Study On Top Coal Caving Of Horizontal Section Top Caving In Steep Seam

In this paper, comprehensive researches are carried on the top coal caving of horizontal section top caving in steep seam. Creative results were educed in similar material model test, numerical simulation, computer simulation, theoretical analysis and engineering practice.Fist, based on similar material model test, the top caving were studied in single ore passes of nonentity boundary. Then further study were carried on the top coal caving below roof and floor for horizontal section top coal caving in steep seam. Thereby, based on the caving radio of triangular coal below floor we refer to how to set rational sublevel height of top coal. Furthermore, we put forward the principle of top coal caving that is use time to control close and open the exit of coal caving, this principle is differ to that principle of which close support exit when meet the waste rock.PFC2D were used for simulate the course of top caving. And Visual Basic program were also used to develop a new program named . This new program can make dynamic simulation to the whole course of top caving and can provide an approach for find sound parameter about top caving.Be base on the theory of ellipsoidal draw, the rule about top caving of steep seam were studied, the analyses focused on the caving process below roof and floor were made, all kinds of parameter were also computed. All this study can instruct the parameter design to working face in steep seam immediately. Finally an instance were gave for interpret the use.