Study On Pressure Relief Mechanism And Space Adaptability For Stagger Arrangement Gob-side Entry

Characteristics of backfill for gob-side entry retaining and coal pillar supporting roof directly for gob-side entry driving, which are easy to cause floor heave, mine earthquake, difficult support, and high cost of section roadway. Filling technology is complicated when retaining roadway. Therefore, science mining had been affected. For stagger arrangement gob-side entry, its position relation changes forced state. A new mechanical system was formed in roadway and surrounding rock. Application key of stagger arrangement mining are as follows:(1) mechanical environment of roadway and surrounding rock for stagger arrangement gob-side entry;(2) adaptability of reasonable change in low stress space for stagger arrangement gob-side entry. Hereby, based on triple shear energy yield criterion, elasto-plastic was analyzed for roadway and surrounding rock; Using energy theory, from the point of view of complete and incomplete gob-side entry, this paper derived energy dissipation equation of roadway and surrounding rock, revealed the pressure relief mechanism of stagger arrangement gob-side entry, that is to say, roadway surrounding rock is a system of energy absorption and dissipation, thus improved the ground pressure theory of mining roadway. According to stress distribution characteristics of entity coal side in goaf, making use of stress slip line field theory in plasticity, on the basis of mechanical properties of limit equilibrium zone from coal seam floor, determined stress zones, and deduced the formula of bottom maximum failure depth. Through theoretical calculation and comparison of zoning stress values, the author gives theoretical basis of position change of gob-side entry in the level and vertical direction, proposed various stagger arrangement mining system satisfying pressure relief condition. In the course of studying, some conclusions were proved by similarity simulation experiment, numerical modeling and field observation. The research is of great importance to reveal surrounding rock stress, displacement distributions and destressing mechanism from stagger arrangement gob-side entry, also provides theory and technique to stagger arrangement mining in china’s huge thick coal seam.