Study On Regularity Of Surface Deformation Due To Layer Mining Thick Seam

There has been a complete theorrtical system about the surface movement and deformation law under the condition of general mining.But with regard to the regularity of surface deformation due to layer mining thick seam,there has less research productions.Because of different from the general mining conditions,the surface subsidence law of mining thick seam has its characteristics.In order to direct to productive practice better,it is necessary to do correlation reseach with this problem.In this paper,Barapukuria mining area is as the object of study,with four test measured surface observation data.This paper analyzes the surface movement and deformation law under the condition of the ultra thick seam mining and its particularity.The mechanism and influence factors of surface movement and deformation are analyzed by the means of classical theory and numerical simulation,by the time,the calculation method of surface subsidence coefficient has been studied.In this paper,it made the following results:(1)By processing the measured data of four test working faces in Barapukuria mine second layer,the dynamic and steady state rule of surface movement and deformation in Barapukuria mining area have been grasped.Final,a set of probability integral parameters about Barapukuria mine second layer has been summed up.(2)Starting from the non-fully mining,the relationship between mining degree and surface subsidence coefficient is analyzed,and the expression based on Boltzmann function which reflects the relation of the surface subsidence coefficient and degree of mining.By this relation expression,we have access to mutually convert the surface subsidence coefficient under the fully mining and non-fully mining.(3)By reading a large number of relevant literatures,the geological and mining conditions on surface subsidence coefficient have been analyzed better.Inoder to calculate the surface subsidence coefficient,a machine learning algorithm,random forest regression algorithm has been introduced.This paper establish a calculation model for surface subsidence coefficient by random forest,and through experiment,the results meet the requirements of engineering practice.(4)Combining with the measured data and the special geological and mining conditions of Barapukuria mine area,the special regularity of surface deformation due to layer mining ultra thick seam has been studied.Using the UDEC numerical simulation software,the mining thickness and repeat mining influence have been studied.