Study On Nonlinear Seepage Characteristics Of Variable And Broken Rock Mass In Water Diversion Fracture Zone

At present,as one of the major disasters that seriously affect the safe and efficient production and mining of coal mines,mine water inrush disasters cause casualties and direct economic losses in the forefront of all kinds of geological disasters.In order to study the disaster mechanism of broken rock mass seepage in water diversion fracture zone,this paper takes Wenjiapo Coal Mine in Binchang mining area as the research object,starting with the study of the development characteristics of broken rock mass in water diversion fracture zone.by means of similar material simulation experiment,seepage test of broken rock mass and numerical analysis and simulation of broken rock mass,the nonlinear seepage characteristics of variable quality broken rock mass in water diversion fracture zone are studied and analyzed systematically.The results are as follows:（1）Based on the basic data of geological survey in Wenjiapo Coal Mine,the stratum lithology model of 4103 working face in Wenjiapo Coal Mine is established through similar material simulation experimental device,and the development characteristics of water conducting fracture zone and broken rock mass in the zone are simulated.The final development height of the water conducting fracture zone,the development shape of the broken rock mass in the water conducting fracture zone and the lithology of the strata affected in the zone are obtained.（2）According to the generalization results of the lithology of the broken rock mass in the water-conducting fracture zone,the samples of the broken rock mass in the water-conducting fracture zone are prepared,and the seepage tests of the broken rock mass in the water-conducting fracture zone are carried out by using DDL-600 electronic universal testing machine and seepage system,and the variation rules of porosity,permeability,seepage velocity,pore pressure gradient,non-Darcy flowβfactor and other permeability parameters of the broken rock mass in the water-conducting fracture zone are obtained.It is obtained that the relationship between pore pressure gradient and seepage velocity obeys Forchheimer nonlinear relationship.（3）With the help of COMSOL Multiphysics and PFC^3D numerical simulation software,the seepage characteristics of broken rock mass in water diversion fracture zone are studied macroscopically and microscopically.According to the time-varying law of porosity and mass loss,the seepage stage of broken rock mass in the water-conducting fracture zone can be divided into the initial stage of seepage,the stage of rapid increase of seepage and the stage of seepage tends to be stable.The"C"value of the loss quality coefficient of broken rock mass is used to determine the beginning and end of the seepage stage,and there is a positive correlation between the seepage pressure and the time of the rapidly increasing stage of seepage.The paper has 160 diagrams,12tables and 57 references.