Research On Problems Of Coal Mine Water Inrush Spreading And Avoidance Routes

In recent years, the probability of coal mine accidents has been high which constantly threaten the safety of the workers and bring a heavy price to the enterprise. It is necessary to investigate the water flow law in the complex topological structure of underground mine roadways systematically and establish the corresponding simulation models. In order to make the workers safely escape when the water accidents happens in the underground, it is important to formulate the corresponding avoidance routes according to the actual situation of water inrush spreading. Therefore, related research on the numerical simulation of mine water inrush spreading and the shortest path of avoidance routes in the underground is done in this dissertation. The study includes following contents:(1) In order to simulate the spread of underground water, this dissertation analyzes the changing process of tunnel water inrush. Through the analysis, it is found that tunnels water inrush spreading process can be divided into two stages, namely early stage of dynamic change and dynamic equilibrium stage, according to the difference of the correlation factors to the velocity of the water in different time. The initial stage of dynamic change occurs in the initial stage of water inrush, which is characterized by the velocity of the water flow in the tunnel and the elevation of the water level which change dynamically. After a period of time, the flow of water in the roadway will reach the dynamic equilibrium stage. Water level elevation almost reach dynamic balance and water inrush spreading speed basically not changes with time units of water inrush and change in this stage.(2) In order to simulate the process of underground water inrush spreading, corresponding models are constructed which are based on lattice Boltzmann method(LBM). Firstly, this dissertation demonstrates that LBM can be used to simulate the law of underground water inrush spreading. Then the corresponding models of water inrush spreading are established which are aimed at the common tunnel structures. Due to angles of "Y" type roadways are not the only case, a new method of boundary coupling is proposed. After doing simulation experiments and comparing with the simulation results of comsol software, the feasibility of this model is proved.(3) This dissertation presents a searching method of shortest path which is based on discrete firefly algorithm and can be used to solve the shortest of avoidance routes in the underground. By using the transfer probability initialization method to initialize the firefly individual, redefining the space distance of fireflies, maximum fluorescence intensity and fluorescence relative brightness, the algorithm can use a firefly individual state to express a valid path from the starting point to the target point. A perturbation operation, that is, using a certain probability to change the path of every firefly, is added to the method to increase the diversity of solutions and to prevent the results into a local optimal solution. After several iterations, the shortest path of the solution can be obtained.(4) This dissertation puts forward a searching method of shortest path which is based on the simulation of plant growth algorithm and can be used to solve the shortest of avoidance routes in the underground. This method uses each new growth point to represent a valid path from the start point to the target point. Because of adopting the proportional selection strategy, the better objective function value is, the easier it is to be selected. By constantly selecting new basic point, some new branch growth points will be generated on the basic point. In this way, the optimal solution can be obtained after several times of calculation which is just the shortest path of avoidance routes. Finally, through analysis and experiments, it is proved that this algorithm can be used to solve this problem.