump. Many mining waste dumps have reached the height of dumping 200÷400 m, especially up to over 500 m. The rock mass pressure due to the weight of the rock mass in the mining waste dump is considered an artificial pressure formed from the process of dumping soil and rock, it will be part of the pressure acting on the furnace lines located under the mining waste dump. The article presents the current status of the mining waste dump and the coal seams that have been and will be exploited located below the mining waste dump in Cam Pha, Quang Ninh and based on the actual conditions of the Mong Duong coal mining waste dump. The studies used Phase2 software to create simulation models in which the model size 600x800 m without the mining waste dump, model size of 800x800 m with the mining waste dump to study the primary stress distribution in the rock mass. The results show that the distribution values of the largest primary sigma 1 stress and the smallest primary sigma 3 stress in the rock mass increase with depth. The value of initial stress without the mining waste dump is smaller than the one with the mining waste dump. The simulation results will help the consulting and construction companies to calculate the rock pressure acting on the roadways located under the mining waste dump.